[bec]

Anyone ever do a back to back test to just how much is gained by going to a light crank?

 

[10.5 Dave]

I had a lightweight crank in my billet LS engine.My engine builder told be there would be very little HP increase if any.The biggest advantage is a lighter rotating assembly will rev faster and recover quicker on every upshift.

 

[cgeise]

I talked to a high end crank manufacturer I bit ago about this and they said they have gone away from the real lite wt stuff - it does more harm than good

 

[Warp Speed]

I talked to a high end crank manufacturer I bit ago about this and they said they have gone away from the real lite wt stuff - it does more harm than good

X10!

You can reduce the "Inertia-Weight" through proper design, but most times, a real light-weight crank is a flexi-flyer, and isn't good for making HP, or getting it to the ground. It takes energy to flex that crank, and I would rather use that energy to move the vehicle if at all possible!
Now I'm not saying to put the heaviest piece you can find in it, but allot of times weight reduction is done in areas that have little to no effect on inertia, but have a big effect on integrity.

 

[WarnerRacingEngines]

just quicker revs id imagine

 

[Warp Speed]

just quicker revs id imagine

Only un-loaded!!!! LOL

The acceleration rate is controlled by work produced vs resistance, and I think the weight of the crank isn't the biggest factor in the resistance area! I don't know of any acceleration rates that are high enough for the crank to be the limiting factor, unless it becomes un-loaded, as in traction loss, but then it's all over anyway right?!?

I guess a way to look at it is, you want it heavy enough for the required stiffness of the work produced?

 

[Deleted member 4436]

Anyone ever do a back to back test to just how much is gained by going to a light crank?

Yup...and...nope.

 

[Fisher-Racing]

I see no benifits to a light weight crank in a drag race application, actually just the opposite happens most often,,, in a dirt track application they do have benifits but not on the drag strip and the lighter you go the more strenth you give up,,,,

 

[.gearhead.]

Not on lightened cranks, but I recall seeing a test online for the Eagle cranks, with their Armor coating process. It showed improved oil sling characteristics and a small HP gain. I couldn't locate it though.

 

[teufeltruck60]

less nose weight--always good

 

[WarnerRacingEngines]

yea buuuuut not by that much

 

[Cs19]

I hope it helps, I just switched from an 83 lb. Lunati to a 57 lb. Bryant. Not planning on making extra power but planning on having a lighter boat and thats everything.

 

[WarnerRacingEngines]

damn 83lbs?

 

[FrankieV]

A light weight crank does not help in drag racing, they were initially designed for circle track racing and not for power but mileage.

 

[Scott McMullen]

I think my Dads SBC is 47 LBS so its not that light but it was on Sale when he bought it!

 

[DewRonInc]

Light weight rotating assy has its place, round track where it is super important to stay in RPM and on offg throttle, in drag racing i ain't so sure of any benifit that could be gained except a much shorter life due to the sudden loading....

 

[lsp]

Anyone ever do a back to back test to just how much is gained by going to a light crank?

I bet Warp Speed could tell you all about doing back to back testing showing a performance loss by going with too light a crank for the job.

 

[DewRonInc]

X2 on that....

 

[Warp Speed]

I bet Warp Speed could tell you all about doing back to back testing showing a performance loss by going with too light a crank for the job.

I would like to, but unfortunately, I'm only allowed to say so much!!
That is why, with some regret (not too much on some subjects though!!! LOL), I leave allot of things open ended, hoping some can/will read between the lines, and maybe get some "food for thought" anyway!

 

[RCM Racing engines]

I bet they are light in a cup motor, but NOT to light, as for the oil clearances they run to keep windage down will NOT allow for a

Crankshaft in there flexing all over the place @ 9700 rpm.... therefore letting the motor survive 750 miles

there light enough to see the benefits, but are safe enough not to flex and blow up....... only way to know is the R&D they have

am i I close ....................WARP.....????...........