[BBCBLOWEN]

Hi guy i have had lots of blower motors and the main problem u are having is that if u read arctics about blowers or talk to bds,weiand,bhj etc they all tell u (do not recomend fluid dampers) use ati or a good steel balancer ,i personally would recommended using Ati super damper ,it already has your 6 drill holes for your blower pulley and it is also rebiuldable,and to be sent in every 10 years and they are priced at 300 bucks and if thats not good enuff for u then bhj also has a balancer that is double keyed with the 1/4 and 3/16 and also has the 6 holes for the blower pulley but crushies the wallet at a whooping 550 buck but u guys buy what u want i just recommend getting rid of the fluid filled balancers on a blower application hope this helps u out and good luck

[1932bantam]

run the plain old crank hub.....Also on smallblks we have had the crank drilled back to the front main bearing and run a bbc headstud to try to take some of the stress further back. not saying this works but this is something I have had done. the belt will take care of the harmonics

[bentwings]

I don't think there is a need for a balancer on a X-71 blower motor. It just causes the broken balancer and sheared hub syndrome. I just run a crank hub. Mine came from Don Hampton blowers. I have 18,000 + miles on mine now and no problems at all.

You have to look at the end of the crank on SBC . It is not very big,,,this is why you can get a forged crank with a big block snout machined right from the mfg. Not the cheapest fix but at least the snout stays on the crank.

I would recommend adding a single full keyway in the crank. I don't have one on my motor but it was already in the car when I installed the blower. I'm playing with fire but part of my car is that it is a test machine to try things out. Some work some don't but at least I know for fact.

You need a good grade 8 bolt and a thick hardened washer, properly torqued with loctite for the crank hub. Do not try to turn the motor over with this bolt.!!! There are blower hubs with a 1/2" square drive hole in them for a breaker bar or long ratchet for this purpose.

Somewhere above there was mention of backfire on shut down. This needs to be corrected or you can also break the crank snout right off keyway or not. This may take the block with it and numerous other parts.

The belt should have about 1" play on the long side when the motor is cold with aluminum heads. With steel heads you can reduce this to about 3/4". Loose will be better than tight. Too loose will cause excess noise with 8mm belts. Hot you should see about 1/2 play either way. You really have to check you system out both hot and cold to get it right.

BTW it takes about 1/2 hour running to get to full operating temp.