A833 OD Behind a Ford Engine
i have a A833 OD, and can't really find any molar engine in my country. but i have a 260 cui ford engine laying around, and was thinking about if i could use that on my a833 od
100 more cubes and you can forget the od, just gear your vehicle appropriately.
Say what?
well the od ratio of the Mopar box is .73, which is the same as 1/.73=1.37, and
1.37 x260=356 cubes.
The 356 cuber will make enough low-rpm torque to pull any hiway gear you want.
Here's an example;
for the 260
suppose you target 65mph @2000 rpm with .73od.. That would take 3.35 gears. The low gear is 3.09 so your starter is
3.09 x3.35= 10.35 not bad. Now say your 260 puts out 260 ftlbs at IDK, say 2400 rpm. That means, your most torque-ful take off will be 260 x10.35=
2690 ftlbs.
Ok, so now lets look at at that 356 cuber. To hit 65@2000 with a direct gear would take a 2.45 rear gear. Suppose you found a NON-od manual trans with a 2.66 low, your starter would now be
2.66 x 2.45=6.52 and to equal that 2690 ftlbs of the 260 would require; 2690/6.52=413 ftlbs.. Ok that's a bit of a stretch.
Lets try it with an automatic, say a 998 loc-up with a 2.45 low gear, and a 2800TC with a TC ratio of 1.8.
To get 2000 @65 will take 2.45s again for a starter of 2.45 x 2.45=6.00 sounds bad right? But recall that the TC has a multiplier, at zero mph of ~1.8 so then;
1.8 x 6.00=10.80!, surprise surprise. So to get 2690ftlbs we need 2690/10.8=259 ftlbs from our 356 cuber. Easy-peasy
Ok but that 1.8 ratio starts shrinking just as soon as the car starts moving. And in first gear will eventually reduce to maybe 1.4. so then
1.4 x 6.00=8.4, and now that 356 needs to put out 2690/8.4=320 ftlbs, hah!, she ain't even working hard yet; that is easily doable with a 2800TC.
But hang on, you really want a manual trans.
Ok, then choose a Mopar Commando trans with a 3.09 low gear.
To hit 60 you still need the 2.45 rear gear, but your starter is now
3.09 x 2.45=7.57 and 2690/7.57 will then require 355 ftlbs from the 356 cuber. That is still doable.
Now, to throw a monkey wrench in here, that 833-od has ratios of
3.09-1.67-1.00-.73 with splits of .54-.60-.73 Which means the 260 is gonna struggle to be anything but a grocery getter. whereas the Mopar Commando has ratios of
3.09-1.92-1.40-1.00 and splits of .62-.73-.71, which is like a close ratio, and the 356 cuber will rocket thru those.
Lemme line it up for you, as roadgears; first the od with 3.35s then the Commando with 2.45s
10.35-5.59-3.35-2.45
- 7.57-4.70-3.43-2.45
Well lookit that, in this case the od-box kindof makes sense; but, lets put the ftlbs in there;260 max for the 260 and 355max for the 356 cuber.
2690-1453-871-637 ;the 260/A833-od
2687-1668-1217-870 ;the 356/A833 Commando
Badaboom, there it is; the Bigger numbers are better.
Btw;
say the 260 makes its 260 ftlbs at 2400 rpm; that would be 119hp. If the 356 cuber makes it's peak torque at 2800, that would be 190 hp. Easy numbers for either/both of them.
Ok but
you have this od box and you reeeeeeally want to make something of it with the 260. Riddle me this; Can you make the adapter, and all the mounts, put together a flywheel and clutch, hook up an exhast, etc..... for less or the same money as just getting a SBM delivered. And afterwards, will the 260 make better fuel mileage, and how many years will it take to pay for all this in fuel savings?
Is it doable? sure.
Will it be cost-effective, IDK
Will it be frustrating? probably.
In the end; will the 260/3+1 satisfy your need?
Only you can say.
