well i have a 330 pro-x cylinder im drag racing, it works pretty well but dosent get out of the hole great, running 1/8th mile, has a little bog off the line. leaving the line full throttle,cylinder is a mx ported running 14/37 gearing, im by no means the lightest rider(working on that) i also still have a plus 4 axle. this winter im gonna buy a jj&a drag axle, that should reduce alot of rotational mass but id still like to get a nice hard hit out of the hole, im running 20.5" hoosiers,the bog has gotten worse when i went to the cr250 ignition, but thats to be expected with the lighter fly wheel, if any one has any suggestions i would be open to suggestions, my main question is will a stroker help down low? and is there anything wrong with my setup that i could possibly change
will adding 4mm stroker crank help me get out of the hole any better drag racing
arens330r
1 - 11 of 11 Posts
Joined
·
99 Posts
well i have a 330 pro-x cylinder im drag racing, it works pretty well but dosent get out of the hole great, running 1/8th mile, has a little bog off the line. leaving the line full throttle,cylinder is a mx ported running 14/37 gearing, im by no means the lightest rider(working on that) i also still have a plus 4 axle. this winter im gonna buy a jj&a drag axle, that should reduce alot of rotational mass but id still like to get a nice hard hit out of the hole, im running 20.5" hoosiers,the bog has gotten worse when i went to the cr250 ignition, but thats to be expected with the lighter fly wheel, if any one has any suggestions i would be open to suggestions, my main question is will a stroker help down low? and is there anything wrong with my setup that i could possibly change
Joined
·
13,288 Posts
A stroker or added stroke will help down low, it will have more torque in the low and mid, however, may hurt the top end. Your MX cylinder will need to be re-ported to match the added stroke. Sometimes re-porting is not possible as to much material has already been removed from the ports.
You can add weight to the CR250R flywheel, add 200 to 300 grams to help pull down low. You can also advance your timing, add 4 to 6 degrees, this will also help down low. Gearing, tire selection, clutch slippage all are important factors in getting out as quickly as possible.
Keep in mind, Drag engines need to rev out quickly, adding stroke slows the engines ability to rev quickly, this becomes a fine balance between stroke, bore and displacement. However, a 330 CC engine with a square bore x stroke at 76 x 76 MM makes for areal nice 'sqaure' engine, one of the more efficient runners in the ProX cylinder category.
Carlos
You can add weight to the CR250R flywheel, add 200 to 300 grams to help pull down low. You can also advance your timing, add 4 to 6 degrees, this will also help down low. Gearing, tire selection, clutch slippage all are important factors in getting out as quickly as possible.
Keep in mind, Drag engines need to rev out quickly, adding stroke slows the engines ability to rev quickly, this becomes a fine balance between stroke, bore and displacement. However, a 330 CC engine with a square bore x stroke at 76 x 76 MM makes for areal nice 'sqaure' engine, one of the more efficient runners in the ProX cylinder category.
Carlos
Joined
·
99 Posts
Well today i stubled onto some of the issue i believe my clutch cable was hanging up, i lubed it up and it seems to have smoother and a more positive engagement, going to the track sunday gonna take a bunch of plugs and play with timing alittle and see how it goes from there may just end up buying a puma cylinder and going from there
Joined
·
99 Posts
So i just got back from the drags and when im in staging and hold the rpm to launch its not holding or reving cleanly, pull fine once in gear and going down the track, jetting seems to be on, pulled the plug but didnt do a chop, is this a timing issue first pass was with the ignition lockdown plate on then i pulled it and moved the ignition all the way. Counter clock wise
Joined
·
4,308 Posts
counter clockwise is retarding the timming.you might want to advance it some.
1 - 11 of 11 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
