4.3 with no compression on 2 cyl....why?

[pmtom1]

Hey guys, Ive just started a new project on a 1989 Wellcraft. Looking at replacement engine for a seized 3.7. I have a 4.3 (I understand the mounting and gear issues) available cheap that has no comp on two cylinders. What are the most common causes and repairs of this? Piston, rings and maybe some cylinder wall damage?

PS...any one that has successfully gone from 3.7 to 4.3, Id love to ask a couple questions via email!

Thanks.... tom

 

[Haut Medoc]

Re: 4.3 with no compression on 2 cyl....why?

0 compression is usually a valve issue.....
Or a hole in the top of the piston caused by detonation.....
You will still get some compression with scored walls, cracked rings...

 

[captcrankshaft]

Re: 4.3 with no compression on 2 cyl....why?

If the cylinders are adjacent it could be a head gasket.

A leak down test on those two cylinders will get you much closer to the answer.

 

[Bifflefan]

Re: 4.3 with no compression on 2 cyl....why?

that has no comp on two cylinders.
Thanks.... tom

What 2 cylinders?
If they are side by each then its probably a blown head gasket. If not, like stated above, a valve or a hole the piston.

 

[pmtom1]

Re: 4.3 with no compression on 2 cyl....why?

Thanks Guys.... Will check and report back!