Flywheel cracks

[WesleyK]

So I was cleaning my flywheel up today to get ready to install. It’s been off the car and in the shelf for about 5 years while doing the resto. While cleaning it I noticed small cracks. I know they’re from heat build up. I can’t feel any with my fingernail they’re just visible. It’s a stock rebuild 383. Would you resurface it and run it? The clutch was just put in when I bought the car and I didn’t drive it but a couple miles before I started tearing it down. So i hate to have to buy a whole new set up. It’s a 11” setup btw.

 

[BeatersRus]

a flywheel spinning at 6500 rpm inside a alum housing...
with cracks in the surface.
yeah,id buy a new one if it was me.

btw,has anyone got a recommendation for a lighter mass assembly for a setup like Wes has?
is it even a good idea?

 

[WesleyK]

I like the idea of a lighter weight assembly. My flywheel weighs in about 47lbs. 440 source is 37lbs. Lighter rotating weight means mo power. Here’s some pics of my cracks.

 

[Challenger340]

Depends what it looks like after it gets resurfaced ?
just saying..... the heat cracks don't usually propagate too deep and can be removed when surfacing within a reasonable amount of material removal ?
Maybe ask the guy when having it resurfaced for his opinion, and how much he ends up removing.

 

[dadsbee]

Mine's the same and also looked that way 40 years ago when I was changing clutches. I just threw it in the lathe to resurfaced and reinstalled. Figure I'm basically stock HP and the scatter shield is always there...

First I turned it and took a skim off to clean any major humps or bumps and then while still turning in the lathe I cross hatched it lightly with the flap wheel. Clutch is chatter free and runs smooth.

Everyone else is going to tell you to throw that cast thing away and buy a billet..

 

[WesleyK]

Mine's the same and also looked that way 40 years ago when I was changing clutches. I just threw it in the lathe to resurfaced and reinstalled. Figure I'm basically stock HP and the scatter shield is always there...

First I turned it and took a skim off to clean any major humps or bumps and then while still turning in the lathe I cross hatched it lightly with the flap wheel. Clutch is chatter free and runs smooth.

Everyone else is going to tell you to throw that cast thing away and buy a billet..

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Haha I know they will and I was almost not gonna ask because of that. My neighbor down the road has a machine shop. I’ll run down there and let him have a look.

 

[Cranky]

Are you planning on drag racing the car? IMO, any flywheel should be housed in a blowproof housing. A buddy of mine built a 289 Mudstain years ago and it ran mid/low 12's. He ran out of money so he stuck in a decent clutch but used the stock aluminum BH. One day out on a road with a 50 mph speed limit, he aired it out a bit and hit maybe 80 and on the coast down, things came apart at around 4500. It totaled the car. Luckily, the stock flywheel stayed intact and most of the clutch parts stayed away from his feet....but he lost his new high dollar (for the time) in dash stereo. I never knew a clutch failure could do so much damage!

Based on your pics, it still looks usable to me....after refinishing, but a light flywheel doesn't mean more power. It just allows the engine to rev quicker. Back in the day, a heavy wheel helped a heavy car get off the line without much losing much rpm at the hit of the clutch. I remember seeing some guys using a light wheel in a heavy car and they usually sounded like the engine bogged if their rpm wasn't up there at the hit....especially with a small block.

 

[WesleyK]

I’m not going to be doing much if any drag racing with it. Just going to be driven regularly with the occasional burn out. I have a gasser project on the waiting list to do all my racing and abusing in.

 

[Dennis H]

I was told that machining cost more than replacement so it was replaced recently.

 

[WesleyK]

I was told that machining cost more than replacement so it was replaced recently.

Yeah if it’s the same or even close it’ll be replaced. My neighbor has a huge machine shop right down the road and he usually trade out work. I’ll see what he says and go from there.

 

[dadsbee]

Bring it over Wesley.. I'll put it up in my old 1942 Forward!!

 

[Dennis H]

Ended up with this Brazilian? WTH. Light and nice engagement. Sachs.

 

[WesleyK]

Bring it over Wesley.. I'll put it up in my old 1942 Forward!!

Haha yeah sure I’ll be right over

 

[biomedtechguy]

My flywheel weighs in about 47lbs. 440 source is 37lbs. Lighter rotating weight means mo power.

Lighter weight flywheel means RPMs can climb faster, but less stored energy.
IMO, lighter car, lighter flywheel and vice versa, to a point.

 

[WesleyK]

Lighter weight flywheel means RPMs can climb faster, but less stored energy.
IMO, lighter car, lighter flywheel and vice versa, to a point.

Yeah I had never considered that till Cranky mentioned it. Makes perfect sense.

 

[slimt]

Mine's the same and also looked that way 40 years ago when I was changing clutches. I just threw it in the lathe to resurfaced and reinstalled. Figure I'm basically stock HP and the scatter shield is always there...

First I turned it and took a skim off to clean any major humps or bumps and then while still turning in the lathe I cross hatched it lightly with the flap wheel. Clutch is chatter free and runs smooth.

Everyone else is going to tell you to throw that cast thing away and buy a billet..

View attachment 772038 View attachment 772039 View attachment 772040 View attachment 772041

Those Petro Canada Calanders?

 

[dadsbee]

Those Petro Canada Calanders?

YEP.. and you've gotta be quick to get one, or bribe the driver to save a few before they get to your place to get one.. or two.. LOL My driver likes airplanes, so I always save him a Super Cub calendar !

 

[70sixpkrt]

Get a new one.
https://bobmazzoliniracing.com/store/#!/Flywheels/c/5253082/offset=0&sort=normal

 

[Cranky]

Bring it over Wesley.. I'll put it up in my old 1942 Forward!!

PICS PICS!!

 

[dadsbee]

PICS PICS!!

LOL.. here... and my mini bench top too, that I use for doing engine mount spools.