Hi guys,
Now that the wiring harness is in process, I need to queue up my next sub-project.

Any chance someone would know the HP drain and fit for an AOD?
I'm currently running a C4 which isn't ideal for interstate driving but I know I have a limited corral of ponies to draw from. IIRC, the C4 uses +/- 30'ish HP and the C6 somewhere North of 50HP. It looks like the C4 was welded to the cross-member.

Depending on that answer, my next question is has anyone installed offy heads/intake/2-2 to their, otherwise stock flattie?
Other than moving to an electric fuel pump, what else would you recommend if I start getting into the engine at that level?

Thanks

I just found this. It looks like the numbers are loosely based on fact but good enough to answer my question.
Powerglide_____18 hp
TH-350________36 hp
TH-400________44 hp
Ford_C-6______55-60 hp
Ford AOD______45 hp
Ford_C-4______28 hp
Ford_FMX______25 hp
Chrysler_A904__25 hp
Chrysler_727___45 hp



Automatic Transmission Gear Ratio's
Transmission
_Model----------First Second Third Fourth

GM :

Powerglide...........1.76/1.82 1.000
TH-350................2.52 1.52 1.000
TH-400 (3L80)......2.482 1.482 1.000

Ford:

C-4.....................2.46 1.46 1.00
C-6.....................2.46 1.46 1.00
AOD....................2.40 1.47 1.00 .67
AOD Wide.............2.84 1.55 1.00 .67
AODE/4R70W........2.84 1.55 1.00 .70


TRANSMISSION LENGTHS:

A= total length
C= from front of bell housing to center of mount



Powerglide (bellhousing pattern - Chevrolet, Fit-all)

Style A C
short shaft 25 23/64 20 9/16
TCI shorty 17 15/16 20 9/16
long shaft 27 9/16 20 9/16




TH350 (bellhousing pattern - Chevrolet, BOP, Fit-All)

Style A C
6" tailshaft 27 11/16 20 3/8
9" tailshaft 30 11/16 20 3/8
12" tailshaft 33 27/32 20 3/8




TH400 (bellhousing pattern - Chevrolet, BOP)

Style A C
C tailshaft 28 3/8 26 15/16
D tailshaft 33 27/32 27 15/16
13" tailshaft 37 7/8 27 21/32



C4 (bellhousing pattern (removable) - 4 Cylinder, Small Block, Big Block)

Style A C
Pan Fill 24 5/16 +bell 19 ½
Case Fill 30 19/32 20 ½





C6 (bellhousing pattern - FE Big Block, Big Block, Small Block)

Style A C
FE Big Block 33 ½ 22 3/8
Big Block 33 ½ 22 3/8
Small Block 33 ½ 22 3/8




AOD (bellhousing pattern - Small Block)

Style A C
Small Block 30 3/8 22 5/16




AODE/4R70W (bellhousing pattern - Small Block, Modular)

Style A C
Small Block 31 3/16 23 5/16


For more info on dimensions..............http://www.tciauto.com/Products/Tech...bles_print.htm

 

It's obvious I'm trying to see the viability of changing some top end pieces to get the power I need for the AOD.

decent heads +intake manifold+2-2 = 20 hp? Seems like a stretch to me but worth asking.

Thanks,

 

I was going to say ~50ish... so 45 seems reasonable. depends on in what gear, type of converter, etc... In drive with lockup, probably a lot less than that. Not too many good ford automatics to choose from.

 

Thanks for the reply.

Yeah, If I can make it happen, I'm shooting for the 92-93 AOD.

I'm hoping someone has some wisdom/insight on fitting one in place of the current C4 and if the hop-up will give me what I'm looking for power wise.

Trying to find a good electric Fan too. that has to be a solid 1-2 HP.

 

Keep in mind, a lot of the "HP absorbed" numbers are at or near rated input, in other words, at full power. If you trace back to the various tests in magazines, they were with 400+ HP in most cases. They have a certain amount of losses at any HP level due to the pumps, but gear losses are fairly proportional to HP input. I wouldn't obsess on the numbers.

Are you dead set on an automatic? A T-5 is a really good match to the flatheads and has none of the parasitic losses.

Most flathead guys running C-4's simply drop the rear gearing a little more to end up with decent highway RPM, and seem happy with them. The t.c. helps maintain decent acceleration. What gears do you have now?

The Offy or Edelbrock heads give a good increase in responsiveness, and bump the torque. If you look at all it takes to run them, they aren't cheap.

The key thing with flatties is they run out of breath, with restrictive ports and valves. On a typical OHV you can cam it and add carbs to get more power at a higher RPM, on a flattie it takes some special work to get that to work, and you don't have the RPM band to play with. A flathead at 4500+ RPM is not a happy engine, not for long anyway, without some serious $$$ infusions.

In terms of bang for the buck, and driveability, boring and a Merc stroker crank are high on the list, if you are rebuilding anyway. If your engine is in good shape already, a good bet is a Merc 4-bolt intake manifold with a Rochester 2GC carb. You can pick up the manifolds for $50 - $100, and the carbs for $75 - $200 depending on shape. Getting rid of the Load-a-crapic distributor is also a big help, going to either aftermarket units with vacuum and mechanical advance (MSD and others) or a Chevy distributor modified to fit. None of these will tank your gas mileage either, in fact they may improve it.

 

Thanks for the reply, Ross.

I would absolutely love to be able to use a 5 speed in this truck but I'm 6'6" and 300 pounds. It's interesting enough using the brake..

I'm running the stock 3.73 rear with 15" 235/75-15s. After a bunch of maint, etc this last month and increasingly longer trips, I finally decided to set the world land speed record and jumped on the Interstate doing my best impersonation of (insert NASCAR driver here), timed it perfectly down hill, while drafting a semi, and GPS verified my absolute top end of 71 MPH. There was absolutely nothing left for Luci to give. Getting up the next (small) hill had be choked back to about 55 max.

With all that said, I didn't purchase the truck to win a race but I certainly want to be able to make it up that next hill without enacting a part from the movie, Broke Back Effie... (you know, the scene where a semi runs up your tailpipe?)

I'm still getting familiar with the things the POs have done to the truck but, there is a different distributor than stock in it, now.

I'll start looking into the parts you mentioned. I'm not opposed to going to a 3.25 or possibly a 3.0x rear. it just seems that taller gear would help on these damn hills if I can get enough HP to push an AOD trans.

And I certainly wouldn't be opposed to getting better than 7 MPG.

-Yeti

I won't pull the trigger on the tranny until someone can give me some real world data on using the AOD in this style truck.

 

It's really hard in my experience to gauge the gas mileage on these (unless you fill til it's pouring out the filler), but if you are really getting 7 mpg something is wrong. Can you post a picture of the carb, vacuum line to the distributor, and the distributor? If a non-stock dizzy is hooked up to the stock vacuum connection on the carb, your mileage and power will suffer.

Honestly, 55 up a good hill is about what you can expect with any gears and a stock engine. I have the same tires, a 3.50 axle, and a rebuilt engine with better-than-average power, and a long steep hill will pull it down to 55. Wind resistance is a big factor with these, it just takes HP to go fast in them and if you add in a big hill....

It would help us if we knew where you are, you can add that info in UserCP under Location. Are you in the mountains or flatlands?

 

Let's see if this works..









You'll need to right-click and open in new window.. bleh.

 

it's reasonably flat here. the interstate doesn't have many steep hills until you go about an hour and a half North.

It was running VERY rich when I picked it up. I've since done some much needed maintenance and adjusted the carb a bit. (maybe a bit too lean)

 

A taller gear will give you a theoretical higher speed but will slow you down going up hill. What you really need is more power so you can maintain speed. This can be expensive on a Flathead. Our stock 52 with a 3.50 9" has a top speed of about 70 and can maintain 55-60 up long hills. Considering our proposed uses we decided it was better to go to a different engine to get the power we wanted as the cost to get good power out of the Flathead was actually more.

 

Hmmm... looks a lot like a Mallory distributor with no vacuum advance, and a relatively stock carb. The circled piece is a spark control valve used from maybe '53-on. It looks to me like someone has put the larger throttle section from a later carb onto the stock carb bowl section, which isn't likely to work right. What jets are in it now? Should be maybe #52's at the most.

Mallory's are ornery in my opinion, and lack of vacuum advance isn't helping your mileage. Have you set timing?

 

I haven't had time to open the carb, yet. When I do, it will be my first go at rebuilding one.

I don't have a timing gun but with your recommendations, I may just order an MSD and a gun.

On a positive note, it looks like I have my next two sub-projects..

RimRock,
I figured that was the case but really do like a flathead. You know, it's funny, a bunch of new cats (of which I'm one) looking for 100 HP and me looking for 10 - 15 yet we're still in the same boat.

Thanks for the help, guys

 

Probably a dumb question (I am known for those), but how did they weld the trans to the crossmember? The trans case is aluminum and I assume, the crossmember is steel. The C4 uses a steel rear mount that is bolted to the bottom pad on the C4. Maybe that pad is welded to the crossmember (that is how I did mine - used an old mount pad, welded it to the crossmember, then bolted the new pad to the old one that was now the crossmember mounting point.

 

I'll take some pictures this afternoon when I get home, but you're probably right and I misspoke.

 

Lets face it, its hard to make one hundred HP push a brick at today's road speed and still have decent speed on the hills. Even with unlimited gearing, it is going to be a tough run. That is why so many folks who enjoy driving these old pieces re power and re gear them.
I agree with Ross, a T5 and regear would put you closer to what you want.