The BSA A7-A10 Forum

Technical (topic titles must be descriptive) => A7 & A10 Engine => Topic started by: dan daughenbaugh on 29.04. 2014 23:58

Title: A7 Bonneville Race Bike DYNOJET results
Post by: dan daughenbaugh on 29.04. 2014 23:58
Hi everyone, I was able to get some dyno time today before this weekends upcoming race at the Ohio Mile. We made 15 pulls and increased 6hp over the day with Jetting changes. Bike has the twin carb alloy a7 head, 12.80:1 static compression ratio,  Harman and Collins  roller cam and 1 1/8 GP carbs with a Delorto float. All runs were made on VP M5 methanol and the valves were .008 and .010. Best pull was with timing at 38* with a 2mm drilled main jet and the needle in the leanest notch with a standard GP needle It was 67 degrees outside with 21% humidity at 120ft above sea level.

We wound the motor to 7000 rpm, it was still pulling hard and I intend to rev it to 8000 at the track, I have designed the valve train to handle that.
Musky, I did not blow the base off the barrel thanks to tour through bolt design
Max power with this setup was 35.39 HP at the wheel. Based on the only comps I could find here Im pretty stoked on the results
Title: Re: A7 Bonneville Race Bike DYNOJET results
Post by: muskrat on 30.04. 2014 10:03
That sounds great Dan. I never did a dyno on my A7SS. Running a little more comp and two 932 concentrics with 640 main jets. Most tracks were close to sea level or under 1000ft. What height is Ohio? I know Bonneville is up there.