Found the shake, it was the dampner ..sheared the key off the crank. Apparently the builder didn't double key the crank for the blower application. Now I'm pulling the motor and taking the crank out to have this done. My question is this , it currently has a 50oz dampner. If I take the machinist the crank, dampner and flywheel /flexplate can I change to a 28 oz? I would like to get some of that weight off the crank snout . ps c-4 auto car. Weind 174 blower. Thanks, Steve
Not without a lot of work and money, I don't know why you would want a 28 oz balance anyway, these cranks are heavier, the 50 oz has far less reciprocation mass.(thats part of the reason the 5.0 was a better running motor than the old school 302) Also you don't need to have the crank double keyed for the 174, I don't think you are running anywhere near the boost i have ran with these blowers. YOU need a GOOD BALANCER. I had a customer who kept shearing keys and cracking balancers ( i bet yours is cracked if you ll look real close) He put on a GOOD balancer and problem was solved. I would try a GOOD balancer before i pulled the motor. May save you some aggravation. If you are going to do the double key thing anyway, Be sure the machine shop is a reputable one, I have a buddy that had a high dollar racing crank ( big MOPAR) bungled up with a double key way crank job at the local machine shop. ( He has a 14-71) Also remember that all balancers that have a double key are not created equal, So buy two ( or have two made) of the same brand when you buy then you ll have a spare that will fit, if ever needed.
shakey Thanks- so are you saying I should NOT go to a lighter dampner ? Is there a reason I shouldn't run a lighter balancer? The one that came off and is now ruined is a Romac. As for buying a spare ATIs are 400.00 each for a blower dampner.... machinist does quite a bit of turbo and blown race motors and he suggested I consider getting some of that weight off the crank snout. He says not necessary to double key the balancer and crank , but ... I would be back next year with same problem based on his experience. $120.00 to do both and check the new balancer, if I take the crank, new and old balancer to him. Probably 300-400 if I take him the engine and let him handle it all. Sounds reasonable to me. I am running 12 lbs boost. Anxious to learn here, tell me what your experiences have been. Thanks.
A lighter setup is usually intended for higher rpm n.a. motors. With the roots setup you dont need the rpm. A lighter balancer is going to require a heavy, and or High Dollar , Crankshaft. There is not that much difference in the 28 to 50 oz balance, But there is a big difference in the 28 oz crank weights compared to the 50 oz crank weights. The only reason to run the lighter set up, would be if you were going to spin the motor past 7000 rpm, Which with a roots type supercharger is useless, ( only serves to put undue stress on parts)The romac is a Cheaper line of balancer. Yes i have used them and got by at times, But the friend with the balancer problem that i mentioned had problems with the romac, I have ran my combo since 1995 and have yet to have a balancer failure. I am presently turning my Blower@ three times crank speed, which on a stock bore and stroke 302 will equal about 15 psi boost. If i were you i would order a good ATI in your flavor, Get a NEW crank key( NOT ONE OF THE CHINA MADE KEYS) Put it all back together and see if this dont cure your problem. Hope this helps, let me know how it turns out.
thanks and 1 more question So do you feel it is necessary to get the ATI blower type balancer ( double keyed and thicker shank) or do you run just a good ATI standard 50 oz ??? My machinist says no problem with either from his viewpoint , he will cut the 2nd keyway in whatever I bring him. the ATI I was looking at is a 918913 400.00 from summitt, and of course that would require a different frt seal due to the thicker shank. Which one are you using on your setup? The machinist feels any quality 50 oz dampner will do. Thanks man
I would have to look up the part #, But it wouldn't work on yours anyway, Mine is neutral balance. I would either get the ATI or A Fluid Damp.( I do think the Fluid Damp makes the engine a little smoother) I have used and ran both, They are both top quality balancers. P.S. I talked to some of my other blower buddy's today, One other had a romac to spin on the shaft.
i am having the same issue with the shake, i have being trying to find a dampner, any idea were they might sell used-rebuild-or new?
If your just looking for a stock dampner, Pioneer sells one about 65.00. If you get a used one your liable to end up worse off than what you are now.Autozone, Napa, Orilleys any one sells new.
