| Author | Message | ||
     Bob_thompson |
In the "70's" a guy from the Chicago area named Warner Riley got into the prestidous 200 MPH club at Bonneville and one of his tricks was to put a three degree bevel on the carb mounting surface to favor one cylinder over the other therby overcoming the difference in cylinder intake due to the difference in timing inpulses of the 45 degree cylinder spacing. I did this to my 86 cu.in. Sporster back then and plug readings were identicle I can still see a difference on plug reading on my M2 today and I believe it has nothing to do with heat from front cylinder to rear cylinder. For all you super tuners; has Buell addressed this at all and can we still benefit from this simple machining to the front face of the intake manifold? Thanks for any input, Bob | ||
| Djkaplan |
I've never heard about this: does the carb point forward or backward after the mod? | ||
| Bob_thompson |
Dan, trying hard to remember but has to do with intake valve opening times. It seems, if I remember right, when one valve opens, the other cylinder opens close to it due to 45 degree spacing which robs first cylinders stuffing. This doesn't happen the other way around because of much longer time before first valve opens again. The carb faces and favors the first cylinder which I THINK is the front cylinder. I could be wrong though. At least on my M2 the front cylinder is showing leaner. Warner tried several degrees of offset and settled on three. Also cams with longer duration this is compounded. At that time I ran Sifton -- type. Can anybody out there help with timing specs for HD's? |
