Flywheels

[hollywood63]

Has anyone lightened S&S flywheels to get a 93 inch to spin up faster?

[Hybredhog]

   WHY?, they're probably a 1/4 lighter than a stock wheel assembly already, and you'll loose torque.  Rebalancing them will be a PIA, as you'll probably need to add lead plugs to counter act the rod assembly, (kind of defeats the purpose). knife blading them will screw up your oil scavaging, do I need to go on? Unless your drag racing, it'll be counter productive. ....Jeff

[tiburontropic]

I have 28lbs flywheels in mine and it runs great. Good acceleration from a start. There is more high frequency vibration.

[76shuvlinoff]

On my 93 I always felt they were a little too light to start with.  The way I have it geared I shift a lot if I'm keeping it under 60.

[Old Crow]

On the overhaul I'm in the midst of, I've ditched the compensator and gone with a solid front primary sprocket.  There's quite a bit of weight hanging off the crankpin, and eliminating most of it ought to make the motor spin up faster.
Not to mention the over $200 savings since my compensator was shot when I torn it apart.

[shov60]

I try shaving a set a few years ago and it will rev faster when you drop the hammer but lighten fly wheels will make your bike lug a little you'll find yourself kicking back to 3 rd a lot in town,but if your going fast it will really rev past 2500 rpm

[Ultrashovel]

Light flywheels ar a waste of time. My original -78A left flywheel got damaged when the inner nut came loose shortly after I got the bike. ('82 Shovel, 6 degree taper, no key). I looked all over for a flywheel or a set but couldn't find any at the time. I bought a new set from Harley that were "commonized". That means they took a set of Evolution flywheels (-93, three piece) and balanced them for the Shovelhead.

While they worked nicely and got rid of a lot of the vibration, they also changed the entire sound and feel of the bike. It no longer had the extreme low end torque that I loved. it also sounded like an Evolution. If I could find another good set of original flywheels I would probably change back. The Evolution crank is approximately ten pounds lighter than the Shovelhead set. That's just too much of a change.

If you want to go fast and have an engine wind up tight and quickly, buy any Japanese four cylinder sportbike. Leave your Shovelhead alone. Aonther 10 years and there won't be an original Shovelhead left. I wish people would just ride them instead of changing them so that they are totally different.

Save your money on light flywheels. They won't do a thing for your bike.

[stroker800]

  YES,,,I run a 4 3/4 stroke shovel with S&S 8" wheels,,,,which are lightened for the strip.. After doin some reading and talkin to some engine builders...A few recommend a lighter flywheel for strokers,,,never have built one this big for myself ,,,we did it...My bike will pull hard outta the hole and get down the track quicker than most,,,just have to watch that during daily drivin I don't lug it...The buzz is a higher frequency and I can't pull a trailer...Mike Geokan is a great engine builder and he was one of the guys that convinced me too try it.
Dave

[Hillside Motorcycle]

We have even gone as far as "porkchoping" them like an automotive counterweight.
Did that on our 108" AHDRA Mod bike. It would spin up super quick.
Shifted it at 7200 with 4 3/4" stroke.

[Ultrashovel]

We have even gone as far as "porkchoping" them like an automotive counterweight.
Did that on our 108" AHDRA Mod bike. It would spin up super quick.
Shifted it at 7200 with 4 3/4" stroke.

I probably shouldn't ask but once you have "porkchopped" your flywheels, what is done about oul control? Just curous. I don't ever intend doing that myself.

Also at 7,200 rpm, I calculate piston speed at 5,700 F.P.M. That's a lot.

[Hillside Motorcycle]

We have even gone as far as "porkchoping" them like an automotive counterweight.
Did that on our 108" AHDRA Mod bike. It would spin up super quick.
Shifted it at 7200 with 4 3/4" stroke.

I probably shouldn't ask but once you have "porkchopped" your flywheels, what is done about oul control? Just curous. I don't ever intend doing that myself.

Also at 7,200 rpm, I calculate piston speed at 5,700 F.P.M. That's a lot.

It was our racer, and were were looking for any edge we could get. Never really found oiling issues.
Certainly not reccommened for street use as it used to shake at idle(1800 rpms)like a dog chitting razor blades. Instant throttle response, almost like a 2-stroke.
Many folks back in the day had 5" arms in their bikes that they would spool that high.

[hollywood63]

This is a little off post but hey its my post   Whats the biggest cylinder available with a 4.5 stroke. I'm running 3 5/8 cylinders now and was looking to bump it up a bit. I've seen stuff on 3 13/16 cylinders but can not seem to find what strokes its used with.
Thanks Guys

[Hillside Motorcycle]

3 13/16" is the largest with the OE cylinder base bolt pattern.
With a 5" arm, it'll yield 114".
Scott

[hollywood63]

Hillside do you guys offer pistons and cylinders for 3 13/16?

[Hillside Motorcycle]

Yes we do.
Scott