Slant 727 WIW
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BigWhip
New to Mopar land
I saw and wanted a/6 and a 727 out of a airplane tug. The 727 had no tailshaft just a flat plate with a short spline coming out of it. I was wanting it to see if it was built different at the factory for pulling the heavy loads.
Michael
Michael
Did you get it? Was it different internally from a passenger car unit?
That's really interesting, to me...
BigWhip
New to Mopar land
No, The shop would not sell it at that time. Later it was sold for scrap.
cudamark
Well-Known Member
That looks more like a fuel problem! Holley strikes again!
ops:
That looks more like a fuel problem! Holley strikes again!
I can't blame Holley for this one...
I had the main fuel line disconnected (electric pump) and failed to re-connect it to the carburetor. Got in the car and turned on the pump and let it run long enough to fill up the filter, lines and float bowls (I thought) and tried to start it.... When it backfired, it ignited all that gas that had been pumped out the end of that unconnected line... I didn't have the presence of mind to tuen off the pump... so it continued to burn, for like 5 minutes until I realized that the pump was still on...
Couldn't see the end of the unconnected line for the flames...
Not Holley's fault this time...
ops:
replicaracer43
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My statement is that 727s don't just blow up because of some kind of "sheer mass" issue... your own post stated that's what YOUR trans expert said..... That would make him a dumbass as far as I am concerned.. NOW, with that said, smaller and lighter transmissions ARE used in racing applications, but its for a slight ET gain, NOT durability.....but we aint talkin about race cars here, were talkin about the worth of a stocker/low hp trans...Now as far as why the factory would use a 727 behind a slant, I dunno.... a 904 is plenty durable for that.....
This right here is the jest of the discussion. No need calling anyone here, or their friends names. That mutes any point you are trying to make, IMO. Not to mention it's pretty childish. That's not what we're about here.
replicaracer43
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True, but I aint sure exactly who your making reference to........ I stated his trans guy sounded like a dumbass with
the statement that 727s blow up because of there internall mass, not due to the torque applied to them.........I think "I" was was the one refered to in the "now whos the dumbass" comment....
Yes, I should have qualified my statement relative to Len's comment that 727's blow themselves up because of their own excessive mass as regards the usage... He deals in racing transmissions almost exclusively, so when he talks about things like design flaws and the effects of those flaws on transmission longevity, it is usually in reference to how they perform in a competition setting, not in street use. The thing about Torqueflites in a drag racing application that is significant here, is the operation requires that a big, heavy cast iron clutch drum is sped up to high rpm in first gear and then stopped instantly when the intermediate band comes on for the second gear shift, yanking a LOT of rotating weight down from considerable rpm to a dead stop in a microsecond. THAT is the exercise that causes failures (not explosions) in 727s. A 904 has lighter components, and fewer problems in that area, naturally,
When I asked, "What are YOUR credentials???" I was trying to get a quantitative analysis of your experience with failed Torqueflites, compared with my friend, who has had 30+ years of doing nothing but examining failed units brought to him by racers, and diagnosing what went wrong and why (and, fixing them.) He has spent a LOT of time looking at the internal carnage that happens on the drag strip, over a 30-year period. When he talks, I listen...
Sorry for the misunderstanding...
replicaracer43
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No problem Bill, and I agree about the rotating weight in a race situation......and I have drag raced with them, 727s, and 904s, and really, with the power levels I have, both work fine. We use 904s for ovaltrack though, because they are deff lighter
It's a well known fact that 727s DO disintegrate the STOCK drum if it exceeds a certain RPM......and that RPM is not difficult to achieve. Perhaps that's what Bill's friend was referring to. You obviously are very knowledgeable yourself. I was merely pointing out that your points would be better gotten across without the name calling. That's all.
I have been a cyber-junkie since before the Internet existed, serving as the Moderator of the Prodigy Drag Racing Bulletin Board (no kidding!) for a few years before the Internet came online. I say that to emphasize the fact that the thousands of hours I have spent talking to people online has resulted in my having developed a VERY thick skin as regards untoward comments and all the different negativity that crops up on these glorified chat rooms. A lot of it is due to the limited ability of the Internet to convey inflection in comments, and a lot of mis-understanding goes on that would never have happened in face-to-face conversation. Comments made off-the-cuff that would go unnoticed in personal verbal exchanges stand out like a sore thumb on here, and create hard feelings where none is intended.
That's one of the serious flaws in Internet communication... unintended meanings that come through in spite of the best intentions.
I, having been a cyber-junkie for so many years, have seen this so many, many times, and the result of it, tend to ignore it, because I know that if it were a face-to-face, REAL conversation, it probably never would have happened.
So, I usually just ignore it... 'cause it usually wasn't a real, sincere comment...
But, getting back to the 727/904 discussion, the exploding clutch drums in the 727's I am told, are the result of over-speeding of that cast iron cylinder due to the sprag anchor in the rear of the case becoming dislodged and losing its ability to over-run. This excessive rpm creates centrifugal forces that the drum was never designed to withstand, and it explodes as a result. Apparently, the sprag anchor in the 904 doesn't have this problem, so explosions of 904's are pretty much unheard of. That is not, however, the situation Len told me about that is involved with the parts of a 727 being so over-built and heavy that the rotational inertia causes the transmission to damage itself, when subjected to high rpm shifting. That cast iron drum, I believe, is stopped dead, after being spun to a high rpm in 1st gear, imparting severe inertia-loads on the shafts, planetaries, etc.... That is what he was talking about. It's not a problem that would occur in daily street driving.
I tried to call his shop just now, for more specific information (I am a transmission idiot) but he wasn't there right now.
He has resumed racing in NHRA's Super Stock Eliminator, after about a 7 or 8-year layoff due to his particular engine receiving a lot of horsepower from the "Automatic Horsepower Factoring System' (a method that NHRA uses to adjust factored horsepower on combinations that seem to need it.) The extra horsepower put him at a severe disadvantage and moved him up a class, so he took a hiatus and eventually built an engine that has different specs, so has no increase in factored horsepower. He runs in a GT class, which gives him the ability to use a variety of different engines, legally.
I'll try to get more information on that 727-inertia problem at some later date.
That's right Bill and exactly what I was referring to....as I am sure your friend was, too.
Yes; aluminum clutch drums are available for both the 727 and the 904. But, the 904 will always be lighter, because it's smaller.
Yes, aluminum and steel drums are available. The problem is plenty fixable. My solution is a simple one. Put in a manual valve body and do the burnout in 2nd. Problem solved.
That will fix the exploding problem but the problem of the transmission slowly destroying itself with its own inertia remains (727.) The aluminum clutch drum will go a long way toward alleviating that problem.
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