clutch flite

Any one ever run one of these in a healthy drag car. Since the class we are going to race in has changed the rules that you must use a clutch pedal was thinking using or changing out the auto and running all the good stuff in a clutch flite. Wondered what is the weak point in this set up and if there are any aftermarket billet stuff to correct the weak points. Motor likely will be a 605 Hemi around 1200 HP 3200 lbs E Body with a ladder bar.

My buddy blew one apart in his high 8 second front engine dragster. Hit a guy in the stands and the trans blanket looked like ground up fiberglass. Pretty sure Norwalk got sued over it.

1200 horse and a Clutch-Flite? That just seems like a bad idea.

hello G force........yes I would like to get a transmission please. Or lenco or others should be your next phone call.

The problem is getting parts. Unless you have the ability to make them, or are able to find parts in useable condition, you are going to have a tough time. Im building one for my early hemi. Doing something odd though... using an overdrive version, so the parts up front are not really available. I also plan on using a transbrake valvebody for holding the car in the beams. (Clutch pedal release switch)
Im making 3 input shafts out of 300m. The cost of the extra two is minimal.
With the internals built like a good modern race TF, there is no reason I can think of that would cause any concerns of explosion.
A well built 727 will take that power without issue. Finding an existing clutchflite input shaft that will hold up to that power will be your stumbling block.

With a modern clutch in front of it you could soften the hit and you would be fine. Like already said finding parts would be difficult because much of that stuff is collecting dust WAY in the back of the shop. The few clutch-flites I have seen were 23 spline which is pretty small for an input shaft being sent 1000 HP

Good luck

Gus

The internals would be all A&A like the TF in the car now so the basic build is as good as it gets. Have acccess to two clutch flites and want to find out the weak points and have stuff made if needed to eliminate these points. If you ever have put all the good stuff in a TF you know it is not a cheap build but to make things last you have to spend money and have access to parts if things go wrong and they will over time, I agree if you are getting one part made that is a one off, build three of them so you are not out for the season waiting for a part. Thank you for the replies, I had heard the input shaft was one of the weak points and posted here to see if anyone had solved that issue. Might have to go back to a Liberty, wanted something that fit like the factory transmission without having to cut more of the car up and using a Clutch Flite things just fit right if it would stand up to the Power and have most of the parts to make one last.

Liberty's might be able to make you an input that will hold up

Good luck with your project!

How are you going to provide oil pressure to the transmission?

I have seen some that use fingers that engage the fingers in the clutch to drive the front pump and others that use an external oil pump. Actually a power steering pump back in the day.

I was thinking that the fingers off the front pump might have trouble with modern clutches, especially a diaphragm type.

Please keep us posted on this project, very interesting.

Build a turbo 400 clutch asist

I used a B&M clutchflite in the mid '70's in a big block Nova that ran 9.80's @ 140mph.It required maintenance regularly and regular small leakage due to "shaky"seal design in input shaft/pump driveshaft area.Regularly cleaning trans blanket and scattershield.Heard of double sealing modification, but never tried it. I was building and maintaining this trans myself on a 20yr old's shoestring budget(lots of used parts).ET's lead me to believe at 3200lbs race ready, we're probably talking about 670-680hp.Used a stock Hemi front drum and rear sprag.Was riding on a handgrenade and didn't realize it! 3finger clutch to drive front pump required.Found that you had to be on top of kick down band adjustment as it took a beating.I'm sure I was at the max or over for a reliable combination.At the horsepower you are talking I think it is a poor choice, especially towards personal injuries.Check back on old articles on Motown Missle Prostock using a clutchflite, they eventually were scared to ride in that thing as they could feel it shake as it was coming apart regularly.They went back to a fourspeed.I do admit that setup was extremely fun to drive but I was only at about 60% of the h.p. that you are going to have. Save your feet! Bill

Is the Bruno around anymore[Brunoglide]

There was a rule change a few years ago and I seen a few Bruno drives for sale on RJ, I still think with a good adjustable clutch set on stun would act like a lock up converter once you get the tune right on the CW

Gus

Thats an interesting concept of controlling a transbrake the way TRENDZ was describing in the post above. Just like launching a stick car, if I'm understanding it right. Release button activated by clutch pedal. Would require some inhibitor switch integration, preventing against untimely activation.Hemicar1971, would that be legal by the rules you are building to? It seems many convertor driven Torqueflites are staying together in vehicles with weight and horsepower similar to yours.Taking a stout clutch hit of that magnitude with the scattershield adaptor housing, front pump,and trans case being sandwiched together with those skimpy, now longer front pump bolts is asking a lot.
Something else that comes to mind is dialing in bellhousing run-out with all those pieces assembled together.I never checked that on mine,being a youngster , but realize that could have been an influence on the seepage that I continually chased.TRENDZ idea of controlling the transbrake with a clutch pedal switch while retaining a torque converter seems worth a look if it were legal for your class.Would definitely need proper electrical/interrupting system to prevent accidental reverse gear engagement as that left leg may want to step on clutch pedal at a BAD time. I am very interested to see where this thread goes as racing with a clutch pedal is ALWAYS a thrill. Bill

2000 hp nitro funny cars used to run them. Lots better internal parts available nowadays.

Big difference between today's tires that grip, and yesterdays tires that would slip and spin.

That’s the beauty of the clutch... tune the slip in the bell. Control wheel speed with chassis.

Car we are building is an old Pro Stock E Body. It had both a Liberty and a Clutch Flite in it at different times. Ran quicker with the Liberty but things were different back in 1972, but I have no idea of the internals of each transmission when in the car. Looking at running Nostalgia Pro Stock but they have gone to a Clutch pedal format. Every day of the week I would run the A&A TF, that thing in another one of the cars has been the best money spent with little to nothing being hurt. Just rebuild it when needed and everything has been nice when taking it apart. Talked about the pump on another board. Looks like the weak points are the input shaft and the pump. Do not really want to run a Lenco and sold all the the Liberty and Nash stuff a long time ago. I am listening anything else out there that might work, I kind of liked keeping it Chrysler and near to the same as some of the other cars we have. Big Cubes and HP/Torque are one thing that will destroy the Clutch Flite but a slipper clutch might solve one problem. More research needed and a call to A&A might give some answers either good or bad.

Please keep posting anything you know or think, this is a learning curve for us.

I may have not been clear. I fully intend to use a clutch in combination with a trans brake valve body. No t converter. Transbrake will hold the car in the beams.(no three pedal dance) No plan to use it with the engine power loaded against the trans.
By arming a momentary switch on the shifter, with the pedal depressed. In essence, two momentary switches would need to be armed for the transbrake to be on. Release will be a switch on the pedal.

Sorry,thanks for the clarification. I misunderstood you, but I started to contemplate how it might work out with a converter verses a clutch.The currently redesigned race torqueflite parts aren't what worries me. It's the conversion parts that do, by design.The vehicle weight and tire technology capabilities are the killer here.As I mentioned before the Motown Missle went through a bunch of these clutchflites even trying two in tandem for better gear spread and went back to a stick trans. Even when the trans was working right, their car would not launch consistantly. With only a 2.45 first gear and depending on flywheel weight,the car would either spin the tires or bog off the line. I myself battled that same situation. Car was fast and very fun to drive but consistancy was a battle. Bill

That's why we introduce the "slip" in the clutch with low base pressure and a sintered iron disc then your drivetrain will accept the power gradually down the track after the initial hit. Then your counter weights on the release levers add pressure to lock the system together. I always thought the clutch-flite would be a perfect setup in a F,A,S,T, type of class.

Gus

I have a clutch Flite going in my current project, runner with 528 cubes. It’s the car in my avatar. I am hoping it will be ready prior to winter. The Flite is the fairbanks version, I think built in the early 2000s. I’ve had it for quite a long time so it will very interesting when the car is ready. I got a clutch setup, twin disc from McCleod.

Trendz- will your unit have the same input shaft as a typical clutch flite? If yes, would you consider making an extra input shaft or two to sell? I wouldn’t mind having an extra one or two just in case. I don’t know what drum is in it, I did have the plates refreshed a while ago but that is about it.

I will be using an old Anson blowproof bell. I have a trans body shield but I was thinking of not using it. I wont be racing the car, but should I use the body shield any way? I dont know it hits the tunnel or not.

That is a pretty stout clutch I hope it doesn't dead hook. I broke a HEMI box with that clutch before I knew better about having slip in the drivetrain somewhere.

Gus

Brother inlaw used a Faribanks TF in his 1971 383 Cuda street car in 1972 and up. Worked OK. There was a 1971 Charger that ran a Fairbanks clutch flite on the street back in the late 70s but no idea how well it worked. Never understood why someone would do that back then but maybe it was what he had or was told that it worked. So how many different makers were there of Clutch Flites and is there one better than another.

Installing an adjustable clutch would be highly recommended.

605" Hemi is going to hold quite a bit of inertia in it's rotating assy, 727 ratios say it it would dump about 65% of that inertia on 7500rpm 1st to 2nd shift. All that energy has to go somewhere, either the clutch, tires, or the transmission has to slip to keep the drivetrain alive. Dual disc clutch says the clutch isn't going to be doing much slipping, so you are left with either the tires or the transmission slipping on the 1/2 shift. 65% of that inertia represents quite a bit of energy to waste in a wheelspeed spike, but the alternative is slipping the transmission's clutches long enough to recover some of that energy. Adding an adjustable clutch would allow you to recover more of that inertia without smoking the transmission's clutches.

Grant

Ran clutchflites behind injected hemis in dragsters and cars in the 70s and 80s though they worked well then I wouldn't recommend using it with the high torque high HP engines of today
There isn't much development on clutch driven automatic transmissions with the advanced technology of converters.

I have not come across much improvements with a clutch flite. If the weak points can be known maybe something can be built. We have SRT4s and the 5 speeds in those car would come apartand so do the axles, One person Darrell Cox of DCRacing came up with billet axles and all kinds of internal fixes for the transmission and the motors, He had a 790 SRT4 Neon. So maybe some stuff can be produced.

The weak point is the input shaft. That can be made today with better materials than were available when these things were built.
I have an input shaft in good shape, but it won’t work with the lockup style trans Im using as the core. The shafts Im having done will be 300m rough machined by me, then hardened , straightened and ground by a local place.
My plan is to use the McLeod softlock clutch.

Weedburner is correct about 1st to 2nd gear change taking the hit as that was the first thing that went away on mine, due in part to it's 3200lb weight.The now defunct Vitar Transmissions was the original builder of my B&M cluchflite.At that weight and probably around 575hp at that time,went away after about 75 runs, part my fault as I neglected to check and adjust the wide Hemi-style kickdown band overheating the front drum and trashing front clutch plates and discs.Learned that lesson and how to build clutchflites for the future.Made access hole in floor and fabbed some tools and I could check the bandfrom the front seat every 5-8 runs.That seemed to work better even with about 100hp more.Used a McLeod single disc clutch the whole time and it lasted.With that gearspread, not many consistant mid-weight ,high hp cars run a 3spd trans with a clutch in front of it. I had originaly found a clutchflite for my current car but donated it to a friend for a Big Willie Robinson tribute Charger he is putting together,as it will be mostly for car shows and fun driving.One last thing, I PROMISE,remember that cluchflite goes in and out of the vehicle with the scattershield bolted on the front. You need room, as its a little bit of fun lining up the splines, pilot bushing , and the3 finger pump drive mechanism all at the same time with the scattershield on the front. Bill

I had the clutch built by the guy at McCleod. I called him up and told him what I had. There is a gentleman there that is familiar with them. He said he asked me some questions and I gave him the info and he built it. It is in the box at the moment, but hoping to go in the car with engine within a month or two. Car is just going to be a street cruiser, not really any racing. I won't be dropping the clutch or shifting at 7500 RPMs, so I hope I won't break anything.

If you guys are interested in getting a group deal for having a bunch of input shafts made, I would be up for 2. Trendz, would you help out as it seems you are very knowledgeable about this subject?

The problem would be the original manufacturers all had different designs. The one I have is a B&M. I have not seen them all, but from what I’ve read, the B&M were the most popular, but had the worst design when it came to keeping trans sauce out of the bell. If you have a need for a specific shaft, it was stated earlier in this thread that liberty or g-force trans will make you anything you want. I believe it. I just put a 100% billet 6 speed sequential gear box in a car for a guy. Every part of the trans was made to order. They will make you anything you can dream up. And as you know, the more you make, the better the cost per shaft would be. I believe Winters still has drawings of the parts on their site. I called for parts, but they said they only had a few things left for the 727. You can still buy a new complete conversion for a TH400 from them though.

I would think the rear sprag would be the first concern.

A Clutchflite is just slightly more sophisticated than a neutral drop isn't it?

Kevin

Thanks for that information, Trendz. With the Fairbanks unit, would they have the drawings on that as well or would I have to take it apart and send them the part? Sounds like I should upgrade the input shaft. I wish I knew about all this stuff at the beginning of the year, I would have had time to take it out and send it they needed it. The guy I bought it from put it behind a chevy big block and mentioned something about trimming down the input shaft but that was so long ago, I can't remember. If the input shaft was trimmed down some, can I still use it with some kind of sleeve to the pilot bearing/bushing or would I need another input shaft? This will set be back a while I fear if the input shaft will not work for me.

I have one I’ve aquired. Don’t know much about it, it’s a 727, 10 spline gm input and cut down short tail housing. Looks almost like it’s for a rail dragster. Idk if you could use anything from it or not, but I’d sell it. Doesn’t have a bellhousing either, looks like it takes a normal 4 speed bellhousing though.

This is your weak link, not the input shaft although that's a close second. Sprag lets go, planetaries spin 3 times engine speed, taking out tranny case, floorboard, and on a bad day, a foot or a leg. Can make for a fun street car setup but not at the power levels you mentioned.

Clutchflite will have the hydraulic circuits loaded before input shaft spins, including the low band if the valvebody has lba.
So, not quite a neutral drop. And like any race 727, the forward drum should be replaced for assured safe operation. No extra danger running a CF compared to an equally built race 727.

Makes me wonder what the safe level of building a clutch flite with all the good parts A&A sells and improving all the other weak links. This car is not going to be a car that goes to the track every weekend. It likely will go to either NProStock events just for fun and maybe some NSuperStock Events with the other SSBA car that has a 572 Hemi in it now with an A&A parts 727. Just a guess but maybe 50-75 passes at the most every year and a tear down and a look inside every Winter both motor and transmission. Could always pull a bunch of HP out of the Hemi to keep it fun maybe under 1000 HP and not be fixing it constantly if there is a weak point. It is not like we need to win every weekend with the car. The Old Pro Stock would be more of a go fast show car but we do like to run some faster numbers better than it did with the small Hemi.

Members on Moparts sure have opened up our eyes on a lot more stuff so keep posting, I know this is not a couple of day learning curve and will need something for next season not this season while the car is stripped and repainted in its previous paint colors and updating Safety Equipment and up grading the car to an 850 tag. Keeping ahead of the game for next year is what we are trying to do right now and the transmission choice need to be made. Myself I liked the Liberty Crash box I ran in my car back in the 70s but Hemis make a lot more power now than back then. Would like to keep the car looking like a factory piece both body and drive train.

Not widely known but, back in the day, a LBA valve body was available from B&M for use with the CF and the factory offered steel front planetaries. Only item not available back then was the billet front clutch drum.

In the case of the nitro funny cars, many of them used only 2nd and 3rd gear so the sprag wasn't in play.

Other than the internal upgrades like sprag,billit drums and LBA as well as better shafts the weak areas were the pump drives and the front cover housing that the bellhousing bolted to.These were pron to crack and even split at the bolt holes.On one attempt to fix the drive issue I installed a belt driven pump to eliminate the spider front pump drive,Another issue with the clutch driven pump drive required a 3 finger Ford style clutch.The other problem was the critical runout to the centerline of the crank anything more than .020 could cause the front sleeve to break.I finally gave up and gave away 2 B&Ms and 1 Fairbanks and went to converters.

Can one of you guys do me a favor and measure the distance the input shaft should be? Please measure from the face of the transmission to the end of the input shaft. I need to see if I need a new shaft before the shop tries to put it in the car and it doesn’t reach the pilot bearing. Thanks