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Re: Using a solid hub instead of a damper? Will this fix it
[Re: domingo]
#1694311
11/05/14 02:57 PM
11/05/14 02:57 PM
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Joined: Jan 2003
Posts: 9,670
Lima, Peru
domingo
OP
EL Master
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OP
EL Master
Joined: Jan 2003
Posts: 9,670
Lima, Peru
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Re: Using a solid hub instead of a damper? Will this fix it
[Re: domingo]
#1694312
11/05/14 02:59 PM
11/05/14 02:59 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,376
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A belt drive on the camshaft will NOT protect the crank. There isn't enough mass on the other end of the belt to have any damping effect on the crankshaft. The belt does dampen the vibrations going to the camshaft, which is why some have found 20+ hp by switching from chain or gears to belt.
Back in the day, chevy 283s with forged cranks did not have dampers. 3" stroke, 200hp or thereabouts.
My Poly 318, 200hp, 3.31" stroke, did not have a damper on the end of its forged crank.
Dirt track racers have tried over the years to use solid hubs instead of the heavier dampers, because the dampers are additional rotating mass to accelerate. But they found out that the cranks, even decent forgings, would break. To finish first, first you have to finish. I remember reading about the need for dampers back in the '70s, and that was with 3.5" stroke cranks.
Now, if you have an engine with a solid hub and a big supercharger hanging on it, connected by belts, I can see how the rotating mass of the supercharger, the horsepower drag of compressing the air, and the flexibility of the belt would serve as a damper.
But take that belt off and I guarantee, you'll break the crank. It may take a while, but it'll break.
R.
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Re: Using a solid hub instead of a damper? Will this fix it
[Re: B G Racing]
#1694314
11/05/14 06:26 PM
11/05/14 06:26 PM
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Joined: Jan 2003
Posts: 9,670
Lima, Peru
domingo
OP
EL Master
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OP
EL Master
Joined: Jan 2003
Posts: 9,670
Lima, Peru
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Quote:
All the Bryant cranks we have seen and the ones here in the shop have Bryant stamped on the front counter weight.It appears that the counterweights where excessively cut for piston/block clearence and externally balanced because too much was removed to be able to internally balance it.Those street hemi rods are questionable at best,years ago we would go through 3 to 4 sets to get 1 good set.So if you have some way of checking them like magging or zilego(penatration) testing it would be a good idea.That flywheel maybe matched to the clutch and external assembly.
You must ask yourself,"when is a deal not a deal" and do you want to "risk the time and effort" for a "hopeful chance of success"My advise is not to use any of the stuff but if you want to take a chance have the crank checked before anything,that might be the deciding factor.
Respectfully Bob  
it is what it is. I either use it and try to do somethign with it and have some fun, or i leave it on a shelf collecting dust forever.
I have enought "junk" parts to put together a 500 cid hemi without having to go buying expensive stuff...
and this stuff I would not use along with other "brand new nice stuff" for the obvious reasons....
So im gonna have some fun putting this thing together and flog it till it blows. I think that the 3k that I might have to throw in it to make it a running engine will be worth the fun for the time it lasts.....
Im just gonna make sure it last for as long as possible. Heck it might run for years! If it runs for years I think it would be a bargain for the 3k I have to throw in it to make it run.
   
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Re: Using a solid hub instead of a damper? Will this fix it
[Re: Twostick]
#1694315
11/06/14 02:01 AM
11/06/14 02:01 AM
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Joined: May 2003
Posts: 6,569
Downtown Roebuck Ont
Twostick
Still wishing...
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Still wishing...
Joined: May 2003
Posts: 6,569
Downtown Roebuck Ont
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Quote:
A stock damper would be better than a solid hub. Solid hub equals broken crank sooner than later.
As was said earlier, if the rotating assembly is neutral balanced then just get a neutral balance damper in whatever brand you like. It will NOT require you to rebalance the rotating assembly.
Kevin
Quote:
having an offset balance flywheel and solid hub installed. The hub has a considerable offset balance, and the whole rotating assy has been balanced like that.
Belay my last response. I missed this part of the thread.
Apologies.
Kevin
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Re: Using a solid hub instead of a damper? Will this fix it
[Re: dthemi]
#1694317
11/06/14 12:06 PM
11/06/14 12:06 PM
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Joined: Jan 2003
Posts: 9,670
Lima, Peru
domingo
OP
EL Master
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OP
EL Master
Joined: Jan 2003
Posts: 9,670
Lima, Peru
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Quote:
Just to cut to the chase. Don't run that pulley set up instead of a damper. The blower pulley/belt set up works because there's around 30 +pounds of rotating rotors and gears in the blower that provide the damping effect through the belt, that is under constant strain. No rotors, no damping.
gotcha!!!!!
Im gonna see what can be done to put a damper in there....gonna take my rotating assembly and an elastomer damper to my buddy who balances rotating assemblies down here in Peru and see what can be done....
Likewise, Im trying to keep things CHEEEEP.
I see the HEMi dampers are THICKER, do you think I can get away with a cheap narrow 440 damper? And which one would you guys suggest? It would be nice if it already has the bolt provisions for adding a counterweight.
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