Need trans swap info

[COBRAIIW]

Thunder,this might be right in your ballpark,
I want to change my four speed out, and put my C-4 in from my parts car.
Four speed is getting too old, auto is only 3yrs old.
Four speed flywheel is shot also.
My motor is an '86 5.0 H.O. and I heard that the balancing might be internal rather than external on the flywheel.
I really need to use the flywheel with the auto that I have now,(no missing teeth).
Funding is also non existent to even think about buying new.
Do you suppose that I will end up with an imbalance this way?
Gotta do this as it is my daily driver that I can't drive right now.
I have all the Auto brackets and lines already.

 

[Dano78]

If you're using a for-sure '86 shortblock, Art Carr may be the only way to truely solve your delima if you're using the Mustang II C4. He makes a 50oz imbalance flexplate-(the correct term for an auto trans flywheel) for around a buck and a quarter last time i bought one. Took forever it seem, though to get it to me.
I've never ran a later block witht he 28oz (stock) flexplate, not sure what it'd do other than probably rattle your gums and slowly rattle your lower end to pieces.

Right now, are you using an MII std. trans bellhousing or a T-5 Bell?

 

[Blue Thunder]

Just to nitpick a little, it's specifically the year of the crankshaft that dictates the counter-balance of the flywheel/flexplate. Starting in late 1981, Ford started using the 50-oz imbalance weight. Also around the same time, Ford switched over to the 1-piece rear seal.

Just some related trivia;
The older 2-piece rear seal 302s had a crankshaft with an oil ridge cast just before the rear seal mating surface. I assume the oil ridge is there to help prevent oil from sloshing against the leak-prone 2-piece seal. The older blocks therefore have a provision for the crankshaft ridge to ride in, sort of like a rotating oil baffle.
The 1-piece rear-seal engines came with a crankshaft that did not have that oil ridge, because there's no need for it, due to the newer style seal's superior quality. However, the newer blocks also don't have the provision for the oil ridge to ride in. This means that if you want to use an older crankshaft in a modern block, you will need to machine(grind) that ridge off the crankshaft or it physically won't fit into the block.

Since you're short on cash, (a familiar spot for me!) I'd check out the option of ordering a 50-oz balance weight(the small weight doesnt actually weigh that much, it's just a spinning imbalance figure, heh) from Ford or other supplier, cut the old smaller 28-oz balance weight from your current flexplate, and weld in the 50oz weight in the same spot. It would probably work OK that way, but I'd still rather not take chances and have it re-balanced to stock 50-oz figures at a shop.(I lie, I'd run it with the new weight welded in place, because I'm the type to take risks) Not sure how much a shop would charge to do the weight swap for you and re-balance the flexplate..
Where in CT are you? Anywhere near Dutchess County, NY? Maybe if you're not too far, you could stop by with the parts, and I could take a look at it.

 

[COBRAIIW]

Are you saying that the flexplate that I have in the C4 setup is a 28oz.?
It may be that I have a 50oz. already,because when I swapped in the 351W into my car I may have used the flexplate that came with it.
I always had a vibration in that car. If so, I may luck out.
Is there a way to tell which weight is on it visually?

 

[Wart]

Are you saying that the flexplate that I have in the C4 setup is a 28oz.?
It may be that I have a 50oz. already,because when I swapped in the 351W into my car I may have used the flexplate that came with it.

Right now it's anyones guess as to which ballance flexplate you have.

If the plate is from a II it's a 28 unit. If it's a 351 windsor (or C) plate it's a 28 unit.

If you don't know where it came from you really cant tell. OTOH there are the part numbers, but they may not be definitive.

Is there a way to tell which weight is on it visually?

I suspect by size and placement. Though I never really looked or measured.


Theres a guy here who ordered the Art Carr part, said it took forever to get it, then wasn't happy with the quality.

He said if he had to do it again he would have just taken the plate he had to the local shop and had it reballanced. He said it would have been cheaper and faster. And probably better.

YMMV.

 

[Blue Thunder]

I just called and verified with my machinist friend that the 50oz weights are visually a lot bigger than the 28oz weights.(which makes sense, since the imbalance is nearly twice as much) He and I are also *almost* sure that either of the two different weights are positioned in the same spot on the flexplate.
If you don't want to attempt the weight swap yourself, I would call up the local guy and see how much it'll cost to rebalance your flexplate.

 

[COBRAIIW]

Thanks guys,I guess I'll find out for sure when the trannys come out of both cars.
Spent a couple hours today removing old rusted bolts and exhaust parts.
Been a while since I've done this, I forgot how much FUN it can be.

 

[THE COBRAMAN]

Are you saying that the flexplate that I have in the C4 setup is a 28oz.?
It may be that I have a 50oz. already,because when I swapped in the 351W into my car I may have used the flexplate that came with it.
I always had a vibration in that car. If so, I may luck out.
Is there a way to tell which weight is on it visually?

Thought I'd mention that if the C4 setup you have now is a II-specific setup that was together and running, it'll be a 28 oz/in plate. The II uses a smaller flexplate than any other application (what a surprise!). To the best of my knowledge, there never was a 50 oz/in plate in the correct diameter offered by Ford.

 

[Dano78]

Theres a guy here who ordered the Art Carr part, said it took forever to get it, then wasn't happy with the quality.

He said if he had to do it again he would have just taken the plate he had to the local shop and had it reballanced. He said it would have been cheaper and faster. And probably better.

YMMV.

That was probably me, Mark. All Art Carr really does is order the same exact plate that you can buy at Napa or Shucks (CSK Auto) and do the weight swap and balance themselves. When i ordered it, I was under the assumption that they had them in stock and ready to ship. After a week, I realized differently. After 2 weeks I started getting pissed. At just about 3 weeks I was quite irate and the customer who's car I was working on, was pretty diasppointed as he'd missed a show he very badly wanted to take tha car to. All I can say is, i hope you have better luck than I did if you go that route.

Just to set the record straight... Is the C4 that you'll be swapping in, ACTUALLY and Mustang Ii specific C4? You have yet to verify that. I ask because it is possible to get an early model C4 to fit in there but there would be a missing strut support brace in the process.

 

[THE COBRAMAN]

I ask because it is possible to get an early model C4 to fit in there but there would be a missing strut support brace in the process.

Depends on the specific car/bellhousing combination. Mine (68 mustang C4)required only minor clearancing. Father-in-law's (76 Granada C4) didn't require any clearancing, but I did anyway, just in case.

 

[Blue Thunder]

I had a '68 Mustang C4 bellhousing in my II for awhile, but with stock exhaust manifolds. I very much doubt headers would fit in the II with any larger bell.

 

[THE COBRAMAN]

I had a '68 Mustang C4 bellhousing in my II for awhile, but with stock exhaust manifolds. I very much doubt headers would fit in the II with any larger bell.

I can vouch for the fact that Dynomax/Blackjack/Cyclone will not fit with the larger (intermediate car) bell.

And the '74 parts car I bought had a pair of Heddmans flattened out (I mean, clear shut flat) and still wouldn't fit past the C5 bell.

 

[COBRAIIW]

Yes ,the C4 is the original one for the car.
Now let's see if it will work with the '86 5.0 HO.

Now I got thinking about it some more,does the position of the weight have anything to do with the firing order? If it DOES, then the firing order for the 5.0 HO is the same as a 351W.
I should look at a 5.0 flywheel next to a 5.0 HO flywheel.
Better yet, let's see if the 5.0 guys on this board know this one.

 

[Blue Thunder]

Yes ,the C4 is the original one for the car.
Now let's see if it will work with the '86 5.0 HO.

Now I got thinking about it some more,does the position of the weight have anything to do with the firing order? If it DOES, then the firing order for the 5.0 HO is the same as a 351W.
I should look at a 5.0 flywheel next to a 5.0 HO flywheel.
Better yet, let's see if the 5.0 guys on this board know this one.

The flexplate balance weight positioning has to do with the where the crankshaft counter-weights are positioned.
And yes, the 302HO has the same 13726548 firing order as the 351W, due to the fact that Ford turned to their 351W Marine Parts division for a performance camshaft for the 1982HO Mustang 302. (a performance cam hadn't been produced for a 289/302 in a LONG time)
The flexplate for the 351W is the same part as for the pre-1981 302.(28oz)

Some more Ford trivia;
The 13726548 firing order was developed by Ford for the 351W in order to try to reduce some of the stresses placed on the #1 main bearing cap when the engine was under load. (the standard early small block 15426378 firing order, ignites the 1 and the 5 cylinders at about the same time, which are the two front cylinders, placing a heavy load on the #1 main cap) The 351W firing order doesnt do that.

I prefer the sound of the older firing order to the new, but that's just me.

 

[Wart]

Yes ,the C4 is the original one for the car.
Now let's see if it will work with the '86 5.0 HO.

IF the trans and plate are from a II, AND the engine is a '86, THEN it won't work. At least not for long.

Now I got thinking about it some more,does the position of the weight have anything to do with the firing order?

No.

When I wrote about the position of the weight I was referring to the weights distance from the center of the plate. The closer tot he center the more mass needed to create a simular force as a weight placed farther from the center.

 

[COBRAIIW]

Thanks guys,I'm now on the hunt for a 10.5 in. 157 tooth 50 oz !!!
I'm all prepped to drop trans tomorrow.

 

[Blue Thunder]

Thanks guys,I'm now on the hunt for a 10.5 in. 157 tooth 50 oz !!!
I'm all prepped to drop trans tomorrow.

If you're using the Mustang II bellhousing, the matching II flexplate has 143 teeth, just so you know.

 

[COBRAIIW]

WHAT??
After all the research and ...
143 teeth? why couldn't I use the 10.5 bolt pattern with 157 teeth?
maybe I should just have the flexplate rebalanced.
the 157 tooth ring gear must be too big a diameter.
I didn't even see that one in Summit's website.

I already have headers installed,the old blackjacks, so I will have to retain that bellhousing.

:damnit:

 

[Blue Thunder]

WHAT??
After all the research and ...
143 teeth? why couldn't I use the 10.5 bolt pattern with 157 teeth?
maybe I should just have the flexplate rebalanced.
the 157 tooth ring gear must be too big a diameter.
I didn't even see that one in Summit's website.

I already have headers installed,the old blackjacks, so I will have to retain that bellhousing.

:damnit:

The 157 tooth flexplate is the standard passenger-car size, it's the correct diameter for the passenger car bellhousing, so that the starter aligns properly with the ring gear.
I don't think a 157 tooth flexplate will physically fit inside the tiny Mustang II bellhousing, and it certainly won't come close to aligning properly with the starter.
If the II flexplate that you have has a good ring gear, then your best deal is to get it rebalanced for use on the HO motor.(50oz-in)
If the II flexplate ring gear teeth look like crap, you might want to buy a new II flexplate (I think I paid $90 for mine back in 2000) and then get it rebalanced.
Nothing worse than running a flexplate with torn up teeth so people turn and grimace at you everytime you start the car..(been there, done that, haha)

 

[Power Surge]

There seems to be a lot of crossed signals in this thread...

CobraIIW, if you are using the stock MII C4, bellhousing and all, you need to use the stock 148 tooth flexplate which was unique to the MII. You will need to get a stock one and have it rebalanced to 50oz.

If you are using a full size C4, then you can use the 5.0 157 tooth 50 oz flexplate.

Even if you are using an MII C4, you can change to the larger bellhousing and use the 5.0 flexplate. Getting a used bell and flexplate will be cheaper than doing the 50oz MII conversion.

My brothers II had the full size bell setup. He was running the Hedmans and they cleared fine. He wanted to step up to the Hooker Super comps, so we switched him back to the MII setup. It cost him $175 to have his MII flexplate redone to 50oz.

I can see if he still has the larger bell and flexplate. Maybe I can get it for you cheap if that helps.