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