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Rob 930 Rob 930 is offline
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Join Date: Dec 2002
Location: Seattle
Posts: 568
Andy,

I hear you on this:

"im so paranoid about every area in this build now, mainly down to the fact that its eaten so much money already. im of the mentality now that i just have to do everything."

I feel like I'm sort of in the same boat. I'm not sure I'd call myself paranoid, but I'm so deep into it now, it's more the "while I'm at it I might as well do ________" mentality. But I'm always looking for a reality check too, and a place to shift hard earned money to a cause that will actually do me some good. I admit that in my build, I've spent where spending probably wasn't necessary.

In fact, just yesterday I bought new rings for my Mahle 3.4 7.5:1 pistons that have 660 miles on them. That's the subject of another thread somewhere. I probably could have re-used them; I may be overly conservative here, but I don't want to risk, after all this work, that my rings wouldn't seat. Then comes the "do I hone the cylinders" question. Again, more threads, including some long ones, as well as a dozen expert opinions, all of them different. The outcome: I'm going to use scotch brite on them, by hand.

But I'd be pretty confident in those rod bolts. The good news is that when you torque them up, you'll have a sense of their consistency, so you'll be in a position to make a final judgement at that time. In fact, you might as well torque them up on the bench right now, as an exploratory/practice run.

My 930 engine is slowly coming together. The bottom end is done. My machinist found one rod journal was slightly undersize (0.0005 in), so he custom fit one of the rods to the crank, using std/std bearings. I'd never seen that done -- very interesting process. Now all the clearances are .0025 in, for all journals, mains and rods. The heads are done and looking beautiful. They are based on 930 heads, but they now have 52.5 mm intake valves (stainless), 42.5 mm exhaust valves (inconel) that are lighter than stock and have 8 mm valve stems instead of 9 mm. The valves alone make a huge difference to airflow. But the porting is incredible. Runner to runner flows are very healthy and consistent, at +/- 1 cfm through the heads and manifolds (either separately or when the manifolds are bolted to the heads). I'm going with GT2 Evo cams. Next step for me is setting deck height, then piston-to-valve clearance. But I'm considering cc'ing the heads and piston domes as well, prior to any of that. So, it's coming, but at my rate, it will still be weeks before I'm done with the mechanical build.

Good luck to you on your build.

Rob
Old 07-14-2005, 07:22 AM
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