Ok let's try this. - Mazdatruckin.com Truck Forum and Tech Site

Gordo · #1 (**permalink**) 10-16-2009, 02:41 AM

Hi there. I have a 91 B2200 with a hole thru #1 piston from dropped exh. valve. Recently acquired a 1984 B2200 diesel. Runs well but was crashed. I'd like to put the diesel from the 84 into the 91. Make one good truck out of two victims. Any info would be appreciated. I know it won't be as much fun as a 350 or a 302 but maybe a bit easier. Anybody done this swap?

Kyrasis6 · #2 (**permalink**) 10-16-2009, 02:49 AM

I believe you would be the first. Any specific questions you have?

dealwithit · #3 (**permalink**) 10-16-2009, 03:01 AM

should be a good swap, crazy cheap on fuel too. the worst part will be the motor mounts, as the trans im pretty sure is the same center section as the one in your gas truck, just swap off the tail housing (really really easy!) and it'll mount right up to your factory tranny mount and the stock driveshaft will work too. just cut the engine mounts out of the crashed 84 and weld them in where they line up on the frame in the 91 ( you'll most likely need to cut out the stock gas engine mounts as well). its always possible that another thing comes into play as well, the best bet is to first swap the tail housing, bolt up the crossmember and sit the engine in place while its hanging from something and see how close the mounts are

i've never done this swap before but i've done enough into mazdas

Gordo · #4 (**permalink**) 10-16-2009, 03:13 AM

Thanks very much for that tranny tip. Not sure what to do about engine mounts yet. Looks like the frame rails are further apart in the 91.

Gordo · #5 (**permalink**) 10-16-2009, 03:18 AM

Not exactly what I wanted to hear; but sometimes one has to be a pioneer.

EmJay · #6 (**permalink**) 10-16-2009, 03:41 AM

I do have to second that the motor mounts are going to be the hardest part of the swap. However when another user put a BP Protege motor into an 84 he was able to use the trannie from the 1st gen and put a miata bellhousing on it. We also know that the miata gearbox will bolt onto the 2nd gen bellhousing so trans should be pretty easy to work out

Gordo · #7 (**permalink**) 10-16-2009, 03:50 AM

Is there any way to tell if the tranny center sections are the same for diesel and gas? Casting number maybe? All I know so far is that they are both 5spd with same shift pattern.

dealwithit · #8 (**permalink**) 10-16-2009, 05:22 AM

they will be exactly the same as far as fitment together, they might have slightly different ratio's, but that won't effect anything.

EmJay · #9 (**permalink**) 10-16-2009, 06:45 AM

all else fails, use the diesel bellhousing and gearbox, and have the tail piece for the 2nd gen.

Gordo · #10 (**permalink**) 10-16-2009, 06:57 AM

Great to hear, custom driveshafts are an expense to avoid if possible. Lots of other things may make this swap too much trouble to bother with though. Fuel tank, exhaust, starter, clutch slave cylinder are all on opposite sides of these trucks. Not giving up just yet...thx very much for your help.

EmJay · #11 (**permalink**) 10-16-2009, 07:39 AM

fuel tank, no problem. just run a longer line. starter should be fine as well, either relocate the battery or run a longer wire. Personally I wish I found a motor like the one that you got.

Kyrasis6 · #12 (**permalink**) 10-16-2009, 07:22 PM

DO NOT USE THE STOCK DIESEL TRANSMISSION, it has some serious design flaws. My dad has the 83 diesel and blew the transmission all over the road 3 times before we figured out the flaws. It will not handle heavy loads, dumping the clutch, or going in reverse quickly or with a load on it. The reverse idler gear is only supported on one side of the shaft and when there is load on the tranny it bends the pin and blows the whole housing apart.

My dad eventually took the entire transmission apart as well as one of my old 2nd gen transmissions and put all of the 1st gen parts together using the housings and reinforcement plates from the 2nd gen. Took him a week to do it. He had to do it this way because the steel plates used in the 2nd gen would not fit with the 1st gen center housings. I would just put the 1st gen bell housing on the 2nd gen transmission and use it.

dealwithit · #13 (**permalink**) 10-17-2009, 04:34 AM

yah, you actually have a pretty simple setup as far as swaps go, you'll have no wiring to deal with once its in except the starter, alt, and glow plugs

Gordo · #14 (**permalink**) 01-09-2010, 08:45 PM

Got the 84/91 b2200 diesel project done. Even moved the "diesel engine" decal to the 91 by cutting the steel from the tailgate along with the decal. Looks like it belongs there.Hoping to post a couple of pics if I can figure out how. I even found a place that can supply a rebuild kit for this orphaned Perkins 4.135 if I ever need it. $1949.00 U.S. plus $88.00 shipping from Michigan. No problems with the tranny yet; but you have me a bit worried now. Oh, well there's always plan B. A V-8!! Thanks for all your help guys.

axel breaker earl · #15 (**permalink**) 01-09-2010, 09:05 PM

What!! No Pics??!!