Thread: Turbocharging the 2.25L Diesel

Originally Posted by Tank

Anyone done this? What are the Pro's and Con's? Is it viable? What results has anyone that has done this got? Have a small Turbo and am doing up a 2.25L diesel, would love to hear comments, good or bad, Regards Frank.

I don't have any experience, but when Landrover turbocharged the 2.5 version of this engine in about 1987, it rapidly gained a reputation for having all sorts of problems, such as excessive blowby which together with the crankcase ventilation system managed to make the engines run away on their oil supply, which continued until they ran out of oil and seized unless they were stalled, plus other problems such as cracked heads and blocks. (This engine was never sold in Australia, and although there may be a few privately imported it seems unlikely - anyone run across any?)

Having said this, I can't see any reason why a very mild boost would cause problems. Why not consider adding LPG? You would get a subsidy for that, and could use it to get a similar increase in power plus additional advantages.

John

Can't see any problems if you are only going to raise boost no more than about 8psi over atmospheric. My experience with engines modified to pressurised intake, over the years, has been that high boost brings multiple problems. You will need the services of a diesel technician with a pump room, to increase fuel delivery to take advantage of the increased volume of intake air.

Reasoning behind Turbo was to compensate for higher gearing to get a reasonable cruise speed in '78 Series III LWB, maybe 4 or 5 PSI over 1 atmosphere and a tweak for the pump to compensate for the extra air and a good exhaust system. I don't want to change the character of the car too much, just enough to make it comfortable at 95/100klms/p/h.
I was hoping that someone on this Forum may have done this conversion and could fill me in on the Pro's and Con's, I do intend adding LPG for a boost as well, any info on that as well would be appreciated, Regards Frank.

I have toyed with this idea over the years and done a bit of research. Not sure if I will turbo my 2.25D or just drop in a 4BD1 though. I have modded the pump to increase performance though.

There was a turbo kit for the 2.25D available in the 70's and 80's - from Janspeed I think. Richard turner (from turner engineering in the UK) built his own 2.25DT for fun also.

I would be conservative with the boost (5-7 psi), no need for an intercooler at that boost level.

As for tweaking the pump, the fuelling is not as easy to adjust on the CAV DPA pump as with in-line type pumps. But what I have done is this:

On the side of the pump barrel there is a large nut (this is the advance mechanism). Under this nut will be 2 concentric springs and a plunger. Removing the inner spring or replacing with one with thinner wire will make the timing advance quicker. I removed the inner spring and replaced it with one made from 0.3mm thinner wire (I think the standard was 1.1 and I fitted a 0.8mm spring). Some diesel shops who mod these pumps also machine the plunger down, but be careful if you are doing this and only try a little bit at a time.

The only other place you can really make any adjustments is in the linkages under the small box on the side of the pump. You need to remove the accelerator and engine stop linkages, then the two nuts which hold the box in place. There are about 9 combinations of the linkage settings available to you. Make sure you write down or photograph the standard config. before changing anything. But this is where you can really up the fuelling after the turbo is fitted.

Originally Posted by isuzurover

I have toyed with this idea over the years and done a bit of research. Not sure if I will turbo my 2.25D or just drop in a 4BD1 though. I have modded the pump to increase performance though.

There was a turbo kit for the 2.25D available in the 70's and 80's - from Janspeed I think. Richard turner (from turner engineering in the UK) built his own 2.25DT for fun also.

I would be conservative with the boost (5-7 psi), no need for an intercooler at that boost level.

As for tweaking the pump, the fuelling is not as easy to adjust on the CAV DPA pump as with in-line type pumps. But what I have done is this:

On the side of the pump barrel there is a large nut (this is the advance mechanism). Under this nut will be 2 concentric springs and a plunger. Removing the inner spring or replacing with one with thinner wire will make the timing advance quicker. I removed the inner spring and replaced it with one made from 0.3mm thinner wire (I think the standard was 1.1 and I fitted a 0.8mm spring). Some diesel shops who mod these pumps also machine the plunger down, but be careful if you are doing this and only try a little bit at a time.

The only other place you can really make any adjustments is in the linkages under the small box on the side of the pump. You need to remove the accelerator and engine stop linkages, then the two nuts which hold the box in place. There are about 9 combinations of the linkage settings available to you. Make sure you write down or photograph the standard config. before changing anything. But this is where you can really up the fuelling after the turbo is fitted.

Ben, thanks very much for that info, I already have a small turbo and the boost will be low, I will have to do some research on LPG injection as well, not sure but if LPG was used in conjunction with the Turbo the pump might not have to be modified, will check it out, Regards Frank.

Tank - I would give the LPG injection a miss if I were you. To do it legally and properly costs about $4k from what I have seen.

Originally Posted by isuzurover

I have toyed with this idea over the years and done a bit of research. Not sure if I will turbo my 2.25D or just drop in a 4BD1 though. ......

I very much doubt whether the 2a's gearbox, rear diff or rear axles will stand the 4BD1, although the transfer case might. This engine, because of the amount of low speed torque from only four cylinders and the fact that it runs pretty roughly at low speed, is very rough on drive trains. Of course, you could put in an LT95 as well, but this implies either converting it to optional 4wd or fitting CV joints to the front axle - either is a pretty big undertaking, and of course, you would have to fit a salisbury rear, which is not a big job. Seems to me that a turbo on the 2.25D would be a lot easier!

John

Yeah the Turbo kit for the 2.25 was done by Janspeed in Salisbury , wiltshire ,UK http://www.janspeed.com/

Have a book on it all , but in a box down stairs , but will be about next week when i move into our new house. So will dig out so more info on it then if you need it

Also my brother is sponsered by them (for his racing) so knows some chaps there. so can get some info direct if you want