Any help with a 4WD diesel swap?

Evergreen · Post by **Evergreen** » Wed Nov 23, 2005 3:45 pm

Hi there,

I am new to this board and I wanted to see if anyone here could help me on my quest. I am currently trying to research the feasabilty of swapping a Toyota diesel into a Terc4WD. Any information you could provide would be most gratefully received.
I am interesed in diesel power for improved fuel economy, durabiltiy and increased torque. I was hoping that it would be possible to use a 1C or 2C or 2C-T. Does anyone know if this is possible. I am trying to figure out if the engine will bolt up to the tranmission and motor mounts. I know that these engines are a bolt in swap for corollas with the 4AC so it seems to me that it could work. Does anyone know the name for the transmission used in the 4wd? Does it have the same bolt pattern as the FWD? Any info or feedback would be great.

My dream is a high-efficiency biodiesel Tercel raised up a couple inches with tougher tires and skidblate trailer hitch etc. I want to get great mileage on the way to Baja and have it be tough enough for fun when I get there.

BTW those action shots in the gallery are great! These little suckers are tough.

tercel4wdrules · Post by **tercel4wdrules** » Wed Nov 23, 2005 7:11 pm

This has been discussed before in at least 2 threads on this board.

The four-wheel-drive transmission, depending what year you have, will be either a Z52F (83-84) or Z54F (85-88). If you have an auto trans that would be the A55F. This is quite a project you got planned here. Good luck! Other members will be able to assist you with the other questions. I was thinking about something like this, but fabricating an adapter and bolting on one of the diesel engines will be a great challenge to do so, but it should be possible.

Typrus · Post by **Typrus** » Wed Nov 23, 2005 7:19 pm

Heh...
Well now. Lets list the issues;
Weak tranny doesn't like over 100ft/lb torque
Conversion from carb to EFI
Conversion from gas to diesel fueling system (essential overhaul of the fuel-carrying parts)
I dunno if the Toyota diesels have crossflow heads, but if they do... Exhaust routing is an issue.
Wiring harness routing and location.

Not only that.... There is more.

Advantages?
Increased fuel economy
(Turbo) Increased power
Torque, torque, torque!!
The smell of diesel in the morning.

I don't know massive amounts about Toyota diesels, but as far as I do know, they are sluggish and smokey.

A diesel option I have repeatedly examined is the 1Z VW TDI. Thats the Volkwagen TDI, 1Z. Particularly the 96 model year from a Passat. My mom has a Passat so I've looked at it a few times and see some advantages. I'll elaborate more later.

Typrus · Post by **Typrus** » Wed Nov 23, 2005 8:00 pm

The TDI is not a cross-flow head, so both the intake and exhaust are configured on the same side as ours. That makes it easy in terms of exhaust routing... Well, kind of easy.... Along with that, there is a large following with the TDI's (more for the Golfs and Jettas) in terms of aftermarket. There are a few that have gone over 1000ft/lb of torque, which is even a large amount for the V-8 diesels (Duramax and Powerstroke)
When I drive my moms Passat, which weighs about 350lbs more than our cars, it still feels very sporty. Heck, I can wrap it up to 110 mph before it starts hesitating to advance. With a redline of 4900 lol.
Additionally, my mom's Passat gets about 52mpg highway @ 70 mph.
I measured the top mounting bolts for the trans and they are about the same (couldn't get exact measure) as the tops of ours. Still have to measure the bottom. At any rate, the engine mounts would be an interesting negotiation.

The next issue- While it would be nice if either the TDI or 1/2-C(T) would be bolt in, the tranny they'd be bolting to wouldn't much appreciate the torque. Nor the front differential. In the case of this, it'd be wise to look into our 4AGE discussions. In terms of driveline, you run into more or less the same issues.

Next contemplation- Gear ratios.
Diesels are low RPM engines (when your stroke is as deep as a diesel and your compression ratio 20:1 or higher, can you imagine revving fast?) and as such, will not go very fast in a low-geared setup. They'll rip your tires off bead but you'll be redlining at 45mph. Trade-off? If you want highway speed you'll sacrifice some of that gut-wrencing torque. Heck, I think the Passat TDI's have a 2.9:1 diff ratio. We have either 4.1:1 or 3.73:1. That 4.1:1 would make a nice rock-climber with the TDI, but good luck down the highway. An option could be to see if Gear Vendor or US Gear makes a range-changer that would work for us, and that would be quite a good option indeed. But its very likely that they do not, as all our transfer case is is a engage/disconnect unit for the rear axle. Has nothing to do with the forward.

If you really want to travel this unbeaten path, you could go so far as to find a Toyota 4wd diesel and transfer engine AND tranny (w/transfer case) over and find a way to mount a 4wd truck front axle on our beasts. This would actually clear up all the near-impossible issues associated with boosting power in these things. Those issues, again, being the front differential and the transmission itself. Not only that, but if you made the connections the same as on a 4wd Toyota truck, or maybe a 4Runner, we could use their lift kits? Imagine a 6 inch lift, or maybe even a 8 inch lift on a Terc.... Wow thats a funny picture.

Heck, if you REALLY wanted to be unique, find a way to fit a Cummins engine and a Ford 4wd system in. Torque-rolls anyone?

If you have anything to counter what I've said, or to help further my education on the matter, PLEASE tell me! I want to know more about this.

AbusedJalopy · Post by **AbusedJalopy** » Wed Dec 07, 2005 1:16 pm

I wish I could do the same mainly because then I would never have to smog it again, which is why it currently isn't being used. Looks like too much hassle from what I can tell and I'm going to try for a diesel truck instead, especially if the state is still giving 1000 bucks to junk your smog violating car.

Post by **ARCHINSTL** » Thu Dec 29, 2005 12:57 pm

Jim -
Wow - what a write-up on your link! I skimmed it out of curiousity and will return to it later just for incidental information.
Very thorough, factual, and to the point.
Tom M.

takza · Post by **takza** » Fri Dec 30, 2005 7:43 am

I owned an Escort with a 2.0L Mazda diesel in it...had grunt power for sure...ideal for offroad...about the same power as the gas engine...49 mpg.

Post by **ARCHINSTL** » Mon Jan 02, 2006 3:09 am

I copped this from a Toyota Nation Tercel Forum thread about Tercel diesels.
It's supposed to be from an early '90s Tercel - complete FWD motor and drive train - JDM.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 8025565118
Tom M.

Evergreen · Post by **Evergreen** » Tue Jan 03, 2006 9:41 am

That seller is a clown and I wouldn't trust him with $5. He doesn't know about his engines and he seems willing to lie to make a sale.