My latest order from Competition Products arrived today. I'm a little ticked about how they packaged my crank (they just dropped the crank in a box and shipped it!). The box was beat to hell and torn open in a couple spots. I hope it isn't bent. Turns out it is nitrided, heck of a bargain at $199.95 if it wasn't damaged in transit.

Anyway, my question is about balancers. I think they sent me the wrong one. I ordered an SFI balancer, all steel, for internal balance (BBC 427) and it should be an 8-inch unit. What I got was a 6.25 inch unit. It looks real nice and is the same price as what I wanted but it isn't what I ordered.

Assuming I'm having the rotating assembly balanced, how important is it to have a large balancer on a street engine? I would think the smaller balancer would allow for slightly quicker revs and a very slightly lower torque output (less rotating mass), but would it really be a noticeable difference? Should I keep what I got or return it for an 8-inch unit? For street use does a larger balancer have advantages over a smaller one? On stock stuff, the HP engines always had a larger balancer.

my only comment is to get a good quality one when you decide what you need. I had a brand new "cheap" one on my motor when I built it and the outer ring was moving around which caused me months of grief trying to find a shake in the motor. I made a clock out of it and its hanging on the wall in the garage, thats all its good for! I replaced it with a high quality sfi piece

Rich,

A larger balancer would be prefferable (sp?), but not necessary. Bottom line is they should give you what you asked for.

Mike

The smaller may be better for short duration racing events... but for a street motor Id want the added control that the larger version offers.

Whatever you do, dont get Professional Products...
Put it on my 489, and it spun the outer hub in short order.
Quality, Quality, Quality.
I now run a ATI super damper.
The biggest one I could get, I might add :D

Well, turns out Competition Products doesn't have one in the same price range that is SFI (steel) for an internal balance application.

To get a reasonably priced one for internal balance applications my choices now appear to be:

-Comp Products, 8-inch, internal, SFI, steel, PowerBond brand, $154.95

-Summit Racing, 8-inch, internal, non-SFI, nodular iron, Summit brand, $79.95

I'm torn as to which way to go. At least I won't have any trouble returning the balance I got in error.

Rich,I'd go with either the Summit one you mentioned or a Pioneer stock replacement,which is also available at Summit.
Actually,I think Gene bought a GM unit from GMparts direct if I'm not mistaken.

I found an OEM balancer on GM Parts Direct and it was about $97 so I guess that one is in the running as well. One advantage the aftermarket units have is the degrees being stamped into the rim of the balancer.

The Summit part is looking better though. While I'd really like to get an SFI-rated one I have to wonder if that's really necessary on a street engine that will see occassional track use.

The Pioneers are available at Competition Products but I don't think they carry the big block internal balance version. Summit's price on a Pioneer puts it in my expected price range.

I don't think you need a SFI unit for the street. NHRA doesn't require one until you get into the 10's. If you get one that is not degreeded, you can add a Proform damper cover. I have one on my bracket car. While building the engine, I checked it and the markings were right on the money.

I've used the timing tapes with good results. The one I put on the 327 in my 57 pickup is still there a quite readable. It was built in 1985.

Tom (did I mention cheap?)

summit has a good oem line under $100.

I have the Pioneer 8" internal balance. Just installed it and took the time to check it when degreeing the cam. It was right on the money.