Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties TIM!! Race question - -

TIM!! Race question - -

Post Sat Mar 26, 2011 7:54 pm

Posts: 42
Tim! (or anyone else who might know)

I'm getting close to getting my race job 45 ready to hit the track. I even had it out for a little run around the other day. I found a bunch of things that I was not satisfied with & need work - the brakes, the clutch, the shifter, the throttle, the carb tuning... Other than that it was perfect! I've got a few things sorted out already & the rest are well on the way to being sorted. One big issue is going to be carb tuning because I can't run it around the streets to tune it. I've got a friend with a dyno but I gotta get coordinated with him to get my scoot on his dyno.

My question:
I've been studying the AHRMA rule book to try to make sure I'm prepared, but I got one stumbling block I would like some advice on. The rule book says "dry-sump machines must use a pan with a minimum capacity of one quart, or approved oil-absorbing material with a screen backing and fastened securely..." I have looked around the interweb & I haven't found any pics of handshifters with any kind of device to meet this requirement. Is this a new rule? How have folks been meeting this requirement? I'm kinda stumped on this cuz there's no room between the frame & the bottom of the engine case, & if I go under the frame the pan is gonna hafta be huge to be at all effective. It will have to go far back enough to turn up a lip to make the rear of the pan, & to do that it would hafta go behind the tranny. I'm stumped. Any ideas out there?

Road America is just over two months away & I got a lotta work!

Post Mon Mar 28, 2011 1:52 am

Posts: 923
Location: South Provence of FRANCE

your answers are in the Japanese WR Racers :
this explains WHY they ALL are equipped with such a strange "womb" under motor and tranny :
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Post Mon Mar 28, 2011 4:57 pm

Posts: 767
Location: Pa. , USA
Hi bob71, haven't been here for awhile, the photo millwaukee belle posted is a good example of a belly pan as we call it at AHRMA, I form mine from a sheet of aluminum, attach the front with a U bolt, come back under the exhaust, primary cover, tranny and curve up behind the tranny cradel and attach, appoxy and safety wire a maxi pad (oil absorbant material) on the inside and your good to go. Its basic purpose is to catch any oil before it hits the track and it doesn't have to be pretty as long as its functional and well attached, if you need more photos let me know and I'll see if I can remember how it's done here, nice to see somebody taking the time and effort to put a 45 on the track, you won't regret it... Tim
Vintage roadracing, Class C, AHRMA # 335

Post Tue Mar 29, 2011 5:43 am

Posts: 42
Thanks for the replies, guys.
I understand the reason for having the belly pan - it's to catch the oil that comes with a catastrophic bottom end failure. They have been required for a long time on modern fully-faired roadrace bikes. I raced SuperSport 600s for several years & always used aftermarket fiberglass fairings. The fiberglass fairings always wrapped around under the engine to create a sealed pan that would catch anything that could come adrift, i.e., in the event that a connecting rod tried to escape out the bottom of the engine - & take all the sump oil with it. On bikes such as the 600s that came from the factory with a fairing it was easy to just continue the fairing under the bike to make a belly pan. Later the rules began to require some sort of belly pans on all bikes, whether they had a fairing or not. Meeting the belly pan requirement on bikes that didn’t normally have a fairing was much more difficult.
The issue I am running into with my 45 is that the frame, exhaust, engine, primary cover, etc. are all pretty tightly packed together & fitting the pan in there too is not going to be easy. I guess in theory I could just wrap the pan around the outside of everything, but I still need to let the exhaust out somewhere so I’d need to cut a hole in the rear of the pan. Seems like it wouldn’t be very effective with a big hole in it.
I’m just kinda hoping there is a clever solution out there that I haven’t thought of. I’m always interested in copying ideas from folks more clever than me!

Post Tue Mar 29, 2011 10:14 am

Posts: 767
Location: Pa. , USA
Bob , e-m me @ , Tim
Vintage roadracing, Class C, AHRMA # 335

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