Alternative to a dakota bellhousing

[Tineoidea]

Hi.
I am restoring a 70 Valiant 318 automatic.
I would like to do a manual 5 speed swap. Preferably a top loader one. My countrys (Switzerland) strict laws won't allow the extensive tunnel cutting required for a 4 speed swap.
I was thinking of swapping for a Supra Turbo transmission. I found a transmission for cheap.
But i cant find a Dakota bellhousing. Not in Europe, nor in th USA. Is there an alternative way to install a top loader 4 or 5 speed (preferably 5 speed) transmission? Or even better: does anyone know, where to get a Dakota bellhousing?
I also had a look at complete kits. But they are to expensive for my budget.

Have a great day!

Greetings: Noah

 

[AJ/FormS]

If you build the 318 right (hi pressure/ hi torque/ small solid lifter cam/ good heads),
Then you can use the A833, or even the Overdrive trans.
But With the od, you have to be extra careful in the engine build. and even more careful in selecting the starter gear. It's real easy to screw up second gear.
The Mopar trans ratio line-up looks like;
2.66-1.92-1.40-1.00 (the standard box)
3.09-1.92-1.40-1.00 (the Commando)
3.09-1.67-1.00-.73od ( the overdrive version)
I recommend the Commando and probably a 3.23 in the back, for up to a 223@.050 cam, with plenty of compression. This will get you 65=2520 with 28" tires. With the Commando, the starter gear is 3.09 x 3.23 x24/25.5=9.39 normalized to a 25.5" tall tire.
If you can afford alloy heads, then you can run 185 psi, with whatever,lol.

In every case, IMO, second gear is where problems will show up. If your road gear is too big, you will not be able to backshift to first. If your road gear is too small, you will be forced to downshift, but then upshift right away. I gear second to run out of rpm at or near 60 mph; running a tad too high is better for me than not high enough. So this is gonna play heavily into your cam selection. which is gonna mess with your Compression ratio.
Bottom line,IMO, is to choose your transmission first, and then build your combo around it.
Lemmee show you;
With the Commando and 27" tires, 60 mph will be 5140 with 3.55s, in second gear. So I want my cam to be done about there or up to 300rpm later as the power lays down, on the backside of the curve. So that allows a powerpeak of 5140 less 300= 4840. So I might chose a cam of 216* to 220*@.050. That cam might have an advertised of 264* and an Ica of 59*.
With iron heads I can't run much over 160psi, say 156psi for 89 gas. Working the Wallace Calculator, my Scr then must be less than 9.4 @200ft elevation
See how those are all interconnected?
If you put a 268 type cam in there with an Ica of say 64* then at the same 9.4, your pressure will fall to 149psi, and your rpm of peak power will go up to about 5300, so now you need different rear gear to peak properly at 60mph.

Now, with alloy heads, In my combo, I still burn 87 gas at 185 psi; so,
with that Ica of 59*, I can now jump the Scr to 10.7, and have BigBlock type torque. (I actually run 10.95 on a 61* Ica, in an alloy-headed 367 cid) And yes, I still run the Commando.and with 3.55s.

At the other end of the scale is your minimum roadspeed without slipping the clutch.
You have to think about this cuz there will be many times that you will want to drive really slowly.
So sticking with 3.55s and 27s, If your slowest possible idle-speed is 700, then, your slowest speed with the regular A833 (2.66low) is 5.9 mph. But with the Commando (3.09 low) your slowest speed is 5.1. If you have chosen a smaller cam and retarded your timing, and can idle at 550, then your slowest speed becomes 4mph almost walkable.
A good streeter operating at WOT, will almost never need more than 2 gears, going from zero to 60. With more gears than that, you will just end up at 60 mph, way off the cam, and probably take longer to get there, so I see no point in more gears for this mode of operation.
But at at Part Throttle 4 gears are the minimum, and if you are looking for fuel economy, AND building for it; then now a 5 speed comes into it's own. But if you are geared wrong for it in the back, then it will not save you even one ounce of gas. You gotta consider the entire combo.
Having said all that;
The AX15 can be had with nice gears and progressive splits
3.83, 2.33, 1.44, 1.00, 0.79, for first through fifth, respectively.
The splits are .61-.62-.69-.79.. pretty nice.
Compare that to the Commando splits of .62-.73-.71.. Here you can see that the Commando has a tighter 2-3. Lets put some rear gears on these to see what your car is gonna see. I'm gonna try and get the Second gears lined up, cuz as far as I am concerned, this is all that counts. To hit 60 at ~5400, requires a road gear of 7.16; So that will be my target.
With the Commando that would take 3.73s on the money, here is what the roadgears look like;
11.53-7.16-5.22-3.73
Now lets do the Ax-15. She needs 3.07s in second or 4.97s in third. 3.07s are an in-between gear so you would chose between 2.94s and 3.23s in the Mopar line-up, depending on how torquey your engine is, ergo maxed out pressure with iron, or with alloys.
With iron heads select 3.23s and here we go with the AX-15;
12.37-7.53-4.65-3.23-2.55; W/alloys,choose 2.94s,and
11.26-6.85-4.23-2.94-2.32 ..And the Commando is
11.53-7.16-5.22-3.73
Oh-Wow can you see this?
The Commando has;
an excellent starter (11.53),
a perfect second gear (7.16),
a better third gear (5.22),
and a tighter 4th gear (3.73).
The only thing lacking is an overdrive.
What about the A833od?
Well it has a lousy second gear and an even lousier 1-2 split, but here goes;
To get the 7.16 second will require 4.30s out back so;
13.29-7.18-4.30-3.14od compared to the Commando;
11.53-7.16-5.22-3.73
As you can see the Commando is better in every way, except no overdrive. (13.29 starter is way too low on the street for any V8. I ran that for a couple of weeks one summer, and it got very old in a very short time.) A good starter gear for most small V8s will be from 11 to 10, maybe even less if a slow roadspeed is not required..


But here's the thing; in every one of my examples I set them up for how I like to drive, with a quick zero to 60 mph. With the Commando, this takes care of every other situation as well.
But you might not care about zero to 60, so that would then require an entirely new look-see.

 

[dartslantsix]

Hi.
I am restoring a 70 Valiant 318 automatic.
I would like to do a manual 5 speed swap. Preferably a top loader one. My countrys (Switzerland) strict laws won't allow the extensive tunnel cutting required for a 4 speed swap.
I was thinking of swapping for a Supra Turbo transmission. I found a transmission for cheap.
But i cant find a Dakota bellhousing. Not in Europe, nor in th USA. Is there an alternative way to install a top loader 4 or 5 speed (preferably 5 speed) transmission? Or even better: does anyone know, where to get a Dakota bellhousing?
I also had a look at complete kits. But they are to expensive for my budget.

Have a great day!

Greetings: Noah

I have an AX15 trans in my car that is related to the Supra trans and the tunnel mods are extensive. Had to rebuild tunnel and torsion bar cross-member. Details are on my blog: www.dartslantsix.wordpress.com A 4-speed swap would be much less extensive.

 

[Tineoidea]

Okay. The fact, that a lot of tunnel work is necessary did slip my attention.
I looked at alternatives for the Supra swap. Unfortunately i couldn'd find one, that fits my budget.
In the meantime i found a place, where i could get both a a bellhousing and a transmission for a good price.
I also stumbled across a replacement transmission tunnel for a TKO 5-speed swap.
Might this tunnel work for the Supra swap?
Or maybe one of the universal tunnels for the market?

Thank you in advance.

 

[AJ/FormS]

My countrys (Switzerland) strict laws won't allow the extensive tunnel cutting required for a 4 speed swap.

The Mopar 4-speed is a bolt-in, no mods of any kind are required. Well except opening the side of the tunnel for the shifter. But that is a minor thing and not structural, if you weld in the "hump."

 

[jbc426]

Hi.
I am restoring a 70 Valiant 318 automatic.
I would like to do a manual 5 speed swap. Preferably a top loader one. My countrys (Switzerland) strict laws won't allow the extensive tunnel cutting required for a 4 speed swap.
I was thinking of swapping for a Supra Turbo transmission. I found a transmission for cheap.
But i cant find a Dakota bellhousing. Not in Europe, nor in th USA. Is there an alternative way to install a top loader 4 or 5 speed (preferably 5 speed) transmission? Or even better: does anyone know, where to get a Dakota bellhousing?
I also had a look at complete kits. But they are to expensive for my budget.

Have a great day!

Greetings: Noah

Wow, we are still a few executive orders away from that intrusive of government inspection of our private property, but why can't you cut the tunnel and re-weld what you need in there, all while making it look like the factory did it? How would they know to look under your carpet ?

 

[AJ/FormS]

In post #2, I showed how the Ax15 offers absolutely no advantage in the first four gears, over a Mopar 4-speed. The one and only advantage is the 5th overdrive gear. By positioning second gear where you need it, with any of these manual transmissions, you will not be "rowing" gears.

In fact, the automatic is/can be a better choice. You may be conditioned to thinking that it is "just" a 3-speed, but are you aware that the Convertor operates as a stand-alone 2-speed fully automatic and continuously varying transmission, with a ratio range of about 1.8 to 1.1 which is a full gear split of .61..
Thus the 3-speed TorqueFlite with the convertor, together, operate as a 4-speed automatic. If the auto also has a Loc-up feature, that adds about a half a gear, so now it is a 4.5-speed.
The Convertor has, internally, a Hydraulic multiplier, that automatically varies it's "gear ratio" in response to input torque and the resistance of the load behind it.
Max resistance occurs at zero Mph, with the throttle at WOT, so this is when the multiplier is greatest.
Minimum resistance also occurs at zero-mph, but now with the throttle at idle. So in between WOT and idle, principally, you control the multiplier with the throttle.
Additionally, the Multiplier is continuously falling with roadspeed, until the car starts bucking the atmosphere which resists increasing speed.

Lemmee show you how this works.
Again, lets gear it for a an optimum Second gear ratio, which I will chose for it's characteristic of running out of rpm at 60Mph. I will target about 60=5200;
At WOT, with the A904 this will require 3.73s
I will use a 1.8 multiplier off the line, and average the multipliers as we go along.
I will select 1.4 in first gear, 1.3 in second,and 1.2 in third for speeds below 85 mph.
First; the A904 ratios are; 2.45-1.45-1.00
Next; off the line will be 3.73 x2.45 x1.8 =16.45
thru the rest of First; 3.73 x2.45 x1.4=12.80
Second will be 3.73 x1.45 x1.3=7.03
Third will be 3.73 x1.00 x1.2=4.78
Relaxing the throttle at 65 to 85 mph will get you about 3.73 x1.00 x1.1=4.10,
and in loc-up 3.73 x1.0=3.73
I will make top of Second gear in bold, and the rear gears in bold
So lets line them up sequentially;
(16.45 diminishing to 12.80)-7.03-(4.78diminishing to 4.1) and 3.73(in loc-up); looks like
16.45/12.80-7.03-4.78/4.10-3.73; for 60=4900@20% slip
I count 6 useful gears, the first four for WOT operation. Compare that to
........... 10.97-6.82-4.97-3.55, ; the Commando, for 60=5140
.......... 11.26-6.85-4.23-2.94-2.32; the AX-15 for 60=5170
16.45/12.80-7.03-4.78/4.10 -(3.73s in lup); for 60=4900(20%slip)
Notice that the A904 adds one ratio at the very bottom, which catapults your car into 12.80. Again the only thing missing is overdrive.
But hang on; 16.45 is pretty steep on the bottom; we could give say half a gear away there to reduce the cruise rpm, and then install a loc-up, for another half a gear. Lets try 3.23s. The new road gears, figured the same as before, are;
14.24/11.08-6.09-3.88/3.55-3.23, second gear still in bold; compared to
.........11.26-6.85-4.23-2.94-2.32 the AX-15 with 2.94s
But hang on, we have lost optimum second gear. So then we might as well equalize first gears between the AX15 and the A904. so let's target that 12.37 starter, and with 2.94s, I get
12.96/10.08-5.54-3.53/3.23-2.94.......... compared to
...,.....11.26-6.85-4.23-2.94-232 the AX-15 with 2.94s

Yeah I admit that the AX-15 with 2.94s might be a hair quicker to 65mph. But I doubt it will be quicker to 40, But you can adjust that with stall....... if you have a loc-up.. With a loc-up, there is no good reason to run a 2000/2200. And that opens the door to say a 2800, which is a game-changer.And in Lup, the fuel consumption difference will be negligible.

In conclusion;
on the street; the right gear to run with the AX-15 is the 2.94, and at WOT, you will shift it one time in the zero to 60 contest, ending at 5170 (top of second) with 26.75 tires.. And it will cruise at 65=1900, Whereas with the A904(2.94s), you will hit 60mph (WOT) at 4200, and cruise at 65= 2400 in loc-up/ say 2520@5% slip.

Lemmee show you one other thing;
say your 318 manages to pump out 280 ftlbs at whatever rpm. Let's see what that will look like to the rear axles. First with Ax-15(2.94s); then the A904(2.94s)
....3153 ..1918-1184 .......823-650
3629/2822-1551-988/904-823 again second gears in bold .
the TF can do amazing things, if you let it.

But
There is no argument in wanting a manual trans, just for the experience. And in the case of the AX-15, the ratios are pretty good.
You just gotta hope it doesn't blow up.

 

[Tineoidea]

Hey AJ/FormS. I really appreciate your input.
I have driven with a Dart swinger with 3 speed Torque Flite. And i just dont like automatic transmissions in a car built for fun. I have a Trans am 4spd automatic as a daily driver. It is fine for everyday use. But not for the project i am working on.
After a lot of research i decided to scrap the idea of a 5 speed swap. If i have to cut the crossmember for it to fit, the car is basically unusuable in my country. You will never pass the 2 Year inspections with a structural part cut to pieces.
So the A833 seems to be the way to go.
I found one for $$$. Rebuilt with an od gearset, including a hurst grip, bellhousing, shift linkage clutch assy and flywheel. The only thing missing is a clutch/brakepedal assembly . Is there a way to add a clutch pedal to the existing hardware, without swapping to a hydraulic actuation System?

 

[AJ/FormS]

Is there a way to add a clutch pedal to the existing hardware, without swapping to a hydraulic actuation System?

Yes, you just put an add on FABO, and somebody will sell you what you need. Don't forget, that you will still need to cut the side of your tunnel out to install the shift rods. And you need a flat area on top of the tunnel to mount your shift boot to. The factory made a part for that and we commonly call it a "hump". You need to weld it in and seal it to prevent water and dirt from getting in.

But I just want to remind you that the gears in that overdrive box are pretty far apart , and unless you have a low-rpm torque monster of a 318 you will not have fun with it.
The ratios are 3.09-1.67-1.00-.73od and splits of .54-.60-.73
The splits indicate to what percent the rpm will fall after the shift. So on the 1-2 the rpm will fall to .54 . In normal driving, it feels natural to shift at about 2800rpm. After the shift, the Rs will fall to 2800 x.54=1510. So your 318 better have some torque down there to continue accelerating.
The 2-3 shift is a lil tighter. Again shifting at 2800, the Rs will fall to 2800 x.60=1680
Now, depending on your rear gears, this could really suck.
For example, with 2.76s, the 1-2 shift might occur at 2800=26 mph, so the 318 now at 1510 will be asked to run to 2800 at 56 mph; that's a really long haul. After that 70mph will get you 2430 in direct/1770 in overdrive. I guarantee you that this will suck, partly because 26mph=1510 in second gear, and this gear does not need to be outshifted until 100 mph@5000. So really, your 4 speed ends up being a 1 or a 2 speed, in town. I don't see that as being any fun at all.
On the other side of the coin, the deepest starter gear that is any good is about 11/1 .. With the 3.09 low gear, this requires a rear gear of 3.55s
So shifting at 2800 again will get you second at 20 mph still at 1510. Second gear is now good to 77 mph, so you still have a 1 or a 2 speed, around town, mostly a second gear only car now.
But say you have 3.23s, and hold first to 4000= 32mph. On the shift, the Rs will fall to 4000 x.54=2160, and second gear will hit 60 at 3530, so from ~30 to 60 you will be in second gear .
I urge you to do your own math with whatever gears you have, and make a decision based on math, leaving emotions on the doorstep.

If I could, I highly recommend the Commando box for you. the ratios are
3.09-1.92-1.40-1.00. In a 318 Swinger, she will like 3.55s. The splits with this box are a much tighter, .62-.73-71

Second best would be the standard box with ratios of 2.66-1.92-1.40-1.00,
And splits of .73-.73-.71.. the only difference between this and the Commando is the low-gear, that gives you 16% more take-off power ; like this;
3.09 x 3.55=10.97, whereas with the 2.66 that 10.97 will cost you
10.97/2.66= 4.12s
The rest of the ratios are all the same.


The formula is; mph= (rpm times TC) / (1056 R1R2)
where Tc = tire circumference, and the Rs are your gear ratios.
To find rpm, you re-arrange the elements like so;
rpm=(mph times R1R2 times 1056)/ the Tc
Happy Hotrodding.