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Alan L Alan L is offline
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Join Date: Apr 2006
Location: New Zealand
Posts: 3,245
Agree with Cole. #1 is the only real suspect, but I doubt enough to cause the issues that you have. The whole lot are down a bit on best spec - but that may just be normal wear and tear, cold motor, little bit of valve/ring leakage. A leakdown test where you pressurise the cylinder to 100 psi (at TDC) and see where the gas goes (out the exhaust, out the intake manifold, or our the crankcase breather) will tell you a whole lot more, especially on #1. But for now, you have not found the source of your problem. You can spend some time checking valve clearances (0.1mm) to see if they contribute to your numbers. But I suggest for further problem diagnosis you now look to valve timing by the eyeball method at least and see if a tensioner has failed and you have slipped a tooth or two. That would cause low readings on one bank - left or right, if it slipped enough. So, it doesnt look likely, but is a logical one to rule out. As you go, you will learn heaps more about your machine, which top me, is half the fun. When it really hooks up and flies like a rocket, the appreciation is even greater, I think.
I note your engine is 3.5, so it is not normal spec anyway, so the target compression numbers may be a bit different - depending how the extra displacement is achieved - eg crank stroke - just thinking out loud here.
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-24-2011, 10:02 PM
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