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We ran this past weekend at Hallett with the ITB/PA 142E, and I'm happy to report we did not DNF, which was the case in 3 previous outings. As has been reported here before, I'm running COMMA challenge races with an ITB 142E, and this puts us in COMMA class PA, which is essentially SCCA classes ITA/ITB/ITC combined. Despite some tire problems (flat-spotted 2 tires in the 2nd practice session) we managed to qualify well and finish 2nd in class, behind a first generation RX7. We actually led for the first 7 laps or so of the 12 lap feature race, driving our butt off to keep the RX7 behind us. But unfortunately, the rear tires started to "go away" and I could no longer hold him off.
Also unfortunately, we were putting oil in the water... not a whole lot, but "...this ain't normal", he said. So to be safe, we removed the head today. Didn't find anything obvious, but I can't imagine the problem being anything but a seeping head gasket, most likely from the area of the oil supply galley that feeds the head. I realize there is also the possibility the block is cracked in the area of the oil galley, but I consider that pretty remote. And BTW, I do not run the old P1800 oil cooler arrangement; mine is a conventional air radiator type. If anyone knows of any other failure modes that would put oil in the water, I'm all ears. The only other thing I can think of that might be germane... we were also apparently putting water in the crankcase, and it was evidently boiling off and recondensing in the crankcase vent "catch can". The catch can is used for both the crankcase and valve cover vents; we don't pull these back to the intake manifold. And we're running non-detergent synthetic oil (Redline 40W), so the water does not mix with the oil.
Our current plan is to have the head checked for flatness, and repair if necessary. We are then going with a new set of head bolts and gasket. And while I'm at it, I think I'll have my torque wrench calibrated, just to be sure.
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1971 142E ITB racer, 1973 1800ES, 2002 S60 T5
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