210K on a rebuild? LP is supposed to be harder on rings due to the dryness, though cleaner burning and easier on oil -- sort of a trade-off. I'd say it's time for rings!! I'll be interested to see how much wear there is in the cylinder bores, especially if you used chrome rings. Besides, when you rebuild you could shave the head (or block deck) and get another half point of compression out of it. If you're going to continue with LP you may as well go to 10:1. Will have to change the timing, but no big deal. -------------- Date: Sat, 25 Aug 2007 15:00:00 -0700 From: Tom Jennings <tomj@xxxxxxx> I've had an increasing problem getting the idle mixture right with this carb going on 17 years, a IMPCO CA-125. Very tweaky, had to fiddle PCVs to get it right... it's been getting worse, with #1 cyl not contributing much at idle. Hadn't done a compression check in a few years, so I did one this AM after 20 highway miles hot; bad news... Only checked #1, #2, and #4. 1 and 2 were 100 psi and #4 105 psi. In the late 1990's they were all around 140 - 145. I'll do them all later (in a hurry to pack today) but no reason to think the others are wildly good or bad, so it sounds like 210K miles and 19 years on this rebuild [about 300K total on this '70 motor] is the problem, probably plain old ring wear. Very little oil blowby, only slight smog out the filler if I pinch off the PCV. I'll probably use a quart of oil this trip, about 1100 miles round trip. -- Frank Swygert Publisher, "American Motors Cars" Magazine (AMC) For all AMC enthusiasts http://farna.home.att.net/AMC.html (free download available!) _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list