Deep engineering tech question - torsional dampers on V8's | FerrariChat

Deep engineering tech question - torsional dampers on V8's

Discussion in 'Technical Q&A' started by Speedmade, Jan 13, 2021.

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  1. Speedmade

    Speedmade Formula Junior
    Rossa Subscribed

    Jul 31, 2004
    387
    Minneapolis, MN
    Full Name:
    Reed H
    All the 308, QV, and 328 motors have a torsional damper on the front of the crankshaft. The 348 and 355 do not. I attributed this to the fact that they have the grease filled flywheel at the far end of the trans. But the 360 has no damper either and has a solid flywheel at the back of the crank. The 430 and subsequent V8s all have dampers on the front, but of course, they are much bigger motors.

    I have a 348 motor I am using in a project. I am not using the original transmission. Opinions on if my application using a custom solid flywheel would need a custom damper.








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  2. Ferrari Tech

    Ferrari Tech Formula 3

    Mar 5, 2010
    1,114
    Georgia
    Full Name:
    Wade Williams
    Having been in a race engine shop for several years, I can tell you that the torsional damper is a critical part for stock crank race engines. As we used higher quality cranks and better cylinder blocks, the damper was not as important. You could get away without one for a longer time. Still, the torsional effects would need to be addressed. Going to a timing belt and not a chain helped as well because the timing chain was usually the first to break without a damper. So, with 430s having chains, I believe they would definitely have a damper. I am not aware of any issues with the 360s because they don't have a damper. We raced a 348 engine without a damper and it lived as long as it needed, between freshening.

    I did have a client with a circle track small block Chevy. He was explaining how he improved his acceleration off the corner by cutting that big ring thing off the outside of the part that holds the lower pulley. Told me it just screams off the corner now. I told him to pull it, bring it in and I would repair whatever damage he had so far and put another damper on. There was some discussion about what "might" happen. I explained excess crank bearing wear and possible timing chain damage or failure. He declined. He did however return Monday with a well broken small block. He was lucky in the fact that the timing chain broke as he was loading the car on his trailer.

    Anyway, that is all I have on that. Well not really, there is another story, but maybe another time.
     
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  3. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    33,736
    Austin TX
    Full Name:
    Brian Crall
    Have been thinking of doing the same. I have a good friend who is an engineer at Cosworth and his speciality is engine balancing in the design phase and how to avoid issues that will cause problems. I got a long drawn out reply that never really asnwered it. We have run V8 and straight six Bonneville engines (mostly Chevys) without them. No race track runs a motor for as long at full power.

    In the 360 Ferrari admitted it was an experiment and told us we might be installing them later. We never did.

    The 360 has a more spindly crank than your 348 or my hotrodded 328 and makes more power per cylinder. My opinion is we can get away with it. They are short, stout crankshafts and any time they are run at full power will be short.
     
    Ferrari Tech, MK1044 and 2NA like this.

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