4 Speed Conversion

[69'Net]

So I'm kicking around the idea of buying a complete 4 speed conversion kit from brewers. I have a mild cast crank 440. I'm almost certain the crank has never been drilled for a 4 speed. From what I've read, I would have to use a Dakota bearing and cut the shaft. Brewers told me they would prefer to have me drill the crank but they could send me everything to do it either way I chose. Is there anyone out there that has done this? Any issues with using the dakota bearing?

Next question, the 440 is externally balanced. I currently have a B & M flex plate and a neutral balance torque converter. Brewers told me I can just use their cast crank flywheel and I'm good to go. The rotating assembly is stock minus the forged pistons. Some people tell me I need to rebalance the engine to do it right though.

Just trying to get as much info as possible before I jump into this.

 

[moparedtn]

This is the input bearing you use with a cast crank in lieu of the brass bushing:
https://www.ebay.com/itm/Mopar-PILO...467386?hash=item4b3a962bfa:g:qTsAAOSwo3pWdGjo
Brewer's sells the same sort of bearing also.

 

[Daves69]

.............I'm almost certain the crank has never been drilled for a 4 speed...........

As in it's just drilled for centers or is the depth already there and it just lacks the bushing diameter?

 

[69'Net]

As in it's just drilled for centers or is the depth already there and it just lacks the bushing diameter?

there is a hole there already for the front of the torque converter to go in. I think it needs to be deeper for the A833 input shaft. I didn't measure it when I put it in last time, but I doubt its been drilled to the correct depth for 4 speed.

 

[Daves69]

These are approximate dimensions of this steel crank I have "not" drilled for the bushing.
The depth is already there on it. The trans input shaft diameter is .750" I believe. The bushing press fit diameter (green) is not to size and would need to be opened up.....

 

[Daves69]

About 2/3 down the page here shows one drilled for centers........
http://www.bigblockdart.com/techpages/4sptech.shtml

 

[vintage chromoly]

Look for the bushing that locates in the torque convertor hub register as opposed to a roller bearing.
You'll have to shorten the input shaft if the crank isn't pre drilled for the input shaft.

 

[FrnkNsteen]

Are you in the process of building the motor, or is it done? If building it, you could find a forged crank, neutral balancer and flywheel and have the whole assembly balanced together?

If motor is already built,.... My Barracuda has a 400 in it with a cast crank (I bought it that way). From what I have been told, they are drilled, but not deep enough to accept the input shaft from the transmission. Previous owner cut about an inch off the input shaft and pressed the roller bearing into the area of the crank that the torque converter register went into. I haven't had any issues with it on mine.

I am in the middle of doing the conversion on my Charger. Just ordered the whole kit this morning in fact. My 440 is a '68 and has a drilled steel crank so I will not have to cut my input shaft down, but I am still going with the roller bearing, per Brewer's recommendations.

From what I have learned, the cast crank motors are externally balanced so you will need an external balance harmonic balancer and flywheel for an external balanced 440. Brewer's knows their stuff and I have learned to trust their recommendations. You just need to let them know which way you are going so they can get you the correct parts.

 

[69'Net]

Are you in the process of building the motor, or is it done? If building it, you could find a forged crank, neutral balancer and flywheel and have the whole assembly balanced together?

If motor is already built,.... My Barracuda has a 400 in it with a cast crank (I bought it that way). From what I have been told, they are drilled, but not deep enough to accept the input shaft from the transmission. Previous owner cut about an inch off the input shaft and pressed the roller bearing into the area of the crank that the torque converter register went into. I haven't had any issues with it on mine.

I am in the middle of doing the conversion on my Charger. Just ordered the whole kit this morning in fact. My 440 is a '68 and has a drilled steel crank so I will not have to cut my input shaft down, but I am still going with the roller bearing, per Brewer's recommendations.

From what I have learned, the cast crank motors are externally balanced so you will need an external balance harmonic balancer and flywheel for an external balanced 440. Brewer's knows their stuff and I have learned to trust their recommendations. You just need to let them know which way you are going so they can get you the correct parts.

My engine is already built, wish I had bought a steel crank now, oh well. I think I will just cut the input shaft and get the bearing that presses into the torque converter hole on the cast crank. Seems to be the easiest route. So I should be fine with the external balance flywheel then?

 

[vintage chromoly]

You really need to have the pressure plate and flywheel balanced.
I'm doing a conversion at present and I just had a brand new hays SFI flywheel and a brand new mcleod pressure plate balanced. It took removing s small amount of material from the flywheel and welding a couple weights to the pressure plate to get them right.
Yes, theoretically, they came out of the boxes "neutral" balanced, but as if oftentimes the case, they needed work.

Don't overlook this easy but important step.

 

[Daves69]

Look for the bushing that locates in the torque convertor hub register as opposed to a roller bearing..........

And if you do happen to find it available, please post a link to it or the name of the source for others!

 

[FrnkNsteen]

Flywheel is only neutral balanced on a internally balanced motor ( forged crank motor). Cast crank motor is externally balanced though.

I agree with what you are saying on an internal balanced motor. My engine guy asked me to order the flywheel for mine so he can verify neutral balance. Doesn't apply to original poster though.

 

[vintage chromoly]

My bad.
I missed that he had an externally
Balanced engine.

Pretty sure he will still want to zero out the pressure plate.

 

[69'Net]

Flywheel is only neutral balanced on a internally balanced motor ( forged crank motor). Cast crank motor is externally balanced though.

I agree with what you are saying on an internal balanced motor. My engine guy asked me to order the flywheel for mine so he can verify neutral balance. Doesn't apply to original poster though.

I feel like that should apply to an "external balance" flywheel as well. I don't understand how you can just take a flywheel out of the box and have it be perfectly balanced to your application. I technically did it with my B & M flex plate though, maybe I'm just thinking about it too hard.

 

[FrnkNsteen]

Well, I'm not engine expert, but they have to have some way of specing out the balance so it can be used right out of the box. I mean, it's not like you're going to tear the motor down anytime you need to replace a flywheel,... or a harmonic balancer for that matter.

I'm with you though.... it does seem strange.

 

[vintage chromoly]

They build the imbalance to a theoretical spec.

 

[flyingfarley]

Recently did the same conversion on my 65 Coronet.....it was an externally balanced 440 with no pilot bearing hole. I used the bearing that required cutting off the end of the trans input shaft, and used a balanced flywheel that I had with a balance plate from Quicktime ....The balance plate goes between the crank and the flywheel when you bolt on the flywheel. everything worked fine...car is much more fun to drive. No vibration at all. Have done this quite a few times with no problems.

 

[69'Net]

Recently did the same conversion on my 65 Coronet.....it was an externally balanced 440 with no pilot bearing hole. I used the bearing that required cutting off the end of the trans input shaft, and used a balanced flywheel that I had with a balance plate from Quicktime ....The balance plate goes between the crank and the flywheel when you bolt on the flywheel. everything worked fine...car is much more fun to drive. No vibration at all. Have done this quite a few times with no problems.

So that would be another alternative to buying a flywheel designed for external balance? Did you pull the motor when you did your conversion? I feel like it might be easier with the engine out to weld on the ball stud bracket and align the bell housing. Especially if I have to put in offset dowels.

 

[vintage chromoly]

Engine out is the way to go

 

[wyrmrider]

use the balance plate
cast cranks are "internally balanced" but with an unballanced dampner and flywheel/ converter- the unballanced items are always the same- balance changes are internal
so use the correct dampner and the insert goodie with a neutral balance flywheel
if you have not changed your engine internals you should be good to go
remember using lighter internal components makes balancing easier if you do make changes i.e lighter pistons or longer rods giving lighter pistons