#1 cylinder down on compression

63comet

Well-known member
Heh Everyone, Looks like I need to step up my 250 rebuild, went out today and tried to start the old comet and it started and ran for about 2 minutes and slowly quit. I haven't started it for about a month, but it was running fine when I ran it then. I pulled the plugs and saw that they were all wet with gas, I had spark and fuel, so I decided to take a compression check which I have never done, #1 cylinder has only about 75#'s all the rest have around 140 to 160. This car ran great all summer long since the rebuild, and I had no problems with the motor, only small carb problems and timing issues which I had pretty much straightened out. Hopefully, it is just a burnt valve. I was not satisfied with the 3 angle job done, when the mechanic did the job, the head already had hardened seats installed and had the valves ground a couple of times already and there wasn't much of the hardened seats left in the head, He said he didn't like that, but they should be good enough. Any suggestions on what else it could be?
 
:lol:good morning and happy new year. i had a motor that acted the same way. i found it to be a sticking valve on #5 cyl. another guy had carbon build up under the seats, ran water through the carb. at fast idle and cleaned it out. :hmmm: i have never done this so i don't know first hand if it works.that is a he said. good luck...frank..
 
Heh Frank, I hope that that's the problem I have, I just built this engine last winter and it ran fine all summer. Looking in the #1 hole, I can see a lot of carbon on the piston top and the plugs are real black. The carb I am running for now is the Carter off a 300, the car started hard but ran fine with no hesitation at all and pretty good high speed. I had the H/W 5200 on it in the spring, but it was running pretty lean, so I put the Carter on it. I think it ran better with the H/W, but I didn't have the other jets at the time to tune it, so I just put the Carter on and it ran fine with that so I didn't change it again. I have plans for a different head with a 2v attached directly to it and I am also building a 250 to install if I can figure out the oilpan issue. I had planned on installing the 250 in this winter anyway, but I think I may have to fabricate an oilpan, and that may take more time than I had planned on , so I was hoping to change out the head and run the 200 until I could get this done.
 
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