engine cc class's???

[snapon14]

So they say u can run up to 265cc 2 strokes in the 250cc with the 450 thumpers. what happens if your 2 stroke is just over 265 at say 265.43. how about 267. just wondering cause a freind is thinking about racing with a longrod in his 250r. yes i know you could get away with it but is it actually legal.

[scrambler250R]

I have no ideal for sure, but it doesn't seem like they would care about half a cc, 2 cc's I don't know.

[3razors]

You could probably get away with it at local event. I've heard for national caliber races they will make the team pull the top-end for inspection.

[TimSr]

You've left out a lot of factors, but in general you can run anything until someone protests. In the case of CRA it costs $100 to file a protest. The unit is then inspected. If its out of spec, the person is disqualified, and the filer gets his $100 back. If it is within spec, the person who was protested gets the $100. Nobody will protest you unless you are beating them by a questionable margin. You didnt mention what kind of racing, but if you are running MX in quad classes, I dont think you have anything to worry about. The 450 thumpers are going to cream you, 265 or not!

[NOS_350X]

It all depends on your sanctioning body.

Some say 265, 2 stroke, 465 4 stroke Typically that is the limit. If your anything over your too big. I have see others recently start going 350 2 stroke, and 450 4 stroke.

Also look real close, Around here there is a bigbore blaster class, 210-249, well a stock 250r is only a 246.

Also a LONG ROD dosnet increase displacement at all.

Everyone at my races assumes my shee is a Stroker. Several guys want to tear down my bike (its $200 here) But all i run is Open, I WONT run the 350cc class just for that reason. I like to mislead the people.

[snapon14]

why wouldn't the longrod increase displacement? it's like putting a +5 stroker in.

[dads]

It changes the torque range. you loose from the low end and gain on the top.

[NOS_350X]

A +4mm stroker makes the piston go up 2 more MM than stock. and DOWN also 2 more MM.

Now a Long rod, on the other hand at Top dead center a +4mm long rod will make the top go up +4 mm BUT It also will move the Bottom up +4mm. Thus equiling everything out, No change.

What a long rod does do is makes a more gental pison rod angle. This makes things less harsh on the intake and exhaust skirts of the pison. When running a spacerplate it also add crankcase volume. '


IMO a long rod is not worth the benifet. If your going to go through the work get the stroker.

Lets go over things again, Stroker, adds travel to the top and bottom of the piston travel.

Long rod, just moves everything up not increasing the overall distance traveled.

[Duner]

A +4mm stroker makes the piston go up 2 more MM than stock. and DOWN also 2 more MM.

Now a Long rod, on the other hand at Top dead center a +4mm long rod will make the top go up +4 mm BUT It also will move the Bottom up +4mm. Thus equiling everything out, No change.

What a long rod does do is makes a more gental pison rod angle. This makes things less harsh on the intake and exhaust skirts of the pison. When running a spacerplate it also add crankcase volume. '


IMO a long rod is not worth the benifet. If your going to go through the work get the stroker.

Lets go over things again, Stroker, adds travel to the top and bottom of the piston travel.

Long rod, just moves everything up not increasing the overall distance traveled.



lol:D

[cr480r]

why wouldn't the longrod increase displacement? it's like putting a +5 stroker in.

displacement is calcutaled by the Bore and stroke... not bore and rod rod length...

stock stroke+ long rod= stock stroke...