Broken B/M Holeshot converter, and pump, and...on a 727 • 2 • The Dodge Challenger Message Board

by **dave-r** » 07 Sep 2005 13:12

Can I add that in my opinion (for what that's worth) a completely stock (but not worn) 440 is safe up to 6500rpm as long as it is;

a) Under load at the time i.e. not in the burnout or not in neutral at the time.

b) Only at that high rpm for a very short time on each shift.

6500rpm will be about 128mph.

Your friend's big torque 509 will slip a lot with a 3500 stall converter. The more torque you have the smaller the stall speed you need.

Your engine has less torque so it will not. You know my engine has a similar cam (but with more torque) and even mine drives normally with a 3000-3200rpm stall. I am sure yours will be fine.

by **plum-crazy** » 08 Sep 2005 5:46

I will do it. I ordered 3000 stall+hughes 727 performance, forward pattern auto/manual shift.

I heard your car with Tim (shit,shit) a lot of times, were you using this 3000-3200 converter this time?

Have you any kind of traction bars to use slicks and beat 11.60 times?

Thanks.

by **dave-r** » 08 Sep 2005 7:36

Yes that video is with that converter. Maybe I should get Tim to make a small clip showing my car drive away from a dead stop in traffic at low rpm so you can see how well it pulls away normally?

And I really was not pushing the car very hard at all in that video. Tim is just a big baby. :wink2:

Street/strip Mopars do not need traction bars. The rear springs are of a superior design over other makes. An adjustable pinion snubber on the diff and subframe connectors is all you need.

by **Tim** » 08 Sep 2005 9:19

Dave said- "And I really was not pushing the car very hard at all in that video. Tim is just a big baby."

My lawyers will be in touch forthwith. :wink:

Excellent thread BTW. :s002:

by **transman** » 08 Sep 2005 15:08

I'm glad to see you've made your decision on your converter. When you update the diff to better gears I'm sure that you will be happy with the purchase you made.
Don't throw out your 727 that's on the floor. Rebuild it yourself, or have someone do it for you. A well built stock 727 transmission will easily handle 500+HP. In the 727, the area of concern is the front drum.
Typically these are made of cast iron, and after years of use and abuse, they can explode under high rpm useage (drag racing).
If you look at our company's web page www.tcsproducts.com you will see our 2004 Jerry Hass Cavilier race car. It has a 1300HP PRO STOCK (500 cubic inch Oldsmobile design) engine in it for power, and we are using a 727 transmission in it. There are a number of items in the transmission that are of course high dollar, but the friction plates, steel plates, gasket set are stock, off the shelf items.

transman

by **dave-r** » 08 Sep 2005 15:38

transman wrote:It has a 1300HP PRO STOCK (500 cubic inch Oldsmobile design) engine in it for power, and we are using a 727 transmission in it.

by **plum-crazy** » 13 Sep 2005 6:06

I won't throw the transmission, we will rebuilt it but not for me, thanks for your page info.
I do not think about frame connectors for chally, if are really useful I will use instead of traction bars.
I only have stock pinion snubber, maybe better use adjustable one?
What kind of transmission oil is needed for this type of use? We are using dexron III but a friend told me that a blue oil exists and it's better, do you know what type of oil is?

by **dave-r** » 13 Sep 2005 7:57

Sub frame connectors are needed NOT for traction but to stop the car cracking in half.

The pinion snubber is used instead of traction bars. You DO need an adjustable one if you go onto a race track. If that is the case adjust it to within about 6mm of the underside of the floor. But never use it this close when driving on the street or it will be hitting under the car on every slight bump and possibly break.

Just use Dextron in the auto trans. Type F will give a firmer shift if i remember right.

by **plum-crazy** » 15 Sep 2005 12:11

Hi guys.

Another question is made to me.
Summit ask me is I need external balanced or neutral balanced converter. Now I don't have the way to know what kind of crankshaft I have in the engine but I'm sure te car has no vibrations with the neutral balanced converter (broken now).

I have a friend that made a mistake with converter in a 502 chevy and he told me that vibrations between 2000 and 3000 rpm were salvage.

I think the correct one will be neutral. Are you agree?

Thanks.

by **dave-r** » 15 Sep 2005 12:48

If the old one was neutral and you had no problems then that is the one for you. :thumbsup:

by **plum-crazy** » 16 Sep 2005 5:50

Thanks Dave but I'm not sure maybe I broke the converter due to wrong choice?
Do you know the way to know what king of crankshaft I have?
I think on the tail, six bolt used to fit flywheel are 7/16 on steel style and 5/16 on iron style, is this sure?
Any other way to know something about it?

From summit told me that is easier to know wrong converter is used due to vibrations but is not easy to know it in mopar engines. :shock:

Thanks.

by **dave-r** » 16 Sep 2005 17:32

plum-crazy wrote:Thanks Dave but I'm not sure maybe I broke the converter due to wrong choice?

I personally would not have thought so.

Here is how you can tell by looking. However if the crank has been shot peened to increase it's strength you might not be able to see a cast or parting line.

However this has no bearing on if the crank was internally or externally balanced. If the forged crank had six pack rods originally it would have been externally balanced.

It is normal for a professional engine builder to change a crank from external balance to internal and even if it was internal from the factory a performance engine should be balanced better than the factory did it in order to live a long time.

by **dave-r** » 17 Sep 2005 12:34

If you fitted new pistons or rods when the engine was rebuilt you should have had it balanced anyway.

by **plum-crazy** » 18 Sep 2005 7:32

I will try to check it before do anything more.

Broken Converter

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