When I built the chassis for two engines, I had to build a lot of extra frame and mount areas on each side of the rear wheel. Even with the tail completely removed, there is not 180 degrees of rim showng, particularly if I mount the radiators so the bike could be ridden two way runs and to pits.
I need the water tank in front of the engine; holds the front end down, and lets me jet without leaning out three miles down. If I jet rich enough for the radiators only, I am only about 150 at the two. Been running this thing at 650 or 680 for several years and pretty much stuck at 159 if I do everything right. Thats why I am building a new bike that is narrower and lower.
The water tank works for SCTA, wont hold that much heat for AMA....takes too long to get the heat out and I cannot bleed it without suspending the bike vertically from that rear frame structure.
It also cant run open at SCTA because the weird frame is too big to lower the seat position below top of
rear tire. There is a lesson here about planning; I hope I am helping some other fool, so they dont do it like I did!! Catch #22 is.....
Regards, JimL