croaker

Just wondering if someone has a Stroker motor without a flex plate how would you know what to replace it with? Say it had a standard trams flywheel and you wanted to swap to automatic

gkull

If it has a flywheel and if the flywheel is weighted on one side because it is externally balanced. You would have to get a shop to equally balance a new flex plate.


Cheap 383's are externally balanced

croaker

It had a standard trans flywheel on it. So the crank would have to come out if going to use a flex plate?

cagotzmann

You can purchase flywheels or flex plates for GM external balanced engines.

They are usually in 2 main categories

1 piece or 2 piece rear main seals

1 piece is usually 1986+ Sbc engines

Next would be the number of teeth for the starter

Usually 168 or 153 teeth

But you need to know how was the engine built for balance.

The other area you can look at the harmonic balancer on the front of the crank

For external balanced motor this will also have external counter weights vs being neutral balanced

fishslayer143

or...http://www.ebay.com/itm/SBC-383-400-External-Balance-Plate-Small-Block-Chevy-2-Piece-Rear-Main-0-100-/191520625282?hash=item2c9784d282

croaker

This is what I have

croaker

This is for a one piece? Someone said they just cut the weight off. Or am I backwards on this?

cagotzmann

Measure the dia for the flex plate mounting center hole.

My 1 peace seal flex plate measure 2"
My 2 peace seal flex plate measure 2.5"

Also my 1 peace is for a GM ZZ383 external balance so it looks similar to your picture.

My 2 peace seal flex plate is for a L48 350 internal balanced. No weights added to the flex plate.

croaker

Thanks for the input. So cutting off the weight or, using my current flex plate that is on my car now is the correct route to take?

larrywalk

To the OP; I've read this thread 3 times and I'm not sure what you have...
Is YOUR engine a 383 or a 350?
Is it manual trans or automatic?
Does your starter have inline bolts or staggered bolts?

To answer your last question, I would not cut a balance weight off a flexplate because it may result in imbalance - it could be close, but get a new flex plate instead because it will be balanced - now we just need to know whether you require a non-neutral balance flex plate or a neutral balance one; and the diameter of the flexplate (starter bolts influence this); and 1-piece or 2-piece rear main seal.

Now that you apparently have the flywheel off your engine, post a picture of the engine side of YOUR flywheel and we can tell you if it is neutral balanced or weighted for a non-neutral 383 engine assembly.

croaker

Ok this is a supposed Stroker motor I've picked up starts good ,sounds good, comp. good engine is on a makeshift stand. Was. I'm considering swapping a tired L48 out of a 75 which I'm still able to run just tired. The engine pictured is the one in question it is a older block. I've been out of the game for a long time. Just trying to learn and figure out what I have most folks I know deal with crates.

Ibanez540r

That is a 2 pc RMS

croaker

I guess now I google neutral and non neutral flex plates?

Ibanez540r

No, as stated before you need to KNOW what you currently have and not wing it.

Based on the picture, you do have a 2 pc RMS. Now if it is a 350, it IS internally balanced. If it's a stroker motor, in can be either internal balance or external balance.

You said you removed a flywheel? Where are those pictures? The flywheel will be the tell if it is internal or external. As Gkull pointed out earlier, you will have to have a machine shop balance the flexplate to match the flywheel if it's external. If its internal, buy a internal balanced felxplate, bolt it on and go.

croaker

Those are the pictures of the motor

larrywalk

Post a picture of the back side of the flywheel.

croaker

Tomorrow morning

croaker

The flywheel is a standard trans style

Metalhead140

We know that. You need to know if the flywheel that came off the engine is neutrally balanced (no weights/drilling, means engine is internally balanced) or not (has weights or is drilled, flexplate will need to be balanced to suit as engine requires external balance). Either way, the balance of the flexplate you wish to install has to match the specs of the engine, and the only way to know that without pulling the engine down is to look at the flywheel that came off the engine. Make sense?

croaker

Yes but I don't have it. The flywheel which was on it is a standard trans type. The engine is used with plenty of life left.