I'm getting ready to stick the ZZ4 in the car, and I was trying to decide if I wanted to pull the stock balancer and use the Fluidampr Streetdampr I purchased last year.
I knew that some of the newer GM engines had pressed on balancers, but I never thought that the ZZ4 would. Externally it is a near duplicate of my old 69, so I figured the balancer would have a bolt in the end of it. I guess you learn something everyday.



[Modified by Smokehouse69, 10:42 PM 10/19/2002]

 

Uh, it should have.

No 350 Chevy motor should be without a bolt at the end of the crank to hold the balancer on. They are all a "press fit", but do require a bolt to hold the works together.


[Modified by BSeery, 10:18 PM 10/19/2002]

 

Smokehouse:
We occasionally run a ZZ4 in a circle track truck ... never noticed "no balancer bolt!" I'm gonna check ours. Most tracks require a 2-barrel (max 500 cfm) but a few allow a ZZ4 w/ small (max 390 cfm) 4-barrel ... our in-house 2-barrel 355's w/ iron (not vortec) GM heads are typically stronger than small 4-barrel ZZ4. But the ZZ4 combo is best on a couple around here. Although not routinely run, ours is a great motor, never been apart and has consistantly seen 6800 rpm. No probs w/ ZZ4's stock rubber balancer ... hasn't slipped. IMO, I'd keep the stock balancer unless you just like the look of a fluid damper. IMHO, fluid may be better for short bursts of max rpm like at drags, but rubber is better for extended runs of varying rpm. If you'd like a really trick, super duty rubber one ... check bhj
http://www.bhjinc.com/dampers/bhj_dynamics.html

bhj also has hi-grade specialized automotive tooling & other stuff at
www.bhjinc.com ... 100% USA made

BTW, most balancers are pressed-on ... but most also have a center-bolt. Many very early sbc were also press-on ... BUT they had NO center-bolt or hole at all! I can't remember em all ... there were/are other makes & models with no center-bolt as well.

For now, if yours has a threaded hole I'd put in a bolt. Does your ZZ4 crank's snout have a threaded hole?

[Modified by jackson, 12:47 AM 10/20/2002]


[Modified by jackson, 12:48 AM 10/20/2002]

 

Mine did not have a bolt either. When I pulled my balancer I only noticed a little RTV on the key to hold it in. Just so you know when you put a streetdampnr on it is smaller by almost an inch so the timing guide needs to be changed, or if you are like me I just get a square stick and run it down to the balancer so I can read timing accuratly. Just a reminder the zz4 comes from the factory with 0 timing so make sure to change it.

Mark B.

 

The snouts are threaded like any other sbc but most crate motors don't come with the balancer bolt. But that doesn't mean you don't need one!!! :smash:

 

run it hard for a couple days and then get back to us and let us know how things turn out :D

 

Steve, is the crank threaded for a bolt?

The 350 in my Vette is dated for a '69 block and there is NO crank bolt either. I don't know if Bubba busted it off or the crank was bolt-less from the get-go.

 

The bolt in the end of the crank isn't the only difference between a threaded and a non threaded crank. The non-threaded (talking older ones in the 50's and 60's here) crank snout is tapered, as is the balancer. The threaded ones are just a straight snout, pressed fit. It is my opinion that when installing the tapered non bolt on version of the balancer that you have a hole drilled and tapped to add a damper bolt, make sure the motor is cold (like freezer, winter cold), boil the damper for 20 minutes, then install it quick with the bolt to make sure it gets all the way on the tapered shaft.

 

Okay, guys you convinced me. It is easy enough to install my old bolt and washer, I think I trust it more than one from the "Help" rack at an autoparts store. Does anyone have an idea of what it should be torqued to?

 

sbc = 7/16"-20 rht ... BBC = 1/2"-20 rht. Might wanna chase the threads first. With a proper press-fit, center-bolt is little more than insurance. Better to have than have not. W/ a bit of lite loctite or paint, 60 ft lb will be fine.