Remanufactured Head (ebay), Need you all experts advise Options

[msk59]

In the near future, I plan on redoing the valves etc on the head and came across some ebay sites that sells remanufactured heads. all work done with cams etc for under $300. Engine is 7A-FE and my car is 1996 Celica ST (AT-200) with manual transmission.

What is your experience with these heads and what advise you can give me that can help me decide.

Thank You
MSK

This post has been edited by msk59: Jun 13, 2014 - 8:09 AM

[Special_Edy]

Three angle valve job; lap the valves in; check the tolerances on the camshafts journals, camshaft lobes, reshim the valves, replace the valve seals, check the valve guides; check the head for cracks and resurface if necessary

[Langing]

Three angle valve job; lap the valves in; check the tolerances on the camshafts journals, camshaft lobes, reshim the valves, replace the valve seals, check the valve guides; check the head for cracks and resurface if necessary

Muchas gracias! With that helpful info I can finally relate to what's going on.

You've done this before, right? Did you do most of it by yourself (DIY) or did you farm out the whole job? Or have you done it more than once?

With 16 valves, I would think that work could take a person a while to finish? Would it be true that most anyone mechanically inclined who has the right tools and is reasonably careful could do that job, with the exception of resurfacing, since that's the only task that requires expensive equipment, or do most of those tasks require expensive equipment? And how about cleaning all those parts, wouldn't that be a monster chore?

If an unskilled person, a DIY guy, just had the hots for taking an engine apart to rebuild it all by himself, wanted to get himself a salvage engine from a junkyard, would you try real hard to discourage him? Or would you stay silent and wait for him to fail?

For how many months would he have to reserve the garage to do this?

[Special_Edy]

Three angle valve job; lap the valves in; check the tolerances on the camshafts journals, camshaft lobes, reshim the valves, replace the valve seals, check the valve guides; check the head for cracks and resurface if necessary

Muchas gracias! With that helpful info I can finally relate to what's going on.

You've done this before, right? Did you do most of it by yourself (DIY) or did you farm out the whole job? Or have you done it more than once?

With 16 valves, I would think that work could take a person a while to finish? Would it be true that most anyone mechanically inclined who has the right tools and is reasonably careful could do that job, with the exception of resurfacing, since that's the only task that requires expensive equipment, or do most of those tasks require expensive equipment? And how about cleaning all those parts, wouldn't that be a monster chore?

If an unskilled person, a DIY guy, just had the hots for taking an engine apart to rebuild it all by himself, wanted to get himself a salvage engine from a junkyard, would you try real hard to discourage him? Or would you stay silent and wait for him to fail?

For how many months would he have to reserve the garage to do this?

Ive had a couple heads worked on, had to have a burnt exhaust valve replaced on my old 5s motor. Last head I had apart was for my '82 Yamaha SECA 750, none of the local shops claimed to have the equipment for that small of valves so I lapped the valves and replaced the stem seals myself. Had to buy a special sized valve removal tool.

Without tens of thousands of dollars worth of equipment, your are limited to-

Removing the valves, replacing the valve stem seals with them out.
Lapping the valves with valve grinding compound.
Using calipers to measure the valves, camshaft lobes and cam journals.
Using plastigauge to measure the clearance inside the cam journals.
Reshimming the valve lifters back into spec.
Checking the straightness of the head.

Grinding the valves and valve seats requires serious machinery, as does replacing the seat or valve guide. But luckly these things are usually only needed on a severely worn head. I would stake money on toyota cylinder heads outliving the block and lower end by several hundred thousand miles as long as the engine is properly maintained. Just make sure the valve shims are in spec, they have something like a 75,000 mile service check interval.

[Langing]

Three angle valve job; lap the valves in; check the tolerances on the camshafts journals, camshaft lobes, reshim the valves, replace the valve seals, check the valve guides; check the head for cracks and resurface if necessary

Muchas gracias! With that helpful info I can finally relate to what's going on.

You've done this before, right? Did you do most of it by yourself (DIY) or did you farm out the whole job? Or have you done it more than once?

With 16 valves, I would think that work could take a person a while to finish? Would it be true that most anyone mechanically inclined who has the right tools and is reasonably careful could do that job, with the exception of resurfacing, since that's the only task that requires expensive equipment, or do most of those tasks require expensive equipment? And how about cleaning all those parts, wouldn't that be a monster chore?

If an unskilled person, a DIY guy, just had the hots for taking an engine apart to rebuild it all by himself, wanted to get himself a salvage engine from a junkyard, would you try real hard to discourage him? Or would you stay silent and wait for him to fail?

For how many months would he have to reserve the garage to do this?

Ive had a couple heads worked on, had to have a burnt exhaust valve replaced on my old 5s motor. Last head I had apart was for my '82 Yamaha SECA 750, none of the local shops claimed to have the equipment for that small of valves so I lapped the valves and replaced the stem seals myself. Had to buy a special sized valve removal tool.

Without tens of thousands of dollars worth of equipment, your are limited to-

Removing the valves, replacing the valve stem seals with them out.
Lapping the valves with valve grinding compound.
Using calipers to measure the valves, camshaft lobes and cam journals.
Using plastigauge to measure the clearance inside the cam journals.
Reshimming the valve lifters back into spec.
Checking the straightness of the head.

Grinding the valves and valve seats requires serious machinery, as does replacing the seat or valve guide. But luckly these things are usually only needed on a severely worn head. I would stake money on toyota cylinder heads outliving the block and lower end by several hundred thousand miles as long as the engine is properly maintained. Just make sure the valve shims are in spec, they have something like a 75,000 mile service check interval.

I sincerely appreciate your helpfulness in introducing me to this (what is to me a) new world. What you just posted is most helpful; made things snap into place. You also pointed out something I have been ignoring for a long time because of my lack of experience and shallow understanding. I'm talking about the importance of keeping the valve shims in spec. Their service interval is 75,000 miles and I've not paid the least attention to them for the 300,000 miles I've put on her. Maybe if I got those shims adjusted, she might be able to go over 70 without me feeling like she needs rest (seems happy at 60)! That adds a new task to my relatively immediate todo list!

Although I find engine guts intimidating, I've had my 7A-FE valve cover off twice since I bought Betsy, once because of an oil leak at the spark plug tube ends (caused by a service mechanic) and the second was when I changed out her timing belt. So, it is not EXACTLY like I see the engine as a complete black box. I have seen her cam shafts

So, when I read your advice I popped open Vol 1 of my BGB and skimmed over the VALVE CLEARANCE INSPECTION AND ADJUSTMENT procedure. It has some terminology that I will have to puzzle but the only thing that caught my eye as being a possible problem for me is their use of two SSTs on the exhaust side used to take out, measure, and replace the adjusting shims (SST A and SST B. . . page EG-22), needed because the exhault cam shaft is not removed in the procedure. Since my experience with Toyota tells me you cannot get your hands on their special service tools, I'm wondering if there are suitable alternative tools? I've got thickness gauge, micrometer, etc., and I can be careful when removing the intake cam shaft, so this job doesn't look all that intimidating to me. Seems I'm slowly being forced to crawl deeper and deeper into her internal organs!


BTW: I googled images of the Yamaha SECA 750. If your 82 is like those images, you had/have a very nice looking motorcycle!