Yeah, I completely understand your point of view. If I had two failures with the same problem I'm 99% sure I would jump ship on the blower thing as well. Giving things a second try is one thing, giving them an 8th is another. If my setup wasn't already designed around a supercharger long ago, I'd be going the turbo route as well.

PM on its way...

 

do you have to do any mod's to the timing cover to get the bb hub to fit or is this a bolt on

 

Yea, the timing cover has to be bored out to the BB chevy size..

--Sean

 

After you bore out the timing cover(what is the cost) where or what gasket do you use..

Would the reg ati hub be ok (2 keys) with D1 or T-trim...

 

For the gasket.. call ati.. they have it...

 

I sent mine to ATI, I think it was like $50.. They have the gasket, but it's just a standard bb chevy front seal..

Some claim the standard ATI hub is too small and will break/crack...

--Sean

 

At what level would the stock hub (keyed) work

450rwhp-?
500rwhp-?
550rwhp-?
600rwhp-?
anything over 600rwhp you should go BB hub ?

 

The HP has less to do with the hub strength than the boost level. Above 15# I would recommend the bigger hub. If you run Cogs.... use the big hub at any boost level.

The seal is not a standard big block part.... it has a much smaller O.D. than a regular BBC seal. I have both & they are very different.

 

Yes ... boost level means how much strength or resistance the impeller will make...

when going to a ys-trim... where the impller is much bigger and boost levels are higher... air flowing is a lot more.. well... a lot of stress is put on the crank snout and hub... the ati hub tends to break exactly on the keyed portion.

Well.. the big bluck is so meatier that it gives me a bit more peace of mind.

 

Interesting, I was just going on what the ATI techs told me..

--Sean

 

So anything under 15ibs of boost the stock set up with a key is good, then anything over that BB hub

 

Well......
This is sort of like the statement that your engine should be safe to 6200rpm.
Most will be fine & some have broken at 6000.

With 8# a stock keyed unit should be safe.
Personally if you are buying a new balancer, get the good one unless you are running an 8 rib, relatively stock combination with 10-12# boost in a daily driver, then the standard ATI should be fine. If you have the slightest vision of going 10's, don't skimp on parts.

Unfortunately there has been no scientific research done on this. If you use the cheap stuff, you may be the source of the research data. Personally Murphys Law gets me anytime I skimp on things, so I tend to overbuild to prevent doing things twice.

I have 1 car running 18# on the standard ATI. I have recommended to the owner to change it now that better parts are available..... If it splits, it may do little damage, or possibly ruin the crank & timing cover as well. If it breaks & comes off the engine, it will likely break the radiator, fans, waterpump, supercharger pulleys, tensioner & the optispark.

I have seen 12# kits (making 10# on a mild build) break a stock keyed balancer hub, ruining the above mentioned parts.

I also just finished a P600B '94 Vette engine with the standard ATI Balancer as it will only be 10# boost with the factory serpentine belt. Larger belts spaced forward amplify the stress on the hub.

Are you willing to risk possibly a few thousand in damage & your personal safety (or others) to save a few hundred? A loose balancer spinning at 6000 is a 10# frisbee. A few years back, just 3 miles from my house, a balancer came off a Chevelle at highway speeds. It hit the road, bounced up & went through the windshield of an oncoming car, killing the driver. How would you feel if this was your car or your mom in the other lane........ just to put things in perspective.

 

Here are pix of what happens if your scrimp:

http://para.noid.org/~lj/Hub1.jpg
http://para.noid.org/~lj/Hub2.jpg

I now have the bb hub plus machined front cover from Lonnie (thx!). I wonder what I'll break next?

 

How did yo do that

 

ys-trim + cog drive + single key hub = Boom #10.