6G Celicas Forums

Welcome Guest ( Log In | Register )

> 7A-FE Compression Ratio, Looking at changing the CR of my 7afe when I rebuild.
post Mar 30, 2012 - 12:00 AM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




Hey all, I'm trying to decide what to do with my 7AFE (have to take it apart due to a rod knock anyway). I've kicked around a few ideas (or maybe a lot rolleyes.gif ), and I'm currently researching what an increase in compression ratio might do. Does anyone have any info on this? I'm unsure of the potential difference in performance, and I can't seem to find any hard data on what pistons (4age, smallport 4age, 4agze) result in what CR. I've been trying to make sense of these tools and formulas - http://www.csgnetwork.com/compcalc.html http://s-86.com/s-cr.html and http://s-86.com/s-cr-chart.html - but I'm having a hard time digging out the relevant numbers. Doing the math myself or using the calculator I come up with significantly different numbers than their little handy chart, so I don't know what to think. Is this a futile exercise? Will I even be able to notice a performance difference over the stock 9.5:1 without having to use higher octane?





--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
3 Pages V   1 2 3 >  
Start new topic
Replies (1 - 57)
post Mar 30, 2012 - 7:31 AM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




9.5:1
Will need cams too
Tune
Higher octane


--------------------
post Apr 2, 2012 - 2:07 AM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




My initial thoughts were to replace the 7AFE pistons with 4AGE pistons, something along these lines:
http://www.toyotanation.com/forum/134-6th-...-fe-engine.html
However, I've been struggling to find definitive info on piston dimensions. I already know the bore/stroke and CR of the stock 7AFE's and 4AGE's, and some other info from various places. 7AFE pistons: 12cc dish. Head gaskets - 4AFE: 1.4mm; 7AFE: 0.7mm; 4AGE: 1.2mm. Head CC - 4AGE: ~36cc; 4AFE (presumably close to 7AFE): ~31cc. Also allegedly 7AFE's piston deck clearance is 0.6mm.
What I'm hoping to find out is the dish or dome cc of the various 4AGE and 4AFE pistons. I have the feeling that even blue-top pistons (9.4:1 CR in 4AGE context) may result in too high of a CR in the 7AFE. I'm also figuring that if I end up with a >10.5:1 CR I'd almost definitely need to use higher octane (possibly before that threshold, but I'm having trouble finding info on that in general). Anyone have any thoughts?


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post Apr 2, 2012 - 11:51 AM
+Quote Post
Smaay

Enthusiast
*****
Joined Dec 8, '03
From Lancaster CA
Currently Offline

Reputation: 6 (100%)




dont bother trying to drop in 4A parts. its not worth the money $$$ just turn your distributor up to about 15 degrees BTC and run higher octane gas. you will notice a huge difference!


--------------------
2001 Celica GT-S Turbo
1997 Supra TT 6speed
1997 Celica 3MZ/1MZ swap
1990 Celica All-Trac
post Apr 2, 2012 - 1:58 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




Hm, I guess it may just be the wrong route to go for the result I want. I was hoping to give my engine a little bit more pep without increasing my operating expense... It's my DD and work vehicle. I deliver pizzas in it, so upgrading my octane would cost me quite a bit more in gas. I'm planning to get the head port/polished before I put it back on, and eventually get a header, but I was hoping to do just a little bit of modification to the internals to get a little more 'zip' out of it. Any other avenues I've overlooked?


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post Apr 3, 2012 - 2:27 PM
+Quote Post
stephen_lee



Enthusiast
*****
Joined Mar 22, '07
From Houston, TX
Currently Offline

Reputation: 4 (100%)




import performance parts . net sell "HP KITS" that you can pick your CR

id go with 11.5:1 and run supreme gas, get your cams reground while you're getting the motor built and get some sort of tune.

i wouldnt expect any more than 130whp though... but with a very strong midrange and slightly improved MPG if the tune is done right


--------------------
QUOTE
"And, as always, your friendship, help, and dedication to the advancement of Texas Celica dominance is GREATLY appreciated. Thanks bro." -DEATH

1994 GT: V6 swap, 5speed E53 W/ LSD, All Power, now RED
1995 ST: SOLD @273k miles, Auto, all power, CarPC, White
1994 ST: Totaled, 5spd, all power, Red RIP 07/09/09 @ 241,810
1994 Lexus LS400: This is my new DD
post Apr 4, 2012 - 8:58 AM
+Quote Post
Smaay

Enthusiast
*****
Joined Dec 8, '03
From Lancaster CA
Currently Offline

Reputation: 6 (100%)




the problem is you have a 7A-FE, that was the economy engine and there is really no aftermarket support for it.


--------------------
2001 Celica GT-S Turbo
1997 Supra TT 6speed
1997 Celica 3MZ/1MZ swap
1990 Celica All-Trac
post Apr 4, 2012 - 11:33 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




QUOTE (Smaay @ Apr 4, 2012 - 9:58 AM) *
the problem is you have a 7A-FE, that was the economy engine and there is really no aftermarket support for it.

QFT. Honestly, both engines I've had in this car have been pretty tired... One with a rod knock, and its junkyard motor stand-in. I'd probably notice a good improvement with just a good stock rebuild and cleaning. I think I'm going to port and polish the head, and possibly get a header at some point... added to the short ram air intake I already have, it'll probably be an outstanding daily driver.

...And all the time I don't spend on the engine I can put toward freshening up everything else! biggrin.gif


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post Apr 5, 2012 - 9:24 AM
+Quote Post
Smaay

Enthusiast
*****
Joined Dec 8, '03
From Lancaster CA
Currently Offline

Reputation: 6 (100%)




did you see the thread i made in the stickys? its step by step rebuild of a 7A-FE. Erynn's car had a slight rod knock. Luckily the crank was fine, i just replaced all the bearings, new piston rings, new gaskets. and the car ran like a bat outta hell.


--------------------
2001 Celica GT-S Turbo
1997 Supra TT 6speed
1997 Celica 3MZ/1MZ swap
1990 Celica All-Trac
post Apr 5, 2012 - 12:37 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




My local import machine shop charges $35 to deck a 4cylinder head and $45 to deck a 4 cylinder block. A chemical dip is included in the price for the heads, Im not sure about the block.
This would be the route I would go, you can also get a thinner head gasket for some extra $s. Im not sure how many thousandths of an inch you can remove but with an inline 4 the only major issues you have to worry about are the valves and sparkplug hitting the piston and taking to much material off where the waterjackets are located.
Do some research and find out how many CCs to remove from the combution chamber. I think you could run 10 to 1 CR without needing high octane(unless you try to advance it) and once you get to 11 to 1 CR you will most likely need to go 93 octane. I think 13 to 1 and up requires racing fuel and that gets real expensive.
post Apr 5, 2012 - 5:38 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




As far as I can tell, it would only take 3cc less combustion chamber area to increase the CR from 9.5:1 to 10:1. 4AFE pistons are an 8cc dish (if random internet searches are to be trusted), so the 4cc difference between the 7AFE pistons and those would make the CR ~10.2:1 with the standard 7AFE head gasket.

At this point I'm most heavily favoring a stock rebuild, since it's most likely to go as planned (and takes the least buying of new parts). I really wish I knew more about CR's, detonation, ignition timing and such, though. Oh well, I'll get there eventually!


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post Apr 5, 2012 - 7:43 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




Just have it decked. Do the stock rebuild.
You are supposed to have the cylinderhead resurfaced anytime you remove/reintall it, which basically involves them grinding a layer of metal off of it. You can specify to the shop how much you want removed if you would like more taken off than the minimum amount needed to bring the head back to specification. I have a '64 chevy straight six in my garage that has an 11-1 CR and all it took was a shop grinding a little off the heads.

As for detonation, there are several factors that can make it happen or help you avoid it.
Ignition advance- more advanced = more power but more likely to detonate. Retarding it will help cure detonation
Fuel octane- Lower octane fuel has more energy per gallon, but lower octane is more likely to knock. Basically octane rating is the fuels resistance to combustion. Increasing octane will reduce detonation.
Air to fuel ratio- should be close to perfect with our EFI systems, but a lean mixture is more likely to knock and a richer mixture will be less likely. Lean mixtures burn hotter and can damage the insides of your engine while rich mixtures will foul your plugs and catalytic converter.
Spark plugs- hotter plugs will burn fuel better, but are more likely to predetonate. Moving to a cooler plug(one that dissipates heat better and stays cooler) will reduce the likelyhood of knocking but will be more susceptible to becoming fouled.
Anyways, theres a few tidbits there I wouldnt worry about overdoing the CR the only thing you should worry about is the clearance between valves and pistons if you do go with a non-standard piston
post Apr 5, 2012 - 8:00 PM
+Quote Post
richee3



Moderator
*****
Joined Jun 29, '08
From Denver
Currently Offline

Reputation: 59 (100%)




QUOTE (Special_Edy @ Apr 5, 2012 - 7:43 PM) *
Fuel octane- Lower octane fuel has more energy per gallon, but lower octane is more likely to knock. Basically octane rating is the fuels resistance to combustion. Increasing octane will reduce detonation.

Quoted for reiteration. Maybe one day the myths will be dispelled....

OP- I would say you're better off with a standard rebuild. The 7A with a higher compression ratio will still not be a high output engine. Even with cams, SAFC, etc. it still wouldn't put a lot of power to the ground. Why be forced to pay for premium fuel for only a little more power than a 5S? If anything, I would personally lower the compression ratio and boost it later.

That's just my opinion, what I would do if I was rebuilding a 7A. Truth is, I'd love to know what a higher compression 7A can do. The sensible side of me says stick to proven methods to make power for the 7A, but that doesn't make me any less curious.


--------------------
"Employ your time in improving yourself by other men's writings, so that you shall gain easily what others labored hard for." -Socrates. Even Socrates told us to use the search button!

2006 Aston Martin V8 Vantage.
1998 Celica GT-
BEAMS Swapped.
2022 4Runner TRD Off Road Prenium.
2021 GMC Sierra AT4.
post Apr 5, 2012 - 9:41 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




timing advance is similar to a compression increase in terms of gains.


--------------------
post Apr 5, 2012 - 10:17 PM
+Quote Post
mandrek



Enthusiast
***
Joined May 4, '05
From western MD/NOVA
Currently Offline

Reputation: 2 (100%)




QUOTE (Special_Edy @ Apr 5, 2012 - 1:37 PM) *
My local import machine shop charges $35 to deck a 4cylinder head and $45 to deck a 4 cylinder block. A chemical dip is included in the price for the heads, Im not sure about the block.
This would be the route I would go, you can also get a thinner head gasket for some extra $s. Im not sure how many thousandths of an inch you can remove but with an inline 4 the only major issues you have to worry about are the valves and sparkplug hitting the piston and taking to much material off where the waterjackets are located.
Do some research and find out how many CCs to remove from the combution chamber. I think you could run 10 to 1 CR without needing high octane(unless you try to advance it) and once you get to 11 to 1 CR you will most likely need to go 93 octane. I think 13 to 1 and up requires racing fuel and that gets real expensive.



WOW!!! $45 to deck the block!!! awesome.. my shop here charged $135 to deck the block.. but he also told me that it was because the block is cast iron.. and not aluminum.. is that $45 for iron block aswell?

and to the OP... IMO do a clean rebuild, and then go turbo.. thats what im doing.. and all of my research shows it the best option, if not doing a swap.


--------------------
post Apr 5, 2012 - 10:36 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




Given what Smaay mentioned about the one he tore down and rebuilt, It's possible that the difference between a tired engine and a clean, fresh rebuilt one may be all I need... My perception of the 7AFE so far has been shaped by 2 tired engines, hardly an objective reference point.

I thought about boosting it, but if it's lively enough to get me around, reliable, and gets good gas mileage, I can always pick up a toy later to go wild on. Or if I pick up a different daily driver, I still have another 7AFE that needs a rebuild - I could always do it differently the 2nd time around.


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post Apr 6, 2012 - 11:47 AM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




QUOTE (mandrek @ Apr 5, 2012 - 10:17 PM) *
QUOTE (Special_Edy @ Apr 5, 2012 - 1:37 PM) *
My local import machine shop charges $35 to deck a 4cylinder head and $45 to deck a 4 cylinder block. A chemical dip is included in the price for the heads, Im not sure about the block.
This would be the route I would go, you can also get a thinner head gasket for some extra $s. Im not sure how many thousandths of an inch you can remove but with an inline 4 the only major issues you have to worry about are the valves and sparkplug hitting the piston and taking to much material off where the waterjackets are located.
Do some research and find out how many CCs to remove from the combution chamber. I think you could run 10 to 1 CR without needing high octane(unless you try to advance it) and once you get to 11 to 1 CR you will most likely need to go 93 octane. I think 13 to 1 and up requires racing fuel and that gets real expensive.



WOW!!! $45 to deck the block!!! awesome.. my shop here charged $135 to deck the block.. but he also told me that it was because the block is cast iron.. and not aluminum.. is that $45 for iron block aswell?

and to the OP... IMO do a clean rebuild, and then go turbo.. thats what im doing.. and all of my research shows it the best option, if not doing a swap.

Yeah the fine print is *prices may vary
the head was definately a good deal.

I would say that for performance mods to your engine, increasing the Compression Ratio is one of those things that doesnt increase your fuel consumption, it just helps you extract more energy from the fuel you are already burning. Increased efficiency plus increased power is a win-win
post Apr 6, 2012 - 11:35 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




It looks like reducing the chamber height by ~ .5mm would put me near 10:1.

If I need to get the block/head decked, I might get it taken down by .3 or .4mm instead of a minimum amount. Taking it down by .3mm would give me a 9.76:1, or .4mm would take it to 9.85:1 (assuming correct math). If I'm already going to get it decked, I doubt I'd run much risk at either of those levels (and it leaves room for error if my math is bad tongue.gif ).

If I don't need to get it decked, though, it's a stock rebuild for me!


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post Apr 7, 2012 - 12:50 AM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




QUOTE (PaukST @ Apr 6, 2012 - 11:35 PM) *
It looks like reducing the chamber height by ~ .5mm would put me near 10:1.

If I need to get the block/head decked, I might get it taken down by .3 or .4mm instead of a minimum amount. Taking it down by .3mm would give me a 9.76:1, or .4mm would take it to 9.85:1 (assuming correct math). If I'm already going to get it decked, I doubt I'd run much risk at either of those levels (and it leaves room for error if my math is bad tongue.gif ).

If I don't need to get it decked, though, it's a stock rebuild for me!

Thats the whole point.
You should get it decked just the same as you should buy a new set of torque to yield headbolts. The headgasket leaves indentations in the head, so you should always at least have it checked for straightness by the shop.
Its a performance mod that may not cost you anything since you will probably need the head resurfaced anyways. Just ask the shop performing the labor for their recommendation, they should be able to give the best advice

This post has been edited by Special_Edy: Apr 7, 2012 - 12:53 AM
post Apr 20, 2012 - 11:01 AM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




Let us know what you decide to do, the progress and the results. Im in the same situation. I know i need a rebuild. Wanna have a little fun when i open it up. Was thinking 4afe pistons or getting it bored to 82mm and running 2zz pistons. Wouldnt know my route until i open her up though. Does anyone by change know how to advance/retard the timing with the distributer on the 7a by chance? Might be useful to know.
post Apr 20, 2012 - 11:23 AM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




QUOTE (celica74 @ Apr 20, 2012 - 11:01 AM) *
Let us know what you decide to do, the progress and the results. Im in the same situation. I know i need a rebuild. Wanna have a little fun when i open it up. Was thinking 4afe pistons or getting it bored to 82mm and running 2zz pistons. Wouldnt know my route until i open her up though. Does anyone by change know how to advance/retard the timing with the distributer on the 7a by chance? Might be useful to know.

Feed it lead paint chips

there should be two bolts on your distributor that bolt it to the head, one on the top left and one on the bottom. This is how it is on the 5SFE but I imagine the 7afe is similar if not identical. Loosen them with a 12mm until you can just barely turn the distrubutor by hand. Turning the distributor clockwise will advance it and spinning it counterclockwise will retard it. Also, the idle will raise up when advanced and slow down when retarded. You could probably go 5 degrees advanced for some more power but make sure to listen for knocking and pinging at higher rpms. And make sure to mark where the distributor was before you moved it if you dont have a timing light, just scratch a mark around the dist hold down bolt.

Another thing to note is that on the later models(maybe 97 and up?) the distributor does not spin and cannot be mechanically advanced or retarded
post Apr 20, 2012 - 2:41 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Special_Edy @ Apr 20, 2012 - 12:23 PM) *
QUOTE (celica74 @ Apr 20, 2012 - 11:01 AM) *
Let us know what you decide to do, the progress and the results. Im in the same situation. I know i need a rebuild. Wanna have a little fun when i open it up. Was thinking 4afe pistons or getting it bored to 82mm and running 2zz pistons. Wouldnt know my route until i open her up though. Does anyone by change know how to advance/retard the timing with the distributer on the 7a by chance? Might be useful to know.

Feed it lead paint chips

there should be two bolts on your distributor that bolt it to the head, one on the top left and one on the bottom. This is how it is on the 5SFE but I imagine the 7afe is similar if not identical. Loosen them with a 12mm until you can just barely turn the distrubutor by hand. Turning the distributor clockwise will advance it and spinning it counterclockwise will retard it. Also, the idle will raise up when advanced and slow down when retarded. You could probably go 5 degrees advanced for some more power but make sure to listen for knocking and pinging at higher rpms. And make sure to mark where the distributor was before you moved it if you dont have a timing light, just scratch a mark around the dist hold down bolt.

Another thing to note is that on the later models(maybe 97 and up?) the distributor does not spin and cannot be mechanically advanced or retarded



Thankyou for the info. Ill have to take some time to mess with it later.
post Apr 21, 2012 - 1:45 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




with 15 degrees total base advance (+5 from stock) I highly suggest just running 89 octane fuel. I had much higher knock counts on 87 than 89 and even lower on 93 but not that much lower than 89 vs 87.


--------------------
post Apr 21, 2012 - 2:13 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




Well and besides the price of higher octane, lower octane fuel has more joules of energy within it. So always run the lowest octane that doesnt make your engine knock. See that sign that says "may contain up to 10% ethanol" next to the pump? Well ethanol is 120 octane i think, so all they do is water down your premium gas with more ethanol to raise the octane rating. That and super/midgrade is just a mix of premium and regular because they only have two tanks in the ground for unleaded.

Sry I just like people knowing the truth about gasoline...

This post has been edited by Special_Edy: Apr 21, 2012 - 2:14 PM
post Apr 22, 2012 - 9:10 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Bitter @ Apr 21, 2012 - 1:45 PM) *
with 15 degrees total base advance (+5 from stock) I highly suggest just running 89 octane fuel. I had much higher knock counts on 87 than 89 and even lower on 93 but not that much lower than 89 vs 87.




So you can advance up to 15 degrees with the distributor? How far would you recommend going on a stock motor?
post Apr 22, 2012 - 9:29 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




I think it'll turn all the way to 25 but the gains pretty much end at 15 from what I was able to research.


--------------------
post Apr 23, 2012 - 1:35 AM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




QUOTE (Bitter @ Apr 22, 2012 - 9:29 PM) *
I think it'll turn all the way to 25 but the gains pretty much end at 15 from what I was able to research.

The more retarded you make it the more low end grunt you will get. The engine will run cooler and the power band will be shifted down with the engine producing less horsepower. The more advanced the engine is the sooner it will fire the spark plug on the compression stroke before the piston reaches top dead center and makes full compression. Firing sooner yeilds more power because the flame front of the combustion coming off the spark plug burns more of the vapor in the cylinder and compression is boosted by the combusting gas.
Because the flame front of the burning gas/air vapor travels at a certain speed(however many feet per second) and piston speed is relative to rpm, higher rpms need the spark sooner(more advanced) and lower rpms need it later(more retarded). If you advance it too much then the explosion will happen too early and compression will be increased so much that it will actually try to push the piston back down in reverse. This will make the engine impossible to start as every combustion trys to turn the engine backwards and it will cause detonation at higher rpm. Adding higher octane will combat this predetonation but at this point your not gaining anything. 15 degrees advanced will probably give your engine a little more hop but realize that the ignition is already electronically advanced so dont overdue it. If you hear any predetonation then dial the distributor back a hair and retest around the neighborhood. You will feel it if its too advanced.

Sorry for the long post but I hope its helpful

This post has been edited by Special_Edy: Apr 23, 2012 - 1:36 AM
post Apr 23, 2012 - 7:16 AM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Special_Edy @ Apr 23, 2012 - 2:35 AM) *
QUOTE (Bitter @ Apr 22, 2012 - 9:29 PM) *
I think it'll turn all the way to 25 but the gains pretty much end at 15 from what I was able to research.

The more retarded you make it the more low end grunt you will get. The engine will run cooler and the power band will be shifted down with the engine producing less horsepower. The more advanced the engine is the sooner it will fire the spark plug on the compression stroke before the piston reaches top dead center and makes full compression. Firing sooner yeilds more power because the flame front of the combustion coming off the spark plug burns more of the vapor in the cylinder and compression is boosted by the combusting gas.
Because the flame front of the burning gas/air vapor travels at a certain speed(however many feet per second) and piston speed is relative to rpm, higher rpms need the spark sooner(more advanced) and lower rpms need it later(more retarded). If you advance it too much then the explosion will happen too early and compression will be increased so much that it will actually try to push the piston back down in reverse. This will make the engine impossible to start as every combustion trys to turn the engine backwards and it will cause detonation at higher rpm. Adding higher octane will combat this predetonation but at this point your not gaining anything. 15 degrees advanced will probably give your engine a little more hop but realize that the ignition is already electronically advanced so dont overdue it. If you hear any predetonation then dial the distributor back a hair and retest around the neighborhood. You will feel it if its too advanced.

Sorry for the long post but I hope its helpful




Sometimes longer post yeild more information. And thus better understanding. Thankyou for a clear response. Gunna have to take an hour to ight to mess with it.
post Apr 23, 2012 - 7:16 AM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Special_Edy @ Apr 23, 2012 - 2:35 AM) *
QUOTE (Bitter @ Apr 22, 2012 - 9:29 PM) *
I think it'll turn all the way to 25 but the gains pretty much end at 15 from what I was able to research.

The more retarded you make it the more low end grunt you will get. The engine will run cooler and the power band will be shifted down with the engine producing less horsepower. The more advanced the engine is the sooner it will fire the spark plug on the compression stroke before the piston reaches top dead center and makes full compression. Firing sooner yeilds more power because the flame front of the combustion coming off the spark plug burns more of the vapor in the cylinder and compression is boosted by the combusting gas.
Because the flame front of the burning gas/air vapor travels at a certain speed(however many feet per second) and piston speed is relative to rpm, higher rpms need the spark sooner(more advanced) and lower rpms need it later(more retarded). If you advance it too much then the explosion will happen too early and compression will be increased so much that it will actually try to push the piston back down in reverse. This will make the engine impossible to start as every combustion trys to turn the engine backwards and it will cause detonation at higher rpm. Adding higher octane will combat this predetonation but at this point your not gaining anything. 15 degrees advanced will probably give your engine a little more hop but realize that the ignition is already electronically advanced so dont overdue it. If you hear any predetonation then dial the distributor back a hair and retest around the neighborhood. You will feel it if its too advanced.

Sorry for the long post but I hope its helpful




Sometimes longer post yeild more information. And thus better understanding. Thankyou for a clear response. Gunna have to take an hour to ight to mess with it.
post Apr 23, 2012 - 7:34 AM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




I found 15 deg gave me more low end actually, there are plenty articles online about this.


--------------------
post Apr 23, 2012 - 8:45 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Bitter @ Apr 23, 2012 - 7:34 AM) *
I found 15 deg gave me more low end actually, there are plenty articles online about this.




Just advanced the timing. Did it a little bit at a time driving it after each time. Didnt really notice much. Little more get up at 5k. Advanced all the way with no knocking. Idels at 900 smoothly. Im thinking the computer is getting the best of the timing.
post Apr 23, 2012 - 8:58 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




What year is yours? I never heard knock, I monitored it with a SAFC2.


--------------------
post Apr 23, 2012 - 9:09 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




http://www.contactmagazine.com/Issue54/EngineBasics.html

I read that, did a little voodoo math which I've long since forgotten, and figured the best gains to be around 15 deg. Read some stuff at Celicatech about the 3S/5S-FE and it agreed about 15 deg. F heads are all similar regardless of block, chamber design plays a big role in flame propagation.


--------------------
post Apr 23, 2012 - 9:48 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Bitter @ Apr 23, 2012 - 8:58 PM) *
What year is yours? I never heard knock, I monitored it with a SAFC2.



Its 95 7afe(stock except intake and exhaust), on a 94 chassis and ecu. Turned the distributor all the way clockwise and running 87(basic pump fuel).
post Apr 23, 2012 - 10:44 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




Did you set the base timing correctly and check with a timing light or just turn the distributor? You have some extra steps beyond just turning the distributor, you have to be in the base timing adjust mode.


--------------------
post Apr 24, 2012 - 12:19 PM
+Quote Post
mandrek



Enthusiast
***
Joined May 4, '05
From western MD/NOVA
Currently Offline

Reputation: 2 (100%)




umm IIRC correctly its TE1 and E1, in the dieg port.. jump those two and it will set it to the base timing... then use a timing light and set it to what you want.. i would suggest 16* no more. hope you are not driving like that cus you will be well in excess of 20* advanced.


--------------------
post Apr 24, 2012 - 1:21 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




Another thing to add- make sure your idle is 650-750 and the motor is at operating temperature. Even with E1 and TE1 jumpered the electronic advance will kick in and screw up your timing at anything above an idle.
post Apr 24, 2012 - 1:38 PM
+Quote Post
mandrek



Enthusiast
***
Joined May 4, '05
From western MD/NOVA
Currently Offline

Reputation: 2 (100%)




indeed, and assuming that the tension on the throttle cable is correct, and the idle set screw is correct, and that the idle up valve is functioning correctly, at *normal* Base timing setting your idle should be 650-750... @ 16* base advance your idle should be purring along at 900 RPM...


--------------------
post Apr 24, 2012 - 1:54 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




Ha more things to do then i thought. Ive been driving all day without a problem. Today idel was right around 700. Havent changed anything sense last night.
post Apr 24, 2012 - 9:39 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




But did you have the pins jumped on a hot engine when setting timing? If not, then you did not set timing.


--------------------
post Apr 24, 2012 - 9:46 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Bitter @ Apr 24, 2012 - 10:39 PM) *
But did you have the pins jumped on a hot engine when setting timing? If not, then you did not set timing.



I did do it with the engine running and at operating temp
post Apr 24, 2012 - 10:59 PM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




Fine, but were the pins jumped?


--------------------
post Apr 25, 2012 - 12:01 AM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Bitter @ Apr 24, 2012 - 10:59 PM) *
Fine, but were the pins jumped?



No. I didnt know about that when i did it. The car runs great. Honestly seems smoother now. Little more top end pull to it
post Apr 25, 2012 - 7:17 AM
+Quote Post
Bitter

Enthusiast
*****
Joined Mar 11, '06
From Way South Chicago
Currently Offline

Reputation: 0 (0%)




QUOTE (celica74 @ Apr 25, 2012 - 12:01 AM) *
QUOTE (Bitter @ Apr 24, 2012 - 10:59 PM) *
Fine, but were the pins jumped?



No. I didnt know about that when i did it. The car runs great. Honestly seems smoother now. Little more top end pull to it

Then you did nothing. Without the pins jumped the ECM just compensates for any rotation of the distributor, your timing is the same. Put it back to where it was and do the procedure correctly.


--------------------
post Apr 25, 2012 - 7:31 AM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (Bitter @ Apr 23, 2012 - 9:58 PM) *
What year is yours? I never heard knock, I monitored it with a SAFC2.


95 7a with on. A 94 ecu
post May 1, 2012 - 12:18 AM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




Got my engine fully apart, I'll put up pics or start a build thread or something later, but my cylinder 3 and 4 rod bearings were obviously damaged, and the two main bearings at that end of the engine as well. The crank shows it, so it looks like I'll be having the crank cut. I was considering boring the cylinders over, but the cylinder walls look like they're in excellent shape... Haven't measured them, though. We'll see what the machine shop has to say about it, I'd enjoy not having to shell out for a new set of pistons if I don't have to. I had thought of porting and polishing the head myself (being that port/polish kits are decently cheap), but after reading into the subject I think I'll pass. It'd cost less up front, but I'm fairly confident I'd get (a lot) more for my money having it professionally done.

I did have a few open questions for anyone who cares to chime in with an opinion:
1) Assuming I do end up getting it milled, would the cam timing be adversely affected by the change in distance between the crank pulley and cam pulley?
2) Assuming that I need to have the cylinders honed, would that necessarily mean I'd need oversize pistons/rings?
3) Does anyone have a machine shop to recommend in the general Charlotte, NC / Rock Hill, SC area? tongue.gif


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post May 1, 2012 - 2:13 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (PaukST @ May 1, 2012 - 1:18 AM) *
Got my engine fully apart, I'll put up pics or start a build thread or something later, but my cylinder 3 and 4 rod bearings were obviously damaged, and the two main bearings at that end of the engine as well. The crank shows it, so it looks like I'll be having the crank cut. I was considering boring the cylinders over, but the cylinder walls look like they're in excellent shape... Haven't measured them, though. We'll see what the machine shop has to say about it, I'd enjoy not having to shell out for a new set of pistons if I don't have to. I had thought of porting and polishing the head myself (being that port/polish kits are decently cheap), but after reading into the subject I think I'll pass. It'd cost less up front, but I'm fairly confident I'd get (a lot) more for my money having it professionally done.

I did have a few open questions for anyone who cares to chime in with an opinion:
1) Assuming I do end up getting it milled, would the cam timing be adversely affected by the change in distance between the crank pulley and cam pulley?
2) Assuming that I need to have the cylinders honed, would that necessarily mean I'd need oversize pistons/rings?
3) Does anyone have a machine shop to recommend in the general Charlotte, NC / Rock Hill, SC area? tongue.gif



Im assuming 1 is when your refering to having the crank cut. It shouldnt make a difference. Just make sure and spec everything to make sure you get the propper size bearings. Shouldnt have to get anything but standard unless the crank was scarred that bad. 2 you always wanna hone the bore anytime you rering. Doing this helps the rings sit and help with oil. It wouldnt take anymore then maybe a thousandth away if done propperly. No need for oversize upless you bore. 3 i live in Raleigh, NC, so im not formillar with the charlotte area.
post May 1, 2012 - 2:28 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




I think he meant having the block or heads milled. Its shouldnt adversly affect the camshaft timing. Something I learned from Chevys is that as much as 4 degrees is not noticible, and im sure you wont have anywhere near that much difference
post May 1, 2012 - 10:10 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




QUOTE (Special_Edy @ May 1, 2012 - 3:28 PM) *
I think he meant having the block or heads milled. Its shouldnt adversly affect the camshaft timing. Something I learned from Chevys is that as much as 4 degrees is not noticible, and im sure you wont have anywhere near that much difference

Hit the nail right on the head. I was a little skeptical that a 0.3mm or 0.4mm difference would cause noticeable differences in cam timing, but my own guess wasn't really reassuring to go on. Thanks for the info! tongue.gif
QUOTE (celica74 @ May 1, 2012 - 3:13 PM) *
Im assuming 1 is when your refering to having the crank cut. It shouldnt make a difference. Just make sure and spec everything to make sure you get the propper size bearings. Shouldnt have to get anything but standard unless the crank was scarred that bad. 2 you always wanna hone the bore anytime you rering. Doing this helps the rings sit and help with oil. It wouldnt take anymore then maybe a thousandth away if done propperly. No need for oversize upless you bore. 3 i live in Raleigh, NC, so im not formillar with the charlotte area.

#1 was about the block/head being milled, but I'm pretty sure my engine would eat itself alive from the inside if I had the crank cut without compensating with proper bearings. Already in the plans! Thanks for the input on honing, I want this rebuild to last a LONG time, so I don't want to leave anything undone that could increase its lifespan. Looks like a hone will be in the plans as well! tongue.gif

I'm planning to replace the exhaust valves, all the seals, the oil pump, and possibly valve springs. Also, aren't the rod bolts one of the stock 7A-FE's weak spots? I'm considering replacing those with ARP bolts or something, but haven't really researched into that yet. I know I need new head bolts, rod bolts, and main cap bolts anyway, so I may as well beef up the durability if I can do it without breaking the bank.




--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post May 1, 2012 - 10:42 PM
+Quote Post
mandrek



Enthusiast
***
Joined May 4, '05
From western MD/NOVA
Currently Offline

Reputation: 2 (100%)




there are no ARP bolts/studs that fit the 7afe stock rods.. you will have to go after-market rods or just get a fresh set of stockers.. ARP 4age head studs, and main studs do fit(ish) the 7afe but two of the head studs absolutely MUST be cut down to fit under the cam gears (far left side, 1 intake and 1 exhaust side stud closest to the timing belt) and the last pair of main studs (last cap closest to the trans) need to be cut down some to fit under the upper oil pan.. i have pix and all from when i did this on my own rebuild.. but i do not have any of this posted up just yet.. need the car finished first and get working first.. as soon as i have time to do it i will start a thread for it in the project section and have all of this covered.

and IMO if you are not planning on boosting the 7a, then a fresh stock set of rod bolts will do fine.. and even if you are, a fresh set will work well for low boost (as far as my research shows), but if you are wanting to go as far out as you are indicating, then just get your self a set of belfab rods and have them include ARP2000 units with them. (an option you can request).. the cost on the rods is not that much (compared to aftermarket rods for other applications)


--------------------
post May 1, 2012 - 11:58 PM
+Quote Post
celica74

Enthusiast
***
Joined Feb 8, '10
From North Carolina
Currently Offline

Reputation: 0 (0%)




QUOTE (mandrek @ May 1, 2012 - 10:42 PM) *
there are no ARP bolts/studs that fit the 7afe stock rods.. you will have to go after-market rods or just get a fresh set of stockers.. ARP 4age head studs, and main studs do fit(ish) the 7afe but two of the head studs absolutely MUST be cut down to fit under the cam gears (far left side, 1 intake and 1 exhaust side stud closest to the timing belt) and the last pair of main studs (last cap closest to the trans) need to be cut down some to fit under the upper oil pan.. i have pix and all from when i did this on my own rebuild.. but i do not have any of this posted up just yet.. need the car finished first and get working first.. as soon as i have time to do it i will start a thread for it in the project section and have all of this covered.

and IMO if you are not planning on boosting the 7a, then a fresh stock set of rod bolts will do fine.. and even if you are, a fresh set will work well for low boost (as far as my research shows), but if you are wanting to go as far out as you are indicating, then just get your self a set of belfab rods and have them include ARP2000 units with them. (an option you can request).. the cost on the rods is not that much (compared to aftermarket rods for other applications)



In your thread iy will be good to show how much you had to cut off the studs. And are those rods easy to find?
post May 3, 2012 - 5:37 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




QUOTE (mandrek @ May 1, 2012 - 11:42 PM) *
there are no ARP bolts/studs that fit the 7afe stock rods.. you will have to go after-market rods or just get a fresh set of stockers..


Is that definite? I'm not being rude or challenging, just trying to find out for sure... Different people say different things, you know! smile.gif I've seen some posts like these that say they'll work, and heard hearsay along the lines of "they'll work but you have to work on the block a little to keep them from contacting it during the stroke"....

... But it's probably a moot point anyway, as it's most likely not going to be boosted at all... However, there are no guarantees of how high I'll be revving it, or how often during the course of just fooling around during random driving, and the state of the main bearings and rod bearings make me nervous. I just wish I knew what caused the damage, that would ease my mind a bit...
QUOTE (mandrek @ May 1, 2012 - 11:42 PM) *
and IMO if you are not planning on boosting the 7a, then a fresh stock set of rod bolts will do fine.. and even if you are, a fresh set will work well for low boost (as far as my research shows), but if you are wanting to go as far out as you are indicating, then just get your self a set of belfab rods and have them include ARP2000 units with them. (an option you can request).. the cost on the rods is not that much (compared to aftermarket rods for other applications)


I will end up just using fresh 7a bolts, though, if there are no reasonable alternatives between that and forged rods.


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post May 4, 2012 - 12:35 PM
+Quote Post
mandrek



Enthusiast
***
Joined May 4, '05
From western MD/NOVA
Currently Offline

Reputation: 2 (100%)




CAN you? yes. its is worth it? NO... sure you can get 4age/fe ARP rod bolts/studs.. but to get it to work on the stock 7a rods you would have to have the rods machined and then re tapped/cut to be able to take the new ARP hardware.. the problem is that the 7a rod is a configuration were the bolt goes through the cap, and into the rod.. the 4age (not sure about the 4afe but pretty sure ARP had no support for that motor) rods use a pass through type configuration. IIRC the 4age rods have bolts that come from the top (wrist pin side) through the bottom of the rod twords the cap. and then secured with the nuts. the top of the "bolt" is square and locked into place with the shape of the rod.. so by the time you do what you need to make the ARP hardware work, you are better off just getting the belfab rods.

link to nice write up on difrences, and lots of pix on page.

This post has been edited by mandrek: May 4, 2012 - 12:38 PM


--------------------
post May 4, 2012 - 12:47 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




QUOTE (PaukST @ May 3, 2012 - 5:37 PM) *
QUOTE (mandrek @ May 1, 2012 - 11:42 PM) *
there are no ARP bolts/studs that fit the 7afe stock rods.. you will have to go after-market rods or just get a fresh set of stockers..


Is that definite? I'm not being rude or challenging, just trying to find out for sure... Different people say different things, you know! smile.gif I've seen some posts like these that say they'll work, and heard hearsay along the lines of "they'll work but you have to work on the block a little to keep them from contacting it during the stroke"....

... But it's probably a moot point anyway, as it's most likely not going to be boosted at all... However, there are no guarantees of how high I'll be revving it, or how often during the course of just fooling around during random driving, and the state of the main bearings and rod bearings make me nervous. I just wish I knew what caused the damage, that would ease my mind a bit...
QUOTE (mandrek @ May 1, 2012 - 11:42 PM) *
and IMO if you are not planning on boosting the 7a, then a fresh stock set of rod bolts will do fine.. and even if you are, a fresh set will work well for low boost (as far as my research shows), but if you are wanting to go as far out as you are indicating, then just get your self a set of belfab rods and have them include ARP2000 units with them. (an option you can request).. the cost on the rods is not that much (compared to aftermarket rods for other applications)


I will end up just using fresh 7a bolts, though, if there are no reasonable alternatives between that and forged rods.

Probably a PO who didnt keep up with the oil changes. At least your cylinder bores are nice and clean.

As for the rods, 4 cylinder engines are hard on the rods. Thats why you dont see big displacement I4s even though they produce superior torque to a equal sized 6 or 8 cylinder
post May 4, 2012 - 1:16 PM
+Quote Post
richee3



Moderator
*****
Joined Jun 29, '08
From Denver
Currently Offline

Reputation: 59 (100%)




^^ I love inline engines smile.gif


--------------------
"Employ your time in improving yourself by other men's writings, so that you shall gain easily what others labored hard for." -Socrates. Even Socrates told us to use the search button!

2006 Aston Martin V8 Vantage.
1998 Celica GT-
BEAMS Swapped.
2022 4Runner TRD Off Road Prenium.
2021 GMC Sierra AT4.
post May 4, 2012 - 2:02 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




QUOTE (richee3 @ May 4, 2012 - 1:16 PM) *
^^ I love inline engines smile.gif

Lol you'd like the 4.1L I6 in my garage. 11 to 1 CR, full length headers(I mean 4 ft long) going into true dual 2.5in exhaust. Offenhauser 4 barrel intake, HEI ignition, high torque ministarter. Timing chain swapped for gear driven. The thing has 7 main bearings in it. Its a frickin beast and its smooth as butter to. Max torque for them stock is at 1200rpm.
But of course a 350 v8 was more bang for the buck so thats whats in my truck now. I know that 4.1L six will outpull my 5.7L v8 any day of the week though. I want to make a trike with the straight six, I6s are awesome.
post May 4, 2012 - 4:59 PM
+Quote Post
PaukST



Enthusiast
*
Joined Mar 15, '12
From Wrightstown, NJ
Currently Offline

Reputation: 6 (100%)




QUOTE (mandrek @ May 4, 2012 - 1:35 PM) *
CAN you? yes. its is worth it? NO... sure you can get 4age/fe ARP rod bolts/studs.. but to get it to work on the stock 7a rods you would have to have the rods machined and then re tapped/cut to be able to take the new ARP hardware.. the problem is that the 7a rod is a configuration were the bolt goes through the cap, and into the rod.. the 4age (not sure about the 4afe but pretty sure ARP had no support for that motor) rods use a pass through type configuration. IIRC the 4age rods have bolts that come from the top (wrist pin side) through the bottom of the rod twords the cap. and then secured with the nuts. the top of the "bolt" is square and locked into place with the shape of the rod.. so by the time you do what you need to make the ARP hardware work, you are better off just getting the belfab rods.

link to nice write up on difrences, and lots of pix on page.

There we go, that's some info I can use. And that link has some good info, bookmarking that mess! Details > generalizations any day.

QUOTE (Special_Edy @ May 4, 2012 - 1:47 PM) *
Probably a PO who didnt keep up with the oil changes. At least your cylinder bores are nice and clean.

As for the rods, 4 cylinder engines are hard on the rods. Thats why you dont see big displacement I4s even though they produce superior torque to a equal sized 6 or 8 cylinder

Thanks for the help, guys! I'm hoping to get this project moving sometime next week, I'm tired of driving around on a gimped, oil burning engine. tongue.gif


--------------------
1989 Celica ST Automatic "King Cobra" -- 2005-2006
1994 Celica ST 5-speed "King Cobra II" -- 2011-????
post May 4, 2012 - 6:53 PM
+Quote Post
Special_Edy



Enthusiast
****
Joined Oct 29, '11
From Haltom City, Texas
Currently Offline

Reputation: 1 (100%)




Id replace the oil pump while you have it apart. So you know you arent burnin the new bearings

3 Pages V   1 2 3 >
Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



Lo-Fi Version Time is now: August 19th, 2025 - 4:18 AM