Hey fellas,
I'm skeptical about using this balancer. There's one crack in the rubber and has a slight bulge, but it's consistent, around the back (is it supposed to be flat?).

I don't mind buying a new one but the rotating assembly was balanced with this one. Would that be an issue? I'm assuming it would.

 

The one on my 350 looks worse and hasn't slipped. To re build them cost about 120 bucks. I forgot where the part number is but there is a replacement for the same style readily available.

 

Thanks dude. But wouldn't a new one throw the assembly balance off?
Good to know that this one isn't in real bad shape.

 

Idk depends on who you ask and what the take on it is. I think the balancer and fly wheel are used as formalities in the balancing process. You add a pulley to the balancer that isn't balanced and weighs significantly more than the tolerances being held and af the fly wheel you add a converter which is balanced but wheight is still added. Not saying balancing isn't important but that's my take on the balancer. the 355 I'm building was balanced with the stock balancer which has a slipped ring but I know they didn't install it because I didn't give them the bolt LOL. But it was re balanced as it had welds that where not there when I gave them the crank. So I'm just going to search for a good 72 350 balancer and make sure the weight is close within oz.

 

Perfect, Copper, thanks. I was thinking the same thing. Where do we draw the line? I'll look for a new one.

 

I sent two to Damper Doctor for rebuild. Both look like brand new. I think he even re-balanced them. Would highly recommend him.

 

Id say, if in doubt, get new. Nothing like getting motor done and something failing, which you could have prevented. Just my opinion.

 

Lotsa stuff wrong here, sorry.
They had to install your balancer unless you did it internally and added Mallory.
The outer ring is just a very small part to the whole equation. Most of the counter weight is in the hub, not the outer ring.
And try balancing a pulley. Short of welding a weight onto it or drilling the crap out of it it'll have little to no effect on the overall balance. Not enough mass there to begin with.
Hope this helps.

 

What about the flex plate or flywheel? My rotating assembly wasn't balanced with the flex plate. That's a bit more mass than the pulley. Not a lot more but I would think the large diameter would play a role.

 

This balancer appears fine and normal for its age. Just make sure its not spun.

 

Again, if they didn't do it with the flexplate then they would've had to add mallory(heavy metal slugs). Did they?

 

I saw the measurement (in degrees of separation from the timing mark) in the CSM. I'm going to check that today. Thanks Joe.

Did he add slugs to the crankshaft? No. But the pistons are aluminum so he did quite a bit of drilling in the counterweights.

 

Huh? Virtually all pistons these days are aluminum.
If he didn't have YOUR flexplate then he obviously did it with another one if he drilled on it. You need to find out what he used.
For the record, ALL Olds engines from 64-90 are external balance, meaning they need the balancer and flexplate in order to be balanced. Otherwise you'd need to add heavy metal in the counterweights to make up for the lack of the external weights on the flexplate and balancer. Comprende?

 

I'm sure he didn't have the flexplate. I asked him if I could paint it before he balanced and he said he didn't need it. Doesn't make much sense.

Just curious about the stock, low compression, pistons that were in this engine. A magnet sticks to areas around the pin openings (no pins) but nowhere else. A steel armature of some kind inside the aluminum?

 

Steel support. You need to get clarification on the balance before you go any further.

 

Will do.

 

Mark, is 100% percent correct. Find out what flywheel they used.

 

Not that it matters on this post but I believe all Old's engines from 57 (371 on )were externally balanced.... Tedd

 

I have flip flopped balancers and flex plates with no issues after balancing. Current 355 in the olds got a PRW high inertia flex plate and I changed the balancer out for one from another 350 because I didn't like the how the rubber looked.

Just my experience on that and engine runs dead smooth for what it is.

 

All standard application Olds balancers, flexplates and flywheels "should" have the same weight offset. Balance with one and you're good with any.

Of course, we all know how often "should" works out in this hobby.

As an example, my aftermarket balancer was significantly heavier (balance offset) than the stock spec, so the balance weight had about 10% drilled out.

I'd bet a buck or two that all OEM stuff is within nominal percentage of each other. Once you start mixing and matching aftermarket stuff, well, it's best to match the specific combo.

 

Between stock stuff i wouldnt worry. I agree on that. I wouldnt put an ati balancet on there. But if it was balanced with a stock one i would not hesitate to puy another good stock one in. My 355 is not stock and drives above 3000 rpm for the most part so if i had anyissues adding a different flex plate i would have known by now.

 

All good stuff. Keep it coming. I'll call my guy so i at least know what's what.