When I was a kid,,,it seemed that the 8 inch one was always on the 4 bolt main engines. Maybe that was a coincidence,,,but it always held true back then for me. Who knows,,,I always used an 8 inch Balancer on all my small blocks back then. I guess it probably doesn’t matter,,,but it worked for me. Tommy
Damper...NO balancing action happening at all. Only in 400's and big Chevys did a counterweight exist on those dampers. And its main function was still as a damper, it just "also" functioned as a balancer. And yea, in both my 327's and 350's in years past was always an 8" damper. While the weight does "slightly" slow the ability to rev...quickly, the thought was that it did a better job of damping the harmonics, thus helping the bearings live longer. I never had a main bearing problem, even racing. Now days, it's an ATI, Super Damper (7.0") on most everything. Mike
Chuck them both and run a blower The smaller one usually looks better, fits better, work good all the time, and sometimes works better
I always was told and seen the 8" on a steel crank, Hence the 4 bolt main as another stated. But then again NOT all 010 blocks had 4 bolts and not all 2 bolts had cast cranks...
Yup. There is only one thing that 010 blocks have in common, and that is they are a casting design intended to be finished with a 4-inch bore. That's all, nothing else.
Small point, the purpose of the damper is to prevent twisting the crank several times more than the power strokes would by themselves, when the engine is running at RPMs numerically related to the "torsional resonant frequency" of the crank rotating assembly. Note the torsional amplitude (degrees difference of the crank end-to-end) of the original Chevy SBC can be 5X higher when running right at a resonant frequency RPM without a damper. The stress in key areas of the poor crankshaft would also be 5X higher under those conditions, and accumulating at a rapid rate, 4 or more times per crank revolution. If you want a crank to develop fatigue cracks and shortly thereafter break, just run it without a damper and run it hard at high rpm. Second point, the Chevy design engineer who authored the paper presented before the SAE annual meeting (sloppily?) called it a "harmonic balancer."
I appreciate the passion and resilience Mike, every time someone calls it a balancer you’re at the forefront to educate and correct. I think your efforts would be better suited by going after bigger fish on this one. Retailers such as Summit, Jegs, amazon and then the manufacturers of these things. They are wrong and may not even know. Worse yet they probably don’t care or possibly the uncontainable,, doing it just to piss you off. On the obscure end it could be a ploy to distract you from bigger and better things to accomplish.
Blow by, Yeah I saw that several months ago on a GM website,,,I didn’t want to cause a stir though. Live and let live I say. Besides,,none of us are perfect,,,,at least I’m not. Tommy
I'd use the same one used on a 327/ 365 er 375 motor.... Same one used on the 302/290 er 465 motor.....
And 327 (325/350 hp). Bought this many years ago at the dealer, #3817173, requires matching front cover with welded timing tab to clear 8 inch BALANCER.
Falsehoods are not elevated to the stature of facts, no matter how many times they are repeated. You can call a pig a duck, but it is highly unlikely that you will ever hear it quack.
You might want a balancer like this Chevy's like Ford moved the timing marks around over the years this balancer has all three different mark locations. https://www.summitracing.com/parts/pfs-80000?rrec=true
There are bolt on timing tabs for each balancer diameter. You need to use the correct one. My current ride came to me with 6 3/4 balancer and tab for 8" balancer. Had to install the correct tab to accurately set the timing. Phil
Chuck them all and buy an ATI superdamper. They are the one with the white ring on the front you see them on so many built engines for a reason.
Balancer, Damper OK pick one. These have been called both a damper and a balancer for as long as I can remember and I am 11 years older than dirt. Who but a few give a flying fart what in the hell it is called. There will always be a few that get there panties in a bunch over the absolute terminology for a part that has been called one or the other of these two names for forever. PICK ONE guys in the big plan for the universe I don't think it is going to matter one damn little bit.
"In balance" is when the weight or effect of two items, entities, etc. equal, or cancel each other. We balance driveshafts, crankshafts, etc. in order to cancel the vibration. It isn't much of a stretch then, that a device used in an attempt to cancel torsional vibration is called a balancer, is it?
On a deuce with a SBC, and probably other set ups too, watch out for clearance with your tie rod. You might have to use a smaller diameter harmonic balancer, especially if the car sits low.
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