Compression

The motor in my ‘48 has compression in all cylinders between 70 and 75 PSI what I find a bit curious is that although I know that that is no bueno it is so even across all 4 cylinders. Here’s the thing though; it runs very, very well. So well that I question the wisdom of doing anything about it. The motor is quite easily able to push the Jeep way beyond speeds I want to go (I’ve had it up to 50 mph and that’s more than I want to go, 45 is my limit). What might I be missing in power and driveability? I have big hopes of going on the FCT this year, would it be a problem?

2X... Enjoy it!!

I don't worry much about the accuracy of the reading of a compression gauge if the results of all four are consistent and within acceptable boundaries, but it would be helpful to do the wet test suggested by Ron.

To be honest it’s been 2 years and I don’t recall how I did the test(s) I know the numbers because I wrote them down. I will get a chance next week to do it again following the advice given by you fine gentleman. My concern is that I am fortunate enough to go on the FCT that my engine won’t be up to the task when getting up to 10,000 ft and above. I do not know how compression would affect performance at those altitudes.

Bruce W wrote: [QUOTE=Bruce W]  Any deficiencies will be magnified at higher elevations.  BW

Edited by oldtime - 28 Jan. 2023 at 9:09am

I don’t know how much a guy can shave an L head without valve clearance issues. 

Edited by oldtime - 28 Jan. 2023 at 1:44pm