Lightening Flywheels

67 1/2 1600 · Post by **67 1/2 1600** » Mon Oct 10, 2005 1:50 am

Anyone know any tips when getting a flywheel lightened and balanced??

Thanks

Post by **spl310** » Mon Oct 10, 2005 5:56 am

Go to Datsun.org and download the Bob Sharp comp manual. It has the details. Be very nice to your friendly neighborhood machinist...

SLOroadster · Post by **SLOroadster** » Mon Oct 10, 2005 4:27 pm

Ive had a few done. About the lightest you can safely get is 15lbs. There is lots of material that can be removed, the last one I had done was about $170 after it was ballanced and cut down. You don't really need the manual, any good machinest should be compitant enough to see where material can safely be removed, and where it can't.

Will

shifty · Post by **shifty** » Mon Oct 10, 2005 10:19 pm

Should you take the pressure plate as well to the machinist and have it balanced at the same time?

Post by **spl310** » Mon Oct 10, 2005 10:48 pm

Personally, I would take the Bob Sharp manual and discuss it in detail with the machinist. I would also take the old clutch disc and the NEW pressure plate. I would ask that he lighten the flywheel and balance it by itself, and then balance the pressure plate and index it on the flywheel. The reason for the old clutch disc is so that he can see the contact area. I would make sure that he understands to do fillet cuts rather than square cuts - more strength. Actually, polishing the freshly machined areas are not a too bad idea.

Of course, that is only if I were going racing. On the street, I would save the money and just put the stock flywheel back in the car. The money saved would be spent on other items like a little hotter cam.

Just my thoughts on the subject....

datsunrides · Post by **datsunrides** » Tue Oct 11, 2005 9:31 pm

In my opinion, a heavier flywheel is better for the street. I installed a 9 Lb. aluminum Tilton on my modified A15 engine in my '72 B110 and it can be a pain in the rear. Try launching a light car with a big cam and a DCOE 45 and a light flywheel after not driving it for a time and you feel like you are learning to drive a stick all over again

Talk about easy to stall

It does make it rev up quite a bit quicker than the stock flywheel though.

SLOroadster · Post by **SLOroadster** » Tue Oct 11, 2005 10:34 pm

I have a 10lb flywheel with a lightened bottom end with a huge cam and 44phhs, its no big deal once you learn to drive it. This is the same setup I learned to drive in.

Will

nomadtrash · Post by **nomadtrash** » Tue Oct 11, 2005 11:06 pm

I've got an aluminum one for sale.

spyder · Post by **spyder** » Wed Oct 12, 2005 10:34 am

I'm using an aluminum flywheel w/ all the go fast engine mods. I heard the chatter, hard to drive, easy to stall and so on. Conclusion; dosen't seem too difficult to drive and is FUN!

nomadtrash · Post by **nomadtrash** » Wed Oct 12, 2005 12:00 pm

I agree. The U20 has a huge amount of reciprocating weight. The crank and rods are heavier than small block Chevy parts. The chains and gears, jackshaft, and other parts all add up to a lot of inertia. I've never had a problem with stalling or drivability issues with the aluminum flywheel. Mine is in the 11-12 pound range. I suspect that a 5 pound unit might have more problems.
http://www.junauto.co.jp/products/drive ... ex.html?en

SLOroadster · Post by **SLOroadster** » Wed Oct 12, 2005 9:39 pm

Those are pretty trick, however it looks like they are 5kg, not pounds. 5 lbs would be crazy.

Will

nomadtrash · Post by **nomadtrash** » Wed Oct 12, 2005 10:45 pm

You're right. That would be 24390 carats or 11 pounds.

nomadtrash · Post by **nomadtrash** » Wed Oct 12, 2005 10:46 pm

Crazy Cool!

Victor_laury · Post by **Victor_laury** » Thu Oct 13, 2005 5:24 pm

Just Bought one from Glen (a roadster owner) at Upgrade Motoring.
U20 L/W 5.0 2001M-N004
http://www.upgrademotoring.com/performa ... ywheel.htm
I blame you guys for keeping me poor.

Post by **ppeters914** » Thu Oct 13, 2005 5:34 pm

THE VOICES!!! THE VOICES!!! I CAN'T STOP THE VOICES IN MY HEAD!!!