TucsonHooligan
Well-known member
Motor is assembled and back in the car, ready to fire up. Cranked it over, and after some troubleshooting realized I had no compression. Pull the valve cover and bring cylinder #1 up on the compression stroke. No space between rocker and top of valve so I took some quick caliper measurements from top of valve to top of head. Removed rocker assembly and could obviously see the valves come up further, and after I remeasured the depth they moved a little over .125 (1/8th). So obviously my compression problem stems from the valves being perpetually open. Question is, whats the best cure? The head is a later model square log from the 80's. I had it fully rebuilt and am using the original rocker assembly that came with it, as well as the stock pushrods. I had the block zero decked and the head milled for compression, but was told by the machinist that any pushrod issues should be cured by the play in the lifters. .125 seems like a lot to just be a result of milling. Is there a possibility that the job done on the head has the valves seating that much further in? I read some tech articles that suggested puting shims underneath the assembly mounts, but that seems kinda shadetree. Best I can figure is shorter pushrods, but how do I find the exact length I need? Buy one adjustable, bring #1 up to TDC and run a trial and error till I get the right adjustment, then order a set at that length? Any help here would be appreciated, and please feel free to ask specific questions about details I may have glossed over.