I thought I would share the findings on my 98k mile 310 hp engine I pulled from the wagon in 2015 that had a rod knock off idle but otherwise seemed in great shape inside. It ran with no exhaust smoke or idle noises and no blow by observed back at the time. I finally began the tear down for overhaul and wanted a baseline compression test being its was a high compression model with a very small factory cam and that made me quite curious. So here ya go. the four lowest were 180-190 psi although one I re-tested after initially getting a low 120 number. The other 4 were 210-230 psi. #7 was the only obvious one with bad rod bearing as the carbon was knocked off the top part of piston from kissing the head deck. Have not looked at bottom end yet. None of the spark plugs had any oil fouling and the lifter valley was very free of sludge as was top of passenger head but oddly the top of drivers head was showing some light sludge flaking. Wonder if that is characteristic of the side with PCV valve ?


So the question is .. Any one share there findings on there stock engines of this type?

 

I have a stock 68 455 high compression motor, originally a 2bbl. Completely stock bottom end, heads have never been off. My compression was all between 200-210. Hope that helps.

 

Good comparison and comparable , Thanks . I did a search and someone was getting 165-180 with one also .