petrol to deisel fourtrak engine change


ive reasently puchased a 1990 fourtrak but have now found it is rotten as a pair :mad:
i've seen a Breg one for sale at the right money but its petrol! so im thinking of swapping the engines. has anyone done this transplant? is there a lot of modifing to be done? will it bolt strait to my gear box or will i have to change that to? any reply's would be greatfuly recived
thank you

Its ok dosnt matter any more

Its ok dosnt matter any more got myself a deisel short wheelbase in mint condition for £695 buzzing! cant pick it up till monday night though aahhhhh!!!! going to have a root down the back of the sofa see if i can get the beast tonight

p to d conversion

the conversion shouldnt be a problem, if you have both complete vehicles you should have all the bits. actually changing engines should be no problem , basically it sits on engine mounts which bolt to the chasis, the engine block bolts via thae bellhousing to the gearbox and connects through the clutch to the gearbox shaft. next the cooling system , rubber pipes to the radiator change the rad if they are different , fuel s ystem may be a bit more fidely , the diesel needs a return pipe from the injection system back to the tank, if the petrol is a single pipe system you will have to run a return line to the tank and maybe swop the tanks if there is no blanked of port for the xtra pipe. then comes the electrics simple things like temp gauge senders may be in different places and need wires extending, but the big difference is the preheat system for starting, you need the diesel ignition switch with the extra preheat position and wiring to the preheat relay, there is a preheat warning light in the dash as well.
As i said at the start if you have both vehicles you will have all the bits, If you have a good understanding of the diesel fuel and electrical systems there should be no insurmountable problems . get the workshop manual its worth it for the wiring diagrams alone.

Definatly easier with a doune

Definatly easier with a douner car. Cheaper too.
I don't know about the bolt on engine mounts though. They bolt to the engine block, but every 4trak I have played with has had the mounts welded to the chassis. A UK spec thing?
The bell housing is diffrent, but the petrol bell housing bolts streight onto the Diesel box. The petrol gearbox primery shaft is longer than the Diesle. In fact all F20 through to F78 gearboxes are the same (except the adition of a 5th gear), but for some reasion when Daihatsu bilt the F80/85 they desided the Toyota engine needed to be just that bit further away from the box. The diffrence in length is not a great deal, but it is enugh.
The rad pipes are on the wronge side. This can be overcome with emaginitive pipe work, (I have an F75 rad in my F80). Again though changing the rad would be the easiest solution. I seem to remember that the heater hoses are also on the opposit side. These again cane be made up with some imagination, or again the doner car is the easiest option.
The fule system I don't remeber having a problem with, (it was some years back though). I seem to remember the fule return on the engine I was using whent back to the rear of the lift pump, negating the need for changing the fule system, apart from to install a Diesel filter.
I did not have a doner car avalible, so I ran my pre-heat from a self returning button on the dash (something I have also done in F50's when the ignition barel desides to stop cooperating). About 10 seconds of preheat on a cold morning, 5 on a not so cold, and not at all if the engine has been running within the last hour or two will see you about right. You do need the relay though unless you are an electronics wiz (or know one), as the voltage is also changed. Putting 12v through your glow plugs will burn them out. I seem to remember 8v being about right.
Totaly agree with Richard though, about there being no majour problems. Just lots of small ones. It took me a day to strip the petrol engine out, and get the Diesle engine bolted into place on it's new mounts, and upto the new bellhousing (new being a relitive term). Then it tokk me three more (long) days playing with all the other bits and getting them to fit and work. As I said though I did not have a doner car, which would have made life so much easier.
Good luck.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.

My first post a hyjack, sorry

My first post a hyjack, sorry but i cant post a new topic it just keeps going round in circles for me some how

Had Daihatsus for years, about 5 years ago i had a 1990 feroza 1.6 carb model. it replaced a F50 vertualy from new and i still run a 1985 turbo fitted with a latter timing belt engine that replaced the this day.
I got hold of a 1987 fourtrak turbo, cheap a couple of years ago and its in the back shed for parts, a decent older geared DL turbo engine and a nice box etc in it.

Allthough i like the fourtrak and actualy prefer it to drive over the feroza i quite fancy a diesel engine in a sportrak, i had the feroza and fourtak for about 1 week before selling it and i looked at if i thought the diesel whould fit, i could see no reason why it whould not fit just by looking, as anyone ever fitted one in a sportrak, there are a few spoirtraks on ebay and my old fourtak had to have a bit of welding done in the back wheel arches for this last test, i was thinking about looking for a sportrak and having a go at converting it.

Any ideas welcome and all advice greatfully recieved, will i get away with just winding the torsion bars up a bit for the extra weight or will i need stronger bars themselves off the fourtrak indy front perhaps. Help!

OH! ps i am Rick by the way thanks for looking at my request.

petrol to diesel

I'm interested too. Please tell me if you have managed the swap.

It can be done. I'd sugest f

It can be done. I'd sugest finding a cheap (body totaly roten for eg) donour car for all the parts you will require. Cheaper in the long run probably. Problems to over come:
1. The bell housing, and primary input shaft intoi the gearbox are diffrent. The gearbox is the same for both modles apart from these two things. Both of them can be fited into you existing box, or a compleat box from a doner car can be used.
2. The engine mounts are in diffrent places. Not difficult to manufacture new mounts from 4mm plate, and 3' box section/channel. Easier is to cut the compleat mounts out of a douner car, and weld them into your moter.
3. The first pipe of the exhoust is diffrent. Bye a new front pipe, or take one from a doner car.
4. The electrics for starting. Take the live feed that was feeding the coil, and take it to the Diesel pump (asuming this is a DL engine).
5. You need to find somewhere to fit the Diesle filter, air filter and other such ansilaries. Again having a doner car alowes both taking of said ansilaries, and seeing where they fit into the vehicle.
That's all I can remember from when I did the same thin a good few years back.
Having hade both Diesel and Petrol Daihats since then though I would sugest you just stick wioth the Petrol, unless you are intending to do lots of towing or carrying heavy loads. I say this becouse exempting those two senarios, I have found the Petrol to be a match for the Terbo Diesle in both econamy and performance. The non Terbo Diesle is more economical, but has all the performance of a snail, on Prozak.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.


Oh boy. I would love to see a snail on Prozak. A Citreon '2CV' would beat it away from the traffic lights,and that takes some do'ing.

(What a terrific quote)

Edward (ews) '92 Fourtrak 2.8 TDX


I was gonna chip in that it is my understanding the drive ratio's on a petrol and diesel diff's are different (1:4.somthing on the diesel vs, 1:5.something on the petrol), therefore if the engine does drop in OK, but the diffs remain petrol diffs, you might find yourself behind the wheel of a rather low-geared fourtrak Wink

n.b. More than willing to be corrected on this - cant remember where I got it in my head that the drive ratio's on petrol/diesel diffs are different, but if anyone can confirm this, it might be an interesting 'fix' for people running such uber-large tyres on a diesel that they are not able to use 5th gear.

But as you've found another fourtrak, no worries Smile


p.s. If you find any spare dosh down the back of the sofa, I always accept donations Wink


warning: may contain traces of nut.

You are correct about diffren

You are correct about diffrent ratios. But it is the Transfure box that is diffrent, not the diff's. Forgot that nugget on my other post in this thread. Oops.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.


Thanks Nev, glad you could clear that up Smile Any maybe it's something that Diesel drivers with large diameter tyres might keep in the back of their mind .... nab a transfer box from a petrol fourtrak.

All the best



warning: may contain traces of nut.