Looking for used 308 (QV) flywheel

Check with GT Car Parts in AZ.


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Gordon try this AASCO They do a lot of flywheel lightening and they may have just the ring gear.
https://www.aascomotorsports.com/

 

Best to phone and speak with Bill. He can be hard to get hold of but worthwhile.


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Aasco built an aluminum flywheel for me with replaceable steel for my 83, $666. I love it

 

Yes I sent them old dead one, it’s in Chronicles of Barron thread somewhere

 

I have one, taken off my car.....ring gear is fine..AFAIK

I always thought it could have been resurfaced but they put a new (used) one one, because of the micro cracks.
Make offer it's heavy....

Love for you to have it...

 

You will need to match the balance (old vs new) or if you engine is apart balance the cranks damper and flywheel together.

 

These are internally balanced engines so the parts SHOULD all be in balance separately, mine were on both the Qv and 400 engines so as long as the new flywheel and clutch setup is balanced it should bolt on and all will be well.

Years ago I on the QV engine I mostly kept the stock flywheel weight but installed a much light/lower I clutch (tilton 3 disc 7.25", carbo/carbon), I'm trying to remember but like 1/4 -1/3 less total weight and like 1/2-2/3 the I number? Anyway I was all scared about taking too much on a street car....couldn't tell the difference if I'm being honest. I'm sure there was an improvement in acceleration that a machine could measure, physics tells me that must be true, but it was not in the butt dyno range but this was a 600+hp engine so the change was just lost in the noise. With an idle at 1000 and normal pull away rpm at 1500 or so I sure couldn't feel the engine wanting to bog or any or the nonsense I'd read and let scare me into not lightening the bajesus out of it.. The only real change I could notice was the new clutch didn't slip/fail no matter how much I abused it and is a bit more digital than a stock setup. The V12 got the same clutch and a pretty light flywheel more to help reduce weight the weight I was adding in the engine bay than anything else...17lbs with the clutch vs 34 stock I think, yielding like 1/4 the original I number iirc, even used the small OD F360 ring gear....seems fine, it idles and pulls away as well as the not yet running great engine would let it....but I didn't to take 17lbs off the 100ish I was adding back out of the engine bay and just kind of hoping it will behave ok in normal in town driving.

I got off track...I machined the thing from 4130 steel and took it to the shop with the crank and damper to have everything balanced. They did all the parts separate and the flywheel needed basically nothing, 2 10mm holes, 1.5mm deep(plus the drill point) because I told them get it as good as they could, they said normally they wouldn't have touched it. They did spin the assembly when they were done to double check, but it didn't need or want anything more done.

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That's what happens when posting after a dinner party and lots of good wine-- I know it's a flat plane, internally balanced but got my wires crossed. I'm building a 347 for my Tiger and need to get it all balanced with bob-weights and the Fidanza flywheel I bought so that has been on my mind. The cam and compression aren't too wild so hoping the lighter flywheel will not require too much additional revs/finesse.

 

I can't imagine 2500lb car with a 250?ft-lbs torque at idle V8 is going to much care about the flywheel weight, its just going to go ......that was my other point

I think a little 100 ft-lb or less mx torque 4 banger in a 2500+ lb car is probably another story. Its only firing 1/2 as often, and each time it does only making 1/2 the torque....they need all the help they can get. But make it an 8 or 12 and with a relatively high 1000rpm idle, I just couldn't tell any difference in the way it idled or drove. Back aroun '95 I was roadracing a H-D V twin and cut a ridiculous amount of the flywheels...it definitely reved quicker off idle, enough quicker the about 5 H-D engineers who heard it in the pits wondered over to inquire what exactly I had done to make it sound like THAT!....really honeslt didn't notice anything different out on the track, maybe a bit higher revs needed at green flag launch? that thing idled at 1000-1200 so again relatively high, WILD cams,....60 ft-lbs, but the bike was about 550lbs with me on it so again it just went regardless.

 

Some old school guys in here now!

I still run the stock flywheel.
But I support this science project, but also agree the flywheel should be closely matched to the engine and the street trim of our cars is almost perfetc.

That said experiment and report back!!
Once it's hooked up flywheel weight no longer enters the acceleration equation..

 

The flywheel definitely help break the tires loose on launch which I think is what you're talking about, but after the tires are hooked you're left with acceleration=force/mass or spinning thing = torque/I where I= rotational inertia. This means things like the flywheel, brake rotors, wheels and tires all need to accelerate BOTH rotationally and linearly. Stuff like big wide wheels and tires, massive brake rotors all make the car accelerate slower...the rule is never use larger wheels, tire, brake than you NEED...no matter how cool and they look. The flywheel is funny in that it is the only one on the list that the factory puts on a harmful to acceleration heavy rotating component....to make the car easier to drive.

I read an article years ago where they bought a small...nissan? all boy racer prepped, exhaust, like 20in wheels, brakes, "super cool". They ran it down the drag strip and I think on the dyno. Then started swaping parts back to stock ad yes the full stock final version was the fastest. I'm remembering on an acceleration dynjet dyno the the brakes ot the wheels were eating 8hp off a 100 hp total.

Anyway, lightening the flywheel has to make the car faster....but when I tried on a highish hp example the 10-20hp effective improvement wasn't noticeable.

 

Will be interesting as recently I have noticed my clutch "failing to operate" if the throttle revs are too high.

My mechanic says it normal as the fingers of the clutch plate won't operate if it's spinning too fast, so a rapid "fall off" would be an improvement, towards faster shifts up thru the gears...

My wheel was 17 pounds "in the box" so it's close!

 

Are you getting a better clutch-- $650 it sounds like a fancy clutch.

 

Maybe. It has to make it rev better/faster, just expect to see about 1/2 the difference you saw on the miata. Remember a V8 is not a 4cyl and already has roughly double torque and double the compression braking so it will already rev up and down much faster than a 4 cyl with similar weight flywheel. When I took about 10lbs on mine I noticed nothing, but that was mostly off the clutch which is a smaller dia so less effective than off the flywheel...but not a lot less effective.

 

I plan to do a clutch job soon and when I do I plant to have my flywheel lighten to at least about 30% since I don’t trac my car.

 

Ooooo ahhhh