About valve adjustment, I think it has to do with the engine design. On my solid lifter V8 engines the pushrods expand when hot and the valves get tighter, if they are loose you only hear them when cold (unless they're really loose) but on my 3.0 P-car I misadjusted a valve on the loose side and guess what, it only makes noise when hot! I think the thermal expansion of the aluminum cam towers being greater than the steel rockers and cam cause the rockers to move farther away from the valves but that's just a theory. As for warming the oil, I'm not that retentive about it, I just let it warm up for a block or two then it's up to 3/4 throttle and about 5000 rpms until it reaches 160 or more. Maybe I'm causing longterm damage maybe not but I have yet to see anything more than advice on the subject, I'd like to see scientific tests. I concede though that I did run a oil heater on my drag car when it's cool outside to keep the temp high enough between runs for consistency yet not heat up the intake and heads.
My .02, correct me if I'm wrong but give me something more than opinion, like facts.
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Email me about 911 exhaust stud repair tools, rsr911@neo.rr.com
1966 912 converted to 3.0 and IROC body SOLD unfortunately
1986 Ford F350 Crew Cab 7.3 IDI diesel, Banks Sidewinder turbo, ZF5 5spd, 4WD Dana 60 king pin front, DRW, pintle hook and receiver hitch, all steel flat bed with gooseneck hidden hitch. Awesome towing capacity!