For those who haven't seen a McLeod RST twin disc up close....

[blykins]

I posted this over on the FE forum and thought some of you may want to see it too.

This one is for the Boss 528BBF build. The clutch is rated for 800hp and is made to accept the 1-1/8x26 input shaft size of a TKO 600. They are of course available in other options.

Both discs are organic and the pressure plate is a diaphragm piece, so this makes for a very streetable clutch kit without chatter or bad engagement characteristics.

Due to the anodized adapter ring, the RST will fit any pressure plate pattern. I have this one bolted to the 11" pattern with 5/16" ARP pressure plate bolts.

I forgot to snap a picture of the floater that goes between the two organic discs.






Brent Lykins
B2 Motorsports, LLC
brent@b2motorsportsllc.com
502.759.1431

[fordracing65]

I use the twin disc, love it.

[vector1]

what's the weight?

[Mark Thompson]

I understand the benefit of a multi-plate clutch where the diameter of the total rotating mass can be reduced and the engine/transmission lowered in the car; what is the advantage where all the primary masses such as flywheel diameter and engine location relative to CG are fixed?

thanks, Mark

[Tim Brewer]

I don't believe the purpose of the twin disc clutch has much to do with C/G or rotating mass. The main purpose is to be able to transfer high HP without slipping. With a twin disc you're getting more SQ/IN of friction area than any single disc can offer. It's my next clutch for that reason alone.

[blykins]

Vector, I'll weigh it for you later on....I think it's about 30 lbs though. It's not a button style multi-disc, but the pressure plate is around 9.5" in diameter.

Mark, with this style of twin disc, as Tim said, it's all about power. To hold 800hp with a single disc would take an adjustable pressure plate and a sintered iron non-sprung hub disc....and some patience. This will do it with no chatter, no on/off engagement and no hard pedal pressure.

[Jerry Clayton]

Brent---that picture isn't a long style pattern is it??? My history with a couple of clutch failures were from 5/16 pressure plate bolts breaking and if I had a choice I would use as many of the holes that would line up(hopefully 12) and would use longer bolts inserted from the back side of the flywheel with the shank providing the shear strength and the nuts just holding the plate on====the shear forces are much greater than the clamping force of the clutch to overcome(or contain)

And I assume it'll fit in a Lakewood(Quicktime)

[blykins]

You're right Jerry...

It looks like I snagged the other 11" 5/16"-thread pattern. Must be an 11" truck diaphragm or something...the McLeod wheel comes with every pattern imaginable. With it being 5/16" thread size, I assumed it was an 11" Long pattern and didn't even pay attention to the bolt pattern spacing.

And yes, all of this will fit in either a Lakewood or Q/T.

[Jerry Clayton]

teasing about the can

The thru bolts I was referring to are 12 point aircraft type that go into flywheel from block side and the 12 point heads are pressed into a counterbored hole with the stright(precision) shank(of the proper length) acting not only as fasteners but like dowel shanks for alignment--kind of important with a 3,4,5 heavy disc pack for a pro car--

You show see my collection of clutch springs, shims, hat finger adjusters and not to forget the spring adjusters---all sorted in groups of 3 at same pressure/lengths--kinda like valve springs but necessarily much more critical to vehicle performance on the track.

[eschaider]

Originally Posted by Jerry Clayton

teasing about the can

The thru bolts I was referring to are 12 point aircraft type that go into flywheel from block side and the 12 point heads are pressed into a counterbored hole with the stright(precision) shank(of the proper length) acting not only as fasteners but like dowel shanks for alignment--kind of important with a 3,4,5 heavy disc pack for a pro car--

You show see my collection of clutch springs, shims, hat finger adjusters and not to forget the spring adjusters---all sorted in groups of 3 at same pressure/lengths--kinda like valve springs but necessarily much more critical to vehicle performance on the track.

Jerry,

That is the right way to do it. Perhaps go up a size in fasteners and make some miniature adjustable stands to reset the ring height between rounds. Just kidding (about the stands).

Sounds like all those years of working with sliders is starting to show ...

Ed

[Jerry Clayton]

Ed

We were the first to make adjustble stands for a Crowerglide--before you had to take the cover off and add/remove shims--our adjusters were of course copied

[Ant]

I am using a Tilton 66-302UG, 7.25" 2-PL, CERAMETALLIC, ULTRA HIGH RATIO, STEP-TYPE (740 LB-FT CAPACITY) with button flywheel and flexplate.

Havent tried this Rally type clutch yet so I cant comment on durability, I have used the std 7.25" sintered bronze race plates and they lasted surprisingly well with limited road use and positive driving!
I am not a fan of the organic riveted linings, go to the track and all I ended up with a disintegrated clutch plate!

With the button flywheel/flexplate the engine will have a noticeable quickness in the way it increases and decreases rpms, I guess there is some power to be gained and not sure as I run a Jerico trans whether there will any advantage in gear changing...!!

[eschaider]

Originally Posted by Jerry Clayton

Ed

We were the first to make adjustble stands for a Crowerglide--before you had to take the cover off and add/remove shims--our adjusters were of course copied

I know. I had one of those early 'glides with shims. I must have lost three layers of skin before we got our hands on a set of those adjustable stands.

We used to horseshoe the shims so we could 'slide them in and out.' Somehow we always ended up with some in the bottom of the can - always the ones you needed!

Ed

[Jerry Clayton]

when we had alum cans you could get them with a magnet

[eschaider]

Now I'm feeling really old ...

[Great Asp]

I just got my RST twin from McLeod, and will install it shortly.

I also sent my TKO-600 out to George Rockland to have the Liberty kit installed with the carbon fiber blocker rings.

Red Roberts said that the 11-1/2" single that I had originally is not a good choice for the TKO-600, and George agreed. The disc diameter seems to have a lot to do with the inertia at high rpms, and George described the TKO-600 as "a truck transmission"...lol

I will post again once it's in with feedback.

E

[RICK LAKE]

Jerry Clayton We are both from about the stone age and wonder if you tryed a clutch flite That was hot thing is the 60's and early 70's. Couple of guys played with them, never got a good leave time each run but a kick down the track with a manual valve body trans. Always thought that a 4 speed trans would work better. Rick l.

[blykins]

Unless someone is running a flywheel that only has an 11.5/12 pattern on it, I always recommend an 11" pressure plate or smaller. With the variety of discs and plates out there, there are plenty of choices that can hold any amount of horsepower without adding extra weight to the back of the crankshaft.

[cobrashoch]

There's old And I'm ancient. Rick Lake - I played w/clutchflites back in the day. Your buddys were wrong, clutchflites let the engine rev. nothing else. If the car couldn't hook on a drop hammer start, that's another problem, it's not the trannys fault. Back in those days the Motown Missile had the pro stock NHRA national record and it used a clutchflite. They still couldn't beat Sox though, heck-fire, nobody could.
Of Note
Clutchflites lived in the days before we had anything like modern converter technology. Todays converters have made such tranny trial misfires obsolete, as backed up by current national NHRA records between most of same classes between sticks and automatics. There's usially not a hoot of differences between most of their record times.
That and the fact that the 727 cases of the tranny couldn't take the bonzi drop hammer starts, the cases tended to crack. We were not detoured though, we would just stick weld em up! Needless to say the NHRA didn't like tranny fluid on their tracks, so tranny blankets were required fair for those trannys in those days. (That included turbo 400's clutched verson too)
In short we've gone somewhere else since those days, and boy do I feel old.

[WildBill3]

Hey Blykins we run the single disc dual friction surface on the back of our 408 in front of the (Truck)tko600. It has a weber pressure plate with only a 3.0 gear it put alot of strain on the clutch if we try to leave hard at the drags, smoked the clutch at the last RNG when the tires hooked.How much will this setup set a guy back.Our only other issue is our engine was balanced with the Flywheel we have.I guess that would all have to be rebalanced again also.Running hard on the roadcorses we have never had any slippage I can remember just at the drags.