Landracing Forum
Tech Information => Technical Discussion => Topic started by: bubruins on April 08, 2019, 06:20:47 PM
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Thumbing through the rulebook here: the $99 harbor freight motors have pushrods and I believe fit the rules for the pushrod classes based on cam location and pushrod length. Before I start throwing money at this not-so-$99 idea, can anyone think of any reason it would not fit the class or to avoid it? Any reason not to do Pushrod Blown Fuel with this combo?
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Bike or car?
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Bike. Thinking 250cc APS-PBF
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"Blown" may be the word you remember.
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Depends on which venue you are talking about. Loring allowed one in the 250-APG class but I don't have my other rulebooks handy to check. I believe that AMA only allows motorcycle motors.
Tom
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I agree with Tom. For motorcycle classes you can only have motors that actually were built for motorcycles with a production run of 500 or more. The rule for BMST is "All classes are to use motorcycle engines. A motorcycle engine is defined as any motor that was specifically designed for use in a motorcycle." I am pretty sure SCTA is the same.
Don
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It might be a good idea to start with an engine having better design and more robust materials than a $99 Harbor Freight specimen.
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The local cart racers have a budget class that specifies the unmodified (yeah right) HF engine.
They thrash them pretty hard and they seem to stand up.
I don't think they would be considered a bike engine though.
Maybe mini bike? :roll:
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I had a feeling I was missing something. Thanks to all for the feedback. I bought a EFI turbo predator 212 project from an friend a few months ago and had it running on a kart but began a mini bike conversion. My goal was to use this on a retro mini bike but I scared myself on it and the 6" wheels with a box stock motor so I figured I'd use the turbo motor on a larger/safer chassis. TBD.
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.. with a production run of 500 or more. ...
Is the 500 or more a new deal? Denis was able to run the one off engine in the BUB Streamliner...
https://en.wikipedia.org/wiki/BUB_Seven_Streamliner
... since the engine only ran in his motorcycle streamliner, so was ruled a motorcycle engine back then. I can't remember if more than one was ever made,
Sumner
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Sum, I think motorcycle streamliners under 7.J.12 Class UG and UF are not bound to motorcycle engines.
At least that's how I read it for the SCTA, for the BMST I have no clue.
Don
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There are a few 250 cc push rod motors that you will have to compete with if you use the HF motor. Think Triumph, BSA, HD and some of the Chinese Honda clone motors. Besides lots of development, these all have gearboxes and clutches that can be strengthened for high speed use. $99 for the motor wouldn't touch the rest of the expenses to make that thing competitive. Try looking at some of the cheaper Chinese bikes and that may be your easiest entry point.
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Moto Guzzi, BMW, and Moto Morini all made 500cc pushrod twins. Some surgery could be used to remove a cylinder. The rest of the drive train should be able to handle the power.
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Interesting. I don't want to give away any secrets here, but it appears that 250cc S-PBF is wide open. Are motorcycle streamliners still permitted to be upright (Burt Munro Style) or do they need to be caged and enclosed (Costella Style)? If so, would the rider use leather riding gear or SFI fire proof?
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All streamliners are enclosed with a cage... the rider wears a fire suit.
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Not only enclosed and caged but feet first too. No prone allowed anymore.
I thought streamliner bike still required the engine to have come from a motorcycle originally, but maybe I am mixing that up with vintage streamliner bike (which is what we are).