Fly Spy

[LoBelly]

on the cusp of ordering my bits for the 347 build/assembly.

decided I'd get a new steel or aluminium flywheel for safety and if possible a lighter one...

however, I have been asked if I need a 164 or 157 tooth flywheel

are they both the same size and will they both work with my starter (to be transferred from the 289)

I suspect that the choice may affect the clutch I can run (confirmation anyone)

I have a practically new clutch (diaphram style replacing long style that came with the engine) that I was intending to re-use - it took some shopping around to get. but I dont have the part # or anything.

a search on the forum revealed so many references to flywheels but after wading through a whole bunch of them I haven't really found the answer

thanks
LoBelly

[Aussie Mike]

Shop local and talk to the guys at Yella Terra. They do some really nice billet steel flywheels. I bought mine throught them. They should be able to supply one to suit what ever clutch hat bolt pattern you have. Their quality is top notch and they ship them all over the world as OEM manufacturers for other brands

They can also do lightweight steel flywheel. I believe a stock LS1 flywheel is 10.5KG but my Yella Terra steel one is only 7KG. An aluminium one is 6.5KG.

Yella Terra

Windsor Flywheels

Cheers

[LoBelly]

sounds like a plan

ta

[sambo]

Are there any issues with having a flywheel that is too light? I've heard that apart from acting as a damper and somewhere for the clutch to grip, they also help maintain inertia between gear changes. I can't remember where I read that but I certainly didn't make it up!

[Aussie Mike]

I guess in simple terms the flywheel stores power. The heavier the flywheel the more power it will store. The heavy flywheel takes more power to wind up but gives back more power as it winds down.

A heavy flywheel is good for getting the car off the mark. The inertia stored helps plug the gap between where your clutch engages and the engine starts feeding power through it. It takes a bit of finess to smoothly engage the clutch whilst applying the power to get the car moving The heavier flywheel makes the car a lot more forgiving to get going.

The cars our engines came from were a lot heavier and designed to be driven by regular joe public regardless of skill. Our cobras are a lot lighter and hence easier to get moving. Most of us drive for the pleasure of driving rather than getting from A-B so we hone our skill. A lighter flywheel can be used and the car will still be easy to get of the mark.

For a sporting car that is accelerating and decelerating rapidly a heavy flywheel isn't so good. A lighter flywheel is better because it spins up quicker and slows down quicker too. Great for accelerating out of one turn before braking hard for the next turn.

That's my theory anyway and others may differ. The 7KG flywheel is fine for getting off the mark in my car even with the copper ceramic button clutch.

Cheers

[batdan]

LoBelly,

I converted my auto engine to manual so had to purchase a new flywheel. I got a 157 tooth fly wheel as I am running a T5 and this requires the smaller wheel. Make sure you get the balancing factor right as well.

This is from the Ford Racing Catalog:
Did you know…
1968-80 302 engines were built with a 28-ounce imbalance factor.
1981-01 302 engines were built with a 50-ounce imbalance factor.
1969-97 351W engines were built with a 28-ounce imbalance factor.
1970-74 351C engines were built with a 28-ounce imbalance factor.
NOTE: Severe engine damage will result if you use the wrong flywheel or damper on your engine.

Download the catalog from Ford Racing Parts . This has more info that will help you choose, look at page 128.

Cheers,
Dan