Boom goes the......

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if i ever run a 727 again two parts it will be sure to get are the billet drum and an ultimate sprag. my legs and life are well worth the extra cash. nuff said.
 
Yall sure do know how to make mountains out of molehills. All this info has been in the MP books for 40 years. The baddest sprag in the world will not stop the problem. A manual valve body and doing burnouts in 2nd gear are really all you need to do. Can you spend 700 bucks on a loaded billet drum and a super dooper bolt in sprag? Yeah, it's your money. But lots of people hauled *** just fine with 727s over the last 4 decades without that stuff with narry a failure. Pretty simple really. Don't be stupid with a 727.
 
hey if you choose not to spend the money thats fine by me. but if i run a 727 again i'll spend the money. cheap insurance for my legs and life.
 
I hear you, but the fact is, the manual valve body is really all that's needed on 90% of the stuff out there. That and a little common sense.
 
Barracuda_Barry said:
Actually it was the Manual Valve Body with no low band apply that started the drum explosions.
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Actually, no it was not. The low band apply will not stop the transmission failure. The only way to stop or drastically cut back the failure is any manual valve body and doing burnouts in 2nd gear. The baddest assed low/reverse band in the world will not stop a 727 drum explosion in extreme situations. Just like a bolt in sprag will not. Read up on how fast the front drum spins. There's no amount of low band apply that will stop it. 2nd gear burnouts will. The low band apply is totally meaningless if you do the burnout correctly in 2nd gear, because the low band is not even applied in 2nd.
 
RustyRatRod said:
Actually, no it was not. The low band apply will not stop the transmission failure. The only way to stop or drastically cut back the failure is any manual valve body and doing burnouts in 2nd gear. The baddest assed low/reverse band in the world will not stop a 727 drum explosion in extreme situations. Just like a bolt in sprag will not. Read up on how fast the front drum spins. There's no amount of low band apply that will stop it. 2nd gear burnouts will. The low band apply is totally meaningless if you do the burnout correctly in 2nd gear, because the low band is not even applied in 2nd.
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It was totally unheard of until the aftermarket did away with the low band apply.
Engine speed needs to exceed 6000 rpm in first gear with a failed sprag and no low band apply before the cast drum comes apart. The drum will spin at 2.2 times the engine rpm in first.
Test have shown the stock cast drum to come apart at 13000 + rpm.

Some of us don't make enough power to start a burn out in second without a line lock or water or both. LOL
 
I have a trans with low band apply, and that low band stops that drum and it exploding.

Spending the money on the lighter internals, low band apply, better sprag and all that good stuff are ALWAYS skipped when people build a 727.
 
Barracuda_Barry said:
Some of us don't make enough power to start a burn out in second without a line lock or water or both. LOL
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Why would you be doing a burnout without line lock? 100$ too pricey? I suppose brake parts must be free?

While there is no water on the street there is at the strip.

Last there is nothing to say you can't get the spinning in first and then shift 2nd. I do this on the street and shift 2nd at 4,500 or 5,000RPm. Never tried a 2nd gear burnout on the street. It would probably do it.. Then again i'm not burning out my 400+$ set of tires routinely on the street.
 
Supershafts said:
Some people don't use a line lock, a line lock is more a must in a stick car.
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I've always had it in my auto toys. When I was young and dumb and ran cheap radial tires (and tires were cheaper) i'd do the "brake stand" burnout. And destroy my tires and brakes.

To me it's dumb, strip or street.
 
RustyRatRod said:
The 727 is one of the best transmissions made. Period. The problem with transmission explosions is one thing. Operator error. Installing a manual valve body and eliminating doing the burnout in first gear will completely eliminate the problem. No need for a bolt in sprag, although it is a nice addition. The fact is, that if you do the burnout in first gear and shift into second and the tires hook shifting into second the shock will rip even a bolt in sprag out and the transmission will likely still explode. Simply doing the burnout in second gear will all but eliminate the problem.
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RustyRatRod said:
People will argue with this till they are blue in the face, but a bolt in sprag is not necessary. It will do nothing to keep the explosion from happening. It will simply make the carnage less.

The failure occurs when the front drum RPMs become so great, the outside or the shell flares out and locks against the case. When this happens, it doesn't matter what kinda sprag you have, that transmission IS comin apart.

Since it is harder to spin the bolt in sprag out of the case because it is bolted in, it absorbs more of the shock of the explosion. In other words, it takes more to tear it out of the case......but it WILL tear out.

It's easy to see in any 727 explosion the kinda force that's dealt with. A bolt in sprag will NOT stop it. It will slow it down. I am sure there have been instances where a 727 with a bolt in sprag didn't come completely apart, but in those cases, the explosion was not as violent......probably because the sprag helped hold it together, or the RPMs were not quite as high as other failures.

The reason the transmission fails has NOT ONE THING to do with the sprag. The reason for the failure comes from doing burnouts in first gear and having the tires hook up on the 1-2 shift. The resulting shock is what causes the transmission failure.

A manual valve body will totally eliminate the entire problem IF the operator will simply do the burnouts in 2nd gear. NOTHING else is required. No bolt in sprag, nothing. They are a nice addition, but the only one thing that stops the failure is the manual valve body that allows 2nd gear burnouts.
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I don't know why this is so hard for people to understand.
 
more fun with 727s
 

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Barracuda_Barry said:
It was totally unheard of until the aftermarket did away with the low band apply.
Engine speed needs to exceed 6000 rpm in first gear with a failed sprag and no low band apply before the cast drum comes apart. The drum will spin at 2.2 times the engine rpm in first.
Test have shown the stock cast drum to come apart at 13000 + rpm.

Some of us don't make enough power to start a burn out in second without a line lock or water or both. LOL
Click to expand...

Then if you cannot do a 2nd gear burnout, you probably shouldn't be using a 727. The bottom line to me is, the low band apply is useless as tits on a boarhog. If the big rule is to do 2nd gear burnouts, you don't even have to worry about low band apply, cause it ain't applied in 2nd. Yall keep on believing the bullshit and spending your money where it's not needed, instead of having a little common sense and not using 1st for a burnout. A fool and his money are soon parted. I would spend the 650 bucks on a billet drum before a low band apply VB, simply because I will not be doing burnouts in 1st. If you're running something that cannot smoke tires in 2nd, you probably have something that cannot pull a greasy string outta a cat's *** anyway.
 
OK, in answer to Jerry6 and others, here is the test results of the billet drums, and the stock MOPAR drums.
Go to www.tcsproducts.com , click on the Mopar Logo, on the next page click the picture of the 727, on the next page, click on the Full Metal Jacket Photo, scroll down to the bottom of the page and then click view results.
These drums are mainly for the hard core racer. They were came about as there was a huge demand for them from racers and various HP transmission people, and nothing was really available.
The Pontiac race car on the opening page is a BA/A race car, runs high 6's, low 7's at around 198-200 MPH. Runs a Steve Schmidt 500" pro-stock GM engine, with a 904 behind it. It originally had a 727 in it, but the 904 was built because of it's lighter weight. It is the Companies test vehicle. All hard core parts built in house, no off shore stuff. Customer base includes virtually all of the performance transmission companies.
The man to talk to here is Paul Parkins. Very knowlegeable, used to run a HP engine shop.
 
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