Actual facts about the "light crank pulley"
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Actual facts about the "light crank pulley"
As many here know, the light crank pulley is a source of great debate. Getting annoyed at the lack of real data, and how rumors were just passed along as fact, I got ahold of a power plant engineer and asked him. (It's in the Design link of my website, but here it is.) The "I" below is my factory contact:
“I talked to an engine builder who builds high performance V8s. He occasionally builds engines without vibration dampers, but only for hill climbing / sprinting. He recommends that the crank is replaced after no more than 4 seasons racing due to the fact that it will eventually fail. The overall milage covered is therefore very low over 4 seasons.
I've been checking out every other possible lead that I have and one of the most interesting is the fact that <mfg name removed> will use the production damper on the new V6 racing engine. The engine is based around a production block and crank and will be used for circuit racing. The milage will be higher than sprinting but not so great. The engineers think that the damper can be improved slightly, (probably reduced mass), but not deleted altogether. This is interesting because with a 6 cylinder engine or multiples of 6 it is possible to achieve perfect primary and secondary balance. The pulses through the crank from each cylinder is what is clearly being damped as you probably already knew by now.
A failure related to the damper will result in a broken crank, possible pressure plate etc rather than bearing damage. I think that any failed bearings etc are as a result of general abuse and not down to the vibration damper.
I think that it is clear that any vehicle that will cover moderate milages should have a vibration damper to prevent the risk of crank failure.”
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Well there you have it. Seems like a good case to keep it on, unless it's destined to be a low milage engine...
“I talked to an engine builder who builds high performance V8s. He occasionally builds engines without vibration dampers, but only for hill climbing / sprinting. He recommends that the crank is replaced after no more than 4 seasons racing due to the fact that it will eventually fail. The overall milage covered is therefore very low over 4 seasons.
I've been checking out every other possible lead that I have and one of the most interesting is the fact that <mfg name removed> will use the production damper on the new V6 racing engine. The engine is based around a production block and crank and will be used for circuit racing. The milage will be higher than sprinting but not so great. The engineers think that the damper can be improved slightly, (probably reduced mass), but not deleted altogether. This is interesting because with a 6 cylinder engine or multiples of 6 it is possible to achieve perfect primary and secondary balance. The pulses through the crank from each cylinder is what is clearly being damped as you probably already knew by now.
A failure related to the damper will result in a broken crank, possible pressure plate etc rather than bearing damage. I think that any failed bearings etc are as a result of general abuse and not down to the vibration damper.
I think that it is clear that any vehicle that will cover moderate milages should have a vibration damper to prevent the risk of crank failure.”
--------------------------
Well there you have it. Seems like a good case to keep it on, unless it's destined to be a low milage engine...
Joined: Jan 2002
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From: North/West, IL
Re: Actual facts about the "light crank pulley" (Spade)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">This is interesting because with a 6 cylinder engine or multiples of 6 it is possible to achieve perfect primary and secondary balance. </TD></TR></TABLE>
Without some clarification on which 6 cylinder configurations...I will have to disagree with this part. But the rest of it looks
Without some clarification on which 6 cylinder configurations...I will have to disagree with this part. But the rest of it looks
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