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Discussion Starter #1
Hello I am new to this forum & I live in Australia.
I own a 1991 Nissan patrol short wheel base it has 2” lift & 33”tyres.
I have had a Turbo 4.2 Diesel engine in it but found that it doesn’t do the job as it gets to hot. (I have been through a few of these engines & they have all blown up )
Anyway I am thinking of going a 4bt first preference or a 6bt if the 4bt can’t do the job.
This vehicle will be use for towing my off-road caravan which weighs 2.2 ton my patrol weighs 3.4ton.
I plan on traveling all over the country on a regular basis so I must have reliablity fuel economy & about 200 - 250hp at the wheels.
I wish to keep the patrol manual 5 speed & 3.9 or maybe 3.5 patrol differentials so I don’t want anything to wild.
I would prefer the 4bt because of more engine room & less weight over the wheels & braking performance
So what would you recommend will the mighty 4bt do the job or should I go 6bt ? THANKS for everyone’s help.
 

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After having installed a 6bt in an Oka and noticing the extra weight over the front end I'd be vary wary of putting a 6bt in a Patrol. They are a very heavy engine, well in excess of 500kg which is probably a good 100kg more than the TD42.
I also doubt that an engineer would pass it for rego either, best to speak to one before committing to the project.
There was an article in a recent online mag here in Oz re preventing the TD42 from overheating, might be an easier and cheaper path.
 

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I know of one here in the West that has a 6 in it, had asked to get a look at it but so far no reply.

Don't think you will need that much RWHP, my 6 has only a bit of extra fuel which will put it a bit above the 160 it came out as. That is engine HP
Truck weighs around 3200Kg , pulling a 3000 boat trailer effortlessly holds 100K's and can pass roadtrains without being scary. 3.32 rear gears and .8 overdrive and don't get out of OD to overtake. Runs around 4.5 Ks to the litre towing at 100.
Cheers Steve
 

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Discussion Starter #4
I know about all the 6bt conversions over here in Australia & they can be blue plated.
I have been right through the cooling system with the td42 Nissan engines as I was running the Nissan infinity fan locked, hiflo performance water pump that had the turbine type impeller, 3 core radiator, hiflo thermostat.
The td42 was on the dyno at 240hp at the wheels, DC6 pump & United fuel injections 18g turbo, with alloy flywheel & UFI harmonic balancer. But I blue up 6 td42 engines cracking the bores every time so my faith in Nissan engines has gone out the window. That is why there’s a hole face book site full of patrol guys over here that have put or are putting 6bts in their patrols. But I would prefer to go the 4bt route if it will do the job.
 

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To give you some ideas, a 4bt tuned to 200 HP will have 500 lb ft torque. That's a lot of pulling power and probably near the limits of some transmissions and differentials. The 4bt and 6bt prefer to normally run in the 1700-1800 RPM range. You can rev higher during gear changes, but the normal speed should be low. The Cummins is designed as a high torque, low RPM unit. Running above 2000 RPM severely hurts fuel economy. With a single turbo, you can probably reach 250 HP which will give you 625 lb ft torque @ around 1700-1800 RPM. That can get destructive on weak drive train parts. When dealing with a 4bt a lot will depend on which injection pump you have. Road units were either the VE pump or the P7100. The VE may give the best fuel economy and the P7100 the highest power potential. Either should be able to reach 250 HP. A good turbo will also be important. One of the HX30W turbos with a 6cm turbine housing can carry you into the 200-250 HP range. Stock injectors if in good condition can also fit that bill. An engine intercooler will be absolutely necessary if the vehicle doesn't have one. More turbo boost creates more heat that you need to get rid of. Your 4.2 radiator is probably sufficient for 4bt but you'd need something much larger for a 6bt. There are many, many other changes that can be made to make the engines more efficient. Installing twin turbos can have several positive effects. Don't know what dash instruments your vehicle has, but the ones that are mandatory are a boost gauge and EGT gauge along with a tachometer. Another area to consider is the air intake. Need to be sure your air filter system is large enough. You have diesel now but going up in power takes more air.
 

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have a look on face stalk there is a mob in nsw i think that is doing a 4.5 cummins in to patrol kit i personally would use the 4 cylinder manialy cause of the weight rember that a 4.2 box does not like more than 800 nm if you go ahead keep us posted cheers bob
 

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Discussion Starter #7
THANKS very much for your very helpful reply char 1355
Yes mistyv6 I have read about the 4.5 Cummins on the 6bt Facebook page but they are quite heavy & would probably be as hard on the Nissan drive train as the 6bt.
If the 3.9 4bt can handle the towing then that’s the way I would prefer to go. Thanks
 

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Actually, the newer 4.5 Cummins probably doesn't weigh any more than the 3.9 if as much. The 4bt 3.9 generally weighs in the 750-800 lb range. The ISBe 4.5 Euro 6 version can be had with 210 HP and 627 lb ft torque. That's a huge amount of power. Dry weight is listed at 697 lbs (316 Kg).That came in buses and trucks. In your country they would be available, but for some reason they never made it to the US market. We got the ISBe 3.9 instead. One down side of those engines is they are rear gear train and have only an SAE transmission adapter plate. Of course they are totally computer controlled. The older B series is totally mechanical and offer a variety of transmission adapters.
 

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Hey lightspeed
What part of Aus are you from?
I had 95 Gq patrol td42 inter cooled safari turbo running 12 psi with a 11mm non aeronoid pump which did get warm when worked hard did most off the same cooling rectifications as you and still ran hot when worked.
As for my project I have a 1942 Dodge wc52 which has a 4bt, Bosch ve pump and a hx 30 super turbo at 24psi ( thanks alcaid) no intercooler at this stage, all bolted to a Gu td42 g/box transfer case diffs are 4.11 with 35s.
Driving up an incline every day on the way home from work the patrol would maintain 80kmh and be working and the dodge I am up shifting and lifting the foot due to speed limits.
I.ve given up tuning for more hp as how fast do you need to go I’m no where near it’s limits but I do keep in mind I have no intercooler and I watch the egt which aren’t a problem. As hard as I.ve pushed it the temp gauge hasn’t gone over 90 deg c
The thermo doesn’t come in till 94 ish.
Hp wise they are not race horses more like draught horses.
Cheer Andy
 

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the isuzu has the fuel pump and turbo on the same side as the nissan . if you are on patrol 4x4 a member has fitted a 4.5 into his patrol lots of pictures
 

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Discussion Starter #12
I am on the Gold coast QLD
I have looked at the isuzu 4bd1t but would prefer a 4bt or 6bt.
The only thing i am worried about is the 4bt towing capacity & reliability otherwise the 4bt would be my choice.
I only plan on towing 2.2ton but on a constant basies. THANKS for every ones posts.
 

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Why are you planning to use a short wheelbase vehicle with 33" tyres for towing around Australia? Isn't that just going to be hard work to drive and cost a fortune in rubber?

You could just buy a diesel ute that'll do the job and drop about 1.4 ton off your GCW and burn a lot less fuel.
 

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I sort of doubt there is any issue whether the 4bt can tow 2.2 tons. The main issue will be can your vehicle parts live with the power stress put on them. Member Eggman's truck may weigh near what your vehicle weighs plus the load you want to tow. On top of that he tows a load almost as much as the truck. He's working now to install his third transmission so he can have a larger clutch to handle the power. 200 HP on a gas engine doesn't sound like much, but with diesels that's a bunch. Have to remember that all the Dodge Cummins trucks up until the late '90's were only 160 HP with 400 lb ft torque.
 

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I sort of doubt there is any issue whether the 4bt can tow 2.2 tons. The main issue will be can your vehicle parts live with the power stress put on them. Member Eggman's truck may weigh near what your vehicle weighs plus the load you want to tow. On top of that he tows a load almost as much as the truck. He's working now to install his third transmission so he can have a larger clutch to handle the power. 200 HP on a gas engine doesn't sound like much, but with diesels that's a bunch. Have to remember that all the Dodge Cummins trucks up until the late '90's were only 160 HP with 400 lb ft torque.
Australia also has issues with police enforcing vehicle GVM and GCM weights on private vehicles. A SWB Nissan Patrol built up to 3.4T may already be past that and will get heavier with a 4BT.

This site says the LWB version was 3060kg GVM and it can be increased to 3495kg. Which still isn't enough. The vehicle would need a steady diet before hand just to stay legal.
http://www.statewide4x4.com.au/gvm-products/nissan-patrol-gu-wagon-lwb.aspx
 

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3495 kg GVM is 7705 lbs GVW here in the US. That's pretty heavy for a light SUV. That takes into consideration fuel, passengers, cargo, and maybe trailer tongue weight. Depending on what the stock engine weighs, you'd probably be adding 300-400 lbs up front. If your load is properly balanced on the trailer the tongue weight may not be too bad. Maybe 500 lbs or possibly a bit less. Need to make a chart of the base gross weight of the vehicle and all you plan to add to see if you're into problems with the local authorities.
 

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Discussion Starter #17
The engine I had in it at one stage was the TD42Ti 6 cylinder Nissan which weighs more than a 4bt so gvm will not be a problem. The 3.4T was when it was checker full of camping & cooking gear.
The main problem I could face with a 4bt is the transmission handling the torque but I am sure a 6bt would be harder on it.
The SWB tows extremely well for those that don’t think so as I tow my off-road caravan well with the td42t engine it had in it till the motor failed. The td42t engine was fully rebuilt & was putting out 240hp at the wheels on the Dyno but got hot & blowed up.
THANKS for all your replies. Cheers Grant.
 

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The stock numbers for that TD42T1 was 143 HP @ 4000 RPM and 244 lb ft torque @ 2000 RPM. On a B series Cummins the HP will max out in the 2500-3000 RPM range and torque peak is in the 1700-1800 RPM area. A general rule of thumb is the torque will be 2.5 times the HP. You must have really had the TD42T1 turned up to get 240 HP out back. That engine was probably putting out around 400 lb ft torque where a 4bt at the same HP level would have around 625 lb ft. That Nissan engine had similar characteristics like a Mercedes diesel. On a B series Cummins you'd want a normal cruise speed in the 1700-2000 RPM range for best fuel economy. At that point you have already reached peak torque. You mentioned the weight of the Nissan was more than a 4bt. What is the weight of a TD42T1? A bare 4bt weights around 742-782 lbs.
 

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Discussion Starter #19
My TD42Ti nissan engine had a larger after market turbo & 12mm pump intercooler, large air box, 3" exhuarst etc I spent around $20,000 on the engine alone.
TD42Ti engines weigh around 992 lbs + fully dressed. About 154 lbs less than a 6bt.
THANKS again for your help.
 

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Hi,
I wanted to do the same thing in 2018 as you Lightspeed,instaling an 4Bt in an Nissan patrol Short body, but I got a job where I have to spend all day, so I give up.
But now with the virus around, looks we get less work, so I am playing again with this idea.
To be honest I never stoped to look for complete trucks with 4 cylinder engines, 160-210 HP:
Mercedes Atego, Iveco, Nissan atleon are my choices.
I am always looking for the complete truck because you can check the engine, you have plenty of parts, cooling, filters and so on.

Did you manage to start the project or you give up??
Please give us some update.

Ben
 
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