Dry Lakes Racers Australia

Hi

I'm new here. I don't have a dlra rule book yet but have been researching all I can and reading the bonneville regulations I have access to.

I'm hoping someone can help me understand and intereperet...

If I use two single cylinder motorcycle engines to make one twin cylinder engine running through one gearbox, is that considered "multiple engines"?

Thanks

JP

(Sorry if it's obvious, it's not to me)

Perhaps you could start by looking at other members running two engines. Another member of the DLRA is running to Sidevalve V8's coupled together.

Sounds interesting, but I don't think it would help me understand if I can make a twin motorcycle engine out of two single cylinder engines and have it considered as one engine?

The only point I was trying to make for you is that it does fit into the DLRA rules. Hopefully some of the Bike guys will post a reply for you.

Ok , the way you are explaining what you are doing , there are 2 crankshafts ? One connected to a gearbox
Sounds like 2 engines to me , A class , special construction
May be more info on what you have in mind , and the class you think or would like to run in
harky

Two engines running through one gearbox is still two engines. Regardless if they are configured side by side or one behind the other.
Two barrels (single cylinders) sharing the same crankcase is one engine.

Thanks for all the replies.
The concept is a two stroke, two cranks joined together inline, two crank cases modified into one.

Does that sound like a single engine?

Thanks for input

M/ag class

barra wrote:Thanks for all the replies.
The concept is a two stroke, two cranks joined together inline, two crank cases modified into one.

Does that sound like a single engine?

Thanks for input

It sure sounds like "one engine" to me ,,Arial square fours had 2 cranks, coupled by gears.
You cant be in modified (M), and special construction(A) with one vehicle, drop the M,,,,,,
My TwoBobs worth
Tiny

DLRA wrote:Two engines running through one gearbox is still two engines. Regardless if they are configured side by side or one behind the other.
Two barrels (single cylinders) sharing the same crankcase is one engine.

That is great clarification and I had not considered it that way.

That's what I thought and was hoping.
How would I go about clarifying for sure?

Maybe I got the class wrong. But I do want to run modified frame, rather than special construction.

Thanks again for the insight

Special Construction.

Does the fact the engine is so customised make it special construction?
I'm confident I can use a factory frame from the same manufacturer modified within the restrictions of modified frame class.

The engine as well as the frame will put you in a specific class. Engine is non standard.

barra wrote:"If I use two single cylinder motorcycle engines to make one twin cylinder engine running through one gearbox, is that considered "multiple engines"?

I think you have just answered your own question ..... It sounds like you are going to couple two separate engines and then through one gearbox like this ... It would be hard to argue that this is not two engines ...



7.F MODIFIED PRODUCTION- M, MPS .....

A single engine with maximum displacement limited to 3000cc.

If you went to the trouble of casting a crankcase and then coupling the two cranks together like a Rotax Based Superkart engine Pic 1 or an Aprilia V Twin GP250 engine Pic 2 you might be able to argue it was one engine .....





But I think even doing that, based on this from Modified Class rules, puts you in Special Construction as you would have to modify the Frame to fit this sort of custom engine .....

7.F MODIFIED PRODUCTION- M, MPS .....

Perimeter type frame engine cradle tubes must remain unmodified.

Spar-style main frame spars must remain unmodified. “Main frame spars” are defined as the large formed tubes which connect the steering neck to the engine mounts and swing arm pivot.

The engine shall be from the same manufacturer as the frame.

A single engine with maximum displacement limited to 3000cc.

A maximum wheelbase not to exceed the original OEM specification plus 10%. Entrants shall provide acceptable documentation for record certification.

You really need to download the Rule Book and contact our Chiel Motorcyle Inspector Graham Hadley .... motorcycle.steward@dlra.org.au and send him the info on your plans, drawings and pictures make it easier to show exactly what you plan to do ....

Pete