SD33 wastegate q's

[mattstar]

Can you adjust what psi it release's by turning in or out the rod at the back of the wastegate, and if so what direction (in or out) to reduce the psi it release's at.
Also, what is the correct/best procedure for adjusting valve clearance, I know about the locknut and adjust.screw, but not the order or position of crank or rockers to ensure proper adjustment, I have been told .35mm at running temp is correct?

[pongo]

block off the waste gate hoses and rely on the preesure relief valve on the intake manifold. Works a treat, and blows off between 6-11 psi

Cant help ya with the rest.

Cheers

[mattstar]

why is there a varyence in "popping" pressure?, can this be regulated?

[tweak'e]

useing a "pop off" to regulate pressure is a poor way of doing it. its very hard to get the vlave to 'pop' at the exact same pressure every time, has very poor regulating and is very inefficent (waste of power makeing boost only to release it).

best thing....get a boost controller. it can also help reduce wastegate creep.

[pongo]

why is there a varyence in "popping" pressure?, can this be regulated?

dunno, but it will get some extra HP till ya can get everything else sorted. Ive been doing it for ages and it always seems to go off at around the same presssure. Cant tell a what it is cause im not running a boost gauge yet.

Cheers

[mattstar]

okay, thanks to everyone's answer's. But does anyone know about adjusting the wastegate via the actuating rod, can that be "wound out" or in to reduce the psi at which it releases pressure, i.e if it release's at 12psi factory can I adjust it to release at say 8 psi?

[Dzltec]

You lengthen the rod to lower the boost pressure. Best to hook a gauge up and road test it to accurately set it, or on the dyno.

Why do you want lower boost pressure?

[DR Frankenstine]

Yes the boost can be adjusted by the rod But first you have to drill the factory pressing out. I think you have to lengthen the rod.
Don't mess around with boost like some idiots do without a guage. Just relying on the over boost valve to pop is just shear stupidity as it doesnt allow you to hold power on. If you remove and plug the over boost valve you should be able to safely run 12lb boost though you will have to re-adjust the fuel as well and thats where a pyrometer comes in. At full throtle up a decent hill steep enough to say hold 2500 revs and full boost adjust the fuel so that the pyro wont go over 550 deg (you will have to stop a few times to make a few adjustments to get this right) this is asuming the pyro is directly after the turbo. Tuned this way you should have plenty of power and I wouldn't drive it over 500 deg if possible after you have it right. The next best thing you can do is hook up an intercooler. This can be done cheaply if you hunt around and can do most of it yourself. Mine was set up and tuned this way and produced 80kw at the wheels on 35's and concidering ithey are only about 50-55kw factory at the wheels on std tyres thats a big increase. To give you an idea a std gxl 80 series turbo diesel cruiser puts out around 79kw at the wheels .
Hope this info helps

[DR Frankenstine]

okay, thanks to everyone's answer's. But does anyone know about adjusting the wastegate via the actuating rod, can that be "wound out" or in to reduce the psi at which it releases pressure, i.e if it release's at 12psi factory can I adjust it to release at say 8 psi?

Why would you want to reduce boost?? factory boost is only 6lb and it will deffinatelly cope with 12lb. The over boost valve will pop at around 11lb

[otis05]

hello. I have disconnected the waste gate and set up a Boost gauge. The blow off valve lets go at around 9-10psi. Previously the waste gate kept boost below 6psi. Can vary a little depending upon load, revs, etc. There is a noticeable increwase in power, but I need to adjust the fuel. After market blow off valves and boost controllrs can fine tune your system.

How is the fuel adjustment done as mentioned earlier in this topic??

[mattstar]

I want to reduce boost because I heard somewhere factory release is 5.7psi, I recently turbo'd my SD33 using SD33T manifolds and turbo with some custom pipe work, I am using the standard SD33 injector pump that measures atmospheric and inlet pressure and adjusts accordingly, I have been told that this are only reliable to about 8 psi, that's fine for me at the moment, but I fired it up the other day and got temps up, just checking for oil leaks, boost leaks and oil pressure etc. I revved it up a couple of times (carefully as I don't know boost press.) and I never heard either the blow-off valve "pop" or saw the wastegate actuator move! This concerns me as the motor hasn't been decompressed, hence why I am happy to run with a lower boost. I know I need to get a boost guage, but I still needed to know how to make adjustments, so thanks to all for help

[zen]

you will get no boost untill engine is under load..ie drive it!!

mine is set at 16psi..the pump seems to handle this no probs..BUT at max fueling,ie pump seeing atmosphere and no boost(on one of the pipes) it will quickly reach 550c+..so to regulate the max fuel you will need to bleed in some of the boost pressure,this in turn causes the pump to fuel less...this can be done by using a boost control valve,in and out connected to pump and boost BEFORE throttle flapper,the other outlet(the one thats controllable)going to atmosphere..with valve closed it gives standard sd33 fueling(as both sides of the pump vacum lines see aprox the same pressure(as per n/a))but as you open the valve it bleeds away the boost to air,thus now the pump sees a big pressure difference and fuels like crazy!!vary the pressure it see's and vary the power..simple..the pump automatically varies the fueling depending upon boost levels..emmisions are good!
my pyro(ESSENTIAL!!!!) sits BEFORE the turbo,i run it at 400c max for pottering around and up to 600c(short while only!)for burning off the v8's!(sd33 1989 engine 2050s turbo,cosworth intercooler)oh the fuel economy varies from 27mpg to less than 10mpg,depending upon power levels..

as a matter of interest,does anyone know how many degrees c the turbo drops the exhaust gases,as you lot are quoting 550c max and i wonder if i can get away with runnimng more c(not wanting to melt my pistons though)

anyway shorten turbo wastegate actuator for more boost..DUMP the pop off valve,fit a blanking plug(plumbers)fit both boost and egt gauges (YOU CAN NOT SET IT UP WITHOUT)get a boost control valve(in car type) fit 2 1/2 exhaust no muffler,fit LARGE k&n filter..have fun!

[Gabriel]

I have a similar problem...I've put a Vortec 2 supercharger on a TD42, that very curiosly has a in-line injection pump...;-(((, that is controled by 2 vacuums from the adimison manifold... So, now I can't "convince" the pump to deliver fuel according with the quantity of air that the supercharger is pumping... Zen, I'll try to get in contact with you, thanks...

Any ideas?!?

Thanks

[DR Frankenstine]

ZEN... You lose about 100deg c through the turbo. You can run up to 650 before and 550 after however it's not reccomended to go over 600 before and 500 after.
EVERYONE ELSE... What causes engine damage is tempurature spiking and cooling off to quick. IE: you may have plenty of power to pull up a steep hill in top and your temp peeks at 550 deg however you go over the crest and back off the throttle then your temp quickly settles down to 200 deg this is what cracks pistons and heads not the high 550 deg temp. what you should do is (even though you don't need to) is back off the throttle 200m before the top even if it slows you up and you have to go back a gear lifting revs and letting the motor breath. This will make a tweeked diesel last a lifetime. Factory's don't make turbo diesels go as hard as they can potentially, because they have to cater for the average idiot driving it.

[mattstar]

Does anybody know if you can get a extra "thick" head gasket aftermarket to reduce combustion ratio?

[DR Frankenstine]

Does anybody know if you can get a extra "thick" head gasket aftermarket to reduce combustion ratio?

What is your compression and how much different is it from a std turbo motor.

[mattstar]

I have a gregory's, and it list's comp. ratio as 26:1, but it doesn't say whether or not that's turbo or n/a, I haven't had a comp test recently so can't tell you what mine is....
the gregory's does list some difference's between sd33t and sd33 so if it doesn't list a difference does that mean their the same?

[pongo]

I have a gregory's, and it list's comp. ratio as 26:1, but it doesn't say whether or not that's turbo or n/a, I haven't had a comp test recently so can't tell you what mine is....
the gregory's does list some difference's between sd33t and sd33 so if it doesn't list a difference does that mean their the same?

Yeah thats what i was thinking, Definatly doesnt have the TD and N/A specs seperatly.

Go figure

[mattstar]

So pongo would it be safe to assume (assumption being the mother of all fu#* up's) that that's the case, their the same unless otherwise said so in gregory's, because on the cover it say's it's for N/A and Turbo'd motors???
haha, just to make you question yourself more before you step into a project ah!?

[zen]

first of all the compression ratio of sd33 and sd33t are virtually the same (maybe slight difference as sd33t pistons have a slightly larger flame thingy(name has escaped me)) at 21.6:1 NOT 26:1..according to nissan manual..why do you want to play around with compression ratios?leave alone!!mine still has the sd33 n/a headgasket,the composite type,the turbo one is layered steel,BUT n/a is $50 turbo $500!!! here in the uk(us dollars)
so guess which one i will be using if i blow mine...??


you be fine,as long as engine is in good order,and you do as reccomended.(INSTALLL BOOST AND EGT gauges!!)oh and drive by them..

[bigbennymq]

yeh u can adjest the wg on the top of the wastegate and what type of wastegate do u have e.g. brand,35mm ect

[RMP&O]

first of all the compression ratio of sd33 and sd33t are virtually the same (maybe slight difference as sd33t pistons have a slightly larger flame thingy(name has escaped me)) at 21.6:1 NOT 26:1..according to nissan manual..why do you want to play around with compression ratios?leave alone!!mine still has the sd33 n/a headgasket,the composite type,the turbo one is layered steel,BUT n/a is $50 turbo $500!!! here in the uk(us dollars)
so guess which one i will be using if i blow mine...??


you be fine,as long as engine is in good order,and you do as reccomended.(INSTALLL BOOST AND EGT gauges!!)oh and drive by them..

Compression is actually 20.6 in the N/A motor or there abouts. It is definately under 21 and the turbo is nearly 22. Not a big difference but more that you stated. True you can bolt the turbo on a NA SD33 and go...many have done it with success. But the turbo motor has a number of differences such as oil jets for pistons, 3 rings instead of 5 rings different pistons as you stated and a different injection pump. Since I am in the USA and the SD33 isn't a dime a dozen if I blow mine by bolting on a turbo I am looking at no less than $2,000 to replace it and maybe as much as $3,500. SD33 sells for a lot here in the states if you can even find one. So when I fit the turbo to my NA SD33 I am fitting turbo pistons, rings and other turbo gear to insure it won't blow up on me no matter what. I would rather spend the moeny to make sure it is all dialed in right than be sol with a blown motor I can't find.

[zen]

given the cost of your engine to replace it i would agree with you..however its not a problem here, as i can buy a scrap nissan patrol for about $200..
the sds33 engine used here has all the turbo mods + more than you get in the usa..ie proper breathing system,piston sqirters etc,but again it is european spec and i can find 1990 engines, so the mods i have done to turbo my engine are not excessive..but i would think twice (maybe) on doing then to a 1977 ihi scout sd33 lump..you state they have different injection pumps,which they do,but that makes no real difference to wether the engine will die or not..

re compression ratios..i think you got them wrong way around,as all the turbo engines i know if using different ratios to n/a use lower ratios not high..(but am sure you just typed it wrong)also you may be correct in stating they are slightly different(but i did point out differnt pistons)but both my patrol manuals(genuine and australian) state they are both 21.6...still who is arguing over 1 point..(oh i am.hmmm
you state they have different injection pumps,which they do,but that makes no real difference to wether the engine will die or not..

anyway,i can see no reason why mattstar will have any problems as long as he is sensible with it..oh intercooler helps loads too..bigger the better..

you using it yet mr mattstar???pics please...

[zen]

mr rmp@o have you thought about coming over here/europe and shipping a load back?? at $2000-3500 a pop in usa and $200 a go here it seems well worth the effort!!

[RMP&O]

ya I did have it ass backwards...N/A is higher compression.

My Patrol and SD33 is Euro spec but it is a 1983 not a 1990. It was imported from Germany to the USA many years ago. Still doesn't change the fact that if I blow the motor I am looking at thousands to get a new one in the Patrol. Just not many SD33's around the states and they always $2K or more unless there is a hole in the block.

Going to have to send you a pm Zen....

[zen]

i can see a lucrative business here...hmm.time to find out how much it costs to ship a container to usa..

[DR Frankenstine]

Dont know if you fellas know or not but the sd33 was put into some early jeep cherokee's around 1980 thereabouts.

[RMP&O]

Dont know if you fellas know or not but the sd33 was put into some early jeep cherokee's around 1980 thereabouts.

I kind of knew that somewhere in the back of my mind. The SD33 is a Chrysler/Nissan venture...

Thing is I never seen a Cherokee with a diesel let alone an SD33. Only Heep I ever seen a SD33 in is the rare air force tug.

I think it would be fair to say a Cherokee with an SD33 in the USA is rare as rocking horse shit! That is partly a quote from my friend Mark.

Oh ya a quick google search turned this up....

The Chrysler nissan sd33 is all Nissan, chrysler put their name on it in some 70´s marine applications.

[DR Frankenstine]

Theres one getting around down here in tassie

[mattstar]

okay...
to adjust wastegate, remove from turbo, measure preset distance ( from wastegate to collar), using 6mm drill, drill out press dents on collar( on the actuator rod) so that the collar may be undone, once this has happened to INCREASE boost pressure shorten the link, i.e screw in the rod.
Note; no power increase unless fuel is increased aswell, may lower egt's but needs to be fueled up to notice power increase