Aluminum Flywheel Users... On the Street?

I'm considering an aluminum flywheel as part of my upcoming 5-speed swap, and I'm wondering how well those things live on the street. Like it or not, my Valiant doesn't see a ton of miles any more, but the miles it does see are primarily on the street. Occasionally, I plan to autoX the car, so some periodic abuse is in the plans. Total weight of the car is 3500-3600# soaking wet with me in the car, and the 340 is fairly mild, built for good vacuum and street manners. I'm looking at an AL FW because I have to go up to a 143-tooth unit, and I want to keep rotating weight down to at least what the existing 130-tooth setup has. The new 5-speed has a 3.3:1 first gear, so getting out of the hole will be a little easier than the 2.9:1 833 in the car now.

Any real world experience out there?

Thanks,

Clair

I'd think it would work just fine in your application. McLeod was selling some Mopar flywheels at bargain basement prices recently on eBay. I picked up an aluminum BB flywheel for next to nothing but I haven't used it yet.

Did you mention your RA ratio and/or tire Dia?

I think you have worthy question, that has not covered much in past. I would like to do the same. I do have a strong 273 in a 3:23 3300lb with an 833 with the deep first gear. The 273 has a 10"?? or smaller FW, its not a 10.5", and on the street, it almost stumbles on first bite. Anything lighter would be a problem, but a beefier motor or another stronger variable and it would be doable. I like the idea of an Alum FW. Let us know.

Well, I should know something some time... The McLeod FW's AndyF mentioned were the ones I was thinking about, and I went ahead and got one. That solves the "problem" I had deciding which way to go with my 5-speed conversion, and gives me an SFI FW as well.

JCC, my car sounds a lot like yours. 3.23's out back, and 26" tall tires, FWIW. Do you have the 3.09 gears in your trans? The situation you're describing is the one I hope to avoid. Smaller engines need more inertia in the FW to get the car moving easily, and it seems like the 340 keeps getting lumped in to the "smaller" engine category. Even knowing what I know about my engine, I worry some about how it will behave, but it's not a weak engine at all. All my experience to date is with cast iron ~30# OEM flywheels, but I've always thought I could live with something lighter. I just wasn't sure if I'd want to cut that weight in half on a daily basis. Knowing that it's NOT on a daily basis made pulling the trigger a bit easier. Knowing that 1st gear is a good bit lower helped, too.

Having driven my car with a close-ratio 833 with a 2.45:1 first gear before, it's a booger to launch even with 3.23:1 cogs out back. I may ultimately end up with 3.55's in back depending on how the OD and autoX shift points play out, so I really don't think the light flywheel will be a big issue. At least I'm more comfortable than I was...

Would still be happy to hear about any other experience out there, though.

Clair

I ran my 470 low deck on the street for quite a while with an 18 lbs steel flywheel. That was a McLeod flywheel which they lightened for me. So it was basically the same weight as an AL flywheel.

That combo was in my B body car with 3.54 rear gears and there was no problem getting off the line.

Yes, mine is a Passon 3.09 1st. And since the 273 and 340 share same stroke, I suspect they have nearly similiar torque at 1000rpms regardless of engine mods. Since I am only driver I can manage. And living in Fla starting on hills is never an issue. In your case I would convert to alum, I just would not expect it to be trouble free. Come to Florida sometime and you can drive my car

Clair where are you getting a bell for a smallblock and 143 tooth wheel? Just thought you might need to check you bell before you get too carried away with a clutch and flywheel you cant use
Gus

On a different car and situation I ran a lightened flywheel - a 1983 BMW 528 with a mildly souped up engine. Running through the gears was great but idle was a problem and it was touchy (but OK) to get it rolling. Between a moderately aggressive cam and very slow 1'st generation Bosch EFI it just didn't like to idle. May or may not apply to your situation.

JCC,
That would be a treat. I've been curious to see how nice the Passon trans/gear set must be. Interesting point on the torque curves. I would guess that the curves might be similar, but the extra displacement would push the whole curve higher. Can't say that I have any tech to back that up.

Gus,
The bellhousing is from a 93 Dakota, and is a peculiar part required to bolt up a Toyota Supra 5-speed. The trans is a heavy-duty relative of the AX-15, with good gear ratios. The Dak uses a 143-tooth flywheel, but only a 10.5" clutch. I had been looking in to some Jeep Liberty parts, but that's going to take a custom flywheel, and I'm trying to keep away from custom parts to the extent I can. I can scab a funky clutch in there if I had to, but it's hard to scab in a funky flywheel...

Clair

One of the guys at ClassicMP5SP said that X-r's they dealt with didn't like aluminum on the street. But they deal more with GM, so ? ? ?

X-r's?

Maybe I just need my coffee...

Clair

Autocross, or Auto-X, sorry, didn't think I needed to spell out autocross. I think a user hear has autoX or something similar as user name.

DOH! Looking at it now, it's obvious what you were getting at. Must be the lack of sleep I've been getting since our newest kiddo got here 1.5 months ago...

I guess I'll see how I like the AL on the street soon enough. Can't wait for the shiny new parts to get in...

Clair

Can't wait to hear how it drives. I'm doing similar swap in
? years. 1 or 2, always looking at stuff.

Jim.

Heh... my 5-speed swap has been "in the works" for about that long already. I'd blame my 2.5-yr-old, but it's really my lack of progress on my EFI project. No point putting 5 gears behind an engine that won't run down the road. Be sure to check out Buschi340's thread on the same trans swap I'm doing.

Clair