View Single Post
Old 08-14-2012, 08:52 PM
maniac57's Avatar
maniac57 maniac57 is offline
Old, Fat, and still faster than you
Join Date: Oct 2011
Location: memphis Tn
Posts: 4,486
Default Re: what did you do to your motor bike today?

Originally Posted by xenodius View Post
Got a new lock because some half-wit tried to steal my bike! It's not even fully assembled at the moment... Cut halfway through my lock at 4:30 AM, thankfully I heard him and scared him off. Bastard bent my lock shut, though...

Wrote a novel. Short version: got SBP chamber. Didn't fit. Set aside the black J-piece that connects to chamber, replacing with all copper to fit my baby's curves in an upside-down U format to get appropriate length. Read about success here with 10" flange-to-chamber, but my approximate measurements show that length of stock setup with shortest header to be about 12" overall. Given that the SBP guide indicates lengths as little as 1/2" make significant differences, I'm uncomfortable with that range. This is a problem because without the J-piece, it's almost impossible for me to get a half-decently sealed exhaust without making it permanent, because I can't "spring" it on. That means I can't really test the header length beforehand.

I expect the header to get quite hot, but I'm not sure if it'd be too hot for JB-weld. For longevity sake, I'm probably going to try to find some thermosteel and use that to close it up tight, then maybe wrap or just paint the fittings for aesthetics.

Question: 66cc chinagirl @ 6,000ft with SBP chamber, .64 jet, NGK 7534 plug. What overall length for a high-rpm powerband? I can't do much for testing because of my mounting limitations. Also, does the shape of the header/setup matter?

I can't even mount it in the up config, not without adding some significant length. bleh.
I always use the fat, short cone for torque, and a longer cone for high-speed... It's a good rule of thumb for experimenting.
Reply With Quote