Injecting a 3L patrol?

Submitted: Sunday, Mar 09, 2008 at 16:13
ThreadID: 55362 Views:3978 Replies:5 FollowUps:4
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G'day all I have a 3L GQ Patrol and I am thinking of injecting it. I am thinking of buying a vl commodore and swapping the top ends is there much to it?
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Reply By: Member - DOZER- Sunday, Mar 09, 2008 at 17:43

Sunday, Mar 09, 2008 at 17:43
It will all be bolt on, but you will also need efi tank from gq efi plus pipework to suit, then a wiring loom to support pump and ecu the end, not much gain, would be good for dual fuel thou, all computer controlled, and...if you got a vl turbo motor.....that would make a big difference to purformance.
AnswerID: 291796

Reply By: Member - Shane D (QLD) - Sunday, Mar 09, 2008 at 18:20

Sunday, Mar 09, 2008 at 18:20
I would go the whole hog and get the turbo version, The mechanical side would be the easy bit, remember that it is electronically controlled and that may take awhile to sort out,It's a big job, you might as well make it worth while.
AnswerID: 291803

Reply By: Tags' GQ - Sunday, Mar 09, 2008 at 20:50

Sunday, Mar 09, 2008 at 20:50
thanks guys, although im not sure the gearbox would withstand a turbo
AnswerID: 291830

Follow Up By: Member - Borgy.. (SA) - Sunday, Mar 09, 2008 at 22:07

Sunday, Mar 09, 2008 at 22:07
G'day Tags

When i rebuilt the gearbox in my old 3L GQ a few years ago , i was told by Motor Traders here in Adelaide that the bearing kit for the GQ was the same as the one for a VL Turbo, so i dont think you would have any problems

FollowupID: 557199

Reply By: ExplorOz Team - Kerry W (QLD) - Sunday, Mar 09, 2008 at 23:09

Sunday, Mar 09, 2008 at 23:09
Yes its a bit of work to change heads and fuel delivery, but much less trouble than an engine transplant and if going to that much trouble - it would be best whack a RB25DE non Turbo (Twin cam Nissan Skyline head straight on rather than the holden mule - it will give you an extra 50 kw or so. (Or if turbo RB25DET up to 200+ Kw I'm not exaggerating)

I am a great fan of the RB30S and I have a mildly modified one as my outback tourer because of its reliability and ease of maintenance and its sheer performance (and flexibility in mud and sand - having up to 6000rpm available in 2nd gear low range is a big advantage)
Fuel economy has improved at high speed (up to 110kph) as well

But first of all make sure you are driving it properly, and have it set up properly search for previous posts on the RB30 exhaust and inlet mods. EG You have the RIGHT extractors and remove the inlet manifold clutter, remember the valves may be a bit leaky after 200,00klm and may be reducing compression.
This motor WAS unpopular because nobody knew how to drive it but nowadays a lot of enthusiasts modify it for their race street cars - and put the RB25 and RB26 heads on them. (google the Nissan Skyline forums) Apparently the RB30 can be modded towell over 800 hp without strengthening the bottom end. (Apparently the gearbox is quite strong despite rumours to the contrary - just not as tough as the diesel box and the toyota boxes.

If it is still stock standard you can just run it on premium fuel and rev it out to 4-5000rpm comfortably. If towing - don't use 5th gear as 3000 rpm at 100kph is quite economical even 4000rpm in 3rd would use less fuel than running flat in 4th or 5th such is the nature of the engine. (apparently the RB30S stands for Race Bred 3 litre Single Overhead Cam - and happily revs and has a strong powerband from 3500rpm on - google it).
The Letters stand for--
RB = Race Bred
S = Single Overhead Cam
D = Double Overhead Cam
E = Electronic Fuel Injection
T = Turbo
TT = Twin Turbo

I was considering engine mods and transplants so researched the Nissan Skylines which share the basics of the RB 30 the RB25 and RB26 have the same bottom end as the RB30 they just have a shorter stroke, same bore and crank the heads bold straight on its just the RB25 head is a easier modification.
(It was a RB26DETT in the GTR Nissan Skyline which won Bathurst 2 times in 91 and 92 before being banned for taking all the fun out of Bathurst for the big V8s. Mind you they were twin turbo)
(To think people swap the motor out without knowing what it can do)
But still a great idea to put a race bred motor into a 4WD - shame Australia detuned them and nobody was told how it was to be driven, - as most 4by owners dont like screaming engines.
However detuned they are unbreakable and will last for 500,000klms. - So if doing remote outback work and deep river crossings keep it basic but if only a highway and state forest vehicle go for it.
Worth doing your homework before doing too much though, just getting the single cam head working properly and knowing its meant to have the fork revved out of its nightie, may be enough for you.

Hope this helps

Kerry W

Kerry W (Qld)
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AnswerID: 291849

Follow Up By: Tags' GQ - Monday, Mar 10, 2008 at 12:37

Monday, Mar 10, 2008 at 12:37
thanks heaps Kerry! So you say a RB25 head will bolt straight on?
FollowupID: 557257

Follow Up By: ExplorOz Team - Kerry W (QLD) - Monday, Mar 10, 2008 at 20:19

Monday, Mar 10, 2008 at 20:19
Yes although you do need to use a 152 tooth timing belt and reposition the cam tensioner (involves tapping a fine thread bolt into the RB30 block) The RB25 idler bolts onto the RB30 block below the water pump.
Here is a link to one such conversion

RB 25/30 conversion

More info here
Skyline Forums

A guideDownload a pdf
and here
Skyline forum info

These have info on adding a turbo as well - let me know how you go.


Kerry W

Kerry W (Qld)
Security is mostly a superstition. It doesnt exist in nature. Life is either a daring adventure or nothing.
-Helen Keller

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FollowupID: 557318

Follow Up By: everydoghasitsday - Monday, Mar 10, 2008 at 22:07

Monday, Mar 10, 2008 at 22:07
HI tag's
Do u play in the mud heaps if so maybe consider a 4.2 diesel.
the turo motors go ok are you sure yours is a 3L not a 4.2
cheers chat u later
FollowupID: 557362

Reply By: Robin Miller - Tuesday, Mar 11, 2008 at 08:24

Tuesday, Mar 11, 2008 at 08:24
Hi Tag's

Did mine and there are a few issues and traps.

Because of some of these I choose to not interfere with the head and block and worked from the manifold back.

At the end of the day the conversion delivered less power than previous carby/exhaust mods but made for a more 4wd driveable car.

Some traps are - in tank fuel pump cannot deliver the fuel and needs to be removed.

ECU needs a start signal.

Have to add oxygen sensor high up in the exhaust system.

Robin Miller

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AnswerID: 292047

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