Fly Wheels

BLACKJACK · #1 (**permalink**) 06-30-2002, 12:40 PM

I'M ABOUT TO GET ERA #273 OUT OF THE BURNED OUT GARAGE. OUT OF DESPERATION - AND HAVING NO PLACE TO WORK ON IT - I'M GOING TO TRAILER IT TO A SHOP AND HAVE THE FLYWHEEL AND/OR RING GEAR REPLACED.

THE ENGINE IS A 427 S/O WITH A MALLORY DISTRIBUTER AND TWO 4-V HOLLEY CARBS. OTHER THAN THAT I DON'T KNOW A THING ABOUT IT. THE PREVIOUS OWNER KNOWS LESS ABOUT IT THAN I DO.

IT SOUNDS GOOD AND RUNS STRONG. I BELIEVE THAT IT'S RELATIVELY MILD. I HAVE NO IDEA WHAT THE C/R MIGHT BE AND THE CAM IS NOT STOCK BUT NEITHER IS IT WILD.

MY QUESTION IS: IS THERE ANY REASON, COMPELLING OR OTHERWISE, WHY I SHOULD - OR SHOULD NOT - HAVE A LIGHTER FLYWHEEL INSTALLED ?? (OF COURSE I DON'T KNOW WHAT FLYWHEEL IS IN THERE NOW).

ANY THOUGHTS AND/OR RECOMMENDATIONS WOULD BE GREATLY APPRECIATED.

THANKS, AND HAVE A REALLY GREAT DAY,

BLACKJACK

Bud Man · #2 (**permalink**) 06-30-2002, 03:30 PM

Blackjack:

An aluminum flywheel generally gives you better (quicker) throttle response than a steel unit. On the down side, if you already have an irregular idle due to a lot of cam, an aluminum unit will often aggravate the situation. One thing is for sure, if it is running a stock iron unit, I would get it out as soon as I could.

I know this is not a lot of help, but it will easier to make the decision when you know more about the engine in question. All things being equal, I would go aluminum.

Bud

Jeff Frigo · #3 (**permalink**) 06-30-2002, 06:11 PM

Unless you are going road racing, stay away from the aluminum.

Steve R · #4 (**permalink**) 06-30-2002, 08:14 PM

Jack,
Do a search on the subject. The Kirkham boyz have some interesting opinions on the matter.
Steven

ERA535 · #5 (**permalink**) 07-01-2002, 12:33 AM

Blackjack -

Do you have a problem with the flywheel that is in there now?

I chose an aluminum flywheel for my car and I love it.

Pat

Steve R · #6 (**permalink**) 07-01-2002, 09:05 AM

Pat,
Can you describe the difference in how the engine behaves? I am going to remove my tranny soon....You guys got me thinking about it.
Steven

ERA535 · #7 (**permalink**) 07-01-2002, 09:19 AM

Steve -

"Blipping the throttle" (don't you love these old weird expressions!) means just that....

Kind of the like difference between revving a Lincoln and revving a Formula car.....

I actually lightened my aluminum flywheel about 2.5 pounds, have been using it for 9000 miles and no problems.

Pat

Mr.Fixit · #8 (**permalink**) 07-01-2002, 10:20 AM

Aluminum (SFI approved) is the way to go. But you'll have to get it balanced to match the flywheel currently on your motor. It will rev quicker, the motor won't torque over so far when you hit thew throttle, all due to a smaller M.O.I.

BLACKJACK · #9 (**permalink**) 07-01-2002, 02:30 PM

HI GUYS,

SORRY - I DIDN'T MAKE THE KEY POINT VERY WELL.

THE REASON FOR THE WHOLE EXECISE IS THAT THERE IS ONE (OR MORE THAN ONE) TOOTH BROKEN OFF OF THE FLYWHEEL.

MR. MURPHY - WHO HAS BEEN MY CONSTANT COMPANION THE PAST YEAR - SEEMS TO BEABLE TO STOP THE ENGINE ROTATION ON EXECTLY THAT SPOT MOST OF THE TIME.

I THOUGHT THAT AS LONG AS I HAD TO TAKE IT APART I WOULD CONSIDER ANY UPGRADES THAT WERE PRACTICAL.

THANKS AND HAVE A REALLY GREAT DAY.

BLACKJACK

flipper35 · #10 (**permalink**) 07-01-2002, 03:12 PM

The only thing I would add is a light flywheel will make it harder to be smooth from a stop. But givin the weight of a Cobra, this shouldn't be an issue.

bmalone · #11 (**permalink**) 07-01-2002, 03:20 PM

Blackjack, I vote aluminum. Have it in my SO and the light weight of the car more than compensates for any difficulty taking off. My SO is a TP, so it does not idle terrific (about 1400 when hot) and my cam is in the .580 lift range and I still have no driveability problems.

Jack21 · #12 (**permalink**) 07-01-2002, 04:58 PM

BJ,

Had the same choice to make. Considering the car, and the way you're likely to drive it, there is no reason to use a lighter flywheel on the motor.

The aluminum flywheel should let you rev quicker on the track, but make the car a little more tempermental on the street.

A NEW iron replacement will work if you intend to keep the revs under 5500 and you're on a tight budget.

The best replacement for a mostly street, sometimes race motor would be the SFI billet steel flywheel. Although they cost about double that of an OEM, or aftermarket iron replacement, the SFI billet for my 351 was about $250. Not wildly expensive, and good insurance.

ERA 626 · #13 (**permalink**) 07-01-2002, 05:03 PM

can any one recomend which flywheel (aluminum) to install on my 428 FE the motor in internally ballanced like a 427. I was going to buy the Hayse one in Summitt racing but after reading this thread I am leaning towards the aluminum one.
Also I am looking for advice on which Clutch to use. My ERA 626 is being painted now...
Mike

ERA535 · #14 (**permalink**) 07-01-2002, 05:10 PM

Mrmike-

I followed ERA's advice and installed a clutch that was one step above stock...so far it has worked perfectly and the pedal effort is easy to live with.

Pat

ERA 626 · #15 (**permalink**) 07-02-2002, 07:52 PM

Pat,
Which clutch did you use? Part #?
Also what about the flywheel?
Mike

Michael C Henry · #16 (**permalink**) 07-02-2002, 09:54 PM

The ring gear is usualy replaceable .That sort of thing happenes to flywheels .Check your starter drive and bendix.They make different grades of bendixs. I don't know anyone that is working on his own car that would settle for anything but the best.The expense difference is minimul.But it would add up for a manufacture that is rebuilding thousands and doesn't expect to see many of them returned.A good bendix will save the ring gear because the drive will stay engaged till engine is started and not release when engine just coughs.