Technical Weber aluminum flywheel I.D.

I just bought a used Weber Aluminum flywheel but there are no markings or part numbers that I can see just the name WEBER . It is 13.5" overall and the clutch surface is 11". I think it may be for a big block Chevy but am hoping it is for a small block. Does anyone know for sure by all the balance holes if it is for internal or external balanced engine? Also was wondering about the value of it. I will attach a couple pictures and will take more if needed. Thanks for your help!

 

There is no difference in SBC and BBC as far as crank holes and diameters. There are 2 sizes, usually designated by the number of teeth on the ring gear. As I recall they are either 157 or 183T.

I believe that the 13.5" diameter is the 157 tooth variety. From all the holes drilled in it, I would guess that it was originally a zero balance wheel and modified for an external balance application.
Usually, this is done with a weight added either to the flywheel itself or with a separate balancing weight.

 

Ok, so you are thinking it is for a big block then. You think the balancing holes were added later or at Weber? They seem original but I could be wrong. Thank you

 

You bought and paid for it, that's what it is currently worth

 

Good point! I will need to resell though if it is for a big block!

 

Could be BB or SB. It's a modified part. SBC 400 was externally balanced, BBC 454 too.

I doubt that that was done @ Weber. The hole spacing is not consistent. And, I don't think they would do it that way. You have to take away 3 times as much aluminum to balance something as you would steel. A small weight bolted to the outer rim would be much more effective use time of and material.
As Budget36 said, you already established the price.

 

The flywheels will interchange with the small block and big block Chevies....

 

Thanx @Deuces,
I thought I said that, but it wasn't getting thru

 

Fill a few of the holes with lead and take it back to zero balance.

 

Nor sure that I'd use lead. Pouring molten lead into an aluminum receptacle could create some issues.
I'd suggest threading the holes and screwing bits of all-thd/bolts/set screws with a dose of red loctitie.
In fact, from the back side, a short bolt with the head would add additional weight.

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I would be afraid to use a flywheel that had been drilled like that. Remember the flywheel gets a lot of stress and heat and it needs to be STRONG as well as light. When you drill all those holes, you reduce the strength of the flywheel. A flywheel explosion is not a pretty sight.

 

153 and 168 tooth counts for SBC/BBC; 400 SBC and 454 BBC have a balance weight, and all the post 87 SBC's have a balance weight as they don't have a weight on the crankshaft flange due to the one piece rear main oil seal.
I am Butch/56sedandelivery.