- Joined
- Jun 30, 2012
- Messages
- 13,261
Rohan, Methanol has only 80% 0f the calorific value of petrol however when both are near their best jetting, you use nearly twice as much methanol. I believe the best fuel option would be the BP JA and JB that I mentioned, where there is a substantial amount of hydrocarbon (benzene) to provide energy, yet still enough methanol to freeze the charge and make it denser. Methanol is poisonous, however it doesn't do to your blood anything like benzene does. I would never try blending my own fuel at home, it is almost impossible to do it safely and accurately.
T Bolt, a standard commando engine converted to methanol using 34 degrees advance and separate pipes will go faster and pull harder than the same motor on petrol. The numbers mean nothing to me. My bike has the cam advanced and a two into one pipe with a large dia. tail pipe and muffler. The ports are tapered and I use 34mm carbs, and previously a 4 speed a CR box. It was fast enough to win, but slow off the start because of the extremely high first gear and the need to slip the clutch. I'm not making claims about my own bike, however from 12 years of difficult road race experience in open capacity class racing back in the 70s, I just know that the way that it performs is enough, - the rest is in the riding and the gears, and avoiding over-revving.
Advancing the standard 850 cam was a crude dodge and I believe it was barely OK, but the error in the exhaust closing point seems to have been compensated for, by the pipe. I've got a combat cam, and when I eventually fit it, the advance I use will be 6 degrees ahead of standard. It is what I intended to use when I first built the bike, however my cam grinder man was hard of hearing. I don't know how the PW3 cam performs, however I don't like increasing the lift over that used in road bikes. I believe that timings which suit the pipe and inlet tract length are far more important. The combat cam looks good to me, and I'm wondering what it will be like when used sensibly.
The commando engine is very impressive, - I like it a lot, however I'm still expecting the big bang. I still find it difficult to believe that anything so agricultural can be raced. It keeps me amused.
T Bolt, a standard commando engine converted to methanol using 34 degrees advance and separate pipes will go faster and pull harder than the same motor on petrol. The numbers mean nothing to me. My bike has the cam advanced and a two into one pipe with a large dia. tail pipe and muffler. The ports are tapered and I use 34mm carbs, and previously a 4 speed a CR box. It was fast enough to win, but slow off the start because of the extremely high first gear and the need to slip the clutch. I'm not making claims about my own bike, however from 12 years of difficult road race experience in open capacity class racing back in the 70s, I just know that the way that it performs is enough, - the rest is in the riding and the gears, and avoiding over-revving.
Advancing the standard 850 cam was a crude dodge and I believe it was barely OK, but the error in the exhaust closing point seems to have been compensated for, by the pipe. I've got a combat cam, and when I eventually fit it, the advance I use will be 6 degrees ahead of standard. It is what I intended to use when I first built the bike, however my cam grinder man was hard of hearing. I don't know how the PW3 cam performs, however I don't like increasing the lift over that used in road bikes. I believe that timings which suit the pipe and inlet tract length are far more important. The combat cam looks good to me, and I'm wondering what it will be like when used sensibly.
The commando engine is very impressive, - I like it a lot, however I'm still expecting the big bang. I still find it difficult to believe that anything so agricultural can be raced. It keeps me amused.