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Compression question: HD vs Jap

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Old May 16, 2019 | 01:18 AM
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I just checked out the stage 4 kit for the Harley M8 for those is 11 to 1. So even Harley’s are getting up there in compression as well! I’m still in Twinkie land, lol.

Dave
 
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Old May 16, 2019 | 10:53 AM
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Originally Posted by TOE_CUTTER
It is also rpm related. At 10,000+ there isn’t very much time for air to enter. There are Harleys with 11 to 12 compression running on the streets, Most don’t want to deal with the costs and/or temperament of running a motor like that.Dave
I set my last 98" build up at 11.2 and have no issues; little motor makes 115/115 numbers with a nice curve crossing the 100TQ line about 2600rpms. It's all in the combination of parts and the tune.
 
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Old May 16, 2019 | 01:20 PM
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Old May 16, 2019 | 03:12 PM
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Originally Posted by djl
I set my last 98" build up at 11.2 and have no issues; little motor makes 115/115 numbers with a nice curve crossing the 100TQ line about 2600rpms. It's all in the combination of parts and the tune.
What's your intake close on the cam?
 
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Old May 21, 2019 | 11:29 AM
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I always thought JAP engines were cool. How is JA P restwick racist?

 
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Old May 21, 2019 | 11:31 AM
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especially on one of the best JAP bikes ever " Brough Superior"
 
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Old May 21, 2019 | 11:56 AM
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I knew a guy in high school who's initials were JAP.

I work with a guy who's initials are JEW. Funny, but true, his name is John E. Walker.
 
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Old May 21, 2019 | 06:09 PM
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Tell me all you can about your build.
 
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Old May 21, 2019 | 06:12 PM
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Originally Posted by djl
I set my last 98" build up at 11.2 and have no issues; little motor makes 115/115 numbers with a nice curve crossing the 100TQ line about 2600rpms. It's all in the combination of parts and the tune.
Tell lme what you can about this build.
 
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Old May 22, 2019 | 09:46 AM
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Originally Posted by Mattbastard
What's your intake close on the cam?
46* on the cam intake close but we tried advancing 2* and 4* and I have to check my notes to see if we left one of those keys in. IIRC, we didn't see a measurable difference on the dyno and did not advance but I need to check my notes to be sure.
 
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