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Author Topic:   2bl motor combination?
Dirt Roller

Total posts: 18
posted July 09, 2005 07:43 PM  
Whats the current trend in building a restricted motor as fas as bore/stroke. I thought more stroke 3.750 would be better, but alot of people say big bore short stroke 3.3 stroke?Why? max compression of 12.5-1 flat tappet cam no ported heads

Dirt Forum Racer

Total posts: 81
posted July 09, 2005 09:56 PM  
it all depends on where you need your power. a 2bbl motor cannot turn as much rpm as a 4bbl so its dumb to try revving it hard and more stroke means more torque, and too much low end will fry tires. on short slick tracks, its hard to beat a 355 thats put together right. on tacky tracks the 3.75 stroke will be useful in planting more torque to the ground. making a 355 around 12:1 compression, a mechanical cam with approx; 550 lift and 285-295 overall duration,(comp # 12-609-5 works well) and a good intake and carb, can make a cheap reliable and strong engine. I try to stick to the 3.48 stroke and make as much useable power between 2500-6500 rpm. hope this helps.

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