Oversized valves 5sfe, checklist Options

[UVZ164]

My friend recently built his 88 bmw head and the difference it makes is unbelieveable. Since the 5sfe has an economy head im sure the difference if done right will be amazing.
After much research ive decided 2mm oversized valves a good port and polish and cams would be great.
The valves are what I need advice on, the 2jz valves are very close to the 5sfe just with bigger heads:

5sfe intake: 32x6x97.6 mm
2jz intake: 33.6x5.98x98.55 mm

5sfe exhaust: 27x6x98.4 mm
2jz exhaust: 29x5.98x99.1 mm

So I would go with stock 2jz exhaust valves and +0.5mm, 2jz intake valves.
This might be a stupid question but apart from the machine shop regrinding the valve seats to fit the OS valves what else do I need to do?
Will i need 2jz stem seals?, will i need different buckets/lifters since the stem length is slightly different?

This isnt a job im going to be undertaking soon more just research and saving the $$ stage because getting beaten by civics at the track is giving me the irrits lol.
Any help would be appreciated!

Thanks

[ricochet1490]

Smaay? surprised he hasn't chimed in here.

[Syaoran]

A GOOD head job will give you a noticeable increase in power, even in our economy heads. While it's true that a GE head flows much better, you don't really NEED it, since ultimately it'll cost you about the same to work your FE head as to get a GE head, and then the wiring nightmare that is swapping heads... etc. It's for someone that's really up to the task.

I believe that with 2JZ valves you don't need new valve stem seals. The valve stems are close to the same on our stock valves, they are just longer, something you might also want to consider.

You will also want to look into new valve springs and retainers.


Whether you are or not going with cams (moreso if you are than if you aren't) you should get something to tune the new airflow, and you might even need bigger injectors. Just some things you should also consider.

[UVZ164]

The work to put a GE head on is just far too much for my liking, so thats def out.

Im def planning on cams and a piggy back too.

For the longer valve stems that means im going to need diff shims in the existing buckets or just get diff buckets all together right? which i may as well do since it all out.

[Syaoran]

Probably shims would be enough... but shimless buckets would be the best. I think 1zz shimless buckets fit our cars and there's like 34 different sizes in very small increments.

[Smaay]

i have heard of doing this very thing. if the stem length is the same, then yes all you need to have done is grind the valve seats to meet the 2JZ valves. are these GE valves or GTE valves? i believe they are not the same. i should know that.

you will still use the 5S-FE valve stem seals. And you will need to change shims. upgrading to 1ZZ buckets will work for you but the stock ones will be fine.

please update with your latest findings this is good information.

[UVZ164]

The GE and GTE valves are identical from what I can find. The stem lengths are 0.95mm longer on intake and 0.7mm on exhaust so that has to be made up with shorter buckets/shims. I also like the idea of the shimless buckets for upgraded cams.

With upgraded springs and retainers isn't that only necessary if I wish to up the rev limit and have the thing go to 9krpm?

[hatchy_gt-s]

I would suggest just getting new shims as shimless buckets are VERY expensive and are really no gain.

[Syaoran]

I would suggest just getting new shims as shimless buckets are VERY expensive and are really no gain.

^+1

Unless you're revving past redline, you don't really NEED shimless buckets, especially when you need smaller shims in the first place.

[UVZ164]

Ok so basically a rough list of what is required:

2JZ valves
Existing 5sfe stem seals
Smaller shims or 1zz buckets
valve seats to be reground (worth it to have a 3 or 5 angle job?)

Still unsure about the springs and retainers if they need to be changed or if that will just allow you to increase the redline.

[UVZ164]

What about valve guides, anyone have an idea what to do for them?

[Smaay]

I would suggest just getting new shims as shimless buckets are VERY expensive and are really no gain.

yes you do have a gain, the shimmless buckets are 30% lighter and when you rev higher you take a chance of spitting out a shim. going to 1ZZ buckets you no longer have this risk. the shimmless buckets are about 12-15 bucks apiece but you can find them online and in junkyards very cheap. there are a TON of 1ZZ engines out there.

the the valve stems are the same diameter then you dont need to do anything. if the supra valve is a little thicker, then you need to hone the guide. any machine shop can do this.