Hi guys.
I just thought I'd start a thread for my foray into Jay's big bore kit. I'll keep updating my experiences with in this thread.
I was going to assemble the whole thing myself but decided to get my heads and valves done at the same time as I had the jugs bored. So I had the shop put the thing together for me for the extra few hundred. Safe than sorry.
So I've had the heads rebuilt and bead blasted, new valve sleeves, and the valves all re-cut. The cams are getting put in as I write this and I'm picking the engine up later today or 1st thing in the morning.
I'm having this work done by Pro6 Cycle in Toronto. Pro6 is one of the top race shops in Canada. They build motors for some of the best racers in Canada and I have been dealing with them since the early 90s. I trust them with my stuff.
Sandy is the main man and owner there and has raced 250gp in the US and Canada. He knows his stuff.
Sandy explained to me what this big bore will actually do to the power of the B4. He said my actual hp will go up only marginally but the rise in torque will be quite noticeable. He said as an example if the bike was say 50hp before the big bore that the hp should go up to about 52-54 but the extra torque I will gain, will give me that peak hp sooner and longer in the rev range. He said this translates into about a 10+/- hp gain throughout.
This is all good! I hope I explained this correctly. I'm just trying to remember what he said. But this all depends on where it was to begin with and I will try to get it on a dyno at some point. If I had 55hp to start, the bike will gain say about 10hp with the torque, that puts me in the 60-65 range. That is all I wanted.
I'm putting the new engine in the bike this week and will be on the track breaking it in on April 22nd which is next Sunday.
I'll keep you all posted.
G
