Advice needed on which TD42 for conversion

Hi all,


I’m after some advice. I have a clean 1997 GQ patrol. The RD28 died so I’m going to put a TD42 into it with a turbo. I’m having trouble deciding on either of the two options below.


1. Buy a low km silver top (I have found two) and then put a garrett turbo on it.

2. Buy a GU TD42T without intercooler and put that into the GQ.


Which is the better way to go? Going by my calculations both are going to be around 10K for the engine and gearbox package. The GQ silvertop is complete car, the GU option just motor and box with a few ancillary things like power steering pump/AC etc. From what I’ve read the GU fuel pump is a little larger and the GU pistons maybe a little stronger? The silvertops are relatively strong for a NA motor it seem.

I've only driven a GQTD42 with turbo, never a GU.


Pros and cons of each choice would be appreciated.

Much of a muchness in my opinion. Buy what ever is in the best condition, and the price is important of course. Just remember if you turbo it, it will require an engineers report for the power output if it over 20% from standard. Which I dare say it might be. Not that many turbo'd GQ's are engineered for this. but I thought to put it out there anyway.
If your not going to chase big hp then either will be fine, If you are, both will still be fine too, condition pending again, the blacktops run a larger gudgeon pin, and some silvertops do aswell, I think. (someone will correct me on that) Different oil pump and oil squirters to for the factory turbo engine. My knowledge is fairly limited on the differences, hopefully someone else will pipe up and and help.

The GU engine will have the bigger fuel pump which can make a lot more power and torque. But if you want to make use of the bigger pump you would need to put a different turbo on it anyway. They are a slightly stronger engine too.

If you get the silver top and turbo it, you will probably end up buying a new fuel pump anyway for 2-3k. The standard GQ pump is very limiting.

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Originally Posted by mudski

Much of a muchness in my opinion. Buy what ever is in the best condition, and the price is important of course. Just remember if you turbo it, it will require an engineers report for the power output if it over 20% from standard. Which I dare say it might be. Not that many turbo'd GQ's are engineered for this. but I thought to put it out there anyway.
If your not going to chase big hp then either will be fine, If you are, both will still be fine too, condition pending again, the blacktops run a larger gudgeon pin, and some silvertops do aswell, I think. (someone will correct me on that) Different oil pump and oil squirters to for the factory turbo engine. My knowledge is fairly limited on the differences, hopefully someone else will pipe up and and help.

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I have to get an engineers certificate for the engine and gearbox conversion which is $880. I never thought of mentioning the turbo. Thanks for the heads up.

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Originally Posted by Winnie

The GU engine will have the bigger fuel pump which can make a lot more power and torque. But if you want to make use of the bigger pump you would need to put a different turbo on it anyway. They are a slightly stronger engine too.

If you get the silver top and turbo it, you will probably end up buying a new fuel pump anyway for 2-3k. The standard GQ pump is very limiting.

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Good info. So what are the turbos on factory GU's good for power and RPM range?

Thanks

If I was choosing Id probably go for the one that was made to suit a Turbo.
It may be beefed up in certain areas, compared to the non turbo motor.
just saying lol

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Originally Posted by Chiro

I have to get an engineers certificate for the engine and gearbox conversion which is $880. I never thought of mentioning the turbo. Thanks for the heads up.

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You don't "need" the engies for the engine swap as the GQ came out with a TD42 from factory. State to state may differ. Same when I went from a ZD to TD in my GU. But as your turbo'ing it...

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Originally Posted by mudski

You don't "need" the engies for the engine swap as the GQ came out with a TD42 from factory. State to state may differ. Same when I went from a ZD to TD in my GU. But as your turbo'ing it...

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Yeah I didnt need engineers for td42t onto gu rd28t. Car came with it so all sorted in Vic. The gq with complete car may be a lot cheaper overall as you will also need to sort things like throttle cable, gearbox crossmember and other bits and bobs that you get with a complete donor car. So the Gu engine will probably cost a fair whack more to complete the conversion.
I would buy the best of either gq/gu that you can afford in your budget. You only want to be doing it once.

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Originally Posted by mudski

You don't "need" the engies for the engine swap as the GQ came out with a TD42 from factory. State to state may differ. Same when I went from a ZD to TD in my GU. But as your turbo'ing it...

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That's what I thought but I rang the RMS (I'm in NSW) and they said it would need certifying. I rang the engineer and he said he wants to check the new welds on the drivers side engine mount before motor goes in.

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Originally Posted by sooty_10

Yeah I didnt need engineers for td42t onto gu rd28t. Car came with it so all sorted in Vic. The gq with complete car may be a lot cheaper overall as you will also need to sort things like throttle cable, gearbox crossmember and other bits and bobs that you get with a complete donor car. So the Gu engine will probably cost a fair whack more to complete the conversion.
I would buy the best of either gq/gu that you can afford in your budget. You only want to be doing it once.

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Yeah I know what you mean about other bits off a donor car. I knew about gearbox crossmember. I didn't know about throttle cable. Doing it right once is a priority hence all of the questions.

Spoke to a guy at Niss4x4 about GU conversion kit. A good thing about this if he said if anything is faulty or doesn't work they'll replace it. This is nice for piece of mind. If I buy an older GQ there's no safety net. Bloody hard choice.

I would go for the donor car

not just because all the parts are there - fuel lines are bigger on the TD42 V's the RD28 - the cross member - the front brakes (maybe) clutch master cylinder (& Vacuum Booster)
diff ratio's, dash for speedo & such, plus all the little bits and bobs that would be nice to replace if you have the parts there... door trims, seats, sliding back window if its good.....

and you can get the measurements for the engine mount

or unbolt your body, and fit it to the TD42 chassis............. probably quicker in the long run.......

Just finished doing this same conversion but in a GU, There is no need to chop up the engine mount bracket, just change the bracket on the engine side instead of the chassis mount :) then no eng cert required. Swap over your oil pressure sensor and speedo sensor out of your rd28 box into the td42 box this will keep your speedo correct without changing clusters. I'd go for the silvertop there a tuff donk and then upgrade to a dc3 or dc6 pump depending on your desires. Then all you have to do is chop up all your wiring and reloom it all so everything works like factory.

http://www.nissanpatrol.com.au/forum...016/08/293.jpg

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Killa Kustom looms may have a plug and play loom ready for this type of conversion???

Ok the wreckers got back to me today. This was their reply

"GU TD42 conversion , from RD28

$9500 complete


Engine complete with turbo 190.000km and all accessories ( starter alternator ac pump ps pump etc )

Gear box cross member

Tail shaft front and rear

Clutch booster and master , with lines

Wiring Harness

Engine mounts and brackets off chassis to be wielded onto the vehicle ( if required )
Air cleaner assy with air induction

Please send me any questions you have regarding the conversion

If you after a GQ engine we can help with a GQ silver top TD42 engine 240.000km, with a DTS turbo kit $4800

Again with all the accessories as mentioned above".

I spoke with a guy that's been in the turbo business for 30 odd years this morning an he recommended going with the GU motor. I'm going to go with one of these so I just need to make my mind up quickly.

Make sure the gu engine is only a td42 T with a non NATS pump and non ecu reliant..
If it's the ecu controlled pump then it's a whole new level of wiring and ecu change.
Not sure if boost compensation is mechanical or ecu controlled either so best check that out.

From memory the 2.8 ran 4.6 diffs so if your throwing the td42 box in you may need to hunt for 4.3 diffs or 4.1 like factory. Unless your going to run 35's full time..
Also I think the 2.8 pinion flange is a bit smaller than the 4.2..

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Originally Posted by bigguwesty

Make sure the gu engine is only a td42 T with a non NATS pump and non ecu reliant..
If it's the ecu controlled pump then it's a whole new level of wiring and ecu change.
Not sure if boost compensation is mechanical or ecu controlled either so best check that out.

From memory the 2.8 ran 4.6 diffs so if your throwing the td42 box in you may need to hunt for 4.3 diffs or 4.1 like factory. Unless your going to run 35's full time..
Also I think the 2.8 pinion flange is a bit smaller than the 4.2..

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Thanks for the reply. I just spoke to the guy who is going to do the conversion and he mentioned not to get the electronic pump if I go the GU route. The guy doing the job thinks the GQ silvertop would be the go at that price.

Do you have an opinion on what the better way to go would be motor wise?

What exactly do you want?? thats the real question, if you want a good ol 4.2 with 100-150hp then go the silvertop for the price + a dc3 pump. If you want 150+ then the factory turbo hands down but you will need a new turbo and pump.
Are you looking to do the conversion yourself or paying someone to do it? Just wondering as it only cost me $5300 for my whole conversion including the motor to do it myself. Diffidently +1 on swapping to the 4.1 diffs ive just down that. 4.66 are fun but for highway cruising way to high in the rev range.

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Originally Posted by Chiro

Thanks for the reply. I just spoke to the guy who is going to do the conversion and he mentioned not to get the electronic pump if I go the GU route. The guy doing the job thinks the GQ silvertop would be the go at that price.

Do you have an opinion on what the better way to go would be motor wise?

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Originally Posted by johno90

What exactly do you want?? thats the real question, if you want a good ol 4.2 with 100-150hp then go the silvertop for the price + a dc3 pump. If you want 150+ then the factory turbo hands down but you will need a new turbo and pump.
Are you looking to do the conversion yourself or paying someone to do it? Just wondering as it only cost me $5300 for my whole conversion including the motor to do it myself. Diffidently +1 on swapping to the 4.1 diffs ive just down that. 4.66 are fun but for highway cruising way to high in the rev range.

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Totally agree with johno.
What are you looking for?
A mild 120-150hp setup go the gq engine for sure..
And blokes have been running these figures since early 90's..

My old silver top is still going at 527*** (when I sold it 6 months ago). Granted it was NA but they are built strong..

Imo if you want a cheap build go the silver top..
If your planning big numbers and room to grow go the newer gu td..

But again as johno has said you'll want new turbo anyway..
A stock gu turbo and 10mm pump will comfortable see 100hp (stock na is about 85hp I think) but it wouldn't be good for much over 120 I would think..

Thanks for the replies fellas.

Well I'm not after big power. I just want enough so it doesn't die when it sees a hill like the RD28 did. Needs to reliable too.

I ended up buying the silvertop with the DTS turbo today. After she's in I'll get a good 3 inch exhaust on it and dyno tune. I think I'll be happy with that. The guy doing the conversion also said I'd need a better turbo on the GU motor if I want good power out of it. I'll post a few pics of it all when done.

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Originally Posted by Chiro

Thanks for the replies fellas.

Well I'm not after big power. I just want enough so it doesn't die when it sees a hill like the RD28 did. Needs to reliable too.

I ended up buying the silvertop with the DTS turbo today. After she's in I'll get a good 3 inch exhaust on it and dyno tune. I think I'll be happy with that. The guy doing the conversion also said I'd need a better turbo on the GU motor if I want good power out of it. I'll post a few pics of it all when done.

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Yea good move imo..
The dts setup is a little better than the stock gu I think..
But even the NA td42 had good down low torque..
Compared to the zd30.. completely different in high range..
Low range I don't notice the lag..