RB30 Compression for turboing

[GQJay]

Howdy, Jay here. Im getting different answers about if it's worth doing due to compression. Ive been told by 1 mechanic that i need to change comp otherwise wont get much boost. Cost 20 k. 2nd opinion from performance workshop is that the RB30 has alright comp to just bolt on a turbo and run up to 10psi. I need to know if I need to rebuild engine? It's in a manual Gq wagon. 91 model. Any advice would be appreciated,
Thanks .

[mudnut]

20k! He's dreamin'.

[GQJay]

What do i do then?

[mudnut]

If you want to run really high boost then you would look at doing something. Have heard that some use thicker head gaskets as quick fix. I will talk to an expert tomorrow, get his opinion, and get back to you.

[mudnut]

Has it already been converted to fuel injection?

[GQJay]

No, still carby.

[mudnut]

I talked to the local Dyno guy. He builds racing engines and is very good at it. He said unless you are running a high boost, high performance engine, then you should be able to get the thing built for around 1/3 to 1/2 the price.

For a low boost engine, all that should be needed is low comp turbo pistons (concave crown) and a turbo compatible camshaft. As the RB30 bottom end is strong, then the original rods should be ok. Using thicker head gaskets is not a good option.

RB30 EFI conversion http://www.nissanpatrol.com.au/forums/showthread.php?36470-RB30-EFI-Conversion

Or use a Weber carby suitable for boost. The original carby is unsuitable for boost as it is a two stage vacuum dependant unit.

[GQJay]

Would i be better doing a Barra conversion as ive heard it can be done for around 6-7 k. Its going to take a while for me to get cash up for anything. I just feel like RB30 needs a little more power for off road, it fairly sluggish on road already. . Thanks again.

[mudnut]

I get 80 kw rear wheel with a set of headers, snorkel, carby rebuild and the heater grid from under the carby removed. I also block the pre-heat flap vacuum hose during the warmer months.
I am very happy after the guy dyno tuned it, as it gets 13.5-14 litres per 100ks highway driving.

http://www.nissanpatrol.com.au/forums/showthread.php?28517-RB30-Facts-Figures-and-Helpful-Hints

What size tyres are you running.

[GQJay]

31" at moment but going to 33".
When i put new timing belt on i noticed that the previous owner had set it 1 tooth different from stock. Ive had it put back to stock.
I haven't been off road in it yet,just feels underpowered. I had to put another oil pump, dizzy and alternater on it when i bought it. . I'll take the heating grill off,has headers already. Thanks for your help. J

[mudnut]

Just smash the grid out and refit the plate. Do not remove the steel deflector under it, as it is designed to give each cylinder the correct air fuel mix.

Is the second stage of the carby working properly?

It is no speed demon but I use my patrol to tow a camper trailer, and go just about everywhere anyone else can get. It only takes 14 seconds to get to from 0 to 100kmh. Not too bad for a carby 3 litre pulling a 2500kg vehicle.

The RB30 is designed to rev, so don't be too averse to letting it wind out.

There has been a few Barra conversions done. Try the search function. Someone also did an RB28 conversion, which is a simpler option as it uses the original gearbox.

Getting the diffs shaved is another option instead of a 2inch lift and 33inch tyres.

[GQJay]

If no heat coming from throttle body with ignition on,do I need to remove heater grid still? Also fitting a snorkel do I need another air box or just conect to air cleaner? Sorry for all the questions but not many people have RB30's.thanks again.

[mudnut]

The heater grid is for colder climates/mountain regions. I had to remove the grid as it was starting to have bits break off and get chewed up in the engine. I found the power was up and fuel economy was better as well as. Others that have done the mod have been happy with it. The safari snorkel fits straight onto the existing dust separator. it is just a matter of drilling out the spot welds and removing the air inlet in the guard. The Safari snorkel came with the necessary fittings to complete the job.

Also be aware that the pre-heat system needs to be operational for the vehicle to pass roadworthy.

[GQJay]

Ive fitted safari snorkel and cos of different size in guard inlet I had made a stainless section to go from guard to air cleaner to replace original piping and vortex box.

[mudnut]

Interesting, as mine came with the aluminium flange plate. All I had to do was drill the mounting holes and fit it straight to the original plastic flange and moulded pipe.

[GQJay]

I didn't buy mine new it came off a 94 duel fuel Rb30. Had to keep my air cleaner cos other was modified and wouldn't fit due to gas system. I cant access your pics, not sure why.

[mudnut]

Gas conversions cause there own problems which have been talked about in the RB30 thread in the link I posted before.

Also here http://www.nissanpatrol.com.au/forums/showthread.php?37458-LPG-Missfiring-rough-idle-and-rough-running


Talk to a forum moderator about the access to the pictures.

[GQJay]

Mines straight fuel. Not bothering with gas. And thanks I'll talk to someone about pics

[mudnut]

If the engine has been continually run on gas in the past, then it is quite possible the carby components are already dried out.

[GQJay]

No never been on gas. I did notice that timing belt had been set a tooth out. Im wondering if that caused damage over time. Or should i reset timing belt back to that. I don't know why previous owner had done that. Ive been told it gives a bit more power but i dont know at what cost. Its done 250,000 kms .

[mudnut]

I misread the post #16 and thought your vehicle was duel fuel.

Advancing the cam one tooth to open the valves earlier is supposed to give the engine a bit more low down grunt, but you loose some top end power.

I have read that Holden and Nissan used different cam timing for the Commodore and Skyline but I don't know if there is any truth in that. If it is, then there should be no engine damage if the ignition timing is set correctly so there is no detonation.

[GQJay]

Do I need to run snorkel to airbox or ok to connect straight to air cleaner?

[mudnut]

Post a picture of your set up, so we can get an idea of the easiest way to do it.

[GQJay]

No worries, do that in morning. Thanks

[GQJay]

Here's a pic of my piping.

[GQJay]

Well that didnt work. Basically, I have stainless piping that runs from aircleaner 60 mm then 90 degree bend then increases 100mm where it meets inner guard. Is yours turbo?

[mudnut]

To post a picture, click on the Go Advanced button on the Quick reply window. Click on the paper clip button. Click the Add Files button. Click the choose files in the small drop down window. Then double click on the picture file. The name of the picture file is displayed in that small window. Press upload and the picture should appear in the attachments window.

Click the preview button and check all is ok before pressing the submit reply.

[GQJay]

Here's the piping i made.

[GQJay]

Don't know why they're upside down.

[mudnut]

You need to have a section of flexible hose between the body and the engine.

Cut a section from the end that attaches to the air filter and fit a corrugated rubber hose similar to the original.

Personally, I would use the original dust spinner. After having driven on dusty roads, especially in convoy, I found the air filter was still fairly clean and the rubber cap was nearly full of dust.

[GQJay]

I was thinking about keeping vortex (spinner). Also piping was just placed there for pic. Was going to attach each end with silicon hose. After reading your repky i might put vortex back on. We're planning a trip to Kimberlys in a yaer or so.

[GQJay]

My brother has a GU ZD30. Do you know much about performance chips?

[mudnut]

There are quite a few threads dealing with the ZD performance chips. Best bet is to start another thread so members in the know can provide you with an answer. If your brother's GU Patrol is an early model, ask him if it has had the NADS mods done to extend the motor's life before doing any other mods.

[GQJay]

Thanks for that. Ive put another thread up. Not sure what NADS mods are. Will have to look up. It has dawes valve, catch can,boost controler and after market intercooler.

[GQJay]

Just googled Nads mods. Looks like been done already. Thanks