[Jimiboy]

Hi guys!

There's been a very long time since i visited, sorry for that...

Now, ya'll that still remember´s me do know i sold my beloved Challenger.

Now.... There's still some Mopar mixed blood running in my veins


Short summary:

I just recently swapped one of my harleys in a trade to get a -68 Charger Special R/T 440 4 barrel from factory in St Louis. (Sadly a smog engine in it, dough).
Pic's willl come in time i promise you.



The car misses it's gearbox.
I 've already ordered a restored A727BB prepared for 7-800 hp's... i asked for a shiftkit installed aswell. This is supposed to be B&M parts all the way if i understood it correctly.

Now to the issue:

I got me a #10415 part numbered B&M converter with 2400rpm stall speed....

My friend Roland kindly offered me help to do this job. Before we lift the trans up, i really want to know this will be correctly done from the start.

So my question is:

Assuming the engine bottom is factory standard and stock, nothing changed..... With the stamping H= year 1972 and 5 31= May 31th and the relevant letters HP= high performance.... to the side of the distributor.... I personally asssume the car should, have a forged crank, right? what else should make a smog engine a "high performance"? right? And from researching, it then equals that it then also is internal balanced? That is my friends... my question here... Anybody?

Because i need to know if i have to get a B&M flexplate or if i can use the one i already got....

Summit racing says balanced: YES
JEG's says external balanced engines needs the B&M flexplate.

Rolands quick research in his books of mopar big block engines tells only that cast cranks is externally balanced. Nothing meantioned about forged cranks....

I remember my 340 LA was a "HP" and with that there was forged crank...

Can i assume my HP high performance 440 (RB=1973-1978) but manufactured in MAY 1972, has a internal balanced crank, and that i therefore should not need to change the flexplate?

All answers appreachiated.

I hope you all guys are well!

Best regards

Jim

[dave-r]

If it has six pack rods it will be externally ballanced. 1970-71 HP 440s came with the six pack rods. I don't know about later.

You will be able to tell by looking at the ballancer on the front of the engine.

[Jimiboy]

If it has six pack rods it will be externally ballanced. 1970-71 HP 440s came with the six pack rods. I don't know about later.

You will be able to tell by looking at the ballancer on the front of the engine.

Thanks Dave for such quick response.
I see small holes on the side of the damper. But "Persåkers" speed shop in Sweden told me it could be internal balanced even with these.

But pherhaps you are suggesting it should be completely round if internally balanced, and significant shaped different then circilular on some spot if ext. Bal.?


Please explain, then pherhaps i can be wiser.

[dave-r]

Yeah I am trying to find my diagram showing the difference in the damper. The face of it is not symetrical.

Cast cranks with external ballance came in 440s from about 1974. But like I say, the HP blocks with the heavy "six pack" rods had to be externally ballanced as well because of the weight of the rods.

[Jimiboy]

Yeah I am trying to find my diagram showing the difference in the damper. The face of it is not symetrical.

Cast cranks with external ballance came in 440s from about 1974. But like I say, the HP blocks with the heavy "six pack" rods had to be externally ballanced as well because of the weight of the rods.

Okay, will it be obvious even with the pulley on place...?
Roland told me it could be hard to descide with it on place.

Anyhow, i wait and see if you find anything. I will try to take a pic. It was pretty big dough. "Fat" not diameter wise, but thickness.

[dave-r]

http://www.440source.com/dampers.htm

[Jimiboy]

http://www.440source.com/dampers.htm

This one looks not like none of those, or what do you say?

And this is how my flexplate looks like...

Pherhaps the #3577785 is close, but then the holes on mine makes it look different.

[Jimiboy]

Jegs states "When used with an externally balanced engine, B&M Chrysler converters require a B&M flexplate
"
Like there is only one to choose from(?)

But Persåkers in Sweden told me that i need to know if it is a forged or a steel crank aswell, besides the fact that it would be external balanced....
(Like that there is at least 2 different B&M ext balanced flexplates?

If i did'nt missunderstood or if pherhaps he got the wrong idea?

Any suggestions?

[dave-r]

That is an aftermarket balancer and it looks like it is externally balanced. You would have to remove the pulley to be sure but I think I can see that it has a counter weight shape to it just to the left of the timing mark and if you look at the external balance dampers in that link I gave you you will be able to see the same shape in relation to the timing mark.

The only reason they would need to know if it was a cast or forged crank would be to know if it was internally or externally balanced.
They obvious do not realise that some of the forged crank engines were also externally balanced.

At the other end of the engine you have two choices. Either use a flex plate with a balance weight on it OR use a torque converter with the weight on which is how the factory did it.

[Jimiboy]

That is an aftermarket balancer and it looks like it is externally balanced. You would have to remove the pulley to be sure but I think I can see that it has a counter weight shape to it just to the left of the timing mark and if you look at the external balance dampers in that link I gave you you will be able to see the same shape in relation to the timing mark.

The only reason they would need to know if it was a cast or forged crank would be to know if it was internally or externally balanced.
They obvious do not realise that some of the forged crank engines were also externally balanced.

At the other end of the engine you have two choices. Either use a flex plate with a balance weight on it OR use a torque converter with the weight on which is how the factory did it.

Yes it has that shape of a counter weight. Strange that they don´t make the aftermarket dampers the same. (I mean, would´nt the balance be affected negative if the damper is replaced to some damper, that is different(?)

But.... With this B&M 2400rpm stall converter already waiting in the garage, i guess my only option now is to order a B&M flexplate then.

I did´nt realize that there where external balanced forged cranks either. So, i can still expect the crank to be forged then, yes? (I mean, what does the "high performance" stamp mean on a -72 cast block?)

Thanks a lot Dave!

[Jimiboy]

Well, now i'm confused again...
While the B&M instructions tells i must "use one of the following flexplates for proper engine balance...."
The chart tells holeshot 2400 converter should use STOCK flexplate or B&M flexplate!

Wtf!?

does it not matter if i go for the stock plate now or what?


What is your experiences?

Advice?


Once again... If i am not looking wrong, i cannot see any advice on summitracings web page for the need of another flexplate then stock to any 440. Only the manual in the box and Jegs states i need B&M special flexplate!

What now....?

[dave-r]

You need the special flexplate if the torque convertor does not have the balance weight. If the torque converter has the weight then you just use a standard flex plate.

[Jimiboy]

You need the special flexplate if the torque convertor does not have the balance weight. If the torque converter has the weight then you just use a standard flex plate.

You have to agree that it seems confusing in the manual, when it says stock OR B&M flexplate, like if it did'nt matter now.

Anyhow. My other question remains, when i look on top of the block there is stamps telling me my block is a high performance engine. Is that = forged crank?
That was my thought dought.

Because it actually seems to matter. Looking at Jegs i see either 130-10237 for externally balanced crank. And 130-10238 for use with factory high performance forged crank.

So i bet i need that one for the forged crank then.

http://www.jegs.com/p/B-M/B-M-Flexplate ... e=90&pno=1

(Is it any other differences between a "HP" engine and the cast crank engine?)


The most enoying thing is, not to know if the bottom of the engine is stock. I don't know if it is another crank for an example. Like if it was forged from factory but now replaced with a cast...

[dave-r]

Cast cranks with external ballance came in 440s from about 1974.

The only difference between forged balanced, forged external balanced, and cast external balanced is the con rods.

Your engine is obviously external balanced with that damper. So you need either a flex plate with a weight or a torque converter with a weight. But not both.

I really wouln't bother with B&M stuff either. Very over priced for what they are. How do you even know what torque convertor you need if you don't know the engine spec?

A convertor needs to match the camshaft in the engine as well as the rear gears and tyre height.

[dave-r]

You can get aftermarket cranks with 6 or 8 bolt ends for fixing the flex plate to. Torque convertors also come in different bolt pattern diameters and two different bolt sizes.

[dave-r]

This is the type of flex plate I used;

http://www.ebay.com/itm/CHRYSLER-DODGE- ... 0574645745

And my torque converter was from TCS http://www.tcsperformance.com/

I highly recommend them.

[Jimiboy]

Cast cranks with external ballance came in 440s from about 1974.

The only difference between forged balanced, forged external balanced, and cast external balanced is the con rods.

Your engine is obviously external balanced with that damper. So you need either a flex plate with a weight or a torque converter with a weight. But not both.

I really wouln't bother with B&M stuff either. Very over priced for what they are. How do you even know what torque convertor you need if you don't know the engine spec?

A convertor needs to match the camshaft in the engine as well as the rear gears and tyre height.

The converter came with the car. The car came with no gearbox.. The B&M converter is not balanced, but has reasonable stall (2400rpm).
I tried to find out what camshaft previous owner put in there, but he lost it. It sounds like a moderate mild cam for street use. I don't know.

But 2400rpm for me, sounds normal for street. And i don't want to use the stock turbine. The old trans was blown apart.

[Jimiboy]

This is the type of flex plate I used;

http://www.ebay.com/itm/CHRYSLER-DODGE- ... 0574645745

And my torque converter was from TCS http://www.tcsperformance.com/

I highly recommend them.

That was a cheap flexplate. I will have to pay like $150-160 next week. But then i get it next week shipped from Hansén in Sweden... I guess the shipping takes it time from the U.S.... And i did'nt find any balanced for that price either on e-bay. I did'nt look that good anyway, 'cause i already made my order.
That link was by the way for internal balance. Did you have internal balanced crank? Or pherhaps balanced converter?

Thanks Dave...

[dave-r]

I had my crank internally balanced. Which is not easy with heavy sixpack rods because weight has to be added to the crank throws. But this opened out my options for SFI approved damper, flex plate, and convertor choice.

[Jimiboy]

Everything set, and seem to fit together... now i only need to get it on place!

[dave-r]

Don't let the torque convertor sit unsupported in the trans input seal like that for long periods. It might leak when you get the engine running. Fit it just before mating up the engine.

[Jimiboy]

Don't let the torque convertor sit unsupported in the trans input seal like that for long periods. It might leak when you get the engine running. Fit it just before mating up the engine.

Oh, ok thanks Dave!

I plan on doing a try this weekend but i will remember that!

Thanks again!