Thoughts on the clutch?

[Yellow Truck]

I'm looking at the flywheel and clutch - I bought new ARP flywheel bolts that will need to be checked for depth based on some scary posts here and elsewhere, but I'm also looking at the clutch.

The flywheel is a McLeod that came off the old 410 (I removed the counter balance), but the clutch is a Chinese piece that was originally on it with the 360. It and the pressure plate are in good shape, but I can't find the clutch to flywheel bolts and was looking around for new ones. I see on the McLeod site most of the clutches are listed at 400 HP max.

Two questions - what do you use for clutch bolts (old ones were of unknown origin, so buying new ones is probably a good idea), and if I'm going to change the clutch, now is the time to do it. Do I trust this part with my new beast - 445?

[blykins]

You can use ARP pressure plate bolts. 

Actually, most of the McLeod pieces are minimum of 400-425 hp.  I would go to a dual friction disc for the new engine.  If you want to go McLeod (and I would recommend using a McLeod disc as some of the manufacturers vary on clutch disc thickness), I'd use a 500 series disc.

[Yellow Truck]

Not familiar with a "dual friction" clutch. I've looked for a decent explanation about how this is different the the clutch I have, but all I can find is that the flywheel side seems to be a different material than the pressure plate side.

[Heo]

You have dual friction plates with a steel plate between them.
Like a multi disc clutch in a auto trans or a motorcycle
so you got more friction surface on a given diameter clutch

[Yellow Truck]

Thanks, probably over much for a pickup.

[Barry_R]

I think he is actually referring to a single disc clutch that uses two types of friction material.  One side will be a normal organic "rag" material while the other will be some sort of Kevlar or ceramic (depending on the brand).  The combination gives you the smooth release and grab of an organic disc along with some of the high temperature durability and grip of the other material.

[turbohunter]

"Thanks, probably over much for a pickup."

I don't know about that Paul.
All it is is a way to connect engine to trans and from what I hear the pedal pressure can be less with a dual disc and still retain the coupling power of a heavily sprung clutch.
For instance I run a McLeod super street set up. It is a beast of a clutch. I'm a big dude so no prob for me. But every now and then in traffic I might wish for less of a push.
I'm going to look into it (the dual disc) for my mustang.

[Heo]

I think he is actually referring to a single disc clutch that uses two types of friction material.  One side will be a normal organic "rag" material while the other will be some sort of Kevlar or ceramic (depending on the brand).  The combination gives you the smooth release and grab of an organic disc along with some of the high temperature durability and grip of the other material.

Oh my bad  not reading properly. It said dual fricton i thought about dual disc

[turbohunter]

Hah, me too.
What I get for reading at work.

[blykins]

Yes, dual friction disc.  In this case, organic on one side, sintered bronze/aluminum on the other side. 

In the "good ole days" you made a clutch clamp harder by adding heavier springs to the pressure plate.  Clamping forces were in the 3000-3500 lb range.   These days, your clamping forces are 1800-2400 lbs, but the capacity of the clutch is manipulated by the disc material. 

[Yellow Truck]

Marc,

From your post I gather you are running a McLeod Super Street Pro, which according to McLeod is a dual friction clutch as described by Barry. You say it is a bit of a beast? I am also a big guy, but an overly stiff pedal is tedious.

This engine will put about 1/3 more torque and twice the horsepower to the clutch. I did find the old pressure plate to flywheel bolts, and the old clutch is in good condition, but changing it out later would be unpleasant. The current clutch has no brand identification (says PHT 200 Made in China). It worked fine, just a bit of shudder which I understand is a characteristic of the NP 435.

[turbohunter]

Yes I am running the Super Street Pro.
My engine is 400hp/500tq.
It's prolly a bit over clutched HOWEVER, as you allude to, NP435s (reputation deserved or not) do chatter and mine does not.
I attribute that to the clutch. It may be the clamping force. It may be the new dual materials.
It's most likely a combination of both.
As far as the pedal pressure goes. I have driven it in stop and go traffic many, many days with no problem. My wife really can't drive it though.
Hope that helps.

[Yellow Truck]

Thinking about a Centerforce  clutch - they offer an easier pedal engagement with a high engagement pressure. Also a bit cheaper.

[blykins]

FWIW, I get more complaints about Centerforce clutches than any other brand.....

I would put a 500 series McLeod disc with your pressure plate and call it a day. 

[cjshaker]

I'd be one of those to complain about the Centerforce's. Smoked it within one year and harder than heck to shift at high RPM. I suppose it might work in a daily driver or a truck, but certainly not the greatest for any hard play in my experience. Some guys have gotten them to live at the occasional track use, but many have not been so lucky.