Putting 8 holes on a 6 hole flywheel

snipped-for-privacy@cloak-and-dagger.com (Oakey) wrote in news: snipped-for-privacy@posting.google.com:

Well,

1. Looks like (no measurements are supplied), that the register holes are different sizes. These need to be an exact size for centering, especially critical in high-horsepower applications.
2. With the current holes at 60°, and the required holes at 45°, I don't think you can fit them in without overlapping a hole to some degree. I could draw it up and see, but I would need the bolt hold diameter and bolt circle diameters to do so, but again, I don't think this will work out though. And even if you did, you take strength out of the flywheel by having the empty holes in there.
3. You definately don't want to do this at home, unless you have a milling machine and dividing head.
4. I think your best bet would be to buy a crank with the proper bolt pattern to fit your flywheel, or buy a flywheel that will interchange between the crank you want to use and the clutch you have.

IF you do this.....I really, Really recommend a safety cover over the bellhousing...it is nasty when a flywheel comes thru the floorboard.

Steve, yours is the second reply I have seen that states a dividing head or index is required. There is another option. If you draw it in AutoCAD, you can pick off the X-Y coordinates of each hole. If you make the center the 0,0 point, then you can locate the flywheel with a centering gauge and move to each hole position. A DRO is a big help, here. As to the old holes, can't they be welded up and faced off?

Jay, this is definitely a job for a machine shop.

Ron Thompson Was On the Beautiful Mississippi Gulf Coast, Now On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

The ultimate result of shielding men from the effects of folly is to fill the world with fools.

--Herbert Spencer, English Philosopher (1820-1903)

Jig drill the pattern using Trig and a DRO on a mill. --Doozer

Ron Thompson wrote in news: snipped-for-privacy@4ax.com:

Agreed.

I might try that with an old 30 hp VW engine...but I seriously would not trust it in a high horsepower application. I don't think you can be certian of the metalurgical and strength properties of the metal after welding. And to be honest, I don't think his legs (or worse) are worth the chance.

I was thinking thatr I would probably have to take it to a machine shop, and have them do it. Possibly fill weld the existing holes and drill new ones, using the original holes as a pattern... what do you all think? here is a schmatic I whipped up.

real easy, with eight holes you need them 45 degrees apart.. with the 6 holes you need them 60 deg. apart.....

If they can make it without bolt holes you might also ask about having it made with the 8-hole pattern. Having it welded up, faced, and redrilled may cost more than buying a new one for the Toyota engine and selling the old one.

I think it is dangerous and foolish. Welding up the existing holes will produce stress risers, and will certainly warp the flywheel. The different hole pattern will upset the flywheel's balance. Etc.

Gary

snipped-for-privacy@cloak-and-dagger.com (Oakey) wrote in news: snipped-for-privacy@posting.google.com:

Jay, Please see this video, it is just the first one I ran across, I am sure there are plenty more like this.

On 9 Apr 2004 21:27:40 -0700, snipped-for-privacy@cloak-and-dagger.com (Oakey) shouted from the rooftop:

Here's a stupid question or two:

2) Refering to this picture:

5) This has to be a racing application- what does the sanctioning body allow as far as clutch or flywheel mods?

Be sure your health insurance is paid up and that you have adequate life insurance for your loved ones.

-Carl

"An honest man doesn't need a long memory"- Jesse Ventura

Never seen a multiplate racing clutch before, eh?

Look up mass moment of inertia and see how it's related to radius. Then check how mass moment of inertia affects angular acceleration.

Richard Coke

On 11 Apr 2004 02:26:34 GMT, snipped-for-privacy@aol.com (Richard Coke) shouted from the rooftop:

Actually, I have. His clutch stack still looks small for a punched and blown Chevy. He needs something along the lines of a Crowerglide (that's not a typo or a transmission, BTW)..

Here's AP's website:

-Carl "An honest man doesn't need a long memory"- Jesse Ventura

I wouldn't touch this with an 8' pole. But if you do get the bolt pattern changed, have you got the starter interface figured out? Have you got a bell housing that will cover this set up and a a throwout bearing set up that will fit? I would think that you should be able to get the proper flywheel for the engine that will take the clutch setup you have. lg no neat sig line

Or at least find a flywheel that fits the engine and adapt the clutch to it. Greg

Thanks for the feedback all,

1. the transmission is a t-56 6-speed.
2. the cutch is designed to work w/ the transmission in question (chevy splined)
3. the clutch comes from a NASCAR application (surplus) and is designed to handle well over 1000 ft.lbs of torque (more than I plan on having)
4. I plan on using a reverse mount starter since the location of the original starter is less than wonderful.
5. steel scattershield is a must, I am considering lakewood, or quartermaster.
6. it is internally balanaced (I am sure you have seen Lexus's wine glass test)
7. the clutch is a triple disc clutch, low inertia etc, in stock form the engine can hit 8000 rpm no problem and is safe to 10K plus with stock internals. the original autotranny is a dog, more useful for boulevard cruising than fun driving.
8. V8's have been effectively banned from most compact racing forums, but the car might see some life in road course racing or drift racing.
9. I believe the flywheel is a small order made explicitly for NASCAR, this is pretty common, as AP/Tilton/QM clutches are used in all manner of non-OEM uses, the schmatics for flywheels are included on AP's site.
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   the nuts welded on the back and the attached studs are from ARP
10. the flywheel is cast iron, if I have one milled I would make it steel (lighter, and more capable at higher rpms)

Jay

From AP's site:

A purpose machined flywheel is required.

The friction face should be a good quality close grained Cast Iron or Steel (0.35 / 0.45% Carbon, Hardness 200 Hb minimum), with a surface finish of 0.75µm RA (30 CLA) maximum.

Run out when assembled to the crankshaft must not exceed 0.08mm (0.003") maximum at 77mm (3.03") radius. Fixing holes and location spigot to be machined as shown on the appropriate flywheel mounting drawings.

Flywheel Mounting details for Ø115mm to Ø184mm, (

N.B. Cast Iron flywheels should not be used above 10000 rpm.

If AP makes a pressure plate that works with a Toyota, buy one and use the appropriate discs for a T-56. Otherwise have a flywheel made.

BTW, this clutch will suck on the street. I raced with one and ones like it for years and they're grabby and hard to modulate. In order to get a small clutch to hold a lot of torque, they're designed not to slip and will overheat easily.

What chassis is this going in? Will you be driving it on the street?

Peter

From AP's site:

A purpose machined flywheel is required.

The friction face should be a good quality close grained Cast Iron or Steel (0.35 / 0.45% Carbon, Hardness 200 Hb minimum), with a surface finish of 0.75µm RA (30 CLA) maximum.

Run out when assembled to the crankshaft must not exceed 0.08mm (0.003") maximum at 77mm (3.03") radius. Fixing holes and location spigot to be machined as shown on the appropriate flywheel mounting drawings.

Flywheel Mounting details for Ø115mm to Ø184mm, (

N.B. Cast Iron flywheels should not be used above 10000 rpm.