5.0 swap flywheel/damper weight?

Hi, I have a 1986 5.0 HO that I am trying to mate to a T18. I believe I need a 164 tooth flywheel to work with the truck bell housing/starter. Can anyone confirm this? Also, do I need a balancer from a truck to match the flywheel? If so what weight in oz's would that be? I plan on using a "short" water pump kit on this engine if that changes anything.

Thanks

The 1986 5.0 uses a 50oz. flywheel. Water pump should not matter, I don't think but I'm not positive. The 50oz flywheel is needed for that crankshaft, weight I was told happened in late '81 5.0's.

roadrunner said:

Hi, I have a 1986 5.0 HO that I am trying to mate to a T18. I believe I need a 164 tooth flywheel to work with the truck bell housing/starter. Can anyone confirm this? Also, do I need a balancer from a truck to match the flywheel? If so what weight in oz's would that be? I plan on using a "short" water pump kit on this engine if that changes anything.

Thanks

Click to expand...

Yes, you'll need the 164 tooth flywheel. Make sure it's a 50 oz. imbalance flywheel and you can keep your existing balancer.

Todd Z.

The 50 oz (or oz-in) is the weight of the counterweight. It is the equlivent of 50 oz of material 1" from the centerline of the balancer or flywheel. What ford did was make a lightweight crankshaft then didn't have enough counterweight inside the engine. So the final counterweights are built into the balancer and flywheel. In '82 the cut more metal out of the 5.0 crank and needed more counterweight on the outside.

'82 and newer 5.0 balancer for the front of the engine and '82 and newer 5.0 flywheels for the back of the engine. These are NOT interchangable with a 351 due to balance (but the 351 will bolt on and give you balance issues)

Best short accessory dress I know of is the '96 to '01 5.0 Explorer. Graat clutched fan, good alternator, strong PS pump and even an A/C compressor if you want A/C

So from reading this, if you are planning on dropping in a 5.0, you will need BOTH the 50 oz balancer AND a matching flywheel. Is this correct?
You cannot use a 50oz balancer and the flywheel from the old 302?
Man, I thought this swap was going to be less complicated (and cheaper).

noreasteb said:

So from reading this, if you are planning on dropping in a 5.0, you will need BOTH the 50 oz balancer AND a matching flywheel. Is this correct?

Click to expand...

correct

noreasteb said:

You cannot use a 50oz balancer and the flywheel from the old 302?

Click to expand...

correct

noreasteb said:

Man, I thought this swap was going to be less complicated (and cheaper).

Click to expand...

Well you are working on a Bronco, they are simple to work on, just a pain when you start changing parts.

Broncobowsher said:

The 50 oz (or oz-in) is the weight of the counterweight. It is the equlivent of 50 oz of material 1" from the centerline of the balancer or flywheel. What ford did was make a lightweight crankshaft then didn't have enough counterweight inside the engine. So the final counterweights are built into the balancer and flywheel. In '82 the cut more metal out of the 5.0 crank and needed more counterweight on the outside.

'82 and newer 5.0 balancer for the front of the engine and '82 and newer 5.0 flywheels for the back of the engine. These are NOT interchangable with a 351 due to balance (but the 351 will bolt on and give you balance issues)

Best short accessory dress I know of is the '96 to '01 5.0 Explorer. Graat clutched fan, good alternator, strong PS pump and even an A/C compressor if you want A/C

Click to expand...

So correct me if I'm wrong, but it sounds like I can keep my 86 5.0 front balancer and get a 164 tooth 5.0 flywheel to match it, as long as it is post 1982?

roadrunner said:

So correct me if I'm wrong, but it sounds like I can keep my 86 5.0 front balancer and get a 164 tooth 5.0 flywheel to match it, as long as it is post 1982?

Click to expand...

correct (I would just say "yes" but it is not happy with a reply of less then 8 charactors. this should suffice now)

Broncobowsher said:

correct (I would just say "yes" but it is not happy with a reply of less then 8 charactors. this should suffice now)

Click to expand...

thanks for the help!

Now for my other dilemma...this engine was professionally balanced using the mustang flywheel...so the mustang flywheel must also use the 50oz counterweight, but would have less teeth and smaller diameter, I am not sure how the machine shop balanced the rotating assembly, whether they drilled holes in the crank, flywheel, damper or whatever combination of the three. I'm thinking that if I just bolt on a 1982 or newer 164 tooth flywheel, that the balance may be off, as this flywheel would not have been included in the original combination...or would it matter since they both would be of the 50oz nature...can i have the 164 matched to the mustang flywheel? I've heard this can be done, but I am not sure how.

Thanks

This is one of those topics that should probably be described in a tech article, since it comes up constantly. Everyone faced with installing a 302/5.0 with the later 50 oz-in external imbalance asks the same question, over and over (including me, 8 years ago).

Late 302/5.0 engines (exact date is the subject of endless debates it seems, but somewhere after 1981 or so) require that both the flywheel (or flex plate, in the case of an automatic transmission) and the harmonic balancer have the correct, later external imbalance of 50 oz-in.

Before that, 302's were the same as 351 Windsors, at 28 oz-in imbalance. And the 351 never did change.

As for your specific balance issue, it's possible (likely, even) that if all the rotating parts were balanced together, then the flywheel was part of that process. Since you need the truck (11") flywheel with the 164 tooth ring gear, if you want the best possible balance you'll need to tear down the engine and get it balanced again with the correct flywheel. Or live with it. Likely it won't be terrible, certainly not as bad as running a 28 oz-in flywheel on a 50 oz-in engine, but if it were mine, my OCD would kick in and I wouldn't rest until it was balanced correctly. But that's just me, an off-kilter old guy...