BUB. Displacement rules for sidevalve-engines

[octane]

Hi I'm new here, and I'm new to the whole LSR thing,
but after spending a week at this years BUB event
as a member of the brilliant Dreamcatcher team, I've got the salt-bug
and plan to run a (side-valve) Indian next year.


Wonder if anyone would care to clarify for me, if the rule
about side-valve engines running in a 'lower' displacement class
does apply to the current BUB event.

I've seen it mentioned a few times but can not seam to find
this particular rule in the
"AMA Racing Supplement Regulations
BUB Motorcycle Speed Trails"

...maybe because the rule is part of the AMA Racing Regulation 'itself'
(that I just can't seam to find online)...or?


A search in this forum came up with this (a couple of years old) post:

"...You are correct on all but the flat-head displacement "advantage".
 They get to according to the rules run a 50% greater displacement
 than the class limit.  i.e.  a 750cc flathead Harley or Indian or whatever you have runs with 500cc OHV..."

but I don't know which event it is for, nor if it is still valid.

Any help would be greatly appreciated.

Thanks.

[ironwigwam]

Lars,
    There are actually two different answers to your question of engine size according to which event you are running.
   By the BNI/SCTA Speed Week event, flat heads are given a two class advantage against OHV of same 750 cc size. So a 750 cc flathead Indian would run in the 500 cc class.
     When you run the AMA rules at BUB 2009, your 750cc Indian flathead will run the 750 cc engine class with no advantage for OHV engines and will run heads up against other 750 cc bikes.
     Rocky

[willieworld]

scta allowes you to discount 33 1/3 of your engine displacement---1500 cc can run in the 1000cc class--i think its just the wording ----33 1/3 less than 1500 cc is 1000cc the same as 50 % more than 1000cc is 1500cc  willie buchta


the bad news is you cant run in the pushrod class except in vintage if your engine is 1955 and older

[bak189]

For a answer contact the BUB people.......and please, don't start the BS "That is not fair" untill you get the officiall AMA/FIM answer.....................

[Dean Los Angeles]

The AMA rules in effect for the BUB event don't give any break on cc's.

SCTA rules for Bonneville and El Mirage allow a 33 1/3% "discount" for flatheads, but only in the vintage pre-1956 class.

[octane]

Thanks Rocky, bak, willie and Dean for replying!

I did in fact try contacting BUB a couple of weeks ago
with that question and a few additional ones,
via the e-mail address posted on the BUB website (salt-tech@bubspeedtrials.com)
but I haven't received an answer yet.

Maybe it's only open for business at the immediate period leading up to the event (?)

Anyone knows where/to whom, I can adress tech-questions at this time?


Thanks

Lars

[bak189]

Contact Drew Gatewood..........his E-Mail contact
is on this forum...........................................................

 

[octane]

Thanks bak.

I just got this from Drew:


"...I hope this is of help for you in determining your specific class.
Please note, the following is in regards to AMA & F.I.M. rules only,
as are used at the BUB Motorcycle Speed Trials.

Your allowable engine displacement limits are as follows,
per 2008 AMA Racing Supplemental Regulations/BUB Motorcycle Speed Trials.

http://www.speedtrialsbybub.com/2008_event/AMA-BonSR%27s-2007-v5.pdf

CHAPTER TWO:
2.A. Engine Displacement
Displacement of the engine is as stated by the manufacturer.
Displacement in excess of the stated manufacturer's displacement
will advance the motorcycle/streamliner to the correct class.

The ONLY exception that allows a larger displacement is in the following engine classes.
CHAPTER TWELVE:
Engine By Classification
Page 44 - section 12.I. "VG" and section 12.J. "VF" (This being the Vintage Classes),
Where a +.050" overbore is allowed on all engines produced prior to 1956.
This includes both Flathead and OHV engines.

F.I.M. rules...
ALL Engine Displacements are absolute.
Meaning if you enter a 750cc class be it non-streamlined, partially streamlined, or streamlined,
your engine must measure no more than 750.000cc.
Otherwise your machine will be moved up to the next larger engine displacement class...."


So that settles it.
Thanks a lot for the clearification Drew.