Aluminum Flywheel Help

[buck95]

Hi
I have a few questions about you aluminum flywheel. I am putting in a new
center force duel friction clutch very soon. This 28oz flywheel with 157 teeth. Would this hurt me in any way with this application
Or would I need the 50oz flywheel? I'm will be putting this on a new DSS pro
bullet motor sometime this spring? I would like to add this mod to my
mustang but I really don't know that much about the aluminum flywheel. Or would i need something else for this too work


Thanks
Darryl

[PKRWUD]

If you install a 28 ounce flywheel, you must also install a matching harmonic balancer.

Take care,
-Chris

[exgmguy]

I personally think that aluminum flywheels are a waste of cash.

The money saved could be best spent elsewhere.

[buck95]

Let me get this right. I can use the 50 oz aluminum flywheel and it wont hurt the crank. If I want to use the 28oz I would haft to use a different fluid damper. Is that right? Also would it hurt on launch or help? 50oz is about 3lb 28oz is about 1.5 lb. It's not much of weight but its rotating weight so the HP gain would be worth the effort

Buck

[PKRWUD]

To answer the first part of your question, the flywheel and the balancer are a matched set. They either add 50 ounces or 28 ounces, at each end, to the engines rotating mass. They MUST be a matched set, or engine failure WILL result. A 50 ounce set will put more load on the crankshaft's #1 & #5 journals than a 28 ounce set will, but for a mild street/strip engine, the effect would be nill. Still, if the parts haven't been purchased yet, you are always better off to go with as little external balancing weight as possible.

Hope this helps.

Take care,
-Chris

[buck95]

Yea! You might be right about the effort. I haven’t got the parts yet but been think about it when I stick the new clutch in. So you are saying the flywheel will come with 28oz if that’s what I want? I think a 50oz weight is $15 extra. You say use the 28oz

Buck

[PKRWUD]

Okay, let's start at the beginning. The 1979 and older 5.0's had a heavy crankshaft. Since the 5.0 is an externally balanced engine, this meant that the counter weights could be small. They placed a 28 ounce counterweight on the flywheel and the balancer to make up for any internal imbalance. The 5.0's built from 1982 on had a lighter crankshaft, which meant there was a greater imbalance, which required larger counterweights on the balancer and the flywheel. Specifically, they placed a 34 ounce weight on the balancer, and a 50 ounce weight on the flywheel. For stock applications, these must remain as they were originally, meaning 1982 and later 5.0's need to have the 50 ounce set (34 ounce balancer and 50 ounce flywheel), and 1979 and earlier 5.0's must retain the 28 ounce set (28 ounce balancer and 28 ounce flywheel).

Now, once the engine becomes modified, things can change. If your engine is an '82-'84, and you installed Forged pistons, or if you install a forged crank for any year 5.0, you will have increased the internal weight enough to justify using the 28 ounce set. If you were to have an engine built, and had it balanced, you could have it done so that you could use the 28 ounce set as opposed to the 50 ounce set, which would put less stress on the crank.

I don't know what the story is on your engine. I read the beginning of this thread where you mentioned installing a 28 ounce flywheel, and I wanted to make sure you knew that your balancer had to be 28 ounces as well. If your engine is a stock '95, you should use a 50 ounce set. If your engine has been modified, then you need to contact the builder and ask them which set you should use. When the choice is yours, before any parts have been purchased, less is always better. In otherwords, if your internal mass weighs enough to justify a 28 ounce set, then by all means, use one. But if it is basically a stock rotating assembly, then a 50 ounce set would be better.

The single most important thing to remember is to have a matched set. A 28 ounce flywheel and a 34 ounce balancer will cause a bad vibration immediately, and will cause damage to the bearings initially, and the journals eventually, not to mention the damage done to the rest of the engine due to the unbalanced vibrations. Also, to avoid confusion, forget that the 50 ounce set balancer actually weighs 34 ounces. Refer to them as either 28 ounce sets (28 ounce flywheel and balancer) or a 50 ounce set (50 ounce flywheel and balancer). Otherwise, you'll drive the parts man crazy.

Take care,
-Chris