Brain Trust Needed - 2L Refresh |
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Brain Trust Needed - 2L Refresh |
yeahmag |
Mar 28 2020, 11:01 AM
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#1
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Advanced Member Group: Members Posts: 2,422 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California |
This might be long...
My current combo runs great, but I've been sitting on a set of Finch heads from Len Hoffman for years. There is no racing right now, so it seems like a good time. Here is the current combo: 2056cc Stock Rods Stock 2L heads (match ported) 86a Cam 9.5:1 I got a set of JE pistons in another deal (brand new, 96mm) and they appear to be stroker pistons. By my calculations I'd only need a 5.294" rod to counter the reduced pin height and am planning on a 5.325" rod or longer. Should be good either way there. Now for the big problem. The Finch heads have a 50cc step-cut chamber. I like to run a tight deck (.04") and that combo would put me at 10:1. To get to the 9.5:1 I've been running I'd need to run almost .06" deck height. So three questions. 1. Can the 86a handle 10:1 on 91 pump gas with proper tuning? 2. Is it better to run a loose deck and keep it at 9.5:1? 3. Put a 2cc (or larger) dish in the piston tops to keep a tight deck and lower the CR to 9.5:1 which I know works? Thanks! -Aaron |
yeahmag |
Apr 1 2020, 11:39 AM
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Advanced Member Group: Members Posts: 2,422 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California |
@injunmort - I've been told this isn't a big deal. You can get to both sides of the rods through the cylinder spigots.
@Mark Henry I talked to Jorge at EMW and he has rods that will work for me. 5.325" length, 2L big end, 22mm small end. http://www.europeanmotorworks.com/pvw/024-...5%22+-+Set+of+4 I'll probably need a small cylinder spacer to get to .040" deck height. Combine that with a 50cc cylinder head chamber and a 3cc dish in the pistons and I should be at 9.5:1 CR which is where I am now. |
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