archtech

Replacing clutch with LUK 04-021 kit. Flywheel had some concerns so mechanic wants it replaced too. I search for flywheels and found some lightweight ones but they say

"This flywheel is NOT compatible with stock-type sprung hub clutch discs with 5 or 6 springs. The larger diameter of the stock springs creates clearance issues with the flywheel bolts"

Is there a decent lightweight one to use with the LUK clutch kit? It's 153 tooth flywheel.

I saw some 29lb (PRW) ones but isnt the stock one 25lbs?

6T5RUSH

archtech,

Here ya' go...GM PARTS DIRECT:

http://www.gmpartsdirect.com/perform...CATID=913.html

Jim
In God We Trust!

Kerrmudgeon

You better read up on the pros and cons of lightweight flywheels before you decide. My engine guy who builds over 300 high performance engines of all makes a year, recommended AGAINST it when we built a 500+hp big block last year. Here's an article and there are others if you search on line.

http://ca.search.yahoo.com/r/_ylt=A0...-flywheel.html

Dr L-88

Just last week I replaced the L-88 light weight flywheel with a Hays 26 lb. unit and Sachs stock clutch assembly in my 67 with ZL-1 engine. Car has an M-22 Rock crusher trans with 2.56 first gear and 3.70 rear. The heavier flywheel makes the car MUCH more streetable. Just my preference.............................. .

Will be selling the L-88 flywheel and an almost new Centerforce Dual Friction clutch assembly soon.

EDinPA

Light weight is good for circle track racing. Bad for everything else. Every shift will be more abrupt and less smooth. It will be a dog off the line from every stop at every light and stop sign. No fun on real roads.

MiguelsC2

I am running the Fidanza aluminum flywheel with the Centerforce II clutch. I experience none of the above symptoms. Spins quick, comes off idle perfectly even with the a/c on. No sharp drops in rpm between shifts etc...

I haven't built 100s of motors. But I have run this clutch and flywheel combo for almost 3 yrs and I recommend it.

midyearvette

it seems this debate can go on forever....i really don't understand the logic copied from the above article..."Cons"
Because a lightweight flywheel spins at an increased rate in comparison with a heavier flywheel, it takes more revolutions to reach maximum engine power. This means that it takes longer to reach the engine's higher gears, decreasing initial acceleration. According to Tim Gilles, author of "Automotive Engines," a lightweight flywheel also has a higher risk of damage from rough shifting."

to me anyway, it's all about driver comfort and it will vary from car to car but i have always liked a lighter wheel in a stock or mildly modified street machine. a real seat of the pants difference in performance with some sacrifice to lowend performance but easily remedied with your clutch foot. also, i like the faster drop in speed when downshifting... with a highly modified mill, a heavier wheel would be more streetable but you still sacrifice horse power.....jmo.....

of course if we are talking about a '53 roadmaster, that's a different story!......

AZDoug

I put a ZL-1 15 lb flywheel on my L-79 motored '61 back in 1978 and never looked back. withe M21 and 4.56 gears, it was rocketship

I put a new GM current replacement 15 lb unit on the 427 SB that went in the the same car a few years ago,and love it.

The lightweight FW does like a 10:1 or so first gear compound ratio, and with the 427 inch motor with its light weight rotating assembly, it can get into a surge situation in higher gears below 15 MPH, but other than that, both motors loved the lighter weight for quick responsiveness.

If I had an old school L-88 cam, and carburation, i would suggest a heavier flywheel, but with the EFI and roller cam in the 427, my motor makes more average HP and tq than a ZL-1 did, between 2500 and 6000 RPM, and accelerates like no L-88 ever did, from the factory, a heavier flywheel would just slow the car down, as I do not do clutch dumping with drag slicks as normal driving conditions.

Doug

Jackfit

I put in the lighter flywheel for my 66 L-79 . Drove almost 40,000 miles in last 2 years. Love it. M-20 and 3.70 rear.

Took a few days to get use to it. No problem in any gear..... Midyearvette drove it and he liked it.

Jack

Kerrmudgeon

Do you remember which one Jack? how heavy is it?

Jackfit

about 15 pounds, it came off a later model corvette , still have the original

Jack