BBC crank support?

When is it needed to run one on a BBC with a ATI balancer and crank trigger. This motor is running methanol with a PSI screw blower. Which one do you recommend to run?

Thanks

 

pm me i am headed down this road, will tell you what i have done

 

PM sent

 

What RPM and overdrive are you running? What model PSI?

 

Rpm is 7400 - 7600
75% of
206c screw blower

 

Are you having current problems, or just thinking ahead to avoid them?

For what you are describing probably not needed.

 

Just thinking ahead so there is no problems taking this balancer off.

 

With that amount of overdrive and RPM it shouldn't be an issue however, having the crank support on that combo will insure maximum strength. I used to run an 8-71 on a BBC with 38% over and I'd see extra wear on the two front upper half main bearings. When I went to a 14-71 with 54% over and I had the crank support, I had no main bearing wear. With a PSI-C at 115% over and a bearing support I see no wear either. I'd say with that combo, if you can afford it, put the crank support on.

 

Thank's for the info Blownalky. Now the only thing to do is try to find a used one in my price range.

 

I always ran one with a Chevy roots and screw assuming that the crank was weaker than a hemi. A hemi actually has a smaller snout and you rarely see a crank support on them. I've been to 9800 rpm and 129% and don't see anything on the upper bearing. Maybe because it's pushing down so hard? Lol. Read the big article about gates belts and top fuel. It explains a lot about belt load on the pulley.

 

Link to article?

 

I think Mike C posted it...an old article from National Dragster

 

It's down at the tail end of this thread, along with some other articles & videos.

Belt Stuff

Chris Saulnier - Team Tigges
Mechanic Falls, Maine

 

Thanks, Chris

 

WTB a crank support ass. for a BBC. What do you have?