Vortec v6 conversion

[77searay197]

I’m replacing my 4.3 non balanced early 90s motor with a 99 vortec 4.3. I have rebuilt the short block right now but My question I have is since the vortec I have didn’t come with a flywheel will the one from the non balance shaft motor work or since the motor is internally balanced will it not work? And since it has a plastic timing cover will the same 6.75” harmonic balancer Work or is it too big? I held it up and it looks pretty big and the factory balancer looks to be a hair over 6” but won’t work because it’s not flush on the outside to where I can mount my marine pulley on it. Also will the same water pump work? Thanks.

 

[alldodge]

Don't use the older balancer on the 99 motor. Since yours will not fit the pump, I would buy another. Prices are 40 to 60 dollars

As for the flywheel, I don't think you can use the old one, but lets check with Bondo and Scott Danforth

 

[77searay197]

I noticed on my balancer from my old boat engine the timing mark didn’t line up so I’ll be looking for a mercruiser vortec balancer. From what I’ve researched it seems I may have to get a flywheel with part number 12557590N

 

[alldodge]

You don't need a Mercruiser balancer, just a GM balancer. Can fin them online at many places like summit racing and others. Flywheel is also a GM product so look it up online by the year of the motor

Use truck not car

 

[77searay197]

Well all the balancers I see for autos aren’t flat on the front like what I need.

 

[alldodge]

One like this won't work?

https://www.summitracing.com/parts/...make/chevrolet/year/1999/model/silverado-1500

 

[77searay197]

No that’s pretty much what came with the vortec motor. The one I need I believe is this one
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/232486098248

 

[77searay197]

The harmonic balancer off my pre vortec boat motor looks like the one on the link I sent but idk if the one I have that is on the old boat motor would work cause the timing mark isn’t in the right spot and wasn’t meant for a vortec motor. The link I sent was a balancer the same size as my old 4.3 motor and it’s meant for a vortec

 

[alldodge]

Looking at the one in your link (way over priced, and old IMO) I would not use if it cannot be verified to be for your year motor. The one in my link should be able to bolt to your pulley, same 3 bolt holes and the raised edge should not interfere. That said go down to your local parts store with your pulley and see if they have one on the shelf for your 99 motor

 

[77searay197]

It won’t work with my pulley set up. I don’t have serpentine pulleys I have v style pulleys

 

[alldodge]

Figured you have V belt, but V or Serp pulley's both get bolted to the balancer.

 

[77searay197]

Listen it won’t work with the stock vortec balancer lol. My pulley is flat on the back and needs a flat damper to meet with it

 

[77searay197]

I have this damper off my old 4.3 that came out of the boat but the rubber doesn’t look too good and the timing mark on the balancer doesn’t line up with the mark on the plastic timing cover

 

[chevymaher]

The old flywheel will work. Both engines are internally balanced. The counter balance is for harmonics the engine puts out and is a different deal.

 

[Lou C]

http://www.michiganmotorz.com/vortec-install-retro-fitted-vortec-a-7.html

Take a look at this, you can't really see the harmonic balancer but it looks like they were able to use the original pulleys. I'd give them a call and ask, I bet they know. I asked them about the 4.3 flywheels and they said the same as above, they are all the same. The addition of the balance shaft did not change this.

 

[77searay197]

Thanks for the link. I kinda wonder if maybe my old balancer off my engine maybe is worn and spun a little causing the timing mark to be off? I put it on another 4.3 tbi motor at the house and it won’t line up with the timing marks on the timing cover either

 

[77searay197]

Thanks for the link. I kinda wonder if maybe my balancer is just worn out and maybe spun a little? I put it on a v6 tbi short block motor at the house and the timing cover from my boat motor on and timing mark won’t line up on it either. And I know it’s at tdc cause the heads are off. It’s about 20 degrees off

 

[77searay197]

Sorry for the double post I thought my first post didn’t go through

 

[Lou C]

If you look at the balancer in the ebay link, the slot in the hole that slides onto the crankshaft almost lines up with the timing mark, Is that how yours is? If yours is a lot off from that then maybe you're right, the rubber failed and allowed the outer ring to slip....

 

[77searay197]

Mine pretty much lines up with the key holes. However if u look at this one which is supposedly for a vortec the mark is a little offset. May just go ahead and get it.