rket56

This is a puzzle to test your knowledge of engines. This is what happened with my 56 Olds, 324 engine. All the info is here and I will post the answer in 3 or 4 days to give everyone a chance to solve this. Info: The engine was torn down including crank removal. Heads re-worked with hardened valve seats and .060 removed from the heads. Installed new timing gear, new chain, new after market cam,new hydraulic lifters. The distributor was removed and rotated to a different position to provide clearance for the new carb linkage.
Problem: The engine tested zero compression on all cylinders after re-assembly. What do you think is wrong and how would you fix it?
P.S. A buddy of mine solved it for me. Chuck

fourtwenty

lifters too tall ?

droldsmorland

Somethings holding the valves open or the timing is way off...chain/cam is 180* out. If 180 out Id still think youd see some compression on a couple of the cylinders. Its likely the head shave...Did you adjust the valve train geometry to compensate for the 60 thou shave? If not you need custom push rods and/or shims under the rockers.

59-59-59

Or did someone forget about the piston rings? Or head gasket? Nah - that would be almost impossible to forget, right?

Stefano

It could be a few things but if all the parts are good and were properly installed (gaskets, rings, etc) then I would surmize;
Valves are not closing all the way / seating

A quick bit of air pressure in cly#1 at TDC would let you know where most of the air was escaping through.

oldcutlass

I'm going with wrong push rods.

69ishHoliday

Did your buddy double the head gasket to solve for valves not completely closing?

Tedd Thompson

Did you use SBC lifters and if you did did you use the correct length push rods to compensate for them?...Tedd

RetroRanger

bad compression guage ?

ankerclanker

I would check the distributer to the original position and start compression checks again....I think? I would reset the distributor to the original position and redo the compression check

Octania

left the rods out

Rocketowner

I'm Guessing Wrong Lifters Or Pushrods Are The Wrong Length. Larry

Allan R

I like this answer.

mrolds88

Decking the heads increased the effective length of the pushrods. When the rocker assemblies were bolted down, they compressed the lifters to collapse and were still long enough to hold the valves open.

kirkwoodken

I think everyone who said push rods is right. This is one of those things that should have been checked. If you didn't check it, it probably went wrong. Any time you do ANYTHING that will change rocker angle geometry, you need to check it, and correct it if wrong by getting different rush rods or shimming rocker pedestals. Correct rocker geometry should ALWAYS checked on ANY rebuild.

Could also be cam in wrong place, but that is a more obvious mistake than push rods too long.

rket56

Yes the problem was corrected by making 16 gage shims for under the rockers. I measured the bolt spacing carefully and made the shims close enough so they couldn't shift and block the oiler hole. Chuck