Engine design

[John H]

Modern bike engines are pretty sofisticated compared to vintage engines, in most cases. Vincents however, had one of the more complicated designs which makes them more difficult and expensive to rebuild. This is a drawing of the valve train I took to the meeting last week. It gets even more complicated when adding big valves, high lift cams, stroker crank and more rpm.
The valves are modified from Chev. big block. Cams are built up with Stelite hard facing and ground for higher lift and more duration. The crankshaft is stroked one inch. The bore is increased from 91mm to 94mm. This takes the motor from 998cc to 1650cc. It's a time consuming project but I'm enjoying it.

ValveTrane.jpg (71.34 KiB) Viewed 42840 times

[ATinkerer]

Great effort John.
Will be interesting to hear it run after all the work you have put into it.

Gordn

[Dragonknee]

I can't wait to hear and see it run.... Very cool project

[John H]

In my project I try to simplify everything. On the other hand, I think George does the opposite.
Somewhere in this photo is a vintage Kawasaki 100cc motor with a 125cc Yamaha water cooked top end hooked to a supercharger. He's on schedule for Bonneville and a couple more records.

GEO.jpg (153.46 KiB) Viewed 42828 times

[Dragonknee]

John, I would like to see that up close again. Its dam interesting and not something normally around the garage at most peoples places...

[John H]

Jim, here's the other side of the 'candy machine'. George is in attack mode right now with last minute details before heading to Bonneville.
I plan to have another 'BBQ/show and tell' in late August so maybe George will bring the little racer again.
I met another local guy today that just started a Yamaha FZR Bonneville racer project for next year.

George r.jpg

[Dragonknee]

Look forward to it..

[John H]

Here's the latest in valve seat finishing.... Actually, it's from the 30s but works quite well. The grinding stone spins on an eccentric pilot and grinds only a small area of the seat at a time. I need to make some special pilots before I can actually use it.

IMG_0011.jpg (130.51 KiB) Viewed 41661 times

[ATinkerer]

Orbital, mounting through the valve guide?

Gordon

[John H]

The stone orbits on the valve guide pilot at 15 rpm while the stone is running at 10,000 rpm.