I have a 1911 w/weber 44's and webb cam and lifter. about 25k on the whole motor, 10k on the cam and lifters. this last weekend we went to P2O in OH from MN. The car ran great on the way down, started great, plenty of power. On the way back it started running rough, it got so bad that it was only firing on the passenger side. I got a hold of Brad Mayeur and we got it to his place. He did a compression check- 60 and 65lbs on the driver side and 85 and 70lbs on the passenger side. we also did a leak down test- that was good on all 4. any ideas?

Brad and I haven't come up with a good reason for this yet. I'm going back down on Friday to get it. I have a big car show in Geneva, IL on the 26th of this month so I don't have a lot time. Any help would be great.

also I'm just running the valves that came with the 1.8 big bore kit, can you recommend something better?

thanks

60 psi on the compression? i thought it was more like 110 psi. but if it was abnormal, i'm sure Brad would have spotted it.

First off- Don't rush to make it to the show- events can kill engines and drain wallets, engines are intolerant of expedited procedures!

It sounds like the engine may have gotten hot and tightened up all the valves..

How much leak down did it have? Was the engine hot and each cylinder tested at exactly TDC?? With those low compression numbers I can't fathom that it would pass a hot leakdown test.

Brad said I should be at 135lbs w/ the set up I have.

The engine was hot when the leak down was done. Brad made sure of TDC. I don't remember the numbers on the leak down, all I remember is Brad saying they were all good. I can get the numbers from him. Brad said the samething Jake. We didn't do much, it was Sunday and I had to get back for work.

Jake before it got real bad, you could feel the engine surging intermitently running rough and then like everything fine.

um, maybe cam gear bolts shhifting?

So if the leak down is fine, that means, valves are sealing tight, and the rings are tight. Air isn't escaping which is the usual cause of low compression numbers. The issue is that the air is restricted on either in intake or the exhaust.

So either that is a restriction in the intake runner system, a restriction in the exhaust system, or a problem with the valves opening and closing correctly. A flat cam is unlikely because of the uniformity of the compression. A flat cam usually only affects two opposing cylinders, not all four.

Have you drained the oil? If it was a multi-lobe flat cam, then there will be a WHOLE LOT of metallic shine to your oil.

Start there. The amount of mileage you imply from when you first noticed the problem to when it was tested might have made the whole cam go flat.

Just got back from Brad's(17hr round trip). Brad found this box in his stack of stuff and the price was right so...

I'll check valves 1st tomorrow and go from there.