Single Cylinder LSR Motorcycles

[Calkins]

I have a fuel question.  I haven't looked at the specs and comparedthe brands.  For the gas spec given in the rulebook, what does that give you for octane?  Is is like Cam2 110, or pump gas 89?

I'm asking because I'm trying to figure out how high I can go with compression.

[desotoman]

Go to ERC racing fuels website to find out the specs on fuel.

Tom G.

[Calkins]

Thanks Tom

[Seldom Seen Slim]

Calkins:

ERC is the fuel provider at SpeedWeek, Word of Speed, and World Finals (maybe Bub's, but I don't know for sure).  Rick Gold is the boss at ERC -- and he arrives with a tanker full of various flavors of fuel.  If you're running in a gas class you need to use fuel from him.  He'll check to see your tank is empty, put in whatever of the five or so flavors he has in stock, and then seal your tank with tape and a few dots of nail polish. 

He usually has A8C, C16, a couple of unleaded (MUL4 -- is that an ERC number?) in 100 and 104 octane, maybe another leaded, and methanol and nitromethane.  The alky and nitro aren't legal for gas class, as you've probably guessed.

Okay -- I might have the names of the fuels wrong, but he's got the gases.  Go to the ERC website, as was eariler stated, and yoi'll see all the types he's got. 

And -- the t-shirts he sells are top-notch, with stupendous colors.  Make sure you save $20 or more out of your t-shirt budget to get a shirt from him.  He'll sell old shirts (from previous years, that is) at a discount -- good way to stock up on shirts if you're like most racers and only have 100 or so in the dresser, the closet, the basement, the shed, and everywhere else.

[John Noonan]

A8C is an ERC fuel and C16 is a fuel from VP, A8C is the closest ERC equivalent fuel to VP C16 

 VP C16 and A8C are usually used in very high compression NA engines over 13-14:1 and Turbo and Nitrous engines as well.

John

[Calkins]

Is a drum rear brake a bad idea?  Less drag, but pretty unless.

[John Noonan]

Drum brakes can and do work however in the event of a bad leak, fuel/oil fire you will want to exit the bike quickly (without falling off) and a rear drum only may not suffice....however a single cylinder bike running under 150mph can be stopped decently with just a rear brake as the bike is not as heavy as larger multi cylinder bikes.

J

[Calkins]

What about the stock plastic fuel tank?  I don't think I saw anything about them in the rulebook.

[754]

If you dont use a disc rear at start of run, try this.

Rap the caliper with soft hammer, it will retract sligtly & have less drag, then will go back when you use it.

[SPARKY]

screwdriver pushed between the puck and disk removes any-

[John Noonan]

What about the stock plastic fuel tank?  I don't think I saw anything about them in the rulebook.

Plastic fuel tank yes, plastic fuel line or petcock no..

John

[Calkins]

Tanks John!  HaHa, I had to!!

[Calkins]

What about a rigid rear suspension?  Keep the stock setup but use a solid tube in place of a shock.

[Calkins]

I have been doing alot of research on the 1986 Yamaha SRX600S.  It was a 8 month only import to the states, and the street bike version of my dirt bike.  I think it would fair better than modding a dirt bike, maybe not.  It's also 100# heavier.  Single cylinder, 600cc, SOHC, 4 valve, 5 speed, twin carb, twin pipe.

So, then I started looking at running that bike in P/P 650.  The records are mostly higher than M/G 650 or 750.  So M/G would make more sense to me, even if it wouldn't go the fast.

My question is, how close to 750cc should I be to concider running that class?  If I can't get "close enough" I'd just run the 650 classes.

[fredvance]

You would have to be 651cc to 750 to run in 750 class