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School me on center counter weighted cranks #2621440
02/14/19 10:03 PM
02/14/19 10:03 PM
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Taxes & Virus's R-US, NY
Dragula Offline OP
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Dragula  Offline OP
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So I see more and more engines being built with "center" counter weighted cranks.

Is this somthing I should consider for a new build?


'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: School me on center counter weighted cranks [Re: Dragula] #2621447
02/14/19 10:13 PM
02/14/19 10:13 PM
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Stuttgart, Arkansas
rickseeman Offline
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The smart people like them. That's good enough for me to want one.


2011 Drag Pak Challenger
Re: School me on center counter weighted cranks [Re: Dragula] #2621450
02/14/19 10:24 PM
02/14/19 10:24 PM
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Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
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Ford stock 2011/19 5.0 cw cranks are sold as thier performance crank. Never had a failure!
I run one from Crower in my 528. No cap walk anymore. They take the extra loads off 2& #4 bearings caus e d by non cw cranks, and put it on #3 where it belongs. Would reduce flexing of the crank also, adding to crank life.


8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: School me on center counter weighted cranks [Re: Dragula] #2621482
02/15/19 12:19 AM
02/15/19 12:19 AM
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New York
polyspheric Offline
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The theory is sound, but the practical aspect?
IIRC CCW cranks were used in 392 fuel engines back when, no improvement (Gene Adams). Perhaps this crank is inherently stiffer than current big blocks due to shorter OAL?


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Re: School me on center counter weighted cranks [Re: Dragula] #2621488
02/15/19 12:22 AM
02/15/19 12:22 AM
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MI, usa
dvw Offline
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I use a Molnar non center ounter weight crank. No issues at 900?+. Sure a center counter weighted would be nice Try and purchase one for $900. Do you want it, sure. Do you need it? More than likely not.
Doug

Re: School me on center counter weighted cranks [Re: Dragula] #2621520
02/15/19 02:09 AM
02/15/19 02:09 AM
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back in Georgia
dthemi Offline
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Adding pounds to you rotating mass isn't going to help the goal of faster...unless either your power is so high or the stability of your crank so low you have to have it. Agreed that sharing the weight mass of 2 through the center of the crank is stressful without them. Why carry them down the track, or have to accelerate them on every shift if you aren't overloading the crank?

There's a reason a PS crank weighs close to 35 pounds.

Re: School me on center counter weighted cranks [Re: dthemi] #2621526
02/15/19 02:25 AM
02/15/19 02:25 AM
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Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
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The practical reasons for a ccw crank are better stock block life, and ultimate life of the crank. Also helping reduce or eliminate cap walk in my Megablock. Most racers won't really need one. But the advantages are there or Ford wouldn't use them in all 11 to 19 year 5.0 Mustang motors. Also as i said earlier , they sell that stock crank as thier performance part, zero failures. Some of those race turbo motors i assume are putting out some serious hp!

Last edited by gregsdart; 02/15/19 02:27 AM.

8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: School me on center counter weighted cranks [Re: dthemi] #2621555
02/15/19 08:58 AM
02/15/19 08:58 AM
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Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline OP
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So they are heavier? Aren't all the current SS/AH engines center weighted? Are LS engines stock from the factory this way?


'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: School me on center counter weighted cranks [Re: Dragula] #2621605
02/15/19 11:48 AM
02/15/19 11:48 AM
Joined: Oct 2004
Posts: 3,097
back in Georgia
dthemi Offline
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Don't forget about additional windage too. I'm all for them when they're required, but that has a lot to do with parts quality, and application to me. A ccw eagle crank would be more damaging than an no ccw bryant for the same application. Comes down to rigidity

Re: School me on center counter weighted cranks [Re: Dragula] #2621641
02/15/19 01:13 PM
02/15/19 01:13 PM
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Tulsa, Oklahoma
340Cuda Offline
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Winberg makes cranks for all classes of drag racing and most other forms of racing.

I can't find a photo of one of their cranks that do not have center counter weights.

The attached photo is of some of their top fuel crankshafts.

TFCRANKS.jpg
Re: School me on center counter weighted cranks [Re: Dragula] #2621660
02/15/19 02:03 PM
02/15/19 02:03 PM
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Salt Lake City
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camastomcat Offline
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The cap walk disappears with the CCW crankshaft. They are around 10#'s heavier depending on the manufacturer. Both of mine are over 80#'s.

Re: School me on center counter weighted cranks [Re: 340Cuda] #2621687
02/15/19 02:48 PM
02/15/19 02:48 PM
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I'm putting another pump gas 400 stock 4.250 stroke block stroker motor that has a Windberg crank with billet steel Crower rods I bought used from a member back east several years back, it doesn't have the center counter weights shruggy
I do have two fully counterweighted older top fuel or blown alcohol cranks, one is a Bryant that was 4.25 stroke with Mopar rod size(now offset ground down to BB Chevy size with 4.375 stroke) and the other is a older KB 4.500 stroke that was cracked in four places that I had fix with Mopar rod size, it couldn't be offset stroked though whiney
I'm planning on using both of those cranks in after market blocks to help prevent cap walk and see if I can exceed 1000 HP + N/A luck

Last edited by Cab_Burge; 02/15/19 02:48 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: School me on center counter weighted cranks [Re: Dragula] #2621842
02/15/19 09:06 PM
02/15/19 09:06 PM
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polyspheric Offline
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Strictly speaking, for greatest control of out-of-balance forces, the counterweights should be moved inboard touching the cheek radius, and made as thin as possible to concentrate inertia as close directly opposite (180°, at the smallest diagonal) to the pins as possible, with the OD increased as needed to get the correct mass back. Any late weight adjustments (holes, Mallory) should be limited to the shallowest correction to the inner face of the CW only.
Not practical.
This is true (and nearly impossible) even for the "inherently perfectly balanced" L6 engines as well.

Note that the Winbergs shown are directionally biased for rotation...


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Re: School me on center counter weighted cranks [Re: polyspheric] #2622089
02/16/19 12:50 PM
02/16/19 12:50 PM
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Originally Posted By polyspheric
Strictly speaking, for greatest control of out-of-balance forces, the counterweights should be moved inboard touching the cheek radius, and made as thin as possible to concentrate inertia as close directly opposite (180°, at the smallest diagonal) to the pins as possible, with the OD increased as needed to get the correct mass back. Any late weight adjustments (holes, Mallory) should be limited to the shallowest correction to the inner face of the CW only.
Not practical.
This is true (and nearly impossible) even for the "inherently perfectly balanced" L6 engines as well.

Note that the Winbergs shown are directionally biased for rotation...


So, is a center counterweighted crank an improvement or not?


'86 Maple Grove KOS Mopar low qualifier......true street legal with no power adders.

NOS-used when losing since 1940.

Re: School me on center counter weighted cranks [Re: Dragula] #2622271
02/16/19 07:38 PM
02/16/19 07:38 PM
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polyspheric Offline
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Yes, but it's:
1. expensive
2. not magic - your power level and specific engine design may make it a conversation piece

You would also be faster if you center-drilled every fastener, like they did with Moto-X in the 1970s. 10 hours of labor to save 1 lb.

Expanding on my prior post: given a clean sheet of paper, a "V" engine can, and has been built with separate crank-pins at the same position (G.M.C. 301 etc. V6), which would allow a counterweight between them. But if you don't need it, it's just one more thing for the engineers to argue with the accountants...


Boffin Emeritus
Re: School me on center counter weighted cranks [Re: polyspheric] #2622294
02/16/19 08:28 PM
02/16/19 08:28 PM
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Taxes & Virus's R-US, NY
Dragula Offline OP
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Last edited by Dragula; 02/16/19 08:29 PM.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: School me on center counter weighted cranks [Re: Dragula] #2622359
02/16/19 11:17 PM
02/16/19 11:17 PM
Joined: Jan 2003
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SoCal
Brian Hafliger Offline
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Higher rpm engines seem to like CCW cranks. The weight becomes rotating inertia...not a bad thing.


Brian Hafliger
Re: School me on center counter weighted cranks [Re: Dragula] #2622367
02/16/19 11:28 PM
02/16/19 11:28 PM
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polyspheric Offline
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Ideally, every mass would be opposed by a counterweight placed exactly opposite: 180° away. This is not possible since the pistons occupy that space.
Any compensating mass NOT correctly placed (alongside, diagonal, etc.) has the effect of forming a bending plane with its axis a line through both centers of mass - a diagonal angled away from the crank's axis of rotation. The greater the misalignment, higher RPM, and greater mass the stronger the bending force. Bad.


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Re: School me on center counter weighted cranks [Re: polyspheric] #2622421
02/17/19 01:59 AM
02/17/19 01:59 AM
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Years ago I saw some SB Chevy NASCAR cranks at ABS in L.A area, they where super light weight,33 lbs., and the counter weights where offset to help longevity for high RPM according to the owner of ABS shruggy
They where very pretty up


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: School me on center counter weighted cranks [Re: polyspheric] #2622477
02/17/19 10:10 AM
02/17/19 10:10 AM
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Originally Posted By polyspheric
Ideally, every mass would be opposed by a counterweight placed exactly opposite: 180° away. This is not possible since the pistons occupy that space.
Any compensating mass NOT correctly placed (alongside, diagonal, etc.) has the effect of forming a bending plane with its axis a line through both centers of mass - a diagonal angled away from the crank's axis of rotation. The greater the misalignment, higher RPM, and greater mass the stronger the bending force. Bad.


So, does that mean CCW cranks do or don't reduce cap walk?


'86 Maple Grove KOS Mopar low qualifier......true street legal with no power adders.

NOS-used when losing since 1940.

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