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Author
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Topic: Sintered iron disc adjustable pressure plate question
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Mike_R_SCJ
Journeyman Posts: 1
From: Indianapolis, IN
Registered: Jul 2004
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posted 07-30-2004 04:24 PM
  
I have recently installed a Mcleod solid hub sintered iron disc mcf (medium coefficient of friction) and a Mcleod adjustable pressure plate which will adjust from 1100-2800 lbs of pressure.This is a street and strip 4000 lb 70 Torino Cobra with a fresh 521 ci with 750(???)hp. I know some of you guys run the adjustable sintered discs. My question is if there is a good method to setting the clutch pressure just high enough to drive okay on the street but low enough to help this car hook up at the strip with 10" tires? I currently have it set on about 2200# of pressure and it drives great on the street with no signs of slippage. However I'm thinking this is going to be too high of pressure for a smooth launch at the strip. I don't like the idea of tearing up a bunch of parts either. So I guess my question is if I start adjusting this clutch down and test driving it on the street what signs do I look for that I have set it too low? Will it start slipping in 4th gear etc? Any help or oppinions appreciated. Thanks
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n2oMike
Gearhead Posts: 2019
From: Spencer, WV
Registered: Jan 2001
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posted 07-30-2004 04:57 PM
I'm not expert, but I've got one. I keep it adjusted fairly tight to keep from wearing the disk out prematurely. So far, my disk has three summers worth of abuse, and still looks great. I guess I'm not taking full advantage of its 'slip' feature. Anyway...A good starting point is to use as little pressure as you can, until it starts slipping in 4th gear... then tighten it up a half turn or so. You have a really strong pressure plate for a sintered iron disk. These typically use WAY less pressure than a standard organic disk. Loosen it up all the way (except for around a half turn) and see what happens. Tighten it up until it doesn't slip in 4th gear under max power. Sometimes, right after starting out of the garage (clutch still stone cold) I'll get into 4th gear, goose the gas, and the clutch slips a second then grabs, which is pretty cool. (these disks work with heat) It's a VERY smooth unit. Absolutely zero clutch chatter. However, it will sometimes let out a metallic squeal when taking off from a stoplight. (sounds like you're chirping the tires) Since the disk is not compressible, (rigid facing, no marcel spring) the friction point is very short. Not a problem though. Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220
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capri man
Gearhead Posts: 5060
From: doerun, ga.
Registered: Nov 2000
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posted 07-30-2004 05:12 PM
yea, what mike said!!  (i dont have a clue)
anyways, welcome to m&m mike!!------------------
mike r
racing is real
everything else is just a game.
81 capri-302-7.33 @92mph 1/8
1.54 60 ft. http://www.angelfire.com/ny5/billswebsite/pg06.html
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clevelandstyle
Gearhead Posts: 864
From: Connersville, IN
Registered: Jul 2001
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posted 07-30-2004 06:51 PM
Yeah. Welcome to M&M from a fellow Hoosier! I can't help with the clutch. I race with a pink shirt and my 4 speed car has been stacked in the garage for a few years.  ------------------
Ben
Grabber Green '70 Mach I 351C 4V
Robbin Egg Blue '79 Fairmont 408C 4V, best time to date is 10.50 @ 125mph
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Mike_R
Gearhead Posts: 165
From: Indianapolis, IN 46237
Registered: Feb 2001
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posted 07-30-2004 09:34 PM
Thanks guys, I've posted on here before but I forgot my password and I didn't have access to my email so I got a new user name. Sorry about that.Mike, Thanks for the info. That exactly the type of info I was looking for. I know my pressure plate is higher than usual on the pressure but because it's a heavy car with alot of hp and a medium friction disc, that's what Mcleod recommended. I'm just going to learn as I go here and hope it does better than the organic clutch did. Clevelandstyle, where do you race that Fairmont? I don't race alot but when I do it's typically at Edgewater and occasionaly IRP. I want to try Muncie though. I've heard it hooks up good.
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clevelandstyle
Gearhead Posts: 864
From: Connersville, IN
Registered: Jul 2001
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posted 07-30-2004 11:23 PM
quote:
Originally posted by Mike_R:
Clevelandstyle, where do you race that Fairmont? I don't race alot but when I do it's typically at Edgewater and occasionaly IRP. I want to try Muncie though. I've heard it hooks up good.
I run at Edgewater and Muncie. Due to things not under my control I haven't been to the track in about 6 weeks. I am planning on going to Eagewater next Saturday.
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Ben
Grabber Green '70 Mach I 351C 4V
Robbin Egg Blue '79 Fairmont 408C 4V, best time to date is 10.50 @ 125mph
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S/Q 2204
Gearhead Posts: 101
From: Ozark, AL(again after a year of being deployed)
Registered: Feb 2001
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posted 07-30-2004 11:34 PM
If you knew someone that would let you use a data collector for a short time it would decrease your learning curve. This is what I did until I could spring for one myself. If this is not an option then seat of the pants and a good play back tach would work. We look for a slight blue coloring of the disks and sand them every 15-20 runs else the aggressiveness will change and reaction times start going all over the place. The tighter we are able to run it the less maintenance we have.
Good luck,
Mark------------------
http://home.usaa.net/~johnson403 [This message has been edited by S/Q 2204 (edited 07-30-2004).]
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Rory McNeil
Gearhead Posts: 1380
From: Surrey, B.C. Canada
Registered: Nov 2000
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posted 07-31-2004 03:26 AM
I run a McLeod "Soft Lok" sintered iron clutch in my 428 Fairmont,however, my pressure plate is much softer than yours, with all 6 springs wound out (9 turns), my PP tops out around 1400lbs. My disc is a high CF version, with an aluminum flywheel & pressure ring. I don`t run my Fairmont on the street at all, I`m at about 700 lbs. pressure, all static (no counterweigt) Is your disc a "full circle" style,or a button/paddle version? Mine is a 10 1/2" full circle.------------------
78 Fairmont 428 4 speed 10.20@130mph
80 Fairmont 302 5 speed 12.8@105mph
85 Mustang NHRA M/Stock 302 5speed. [email protected]
59 Meteor (Canadian Ford) 2 dr sedan 332, auto
74 F350 ramp truck 390 4spd
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XR7
Journeyman Posts: 81
From: north Idaho
Registered: Mar 2003
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posted 07-31-2004 02:27 PM
I have a RAM adjustable p/p 900-1620# and the high cf (5135 compound) 10 1/2" full disc. I run my car on the street and the strip. For disc break-in and street driving you should have the p/p adjusted to the max pressure. For racing you need to back off pressure until it just starts slipping in 4th gear and then go up 1/2 turn pressure, or add counterweight if it has counterweighted levers. The correct racing mode pressure will not work on the street, it will slip at low rpm, heavy load or lugging a heavy car around. At one time I considered going to the medium cf disc and the tech guy said I wouldn't have enough pressure or just barely on my plate so maybe with the medium disc you can only go down to 1600# but you will just have to test, test, test! That's the whole idea of a adjustable plate to tune it to your combo and the current track conditions. Also launch rpm (and rpm range at the strip) has a big influence on how hard it hits (or holds) because of all the centrifical force of the p/p, You can tune the launch with rpm in addition to base pressure, flywheel weight, etc.
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Mike_R
Gearhead Posts: 165
From: Indianapolis, IN 46237
Registered: Feb 2001
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posted 07-31-2004 11:10 PM
Mine is the full circle style, not the paddle style. It is 10.5" disc with an 11" pressure plate.I wasn't aware that they made a medium friction disc but they were trying to set me up with something that would work okay for street and strip and that's what they came up with. The 1100 to 2800# pp gives me alot of adjustment. I believe the fact that this disc is medium friction means it is going to require quite a bit more pressure. You guys have given me some good advice here and I appreciate it. It sounds like what I need to do is try lowering the pressure quite a bit and see when it starts slipping in the higher gears, then take the pressure up a bit. I sure hope it's not too big of a pain in the butt to adjust it up and down. My main concern is that this car is really going to be hard to hook up so I'd like to take advantage of the adjustability. I haven't yet tried changing the pressure with the bellhousing on. That may be challenging. I have a hole that I drilled in the bellhousing for access, but the allen wrench has to go in at an angle, so I'm afraid it might be hard to tell when the adjusters are turning and when they are not. Any tips on how to adjust would also be appreciated. Hey cleveland style, which do you prefer, Muncie or Edgewater? I haven't raced at Muncie yet but I get the impression it may hook up better than Edgewater. Thanks again guys!
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clevelandstyle
Gearhead Posts: 864
From: Connersville, IN
Registered: Jul 2001
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posted 08-01-2004 01:06 AM
quote:
Originally posted by Mike_R:
Hey cleveland style, which do you prefer, Muncie or Edgewater? I haven't raced at Muncie yet but I get the impression it may hook up better than Edgewater.
Mike,
The traction is usually good at Muncie. I have also gotten good traction a Edgewater, but it's not always consistent. I do like the atmosphere at Edgewater better. Most of my friends run there on Saturday (race day). I tend to go to Muncie more for test and tune nights when I need to work on the car.
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Ben
Grabber Green '70 Mach I 351C 4V
Robbin Egg Blue '79 Fairmont 408C 4V, best time to date is 10.50 @ 125mph
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n2oMike
Gearhead Posts: 2019
From: Spencer, WV
Registered: Jan 2001
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posted 08-01-2004 09:51 AM
quote:
Originally posted by Mike_R:
I haven't yet tried changing the pressure with the bellhousing on. That may be challenging. I have a hole that I drilled in the bellhousing for access, but the allen wrench has to go in at an angle, so I'm afraid it might be hard to tell when the adjusters are turning and when they are not.
I drilled a big access hole in my bellhousing. You'll need a way to get the hex wrench in there around the headers, and you'll need to be able to shine a small light to be able to see the adjusters. I took an extra long ball end hex wrench (works way better at angles, cut off the short part with a grinding wheel, and JB-Welded it into an old cheap socket of the right size. I then painted a stripe down one of the flanks to be able to tell how many turns has been made. Now you have an adjusting tool, have a friend turn the engine with a 15/16 socket while you look through the hole with a flashlight for the adjuster to get lined up. You can do this every time, or mark the harmonic balancer in each of the six spots the adjusters lile up. (this will allow you to adjust it yourself in the future) Counterclockwise increases the pressure. But, as you screw the adjuster out, you run it out of threads, so if you go too far, it flips out, and the entire pressure plate needs taken apart to fix it. Moral of the story, Don't back the screws out too far! I believe mine has six turns of adjustment. I turn the adjusters IN all the way clockwise (to make sure I know where they are starting) then, back them out from there. As soon as I feel the resistance of the spring, I start counting revolutions, until it is adjusted. It's not really that bad... unless your hole is really in a bad spot, and/or the headers are super hot. Then it kinda sucks.  Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220
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Rory McNeil
Gearhead Posts: 1380
From: Surrey, B.C. Canada
Registered: Nov 2000
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posted 08-02-2004 04:54 AM
Technically, drilling an acess hole in a scattershield is not acceptable by NHRA, and will render the scattershield non-recertifiable (although I know many people have done it!). On my 428FE Fairmont, before I initially installed the engine, I marked the damper so that I can access the adjusting screws thru the passenger side upper transmission to scattershield bolt hole. Although the Allen head screws don`t line up exactly with the hole, but using a long ball end Allen socket, it works just fine. I have a buddy line up the first mark on the damper, make my adjustment, & have him rotate the crankshaft until the next mark lines up, & so on. Once I have the car jacked up, & the trans bolt removed, I can adjust all 6 screws in a matter of minutes.------------------
78 Fairmont 428 4 speed 10.20@130mph
80 Fairmont 302 5 speed 12.8@105mph
85 Mustang NHRA M/Stock 302 5speed. [email protected]
59 Meteor (Canadian Ford) 2 dr sedan 332, auto
74 F350 ramp truck 390 4spd
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Mike_R
Gearhead Posts: 165
From: Indianapolis, IN 46237
Registered: Feb 2001
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posted 08-02-2004 12:50 PM
Thanks for the tips on adjustement guys. I tried using the tranny mounting holes for adjustment before I installed the tranny but the allen wrench was just at too much of angle to where I couldn't get it to work. So I reluctantly drilled a hole. Luckily my local tracks are not too thorough on the tech inspection. My car looks very factory stock so they usually take one quick look believing it's a 13 second car and then don't really inpect much of anything.Mike I like the idea of cutting the wrench and attaching the socket with a line painted on one side. I'm going to give it a try.
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XR7
Journeyman Posts: 81
From: north Idaho
Registered: Mar 2003
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posted 08-02-2004 07:16 PM
I drilled a 5/16 hole in my scattershield as well, I did it on the pass. side about halfway between the tranny bolts. I think it's nuts that they won't re-certify it and that after 5 years it no good anymore? I bought a big T-handled allen and cut one side off the T, I can stick it in there and make 1/2 turns real easy. I also marked my balancer and can do it myself but have my son turn the crank to the next mark and I can find the adjuster quickly. It's pretty easy just don't lose count, and start and stop in the same place on the balancer.
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steve'66
Gearhead Posts: 7938
From: Sonoma,CA,USA
Registered: Mar 2000
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posted 08-02-2004 10:29 PM
Jeazzz,That sounds like a lot of trouble when you're trying to enjoy a nice day at the track.  Automatics rule lol SteveW
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clevelandstyle
Gearhead Posts: 864
From: Connersville, IN
Registered: Jul 2001
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posted 08-03-2004 12:04 AM
quote:
Originally posted by steve'66:
Jeazzz,That sounds like a lot of trouble when you're trying to enjoy a nice day at the track. Automatics rule lol SteveW
LMAO
------------------
Ben
Grabber Green '70 Mach I 351C 4V
Robbin Egg Blue '79 Fairmont 408C 4V, best time to date is 10.50 @ 125mph
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n2oMike
Gearhead Posts: 2019
From: Spencer, WV
Registered: Jan 2001
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posted 08-03-2004 10:15 AM
REAL men (or women) have race cars with three pedals. Plus, those same REAL men and women can actually drive their cars on the street on a regular basis! 8" converters and real street driving don't mix too well! Hey, we may have to work a little harder than the sissies in the pink t-shirts, but we make adrenalin filled, macho, FUN runs down the track that everyone likes to watch! We don't just 'let go of a button' to take off, and ride the recliner to the other end. BORING!!!  Oh well, I guess there has to be a way for the rest of the non-driving world to race. Slap some nitrous to a stick shifted car, and see what the excitement is all about!!! And no, I do NOT let off the gas, or put on the brakes during while racing somebody! That just seems plain wrong! Oh well... That's about enough harassment for one day.  ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220
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steve'66
Gearhead Posts: 7938
From: Sonoma,CA,USA
Registered: Mar 2000
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posted 08-03-2004 10:27 AM
Mike,How long's it been since your car has been to the track? LOL SteveW
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n2oMike
Gearhead Posts: 2019
From: Spencer, WV
Registered: Jan 2001
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posted 08-03-2004 01:26 PM
Well, the house and family thing, along with a new baby happened, so I have been a bit 'distracted' lately. The car just hasn't been a priority. I'm slowly chipping away at it, but the family, along with crappy machine work pretty much have the motivation set on 'low'. hmmm...I did finally finish porting the TW heads and took them to the machine shop for a 'touch up' valve job. (they were brand new) I poured gas in the ports to test the valve job's seal, and half of them leaked. I did a bunch of hand lapping, but that only cured about half of them. I guess it's time to go back and rip some ass. Oh well.... We need a good race shop around here. ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220
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steve'66
Gearhead Posts: 7938
From: Sonoma,CA,USA
Registered: Mar 2000
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posted 08-03-2004 01:34 PM
quote:
Originally posted by n2oMike:
Well, the house and family thing, along with a new baby happened, so I have been a bit 'distracted' lately. The car just hasn't been a priority.
Mike, You are doing better than most. A lot of guys end up selling the hotrod at this point in life. Most of the racers are either "before kids" or "after kids". The older guys seem to have the best toys. SteveW
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Mike_R
Gearhead Posts: 165
From: Indianapolis, IN 46237
Registered: Feb 2001
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posted 08-04-2004 07:04 PM
Well, I succesfully adjusted the clutch in the car for the first time. I made a tool as described by N20Mike and turned the crank in 60 degree increments. Worked like a charm. It took about 20 minutes to adjust all of them. Much easier than I suspected.So I turned them in 2 turns which took it from about 2400 lbs to 1900 lbs. Still pretty high I know but I didn't want to get too crazy with medium friction clutch. Took it for a test drive and you can definately tell the clutch is not as grabby. Still no slippage in 4th gear. Something worked right though because I launched it on the street with 20# of air in the ET street tires (it usually spins bad like that). Anyway it hooked pretty darn hard for that situation so I think it helped. I may try taking some more pressure out of it but it seems to work pretty good now so I don't want to get too greedy and smoke the clutch. The track may be alot different than that street launch though. Thanks again for your help. I plan to hit the track soon with the new 521 engine, new clutch, and new rearend. Should be interesting to see how things go. I'm hoping to hit some 10 second ET's.
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