727 front drum billet steel vs billet aluminum piston

Talked to John Cope today about billet steel front drum. The billet steel drum is available with a billet steel piston from John, but with billet aluminum from other vendors. Pros and cons of the piston material? Does it really matter?

I've run both. I like the aluminum drum. The billet steel is very heavy. I think the clutch and band wear is better with the aluminum. For sure my car was .10 quicker in the 1/8 back to back.
Doug

Which aluminum drum did you use, full metal jacket or all aluminum. Again, curious to the piston material, billet steel billet aluminum. Does it make any difference?

My steel drum from CRT came with an aluminum piston.

Pretty sure the billet steel A&A drum I bought from CRT came w/ an aluminum piston.

I have run both billet aluminum and billet steel drum. The car lost nothing! Ran exactly the same #'s. Not having to change trans fluid every 25 passes like they say you should with the aluminum drum is a bonus. As far as the piston material goes? We have an aluminum piston but steel should be fine also. I wouldn't give the piston material a second thought.

Both drums came from A&A. Last inspection all clutches and bands looked new. It had 150 passes with no fluid change.
Doug

My mistake. went back to copes site and it does not list piston material, just says billet. He does offer an ultimate billet steel as well as a billet steel drum. More money for the ultimate, just curious to whats included with it.

I would look for and buy the aluminum drum with the steel liner for the band
I should buy several of them now before I need them, huh

My vote is for the aluminum drum with the steel sleeve, and aluminum piston, light weight, is easy on the band. I never tried a back to back test on 1/4 mile times. But since the drum has to be stopped by the band for 2nd gear, the lighter the drum the less stress on the band. Plus it is better material so it will not explode like the stock drum at high RPM'S

I talked to John Cope yesterday about that drum. He said he had one in the shop when they first came out. wasn't impressed with it and thought it looked cheesy. I haven't totally gave up on the full metal jacket just yet. Too bad their isn't someone on here that can give us first hand info on it. ya or nay.

i have the billet steel drum in my scamp, and i recommend it highly. i got mine from cope.

If you knew the facts about a stock drum blowing up you
wouldnt say that last line of your statement.. a stock
drum is fine IF you dont trash your over running clutch..
if you trash the over running clutch you then spin the
drun 2.2 times the engine rpm.. DONT pedal the engine while
your still in low gear( if you spin.. SHIFT).. if you
trashed the over running clutch the drum can take ABOUT
6600 rpm before it reaches the point that centrifugal
force will let it blow.. I'm still running a stock drum
and have been since I started racing(a number of years now)..
if you dont do stupid stuff you wont have a problem.. but
of course a lot of people will say it will blow.. BS..
dont do stupid stuff... OK now all of you can say I'm wrong..
but I've still never blew one up.. and I turn at least 8200 rpm
on every shift.. also this is in the same boat that if you
put a bolt in sprag, your fine.. more BS.. a bolt in sprag
is for one that spun in the housing

so did mine

I agree with you Mike. the only reason I put a steel drum in mine was the old stocker was junk so I needed one anyway and verytrue on the bolt in sprag too.

break a rear gear on launch, shock the driveline and roll the sprag.... what happened that was so stupid in this scenario??

I have been racing since 1974, all but one car mopars. I never have broken a roller clutch, have never blown up a drum either. As you say proper burn out technique will keep the roller clutch in good shape. A broken drive shaft at the wrong time will destroy a roller clutch and no driving technique will stop that from happening. But two of my buddies in one year with just as much experience as me, did blow up their transmissions and it was not pretty, both were hurt, but fortunately not seriously. Both had carbon fiber shields and both got pieces in the car. The drum in a 727 is a bomb waiting to go off, the cost of a good drum is cheap insurance for your car and yourself. I know exactly the science why the drum can and does blow up and have seen the results several times. One night in a hospital will pay for several drums, the cost of a drum is cheaper than a whole transmission case in pieces on the track. Seems common sense to my to buy a good drum. I just figured my luck was no different than my friends.

Then buy one if it makes you feel better

I'm gonna buy the aluminum full metal jacket or the steel billet just for piece of mind. Starting with a fresh build so kinda a no brainer anyway. Just need to make up my mind and get the full order in by friday, my trans builder is waiting.

Fixed it for ya.

^^^that was a bit more eloquent than the reply I was formulating.

while the "super sprag" was designed to help "PREVENT" this, it's better than stock, but not guaranteed.

opinions are fine... but don't preach ____ as gospel. It's my opinion that if you are running slicks at a race track... it can happen. What you do to help prevent is solely up to you.

this car was street/strip with the engine set back about 8". Foot brake, and had been running low 11oh off the spray. 8.75 rear. Early 90's pre internet and we both had no idea that this could even happen. Chuck Lofgren was at the track that weekend and came over for a look and educated us. Blankets/shield for everything from that time on.... and we went away from the 8.75. Again, personal choice, but we were trying to improve on reliability.

btw it wasn't until we had the car home that we discovered we couldn't get the axles out.... rear gear had broken. No indication during burnout or moving up to the beams.



sorry to [censored] into your post Dave... but we make choices in this hobby. Sometimes we wish we made better ones

I use the aluminum/steel drum. As far as cost goes it was small compared to all the $$$ I've spent on that old car. I broke a 8-3/4 gear set once and the trans was filled with small aluminum particles. I never even took that transmission apart, it's still sitting on a shelf because it's the original for my Charger. I expect the O/R clutch spun in the case. I wouldn't use the aluminum drum because I have a problem with using aluminum for ANY wear surface. It just doesn't work well in that situation.






That technical analysis is way beyond "cheezy" I bet he had something different to sell you.

no problem and I understand. I think I made a good decision today. I ordered the full metal jacket today after talking to a bunch of tranny shops. It will come fully loaded with his particular choice of band and it is not red. The clutches are not red either. Man ,did I get an education on transmissions today with a few of Griners so called secrets.