Has Anyone Put The Zz383 In A C4? I Am Putting One In My 88 Vert And I Was Wondering If It Will Require Any Modifications. I Thought Someone Had Mentioned That It Would Require A Smaller Harmonic Balancer. The Zz383 Comes With A 8in. Harmonic Balancer. Any Help Is Always Greatly Appreciated.

 

Engine is same as all SBC.
Requires stock sized balancer or panel beating to X member to fit ZZ4 8" one.

 

Can you just change to a smaller balancer? Or will this throw off the balance of the motor?

 

Any neutral balance harmonic balancer will work.

 

Thanks for all the help Pete. Any idea what size will fit?

 

Hi All,

Joe at Koons chevrolet in Tysons Corner Virginia put a 383 in my 86 vert and changed both engine mounts and the balancer because distances were too close for comfort. The engine looked exactly the same size to me.

I didn't realize what a problem that was until I figured out the corrolation between the damper pulley size and my cooling problems a year and a half later.

Ever since the new engine was installed, my car always ran hot and temps would always creep up and up and I could never get them to stay below 220 unless I hit the open road at 60 plus mph. Idling anywhere was a NIGHTMARE and made driving a horrible experience. I always had to have an open road anywhere I went.

I even posted this question here and did not get the right answer (probably because I didn't KNOW that the balancer was a different size at the time and didn't post that piece of info).

Eventually, I acted on a tip from a forum member and installed a 15% smaller water pump pulley (custom order 125 bucks) and that was the final answer to my cooling problems after NOBODY could figure out what was going on for 18 months. Even Joe himself couldn't explain the overheating tendency.

After personally changing 3 water pumps (new stock pump, stewart hi flow pump, then a flowkooler pump) , installing a ron davis radiator, installing TWO spal fans pulling and 2 permacool fans pushing, I FINALLY realized that the smaller diameter of the stupid harmonic balancer was the reason. You would think that a smaller diameter would speed up the flow but that is NOT what happened.

I put in the overdrive or smaller water pump pulley and the car ran perfectly CORRECTLY cool after that. I even switched back to a 180 degree thermostat after using a 160 for a while. I could finally idle WITH air conditioning. YAAY!!!!


SOOOOOOOO, as agent86 would have said in as few words but saying a whole lot in the process:

Your coolant flow will slow down. Car might run hotter. Get a smaller water pump pulley to compensate.

Just kidding Dan :-) I always appreciate your answers and read them twice.

Anyway, Good luck and I hope you don't end up going through my long and painful learning curve.

Lee

 

"I FINALLY realized that the smaller diameter of the stupid harmonic balancer was the reason. You would think that a smaller diameter would speed up the flow but that is NOT what happened."

Balancer size has no bearing on bottom pulley size; two seperate items.
Can run any size pulley that fits what ever size balancer you have , the three mounting holes are still the same.

In the first instance in your case , I would have the fan start temp changed on your chip.With stock setup ,the coolant is over 220 BEFORE the fans starts which gives little margin when idling.
You are using increased coolant flow to overcome fan problem; what ever works.

My fresh 11:1 383 runs perfect with stock cooling setup.
Fan start is set on @195 ,off @ 180.
WOT run then idle for 10 min never goes over 198.