The Rodding Roundtable
Motorhead Message Central => Rodder's Roundtable => Topic started by: richard 36dodge on November 10, 2005, 10:06:52 PM
I was having a vibration at about 70 mph. I could not find the problem. I just had my driveshaft balanced. I was talking to my life long hot rod buddy of 40 years. He ask if I was running the alumimun pulleys on my small block Chevy w/ short water pump. I said yes and that is not the problem. He said to put the stock steel ones back on and see it the problem goes away. I did and it did. He said that most of the aluminum are not billet but cast and are not balanced. There is one other thing the stock steel pulley overdrives the water pump by 20%. Would that help a vibration ?
The pulleys I was running was the 2 groove 6.6" aluminum. The stock pulleys are the 6 3/16" GM # 3876846 water pump pulley and the crank pulley is 7 11/16" GM # 39110013.
The stock steel don't look as good but they sure work better.
I don't know if any of you have has had this problem.
Thanks , Rick Harris
I've used the alum. pulleys for a number of years on several engines without a problem. Could happen though. You're right though, a lot of "billet" parts are just machined castings - and they are cheap.
Charlie
I've used March aluminum pulleys in the past, the quality is very good.
I've seen some used aluminum pulley sets at swap meets ..... on the back side you could see where the machine work did not fully cut through a rough casting spot.
I can see them vibrating.
Quote from: "Crosley"I've seen some used aluminum pulley sets at swap meets ..... on the back side you could see where the machine work did not fully cut through a rough casting spot.
I can see them vibrating.
These pulleys are not very high quality. I got them off ebay. I would not have bought them if I could have inspected them first. Swap meets are still the best !! Speaking of swap meets there is a BIG one at Moutrie , GA starting on Nov 18 thru 20. Anybody going ? My son and I are planning going Saturday the 19th.
The black steel ones will do just fine, My 36 is a street rod not a trailer queen or a show car.
Thanks , Rick Harris