C-4 Flex Plate Teeth Count

[Anonymous]

I have a 200 Cast-Iron XFlow near ready for assembly. Want to use a
C-4 trans with it. I'm in the states and Auz bellhousings are rare. Need to know if crank bolt pattern is same as US 250. Or if 200 Auz bolt pattern is same as 250 Auz. Need to know what number of teeth the Auz 200 on it's flex plate. Would appreciate any help you gear-heads could give me. :

 

[George]

hi,

Don't know if this is correct for America but I used a flexplate of a 6 cylinder Bronco to hook up a C4/C9 without problems.

Cheers

 

[addo]

I've got a 50 ounce 302 C4 flexplate with the weights drilled off to make a 250 flexplate. (Bolt PCD is same as the eights.) Teeth are 157.

 

[Anonymous]

did you count every teeth addo???

i had enough trouble counting 28 spline on an axle.....

 

[gassed250]

I just counted the one on my 250 twice and marking each with a red marker there is 160 teeth

 

[xctasy]

A US Falcon 250 C4 auto item will do the same job without having to get one from Aussie. They are 157 teeth, neutral balance, 3.0" pcd for the six bolts, and have the same 9.5" converter bolt pattern as the Aussie C4 items.

Any time a C4 was fitted to an Aussie Falcon 6,
it lost 3 teeth form its 160 teeth flexplate,
and got a 157 teeth item.

90% of the flywheels you get have too many teeth for C4 I6's. Best supply of good neutral balance of C4 flexplates are the 1972 to 1980 XA, XB, and XC and XD Falcons.


Fact 1:

If the had Borg Warner transmissions,

All Aussie OHV 2.8 (170)3.1 (188) 3.3 (200), 3.6 (221) and 4.1's since 1966 to 1993 ran 160 teeth flywheels , and the same bell housing bolt pattern. Before 1970, they all had 2.75" pitch bolts to secure the flywheel or flexplate.

Fact 2:

Add an Aussie C4, then both 3.3, 4.1, 4.9 became 157 teeth.

All 351C (5.8's) ran the FMX or detachable pan fill C4 (called the C7, C8, C9, or C10) or Borg Warner or Top Loader, these ran the big diameter 14.375" 164 teeth flywhel or flexplate.


Fact 3:

After 1971, it was all 3.0" pitch centre for the six securing bolts on 3.3 (200) and 4.1 (250) Falcons.

 

[gassed250]

Whats going on X do I have the wrong flex plate?
It was working in the car with a C4 and was supplied by "The Coverter Shop"
when I got my stall converter done
And when say "A 9.5" converter bolt pattern" you mean measuring dirctly across center to center to the bolt on the other side right?

I just done this and I have a 10.5" converter bolt pattern

 

[xctasy]

Fact 2:

Add an Aussie C4, then both 3.3, 4.1, 4.9 became 157 teeth.

So much for my facts!


Gassed 250, your choice of good deed to make up for my miss-information!

Since you can confirm the bolt spacings, we now know the BW I6 and C4 I6 item are different, but not in the way I thought.

Right here, right now, I don't know what the factory Aussie C4 one had in terms of teeth, but the converter bolt spacing is wider

All i can say is that I have before me a Borg Warner 350 item from my 83 XE ute, and I've rechecked the bolt spacing. it has four bolts and is measure from centre to centre.

160 teeth BW 35/40/50 item is 9.75", and not the same as your one.


I know that the Aussie C4 item isn't the same as the Aussie BW item becasue Bob Pinnell (Cortina V8's man, and 351c Capri campaigner) said the 6-cylinder torque converter doesn't fit the 351 C unless the four lugs are moved outwards.


If there was a change in the Aussie C4 used behind the I6, it still doesn't use the Falcon Borg Warner auto flexplate, that's for certian.

It may use the local starter and 160 teeth ring gear, but they don't interchange as far as I'm aware.


The local pre 1992 items before the V8 returned are:-

164 teeth, 11.4375" converter bolts on the FMX used behind the 351C and 351W. 28 oz unbalance.

157 teeth, 10.5" converter bolts on the smaller 289 and 302 Windsor V8's and the 302 C. 28 oz unbalance


160 teeth BW 35/40/50 item is 9.75" Neutral balance, 13.375" diameter.

I will rewrite the post and we can post some photos to id each type.

 

[addo]

So - how does this reflect on what I've got?

I have a neutral balance C4 flexplate that fitted a converter that fitted a 250 model C4. I know, because I mocked it up!

The total diameter for the BW and C4 flexes is almost identical. There's only a few teeth on that starter motor.

I've possibly got pictures; will post if I do. I did have these parts out the other day, but have since "buried" them in a sensible stack of kit. Major anti-junk, anti-clutter, anti-hoarding process underway @ chez Adam.

 

[gassed250]

I dont know , I am so confused
I need to clear my mind with another Woodstock

For all I know the rear half of my converter could be BW and the front C4

But as usual with Ford theres probly 10000 types of flexplates that bolted to the 250

 

[addo]

First picture shows the pre-250/crossflow PCD vs the later PCD.



Second one shows the comparative nature of the two flexplates for BW and case-fill C4. You can see where the balance weights are drilled off.

 

[George]

Hi guys,

All i know is that the stall convertor in my car is out of a V8 and the flex plate is off a 6 cyl bronco. The only thing I can remember doing is changing the input shaft on the C4 to the V8 item making it a C9??

Very confusing..I had the same problem when looking for a flexplate!!


Cheers

 

[gassed250]

First picture shows the pre-250/crossflow PCD vs the later PCD.



Second one shows the comparative nature of the two flexplates for BW and case-fill C4. You can see where the balance weights are drilled off.

The one i have is the same as the one on the right

 

[xctasy]

Addo's shots at top Left. 170/200/221 for 1966-1970. Has 2.75" pitch bolts at crank.

Addo's Right. Case fill 250 C4 flexplate.

My BW 35 auto flexpalte, 1983 item.

BW's have four bolt holes 9.75" appart. If you scale the flexplates via the drawing using the bolt holes, you'll posibly find the C4 one has 10.5" bolt centres. In addition, the C4 flexplate has its ring gear spot welded on, not riveted like mine. There are lots of balance holes that I don't have on mine.


Looks like gassed250 wins...by a nose!

 

[Anonymous]

I just finished installing my C4 to my Crossflow last week. I wanted an SFI approved flexplate so I got one which had been imported from the U.S.

It was definately a 157 tooth neutral balance.

It was intended for a Windsor V8. Same bolt pattern on the crank and even had the relief holes in the right spot for the converter drain plug etc used on the ford six C4's