V8 or P40?? in MQ

[ron]

hi all

i am having to make atough decision about wjhat to do re my motor.
i either find somebody reliable to rebuilt my 4.0l P40 6 cylinder,
but nobody seems to want to do here in brisbane area or i go for the V8 convertion.

what is involbved in the convertion?
where would i look to buy 1?

what else would i need to know?

thanks for all your input,
it will be greatly appreciated.

ron

[bogged]

hi all

i am having to make atough decision about wjhat to do re my motor.
i either find somebody reliable to rebuilt my 4.0l P40 6 cylinder,
but nobody seems to want to do here in brisbane area or i go for the V8 convertion.

The P40. is that the motor out of the G60?
main reason most would not touch it, is that the more you pull it down the more they will find requires replacing. Very hard to give accurate quotes to people on older things. You may quote $3000 then find it needs a new crank, and cam.

I would go the motor swap.. Dave here installed a 400 chev into his MK, he likes it!

[RMP&O]

why in the world would a shop not want to rebuild your P40!? Is it extremly filthy or something...? It is a basic inline 6 and easy to rebuild. You can get parts for it no probs at a decent price. You can also get close to 200hp out of it with headers, carb upgrade and electronic ignition. The P40 is found in Nissan forklifts so it is a common older motor. It should also give you an easy 200,000 kilos or more with no problems if kept up well. On extreme angles I might get a bit concerned with oil pick up though on an old P40.

For v8 conversion try Dellow Automotive. I'm pretty sure they list a kit for your set up. The v8 will drink more though. Check the MQ/MK Patrol bible thread for info on the conversion.

If you go by the Dellow site d/l their product listing. I am pretty sure they also make a GM 6.5L diesel kit that bolts to a Cabstar 5spd. Turbo and intercool the 6.5L v8 diesel and it will be awesome! But you will need at least 10 times the cash than for a P40 rebuild, maybe more! Unless you can find the 6.5L & 5spd cheap...

[RMP&O]

The P40. is that the motor out of the G60?
main reason most would not touch it, is that the more you pull it down the more they will find requires replacing. Very hard to give accurate quotes to people on older things. You may quote $3000 then find it needs a new crank, and cam.

No the P40 was not put in G60's. This is likely one of the biggest misconceptions I see people make on the G60's. Easy to do though as the G60 got a "P" engine and they are very similar even using some of the same parts. They even look damn near the same motor with only tiny noticable things different like the oil filter and housing. Bogged is right about the hard to qoute thing. But it has to have had major useage for the crank to need replacement. Same for the cam and you can get a new camshaft for it. The P40 is a good old tough motor but the key word is old!

I doubt you could go wrong or not like a v8 conversion other than fuel costs.

[bogged]

The P40. is that the motor out of the G60?

No the P40 was not put in G60's. This is likely one of the biggest misconceptions I see people make on the G60's.

yea the only reason I said that is the G60 has a 4ltr donk doesnt it? Whats the Model of that?

[RMP&O]

G60 has a 4ltr donk doesnt it? Whats the Model of that?

"P" engine

Like I say near identical motor but has different internals and few exterior shiat. Should also have a P40 code before the block number whereas a G60 just has P-123456789 This really is an old design as the P dates to 1960 and the earlier 1950's Patrols also had a similar inline 6 power plant. I even been told this inline six was designed off and based on an earlier IH motor. No idea if it a good or bad rumor....

One thing that is funny is back in the day the P(40) was a pretty powerful motor in these types of trucks. In the 1960's it put out more power than all other small 4x4's. In the 1970's it suffered a bit due to emissions so it was neck in neck with the TLC six. otherwise it had more than a stock Jeep, Scout or Rover. In the 1980's it really was getting to be an old motor but still held in there, this around the time Jeep introduced the 4.oL inline six. This Jeep motor is similar to the P40 in it's early days. Same with some 1970's/1980's inline six ford and chevies. This also around the time of fuel price increases so most motor were low hp and better on fuel consumption. Any ways, point is the P & P40 were fairly high hp and torque motors for the day and the type of truck. It also can be water proofed easily and had factory water proofing options. This was Nissans strong point and it is why the old G60s have a shit 3spd tranny. They felt the hp made up for the lack of gearing. And the 3rd is really a wide gear. Rover on the other hand had better gearing but a crap motor in terms of output.

I say if you can afford the v8 and the fuel go with it! If on a budget rebuild the P40...

[V8Patrol]

I say if you can afford the v8 and the fuel go with it! If on a budget rebuild the P40...

Smart reply too I might add.....

And if you decide to go with the V8 then theres the .....

fuel problem >>>>> straight LPG or duel fuel?

what size V8 >>>>> 253, 283, 302, 307, 308, 318, 340, 350, 351, 360, etc !

fuel ecconomy >>> V8s like to drink the stuff and it aint gettin any cheaper !

then theres things like .........

new exhaust system, radiator conversion, wiring conversion, engineers cert, the list just goes on & on....

Dont get me wrong but you will need to appreciate the work thats involved it such a conversion, it isnt just a straight swap by any means.
I love my 350 chevy MQ and I really enjoy driving the 253 MQ too, they both have differant positaves and negatives and realistacly both do an excelent job for what they were setup to do.

Check out the bible then start adding up the costs against the rebuild of the 6 ......

Kingy

[Screwy]

As has been said, it really depends on your budget.
a rebiuld will set ya back under a grand in most cases.

A V8 conversion can cost anything from 3 to 6 grand depending on the motor, kit etc, etc.

screwy

[RMP&O]

If it was me and I didn't have the time or $$$ to spend on the v8 I would rebuild the P40. Then modify it a bit and water proof it. A Weber or other nice carbs will go on that motor with a simple adaptor plate. A tall plate will also increase power a bit. Headers & a flow through exhaust on it and it revs real nice up to 4000rpm's. Sounds great too! Electronic ignition and forgot worrying about points in the bush or having to adjust all the time. Big coil with high spark will finish off the ignition nicely. I have driven a p40 powered Patrol set up this way and believe me it was suprising. It damn near could have been mistaken for a small block v8!

I've rebuilt P engines and a basic kit runs about $500 in the USA. A bigger more complete kit will run over $1000 for the parts here but that is with cam, oil pump and so forth. If you do the rebuild yourself though Screwy is right on cost....

[ron]

hi all

you have given me a lot to think about.

here are the details from under the bonnet on the 2 plates.

nissan 3C patrol wagon

10/84 vg160 738 296



fs5w81a hh41

p 3956 cc

so i take it that its a p40 motor 4.0L
it s definitely an MQ

your help is greatly appreciated

thanks again

ron