MQ turbo questions

[TwistedMQ]

hi guys i have mq sd33 with a for speed box and have just bought another one with a sd33 turbo and a five speed wich has a blown motor, and was thinking of bolting the turbo and gear box on to the other motor is there any problems i could run it doing this or is it all straight forward. is there any difference between the two motors.

[DR Frankenstine]

You deffinatally cant run the turbo on a standard sd33 (the crank will break) But you should be able to fit up the five speed behind the std sd33 motor. With a bit of messing around with tailshaft lengths and gearbox mounts. I think you will also need to use the 5spd clutch and preasure plate and throwout bearing(maybe fork as well).

[TwistedMQ]

Cool thanks! Will have to do some investigations into the gear box. What motor are you running? How much more power to you gain from the turbo?

[DR Frankenstine]

Cool thanks! Will have to do some investigations into the gear box. What motor are you running? How much more power to you gain from the turbo?

sd33t std at the moment but it is getting a straight thru exhaust, an intercooler, boost pumped up and the injection pump tweeked. should produce up to 40% more power than a std turbo diesel (then i'll probably break a crank). I had the same mods on my old packhorse and had no trouble with her. I think the turbo version of the sd33 is quite a strong motor.

[chimpboy]

I think the turbo version of the sd33 is quite a strong motor.

The turbo SD33 has an extremely good reputation as one of the really great, tough little diesels - better (they say) than the normally aspirated 4.2 diesel that came after it.

I am surprised to hear you can't bolt the turbo components to the standard motor. I'm not disagreeing - I really don't know enough about them - but I thought they were basically the same and expected the answer to be a very loud "yeah do it man!"

It would definitely be worth finding a way to get the turbo diesel fitted and running, even if it means more than just swapping external motor components.

Diesels need turbos just to run like they should... kinda like I need caffeine in the morning.

Jason

[Screwy]

With the Turbo, as has been already said. You cant Run a Turbo of any description whether it be aftermarket or a standard one of a SD33T on a Standard natually asperated SD33. The crank in the SD33 is smaller and not designed for the power output, it will only last a few weeks on a turbo before things start to foul up.
The 5 speed box is not a drama. Use the Driveshafts off the other MQ with that the 5 sped came out of, and u will have to modify the gearbox mounts i think also.
Other than that ur right i think.

Screwy

[TwistedMQ]

Thanks guys might have to look into doing a rebuild on the blown turbo motor. The turbo engine is in bits and have discovered that the head gasket is blown and has got a carbon build up on one of the bores, dont know if the carbon if from the blown head gasket or from somthing eles (valves?). Any ideas on cost of a rebuild kit want to do most of the work my self?



John

[mav]

i heard of an engine rebuilder that had rebuilt a sd33t and the customer ended up getting rid of the vehicle so the engine was still at the rebuilders i think he wanted about $3000 for it.

[V8Patrol]

I am surprised to hear you can't bolt the turbo components to the standard motor. I'm not disagreeing - I really don't know enough about them - but I thought they were basically the same and expected the answer to be a very loud "yeah do it man!" Jason

I was an advicate for the "CANT DO IT" crowd as that was what Id been led to belive and have only seen one example that did blow.... after much abuse I might add.

I've since done some investigating on this matter and I'll tell you what I found....

Being 99% of ppl recon the crank "WILL BREAK" after a turbo is fitted, I went to the local nissan dealer and got a quote on a non turbo crank and a turbo crank to suit a SD33 ....... thing is they have the exact same part number !

The crank bearings are the exact same size, as are the rod bearings !

So the only differance I can see is the block.......... but according to the "experts".... its the same block !

Ok so it must be the rods or pistons......... you guessed it ...... SAME part number !

Now either the nissan dealer has the wrong part numbers....possiable, but not likely
Or we've been mistaken all along.......... reasonably possiable,
Someone has been pulling our leg since day 1 ...... very possiable too

So we need someone who can actually fit one and test it for the truth, untill then I will move my ugly butt to the "undecided bench" and await proof so we know for sure whether or not its possiable

Kingy

Please do this someone....old yella needs a turbo !!!!

[bazzle]

The only difference Ive seen is boost compensator on the injecton pump.
Ive also seen a few turboed sd33s over the years with no problems.
Just dont go silly with the fuelling and keep the cooling system clean etc.
The sd33T runs 7lbs boost and fuel to match.

Bazzle

[slacker]

hasn't it got something to do with the compression? wont the SD33 have higher compression than the SD33T with the turbo on it making up for the lower compression? Thats how it goes with petrol motors, so i am sort or asking aswell as quoting on this matter. Do you guys know much about this?

[bazzle]

Same compression.
That doesnt change on a diesel.
Youre thinking about old school petrol motors.

Bazzle

[chimpboy]

Now either the nissan dealer has the wrong part numbers....possiable, but not likely
Or we've been mistaken all along.......... reasonably possiable,
Someone has been pulling our leg since day 1 ...... very possiable too

So we need someone who can actually fit one and test it for the truth, untill then I will move my ugly butt to the "undecided bench" and await proof so we know for sure whether or not its possiable

You know... why not give it a go?

Jason

[Screwy]

In saying that, V8Patrol is usually pretty knowledgeable about this sort of thing, i spose i dont see y u shouldnt give it a go. If anything happens uve got an SD33T with the same part numbers to get a few bits off.

cheers,

Screwy

[TwistedMQ]

V8Patrol you make a very convincing argument. Have noticed a couple of differences in the block but they are only fittings to fit oil lines to the turbo.

[V8Patrol]

TwistedMQ Wrote:
V8Patrol you make a very convincing argument. Have noticed a couple of differences in the block but they are only fittings to fit oil lines to the turbo.

That is about the only differance I could see. Blocks from the 87 model have a couple of extras again but only for other stuff non related to turbos

Like I said "I did for quite awhile belive it wasnt possiable but very much doubt I was right then.
Give me a turbo and I'll try it for you free of charge !............ trust me

[TwistedMQ]

if i decide not to use the turbo then it will probley be up for sale. might have have a talk to the local engine rebuilder and see what he has to say on the subject.

[Screwy]

yeah, may be a good idea though he might say anything to get some more dollars out of u

Screwy

[TwistedMQ]

Talked to engine builder today he said that on a less flogged engine the turbo would be ok but on a older engine there would be to much air blown back past the rings and would chew them out. . The other thing he mentiond was that the heads are different on the turbo motor.

[Juzza]

A mate did this about a year ago, has a n/a sd33 powered (or underpowered ) MQ, sees ad for sd33t motor 4 sale, buys it, motor is sad so fits turbo and pump to his existing sd33, winds up boost and fuel and drives it, things go well untill it cracks a head, has to keep topping up water (too slack to fix it). So i reckon give it a go but be careful with the too much heat factor. Anyone with a good cylinder head for sale??

[Screwy]

come easter and i might be thinking about selling off an SD33 runner when the V8 goes in!

Screwy

[TwistedMQ]

What is the going rate for a decent SD33

[Screwy]

not sure on that note, though a good condition one from a wrecker is about $2000, maybe more. Most motors from wreckers are about that much.
I wouldnt flog mine for much less than $500 though....

Screwy

[pete's GQ]

I have both the SD33t and the sd33 the 5spd and the 4spd, have done the conversion from sd33 4spd to sd33t 5spd
The head is different according to the workshop manual (diesel supplement).
I f you have a specific question i may be able to help.

[Screwy]

Pete have u got a 5 speed MQ gearbox that u would like to sell at all?? Im in dire need of one, ive got it in the wanted section too.

Screwy

[Bush65]

Same compression.
That doesnt change on a diesel.
Youre thinking about old school petrol motors.

Bazzle

I just want to add a general comment related to this (but not particularly to sd33 which I know nothing about).

Lower compression (say about 18:1) is better with a turbo diesel. The lower compression means more volume so the turbo can stuff in more air (this can not occur if NA), therefor can burn more fuel and make more power.

My 2cents.

[RMP&O]

I am going to be attemping to put the turbo on my non-turbo SD33. I have heard dropping compression is the best thing to do. No biggie to do that, I assume new rings. After checking in parts books I saw nothing different in terms of parts. They head may be but I didn't notice the head.

Why do I want the turbo? Well where I live is in the mountains, big ones. Most our 4wheeling is not in mud and I want the added power for the type of wheeling I do plus out on the highway going to Moab and so forth. Plus this is my first diesel and I want to play around with it to get to know diesel motors.

If I blow the motor no biggie really as I know where a SD33T is sitting for sale with a BW attached. Or I can simply go with a different engine such as a newer 3L Patrol turbo diesel. Or even go with the tired and true P40 which is a great gas enegine.

[nicksamaniac]

hi, i've read all of this article a few times, and i have decided to ad my own little oppinion to it.....
so, i own 2 nissans (cos they are the BEST built 4bys ever )
an 81 MQ swb, sd33 n/a, 4sp.
& a 86 MK lwb, sd33t, 5sp.

i got the shorty 1st and wanted to go turbo, was goin to after much reserch and these motors (sd33 n/a & turbo) ARE the same...

BUT there a couple of things different, the pistons are the same comp ratio, but have different rings, n/a has 5 rings, turbo has 3 rings.
there is a hole tapped into an oil gallery behind the turbo to feed oil to it.

the injection pump HASN'T got a boost compensator! that is only on petrol engines, the n/a runs with a throttle body and a venturie inside it to meter the pump via air flow requirment/and what it's using- then the pump govenor meters the injector shot to suit.

The turbo engine uses a throttle on the rear of the pump, this way the pump delivers a set amount of fuel, the turbo spools off the unburnt gas in the exuast and then makes boost, the fuel pump mesures the air usage and then the govner meters out more fuel much the same as the n/a pump, then the engine excelerates (this is why the turbo only boosts when under load!)
oh and they have different rocker covers...........

Feel free to correct me if you think i'm wrong, but i felt i needed to set things straight.
fitting a turbo to your n/a sd33 wont break a crank if you drive normal,
cos a turbo doesn't make it a race engine, my turbo mk has 418,000kms on it and it still gets 530ks to a tank, doesn't use oil and starts every time without a hicup... it runs 5.5lbs of boost and it motors along...
so if you look after it and know that the red line is there for a reason(don't go past it!!!) it go for ever.

[DR Frankenstine]

You forgot one very important thing!!!
The turbo engine has oil squirters onto the inside of the pistons to help with piston cooling.

[RMP&O]

You forgot one very important thing!!!
The turbo engine has oil squirters onto the inside of the pistons to help with piston cooling.

which is exactly why I need a turbo block before I spend lot's of money modifying the old SD33.