Fitting a turbo to a mk3 2.5 DI

[redeemer]

Had been searching in some scrapyards to find a mk5 maniflold completed with a turbo but no luck!
SO I came across a Garret turbo which was fairly prized, and bought it with the intenton of fitting it to the silencer flange.




But no luck and at that position where the silencer fits it became too close that will hit the engine mouting, so I had to work a flange plate and fiting it in a positioncloser to the front.
I had a spare manifold and worked on as the mk2 manifold and mk3 are the same exept of the silencer flange:



Then I blocked the exhaust hole:



Welding of cast iron isn't that of a fun to do because it spaters a lot , and I used the arc welding using adaptable rods.
this is what it going to look like:



Any one here can recognize whet type of turbo is that?
Its a Garret and have been told its a T12 or T 12 5 ?? Don' understand these numbers but what do they mean?

Also another question what is the boost pressue on a 2.5 efi turbo engine??
Have been told by a guy that 1 bar or lowwer is the right range for the boost, and told me that he has two 2.5DI engines on a boat fitted with these kind of turbos and a bosch pump and are boosted up to 2 bar and gave him 130 bhp what do you think?


more piccies to come...

[AndyG]

Nothing on your local E bay or the like

All I can confirm, is that the boost pressure does run at about .9 on mine

Boats use different injectors and don't need to meet the smoke regulations as we do in our vans (in the UK anyway)

[redeemer]

Well the turbo is installed and test driven
well the power has improved considerably and weather its uphill or not the van keeps going in the 5th gear

This is the sump with the elbo brazed to it:



For the intake pipe I used a piece of a scraped transit silencer
as I didn't wanted to spend much £££££ for this conversion, used many things taken from the trannies I scrapped, pipes and hose pipes from the radiators:






for the high pressure supply of oil I mede a T joint from the outlet to the vacuum pump and Whent to a shop to make the high press pipe of about 90cm to supply the turbo.



And return pipe:



The problem after I test driven the van is that the manifold is cracking from the turbo flange to the inside, and I grinded the crack and welded it and added a support rib with the manifold in place (Not my best welding as it was in an awfull postion and cast iron welding -aghhhh)

[redeemer]

Now after a few days of driving I found that the turbo was puting oil in the intake pipe to the engine.
That could mean that the turbo has worn journal bearings and seals, but went to the scrap yard where I bought it and told me to remove the 90 degeres elbow and instead of it use a straight pipe and welded in slanting position. Had done this and now I need to give it a good trip to test it.

Another problem I m observing is that the oil filler cap is being fired out . Every time I open the hood I find a mess
Can anyone tell me if the original turbo di has a breather pipe going into the mainfold, or at least a pic of how the top cover cap is?? I think that execssive pressure is being created in the top cover, from the normal air pressure coming from the cylinder block and from the new added presure of the turbo.
any sugesstions?

[doggypaddle]

1)No turbo diesel will EVER have a breather to the inlet manifold. the breather must go to the intake side of the turbo or you will pressurise the crank case and blow the seals out of the engine......lots of work if its the main bearing one behind the flywheel!
2)if the turbo is putting oil into the manifold its jiggered end of story. are you sure its not oil from the crankcase breather when you let off and all the pressure rushes back out of the rocker box into the inlet manifold carrying oil mist with it??
3) how about trying MIG welding? i succesfully welded up manifolds like that before, if its SG iron it welds OK.
4) How are you getting extra fuel to go with all the extra air you have? have you used a pump with a compensator? or just letting it overfuel at the low end before the boost builds up?? like old school TDs

well done on te conversion its nice to see people having a go at what many tell us isnt possible. i turboed a DI in 87 and it was a success. dont go mad with the fuel or boost though the turbo DIs had stronger pistons and wrist pins, also i believe a spray bar under the pistons to cool them. a little whiff of black and .5 bar boost should be OK.
seen a 6 cylinder york turboed too, in a rangerover. went OK.........for a york!

[redeemer]

1)No turbo diesel will EVER have a breather to the inlet manifold. the breather must go to the intake side of the turbo or you will pressurise the crank case and blow the seals out of the engine......lots of work if its the main bearing one behind the flywheel!
2)if the turbo is putting oil into the manifold its jiggered end of story. are you sure its not oil from the crankcase breather when you let off and all the pressure rushes back out of the rocker box into the inlet manifold carrying oil mist with it??
3) how about trying MIG welding? i succesfully welded up manifolds like that before, if its SG iron it welds OK.
4) How are you getting extra fuel to go with all the extra air you have? have you used a pump with a compensator? or just letting it overfuel at the low end before the boost builds up?? like old school TDs

well done on te conversion its nice to see people having a go at what many tell us isnt possible. i turboed a DI in 87 and it was a success. dont go mad with the fuel or boost though the turbo DIs had stronger pistons and wrist pins, also i believe a spray bar under the pistons to cool them. a little whiff of black and .5 bar boost should be OK.
seen a 6 cylinder york turboed too, in a rangerover. went OK.........for a york!

Thanks for replieing doggy paddle
I have been thinking of that before that the oil is coming from the breather, because all the di's are famous (at least here) that they "smoke" from the top cover, and what I noticed also is that the air cleaner housing that it had before also had a tiny mist of engine oil. maybe the valve stems seals are in there retireing period

Yesterday I opened up the intake pipes from the turbo and it seems to be more likley to have oil nearer the engine than the turbo. The inside of the turbo housing which is the output from the compressor had only a thin mist of oil. But surley that 90*elbo which I made to the sump was somehow restricting oil return, and now changed that to a straight pipe.
Doggypaddle I compensed a little more in diesel by "opening" from under the blue cap of the Lucas Cav. But thats only a temporary measure as I plan to convert to Bosch. I have a mk2 di bosch pump , but I think a turbo di Bosch pump would be greater.??

Now if the breather is carrying a mist of oil I shouldn't put it on the turbo intake either
One more question, where its most suitable to fit the outlet to the boost gauge , in the inlet manifold??

[doggypaddle]

put the boost gauge either in the manifold or if there is a little rubber hose on the turbo to actuate the wastegate you and tee into there if its easier.
crank case breather, lengthen the pipe and shove it in the chassis somewhere or let it drip on the floor or into the turbo intake is OK, but if its a bit breathy the floor may be best!
a turbo DI pump is the best option, at least thats got a compensator diaphragm, so you can get the extra fuel on boost and avoid plumes of smoke when the turbo is playing catchup at low RPM. the compensator diaphragm can connect to the same place you take the boost gauge from.
once you have extra fuel you may find you need to adjust the wastegate a bit on the turbo so you dont overboost,
they are easy to adjust. if you have no wastegate then the fueling is the onlyway to controll the boost.
the bosch pump is better for teeaking than the cav. My last DI i couldnt get it to smoke at all with the cav pump! there is an inteernal adjustment too, and the external is for finer tweaking, so its posible if your unlucky not to have much adjustment there.
your elbow for the oil return looked OK to me, i wouldnt have thought it too restrictive, i would be more concerned about getting enough flow from the pressure side.

[redeemer]

Thanks for the info mate your a star
I have done that Tee on the little waste gate actuator pipe, and it does not mark anything after the engine is reving a bit high.
Now in search of a turbo di inj pump, not easy to find that part here
Anyone have something??

[MinorMatt]

not an easy part to find here either!

[doggypaddle]

do you mean youre not getting any boost pressure?
you wont get any unless the engine is revving and under load, i wouldnt expect to see more than 2-5 psi without a compensator as you wont have a great deal of extra fuel to burn.
My 2.8 tdi doesnt generate any boost by just revving it, it doesnt create much in 1st gear either but once you load the engine up in 2nd you should start to build boost.
It may be worth checking that little hose is clear and the wastegate diaphragm isnt leaking, with a pipe that small it would leave nothing to measure, although the main intake may have a bit of boost.
IT must be doing something because it goes better?
I wonder if a landrover TDI bosch Ve pump is similar enough to adapt? Using bits off the bosh DI pump you have?
or even if you can get ore fuel easier with the bosch pump anyway?

[redeemer]

so as you are saying, the boost gauge is reading correct as it only measures boost when loaded and reving high. I asked that question because Im sort of new to these things, never had a turbo diesel before...
Now The bosch pump I have might have lowwer injection pressure because it comes from a mk2 di (early di), which affect the throttle response and can have emmision problems. It will be much more reasonable if I fit a turbo di pump , since it will be more adapted to work with the turbo.
for now I will settle up things such as the breather problem and be sure thet the turbo isnt faulty , then after I do some university exams I may continue to convert to bosch if I find a pump.

[doggypaddle]

injection pressure is set by the injector crack pressure, changing the pump will not affect that.
personally i would fit the MK2 pump and injectors and pipes if needed, and try it.
looking at a few Ve pumps i have dismantled the only difference between turbo and non turbo pumps is the diaphragm and link that attaches to it. certainly on perkins engines anyway.
the mk2 di bosch pump will be easy to fuel up and fiddle with and cheap!
when the compensator diaphragm split on my engine with the ve pump, it was very flat, as a temporary measure i just screwed the fuel screw in on the back of the ve a few turns, apart from a bit of smoke at low rpm it went really quite well.
if you get the turbo sized right(maybe a smaller unit) it will spool up at low rpm and you might not need a compensator.

[redeemer]

What do you mean by crack presure ? SO the pressure depends on the type of injector? Im always eager to get to know more...
Therefore if I install the mk 2 pump I should get black smoke at low rpm, but else it works fine with the diesel opened up a bit.
Should dismantel it out of the engine and take it to service.

[doggypaddle]

the crack pressure is the pressure at which the fuel pressure in the injector overcomes the pressure exerted by the needle spring in the nozzle, the needle lifts and the injector opens spraying fuel into the cylinder. the higher the pressure the finer the mist and the more effecient the engine will run. the pressure will be factory set to the best setting for the engine with a particular injector pump. modern common crd engines run higher pressures and therefore get better atomisation and burn more effecienttly, this is partly why a 1.9 VW diesel makes nearly double the power of a 2.5 di even with a turbo!
yes i would try the mk2 pump cos its easier to turn the fuel screw in!
you may need to work out the timing marks and/or get the pump locked at injection point at a diesel shop to time it up correctly. you will probably need to fine time it "by ear" to a certain extent anyway, increacing the fuel increaces the injection period and you may get away with more advance, turbo engines tend to run more advance anyway.
you know what it should sound like......if you get no DI clatter advance it a bit, if its noisier than before retard it a bit.
after a few Months of tweaking i got mine right!!
Seems to be a compromise with DIs when they are unbearably noisy they go well,and the quiet ones are flat

[redeemer]

Thanks for that valuable info mate.
I know what you mean by saying to time it by ear, as I have already swaped the pump because the previous one had been given bio diesel (before I bought it) and was fu** up.
Again thanks