grumpyvette
Well-known member
Ok youve decided to buy/build a 383 from parts youve collected from that 350 in your car, youve got the parts an your iching to start assembly....should you take the time to ballance the parts or just slap it together....
ballancing/clearancing the rotating assembly will effectively reduce the stress on the components, the amount that stress will be reduced depends on how far off the components are from the orriginals the crank,damper and flexplate or flywheel were designed for , now I think ballancing the new assemblys a NO BRAINER as its usually under $200 and even if it reduced the stress only 15% its a big improvement, but the truth here is that without reballancing youve more than likely got zero idea how far off the new parts are and you might be assembling a combo that will shake itself to pieces in 10K......Id suggesst spending the $200 and getting it done correctly.
yeah! we all know guys that skip the ballance work and run engines, we all also know guys that have constant freak engine and drive train breakage and tunning, and oil control issues/ problems, with thier cars and can,t seem to locate the source.
you can spend $150-200 in most cases up front to prevent problems or a take a chance on spending a good deal more once they occure, your choice!
and Id figgure the chances ar about like playing russian roulette with two or three cylinders loaded in your revolver.
the next question that comes up,
("can I re-use my 350 damper and flexplate or flywheel ?")
that depends on several factors, 3.75" stroke cranks come in BOTH internally ballanced and EXTERNALLY BALLANCED designs, the 400 crank cut down to use in a 350 block is externally ballanced and requires in most cases a 400 damper and flexplate or flywheel, if the cranks designed for an EXTERNALLY ballanced flexplate and damper like a 400 has ,you CAN get it RE-ballanced for a INTERNALLY ballanced flexplate and damper like a 350, so that you can use internally ballanced components like a 350 damper and flywheel/flexplate... but the cost is frequently higher than just buying a new crank of the correct design, generally your stuck using the type of ballance the cranks originally designed for due to counter weight size, placement and cost issues, as welding in extra mallory metal weights gets expensive fast, and forged 3.75" SBC internally ballanced cranks are not all that expensive.theres also the option of installing counter weights on the 350 components to use with the 400 crank, if you choose to go that route
http://www.scatcrankshafts.com/
theres a DIFFERANCE between CAN, you physically do something and CAN you do it at a reasonable cost!
I know of no-one that will take the time and effort and go thru the expense to modify a 400 crank to run 350 components because an INTERNALLY ballanced 3.75" stroke crank thats designed to run those 350 components is fairly cheap and easily obtainable, but a decent shop can weld up counter weights and add enough mallory metal to reballance almost any crank to internally ballance it
ballancing/clearancing the rotating assembly will effectively reduce the stress on the components, the amount that stress will be reduced depends on how far off the components are from the orriginals the crank,damper and flexplate or flywheel were designed for , now I think ballancing the new assemblys a NO BRAINER as its usually under $200 and even if it reduced the stress only 15% its a big improvement, but the truth here is that without reballancing youve more than likely got zero idea how far off the new parts are and you might be assembling a combo that will shake itself to pieces in 10K......Id suggesst spending the $200 and getting it done correctly.
yeah! we all know guys that skip the ballance work and run engines, we all also know guys that have constant freak engine and drive train breakage and tunning, and oil control issues/ problems, with thier cars and can,t seem to locate the source.
you can spend $150-200 in most cases up front to prevent problems or a take a chance on spending a good deal more once they occure, your choice!
and Id figgure the chances ar about like playing russian roulette with two or three cylinders loaded in your revolver.
the next question that comes up,
("can I re-use my 350 damper and flexplate or flywheel ?")
that depends on several factors, 3.75" stroke cranks come in BOTH internally ballanced and EXTERNALLY BALLANCED designs, the 400 crank cut down to use in a 350 block is externally ballanced and requires in most cases a 400 damper and flexplate or flywheel, if the cranks designed for an EXTERNALLY ballanced flexplate and damper like a 400 has ,you CAN get it RE-ballanced for a INTERNALLY ballanced flexplate and damper like a 350, so that you can use internally ballanced components like a 350 damper and flywheel/flexplate... but the cost is frequently higher than just buying a new crank of the correct design, generally your stuck using the type of ballance the cranks originally designed for due to counter weight size, placement and cost issues, as welding in extra mallory metal weights gets expensive fast, and forged 3.75" SBC internally ballanced cranks are not all that expensive.theres also the option of installing counter weights on the 350 components to use with the 400 crank, if you choose to go that route
http://www.scatcrankshafts.com/
theres a DIFFERANCE between CAN, you physically do something and CAN you do it at a reasonable cost!
I know of no-one that will take the time and effort and go thru the expense to modify a 400 crank to run 350 components because an INTERNALLY ballanced 3.75" stroke crank thats designed to run those 350 components is fairly cheap and easily obtainable, but a decent shop can weld up counter weights and add enough mallory metal to reballance almost any crank to internally ballance it
