Torsion bars and P1 gp.....

You freakin' people and you're looking for loopholes...

You can only use torsion bar valve springs on a CB450 in 500GP. If you move up to heavyweight supervintage, you can do whatever you want.

You can use larger valves and such, but you need to keep the stock torsion bar valve springs.

Did you know that you can swap the torsion bars to get a higher spring pressure? I think you swap them front/back, but I'm not sure.

Curious... what other torsion bar valve design would you put in there?

The big problem with those engines is the bad pressure angles on the cams/rocker arms causing lotsa wear. Hardened rockers just wear out the cam quicker.

http://www.vf750fd.com/vf750f/vintagerace.html sells some trick stuff for cb450s...

quote:
From the research I've done so far, the swap of the torsion bars (flipping them from A to B) is not a reliable exercise, it's been done, but I guess not recommended for road racing. Don't know about the cost of the conversion to coil springs, I think I may have seen something at Megacycle's site.

Click to expand...

$150 for the labor... http://www.intekra.com/ims/TermsPrices.htm