Its a P38 V8!!!! I want to swap the engine :)

So folks im sure this may or may not of been approached before but i was considering doing an engine swap in my P38 4.6 V8 2001, i would like to go with a diesel (M51 / M57 / 1HDTFE) or reliable petrol (1UZFE etc)
SOOOOOO........
I am not a mechanic but i am an engineer with a bias towards electrical and have rebuilt this engine twice now making a mistake the first time by not tightening a bloody coolant hose and causing it to overheat again, then rebuilt it in the hope that the heads could be fine and not warped as i had them skimmed to their limit so cant skim those again, but low and behold the heads are indeed warped!!! so EFF THAT!!! time for the skip!, i could buy two new heads but iv just lost heart in this engine.
The block has been pressure tested whilst at temperature and the dye test was also fine.... the block is a CosCast block so two new heads would sort it but my faith in this particular engine at 108,000mls has disappeared

My questions are...

1. What engine would literally be a straight swap? (bar a 4.6 as i now have a vicious hatred of them)

2. I assume that as i have ripped out the air suspension so no need to worry about the BECM? (im happy to go full redneck and do away with any immobiliser system or central locking for that matter)

3. what advice and or pointers would you give? its happening one way or the other i just some hints and tips

My P38 still has still retained all of its luxury but below the body it is effectively a full competition winch truck! , front and rear winches, front and rear air lockers, Ashcroft upgraded transfer box etc etc

I just want to make it as reliable as possible and if it means spending some cash then so be it as i will be doing all of the project myself.

Thanks

Rover V8’s are good engines. Hence why they were fitted to so many different vehicles and used for decades.

Any engine swap is going to be major amounts more effort and cost and more risk in something else going wrong.

No engine swap is going to be easy, cheap or straight forward.

If you really dont trust that engine, but think it has a good block. why not contact 1 of the V8 companies and invest in a top hat linered long engine.
It would probably work out just as cheap and a whole lot easier.

If you wanted to push the boat out a little then you could always go with a bigger displacement at the same time up to 5.2 i think.

You could always go the LS/ SBC engine route as this has been done so all bits are out there, wont be cheap.

As for getting rid of the BECM if you are running road legal then you with have all sorts of things to sort out, I am not even gonna guess if or how they could be overcome.

J

The M51 would be the easiest swap, with right bell housing it will mate directly to the auto box and the engine settings in the BECM can be changed to diesel.

I

marjon said:

No engine swap is going to be easy, cheap or straight forward.

If you really dont trust that engine, but think it has a good block. why not contact 1 of the V8 companies and invest in a top hat linered long engine.
It would probably work out just as cheap and a whole lot easier.

If you wanted to push the boat out a little then you could always go with a bigger displacement at the same time up to 5.2 i think.

You could always go the LS/ SBC engine route as this has been done so all bits are out there, wont be cheap.

As for getting rid of the BECM if you are running road legal then you with have all sorts of things to sort out, I am not even gonna guess if or how they could be overcome.

J

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My thinking was that if I plopped whatever lump in there I could trace the circuits (door locking, lighting, wipers, heating system etc and configure a separate control unit (distribution board with integrated protection and relays still triggered by the indicator stalks, knobs and buttons?)

Datatek said:

The M51 would be the easiest swap, with right bell housing it will mate directly to the auto box and the engine settings in the BECM can be changed to diesel.

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yeah it’s looking to be the most likely option for ease….. I could theoretically use the main ECU from the diesel motor with the assumption that obviously it will work with the engine it came along with and would hopefully communicate with any other nodes (BCM, SLABS or whatever?)………

300bhp/ton said:

Rover V8’s are good engines. Hence why they were fitted to so many different vehicles and used for decades.

Any engine swap is going to be major amounts more effort and cost and more risk in something else going wrong.

Click to expand...

Y

yeah I know there are some great success stories etc but mine at present certainly isn’t one sadly, block is fine the replacement heads are running into £1000 for a set of new standard ones……. I would love to stick with it as it sounds AMAZING but it’s just been such a let down (my own mistake included), I replaced the stretch bolts with ARP head studs, new water pump, thermostat, radiator, coolant hoses, hydraulic tappets etc etc

Both reasons for the V8 giving up was human error not really fault of the engine itself.

A good Rover V8 will be more than reliable enough and has near enough twice the torque of the diesel even in stock form..

Slightly built 4.6 will push 240hp and around 460-480nm quite easily, perfect for a working vehicle..

By the time you've fiddlefúcked around with fitting a different engine it would of been far more cost effective to just replace like for like.

Farmer Dan said:

Y

yeah I know there are some great success stories etc but mine at present certainly isn’t one sadly, block is fine the replacement heads are running into £1000 for a set of new standard ones……. I would love to stick with it as it sounds AMAZING but it’s just been such a let down (my own mistake included), I replaced the stretch bolts with ARP head studs, new water pump, thermostat, radiator, coolant hoses, hydraulic tappets etc etc

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Don't get me wrong. I love modding and engine swaps. But the RV8 is often the engine being swapped 'in'!

The M51 diesel is an ok engine. But they aren't without issues, esp in p38's. They also lack low end grunt and you'll be giving a lot of power up over a good 4.6 RV8.

The M57 is a good bet powerwise. But a much more expensive swap. And I don't actually know of any in p38's only D2's and Defenders. I'm sure it could be made to work, but likely more complex and more money than keeping the RV8.

As for other V8's. There are loads of great ones, the Lexus lump, Chevy LS motors or maybe even a Jag/Land Rover AJV8. But all are going to need some major R&D to fit and get running. Joking aside I'd guess you'd need to budget £5-20k to get these options running, depending on which engine you actually go for. And human error could certainly knacker any of them.

Can you not simply buy some used RV8 heads?

300bhp/ton said:

Don't get me wrong. I love modding and engine swaps. But the RV8 is often the engine being swapped 'in'!

The M51 diesel is an ok engine. But they aren't without issues, esp in p38's. They also lack low end grunt and you'll be giving a lot of power up over a good 4.6 RV8.

The M57 is a good bet powerwise. But a much more expensive swap. And I don't actually know of any in p38's only D2's and Defenders. I'm sure it could be made to work, but likely more complex and more money than keeping the RV8.

As for other V8's. There are loads of great ones, the Lexus lump, Chevy LS motors or maybe even a Jag/Land Rover AJV8. But all are going to need some major R&D to fit and get running. Joking aside I'd guess you'd need to budget £5-20k to get these options running, depending on which engine you actually go for. And human error could certainly knacker any of them.

Can you not simply buy some used RV8 heads?

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I have a used set that I can source for £150 each…… it’s finding the balance for me (emotionally as it has annoyed me so much and logically)
I suppose from a logical perspective I could go and pop the two used heads on as a matter of course and see how we fair, I just want to “financially” keep as much in the pot as possible for an engine swap job

Henry_b said:

Both reasons for the V8 giving up was human error not really fault of the engine itself.

A good Rover V8 will be more than reliable enough and has near enough twice the torque of the diesel even in stock form..

Slightly built 4.6 will push 240hp and around 460-480nm quite easily, perfect for a working vehicle..

By the time you've fiddlefúcked around with fitting a different engine it would of been far more cost effective to just replace like for like.

Click to expand...

I know that this block was and always has been a bone of contention so to speak as there were issues with poor casting etc etc etc…… but my block thankfully is fine, (one of the lucky ones I guess from what Iv read and been told) that said it is a nice engine to work on and sounds AWESOME my heart wants to keep it in with two replacement heads but my head want me to shoe horn a Toyota engine in there

Seen a company drop in the TDV6 from a Disco 3/4, although they charge around 15k for the conversion, so I imagine even without labour it'd be an expensive job.
Seen a few M57s fitted to P38s recently, but it is a labour of love.

LS is a common goto, but getting one in the UK isn't cheap. I guess for ease of work, any of the engines from the 80s/90s that were mated to the ZF 4HP24 ease of conversion.

But realistically, it'd be cheaper to rebuild your RV8, although the lack of faith in that engine is understandable.

[Edit: I know a few blokes who dropped in Isuzu lumps, not exactly refined, but reliable.]

Farmer Dan said:

I know that this block was and always has been a bone of contention so to speak as there were issues with poor casting etc etc etc…… but my block thankfully is fine, (one of the lucky ones I guess from what Iv read and been told) that said it is a nice engine to work on and sounds AWESOME my heart wants to keep it in with two replacement heads but my head want me to shoe horn a Toyota engine in there

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A 2nd hand set of heads can be bought for a reasonable sum..

Gasket set and you're off, trying to shoe horn a toyota engine in to it is not viable, or in other words a waste of your time.

Take the winches off and change the vehicle.

I have two heads sat in my spares box that came with my P38 and would love to have a spare engine to join them! Shame you are in NI or we could have had a deal I am sure

tomcat59alan said:

Take the winches off and change the vehicle.

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it’s the character building and the hatred that makes you fall in love with the green oval….. ease of finding parts etc….. god damn I hate it…… I do love it though

Bix said:

Seen a company drop in the TDV6 from a Disco 3/4, although they charge around 15k for the conversion, so I imagine even without labour it'd be an expensive job.
Seen a few M57s fitted to P38s recently, but it is a labour of love.

LS is a common goto, but getting one in the UK isn't cheap. I guess for ease of work, any of the engines from the 80s/90s that were mated to the ZF 4HP24 ease of conversion.

But realistically, it'd be cheaper to rebuild your RV8, although the lack of faith in that engine is understandable.

[Edit: I know a few blokes who dropped in Isuzu lumps, not exactly refined, but reliable.]

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The TDV6 breaks cranks

Farmer Dan said:

yeah it’s looking to be the most likely option for ease….. I could theoretically use the main ECU from the diesel motor with the assumption that obviously it will work with the engine it came along with and would hopefully communicate with any other nodes (BCM, SLABS or whatever?)………

Click to expand...

You would of course have to fit the diesel ECU along with it's wiring harness, it will talk to the BECM but you may need to change the auto box ECU and that could lead to more wiring changes. All the rest should be OK but still no easy task.
There is a reason that Buick abandoned the alloy V8 and off loaded it on Land Rover

Mercedes OM606 another commonish swap. 3.0 straight 6 diesel with double overhead cam.
Could always follow JLRs example and stick a transit engine in there

Farmer Dan said:

it’s the character building and the hatred that makes you fall in love with the green oval….. ease of finding parts etc….. god damn I hate it…… I do love it though

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I didn't mean anything but another green oval.