Clutch- what have I done

[boilermaster]

OMG,

Fail, Fail,fail

(it will feel like stock with a high performance pressure plate and disc.

Or at least mine does.

Boilermaster

 

[barnett468]

OMG,

Fail, Fail,fail

(it will feel like stock with a high performance pressure plate and disc.

Or at least mine does.

Boilermaster

OMG

Fail, Fail, fail, lol

Not quite because it depends what pressure the plate is since not all "high performance" pressure plates have the same pressure, which as I previously stated, is the reason I asked the op to get me this info for his system so I can determine what might help him the most.

 

[barnett468]

So last Fall my faithful 351C spun a low main bearing in back of motor. I had a good pro shop rebuild and stroke it to a 408. Its dyno'd at 460HP/500FPT.

I have a local shop I use a lot for car maintenance, thats good to me, reinstall the rebuilt motor. Since I had motor rebuilt I figured we gotta put in new clutch and pressure plate that would be stupid not to. I order from Summit Racing at McLeod StreetPro 11" 10 spline clutch and pp. My logic, be it right or wrong, was that I now own almost 500HP mustang and stock clutch may vaporize quick if I enjoy dumping it (jury is out on that). So Now that motor is in, I get in car and push clutch pedal and holy crap thats hard to press!   The motor dude told me to just buy a stock clutch and pp at local auto parts store but like a idiot I didnt listen. I seriously didnt think one step up in clutch would be that much noticeable but dear Lord you can really feel it.  What do you say? Its ok if you tell me I'm a idiot sometimes I learn best at the school of hard knocks.  I may have to bite bulllet and pay for new clutch install, I dont have a lift.

https://www.summitracing.com/parts/mcl-75111

If the plate they clutch disc they gave you is the same as the one in the photo, I have had some problems with those and therefore would not use it but other people may not have had any problems. Mcleod themselves don't really like that plate and were considering switching to the material that centerforce uses on their street disc at one point but never did.

The centerforce street disc uses strands of asbestos instead of powdered asbestos like the old pre asbestos ban discs often had, and the powdered asbestos works better to some degree.

Their dual friction discs are far better for high perf apps. Also, you "should" be able to use centerforce discs with the mcleod pressure plate.

 

[Hemikiller]

So you're thinking Centerforce disc with a stock type PP?

 

[barnett468]

So you're thinking Centerforce disc with a stock type PP?

No, because the stock pressure plate is too light even though they used them on boss cars and cobra jets etc. The stock 11" ford cobra jet plate is 1850 lbs at the most and the stock 10" ones are round 1575. I know this because I took a few stock pressure plates to mcleod and had them measure them for me so I knew what the baseline pressure was and could then determine what pressure I wanted to use. On stock and mild performance builds that usa a 10" plate, I use 1650 pressure. This along with the bigger 10 1/2" mcleod set up is more than enough for moderate builds that aren't being drag raced. Mcleod will make whatever pressure one wants for no additional cost. I helped talk them into making a line of plates that were just slightly stiffer than stock also but I don't know if they advertise those anymore.

I use 2250 on some apps and that is too stiff for my liking in heavy traffic but I'm not a weight lifter easier, plus I'm a bit lazy. I have never used a centerforce disc with a mcleod pressure plate but I see no reason why it would not fit and work properly. I do know for a fact that the centerforce street discs are far better than the mcleod street discs which is why I suggested this. I also have some experience with both centerforce and mcleod dual friction discs and didn't notice any difference but I didn't do back to back drag race tests with them etc.

 

[digithead]

OMG,

Fail, Fail,fail

(it will feel like stock with a high performance pressure plate and disc.

Or at least mine does.

Boilermaster

Thanks but I dont follow what is a fail fail fail? Putting in the clutch I chose, or someone elses reply?

 

[digithead]

So heres a update. I got car running today and took on a easy maiden voyage. THe clutch wasnt quite as bad as I thought when sitting in garage with car off.

I think its livable. I see people post that they wish the didnt go stock, and I dont want to be that guy either where you get on it and it spins the clutch. I think I will drive it for 1 summer and see how I feel about it. It may be worth it in the long run if burnouts dont bother it. Thanks all.

 

[Don C]

Frictional force is directly proportional to the applied load. In other words, if you increase the force required to operate the clutch (pressure plate) by 25% the frictional force (the force required to overcome the static friction -stiction- and kinetic friction -friction when it is moving) at the bushings and metal-to-metal connections also goes up 25%.

Reducing the friction with bearings and Heim joints will make a noticeable difference.

 

[digithead]

Digithead,

Suck it up big boy,

The way I look at it you can rollerize your complete clutch release mechanism (2 roller bearings at the

pedal assembly, heim joints on the rod ends and spherical bearings at the z bar.

if you do all of this it will get you back to the stock feel with the wimpy pressure plate.

I did all of the rollerizing before I went to the 408.

Boilermaster

Thanks for the advice, makes sense. Is there some kit out there or did you basically pull it all out and find bearings that fit?

I've never pull pedal/linage assembly so I am assuming its all just simple bushings, so you figured out bearings would be better.

THanks for the links but that kit at CJ Pony only goes to 1970. Mine is a 1973.

a roller and heim type system only eliminates friction cause by the mechanical linkage so it will not make a huge difference in the amount of force required to depress the pedal.

yes the stock pedal support uses bushings.

heres the instruction info and the kit info for the pedal support conversion.

http://www.virginiaclassicmustang.com/howto/instructions/64-70ClutchPedalBearingInstr.pdf

https://www.cjponyparts.com/roller-bearing-clutch-and-brake-pedal-support-bushing-kit-1965-1970/p/HW1015/

SOME HEIM JOINT CONVERSION INFO

http://forums.vintage-mustang.com/general-discussion-non-vintage-mustang/533472-heim-joint-clutch-linkage.html

 

[barnett468]

THanks for the links but that kit at CJ Pony only goes to 1970. Mine is a 1973.

Ahhh, sorry about that. I had 69/70 on the brain because that's one of the cars I am currently helping somebody with.

Reducing friction is great and I am all for it, however, my point is that if it takes nearly 2 feet to depress a clutch with a standard mechanical linkage, It will still be hard to depress with a heim joint system. Just because it will be less hard does not mean that it will still not suck to drive it in traffic etc. I know this for a fact because I have already done this exact test.

Reducing the pressure of the pressure plate also reduces the frictional load on the stock linkage system, which is why it is better to install a lighter pressure plate if a car has one that is pretty hard to depress or at least tiring to depress many times in a row if it is driven in traffic.

In short, heim joints and bearings will not make a 2800 lb clutch feel like a stock one, so the difference will not be day and night, however, one will definitely be able to feel an improvement.

 

[barnett468]

THanks for the links but that kit at CJ Pony only goes to 1970. Mine is a 1973.

The pedal support kit is the same thru 73 but 69 thru 73 will need modifications to the pedal support to make it work.

 

[Hemikiller]

So you're thinking Centerforce disc with a stock type PP?

No, because the stock pressure plate is too light even though they used them on boss cars and cobra jets etc. The stock 11" ford cobra jet plate is 1850 lbs at the most and the stock 10" ones are round 1575. I know this because I took a few stock pressure plates to mcleod and had them measure them for me so I knew what the baseline pressure was and could then determine what pressure I wanted to use. On stock and mild performance builds that usa a 10" plate, I use 1650 pressure. This along with the bigger 10 1/2" mcleod set up is more than enough for moderate builds that aren't being drag raced. Mcleod will make whatever pressure one wants for no additional cost. I helped talk them into making a line of plates that were just slightly stiffer than stock also but I don't know if they advertise those anymore.

I use 2250 on some apps and that is too stiff for my liking in heavy traffic but I'm not a weight lifter easier, plus I'm a bit lazy. I have never used a centerforce disc with a mcleod pressure plate but I see no reason why it would not fit and work properly. I do know for a fact that the centerforce street discs are far better than the mcleod street discs which is why I suggested this. I also have some experience with both centerforce and mcleod dual friction discs and didn't notice any difference but I didn't do back to back drag race tests with them etc.

Good info, thanks! The guys I know using the C-force dual Friction had excellent luck with them, until the power levels exceeded the clutch's capacity. Two friends are using the RXT dual disc and love them.

So heres a update. I got car running today and took on a easy maiden voyage. THe clutch wasnt quite as bad as I thought when sitting in garage with car off.

I think its livable. I see people post that they wish the didnt go stock, and I dont want to be that guy either where you get on it and it spins the clutch. I think I will drive it for 1 summer and see how I feel about it. It may be worth it in the long run if burnouts dont bother it. Thanks all.

You'll get used to it. Your left leg will get stronger as a result...

 

[boilermaster]

OMG,

Fail, Fail,fail

(it will feel like stock with a high performance pressure plate and disc.

Or at least mine does.

Boilermaster

Thanks but I dont follow what is a fail fail fail? Putting in the clutch I chose, or someone elses reply?

Sorry digithead,

I mis spoke, and was trying to correct my reply.

                   Boilermaster

 

[barnett468]

I emailed mcleod to find out what pressure that plate is.

 

[digithead]

I emailed mcleod to find out what pressure that plate is.

THank you!! THat makes sense. I never knew you could get the actual pressure in force of the pp. At least then you have some benchmark to compare by. Learn something new everyday!  I drove it a bit yesterday and its tolerable. Gotta wear sneakers for sure, no more sandals driving or something bad might happen lol (read me going thru the back of my garage).

 

[barnett468]

I emailed mcleod to find out what pressure that plate is.

THank you!! THat makes sense. I never knew you could get the actual pressure in force of the pp. At least then you have some benchmark to compare by. Learn something new everyday! 

Yes it makes it extremely simple and they even used to list the pressure of the plates in their online catalog but they don't have that anymore so it makes it difficult to know what the heck you are installing. It just seems many of the mfg's are going downhill a bit these days. I will let you know what I find out.

They can also install different springs in yours so I also asked how much that would be.

 

[barnett468]

ok, well this makes absolutely no sense at all. Mcleod says that pressure plate is only 1800 lbs which is fairly close to stock on the high perf engines, so it definitely should not be overly hard to push the pedal in.

They can respring it to make it lighter for $150.00 but then you run the risk of having it wear prematurely or possibly slip if you have good traction and dump the clutch. If you don't have sticky tires and don't beat the heck out of it frequently and your linkage is not causing any problem, you could have it resprung 100 lbs lighter and use their dual friction disc and it will be fine.

Also, if you find it "almost" tolerable but would like it a little easier to push the pedal in, then installing the needle bearing kit on the pedal bracket may help enough and if it doesn't you could still add the heim joints or you could leave the pedal support and try the heim joints first which would be easier.

 

[73pony]

That does seem light. The one I was looking at shows 2,350 lbs. Mine is also set up on a cable and not a Z-Bar.

 

[barnett468]

That does seem light. The one I was looking at shows 2,350 lbs. Mine is also set up on a cable and not a Z-Bar.

Yeah it's a bit odd. The lightest stock one is around 1575 lbs and that is pretty easy to depress. Before I went down there, the lightest one they made for a Ford was 1950 lbs.

2350 nearly takes me 2 feet to depress the pedal on but I'm a bit wimpy and a bit lazy but it is still a pretty stout clutch, but 1800 is not all that hard.

 

[tony-muscle]

The clutch pedal bearing kit is relatively easy to install once you get past removing the bracket.

Here is my experience with it: https://www.7173mustangs.com/thread-bearing-kit-for-clutch-pedal

In my case I am installing it together with a cable kit.