2F build goof (1 Viewer)

[kbill45]

Had my 77 2F rebuilt at local very reputable automotive machine shop. Noticed right off that low end power was very weak. Did a compression check and number 2 registered 95psi and the other 5 were at 100psi. The old standard pistons wered domed so I pulled a plug and was able to determine that the new .020 pistons are flattop. When I contacted the shop the engine builder remembered that he installed what the shop owner provided which were flattops. He also installed a head from stock that annother owner had failed to pick up. So here is what I have.

head - #61031 In faq is open chambered

engine - # 2f- 166597 in faq sounds right for a 77

pistons - flat top but should be domed

The shop has now been bought out by the employees. During a clean up my original head went to scrap. They acknowledge the error and want to make it right. These are really nice guys and I want to make it as easy for them as possible. Should I have them find a closed chambered head or replace the pistons?

What would you do???????????? Thanks for any comments and opinions. Bill

 

[Cruiserdrew]

If the rotating assembly was balanced, then different pistons would throw that off. I don't know how hard it will be to find the correct head, but I think that's what I would want. That would also involve the least down time.

If they are willing to fully rework your motor, then let them do what they want, as long as you end up with what you want.

 

[Spike Strip]

I *think* you can just put on a 61040 head (or 61010 if you're desmogged) and it would be good to go... FJ40Jim has posted all this info somewhere...

 

[Mark W]

Most 2F builds are gonna be static balanced only (if that). No big deal to redo it.

But you are doing it the hard (and expensive) way if you replace pistons. Easier to find a closed chamber head.

Could also cut the head and get most of your compression back.


Mark...

 

[kbill45]

It is desmogged.

I am all for just using a closed chambered head.

Mark, how much could this head be cut to get reasonably close to an accepable psi?

 

[Fast Eddy]

reasonably close to an accepable psi?

^^ This is not where I'd want to be with a new engine. ^^

 

[kbill45]

^^ This is not where I'd want to be with a new engine. ^^

I know but they are being so humble about it. They could just tell me to take it up with the former owner who is not around.

 

[Mark W]

It is desmogged.

I am all for just using a closed chambered head.

Mark, how much could this head be cut to get reasonably close to an accepable psi?

These heads can be cut .100. I have cut a few heads this much.


Mark...