Paj Evo Engine Swap

[the_new_nomad]

I recently joined the Montero club with a '99 3.5 with 200k on it. There's currently a 3.5 MIVEC longblock from a Pajero Evo on ebay. Long Block consists of Cylinder Head, Block, Oil Pan and all Internals but without AC Compressor, Alternator, Wiring Harness with low miles. Would this be the ideal engine to swap in or is the 6G75 ideal? I would find a shop in socal to do the swap.

Mitsubishi Pajero Evolution 6G74 Engine Long Block Motor 3.5L V6 Mivec VVT OEM

Mitsubishi Pajero Evolution 6G74 Engine Long Block Motor 3.5L V6 Mivec VVT OEM in eBay Motors, Parts & Accessories, Car & Truck Parts, Engines & Components, Complete Engines | eBay

www.ebay.com

Thoughts:
Replacement parts could be very difficult to find
Would the missing accessories from my 3.5 bolt on?
Would it require the wiring harness from an evo?
Looks like the timing cover is cracked on the upper right of the engine as viewable in the video
Any recommendations on shop for the project?

 

[dos531]

No its not worth it. A 3.8 mivec would be the same amount of work, less money, and more power.

 

[plh]

yeah, I'd skip that and go straight to the 3.8 mivec

 

[Toasty]

Actually the 3.5 MIVEC makes more power, not just the advertised 10-15 extra horsepower either. That 3.5 is an all aluminum race engine and it probably makes 300+ horsepower and the hint at this is the "276" horsepower. That's the magic number in 90's Japanese race cars which means it's far exceeding what's advertised. Google "Japanese Gentleman's Agreement".
The 3.8 is less money, more common and it'll make you happy for sure. That 3.5 however is the legend, it is a race engine and it should be treated as such. It won't be cheap to maintain but you WILL have one haul ass Montero if you pull it off.

 

[Toasty]

Another HUGE detail i forgot, IF the donor Evo was an automatic it can be paired up with the V5A51 from the Gen 3 which will make a huge difference in efficiency and putting the power to the ground. Those ECU's have integrated transmission controllers, unfortunately this also very likely means it won't be happy if it doesn't see a V5A51 possibly making it run in a sort of limp mode.

 

[plh]

Another HUGE detail i forgot, IF the donor Evo was an automatic it can be paired up with the V5A51 from the Gen 3 which will make a huge difference in efficiency and putting the power to the ground. Those ECU's have integrated transmission controllers, unfortunately this also very likely means it won't be happy if it doesn't see a V5A51 possibly making it run in a sort of limp mode.

according to the ebay ad, it is indeed a V5A51 in back of this engine. but it is also $5K plus shipping.... It is also very unclear if that cost includes the accessories, harness, ECU etc. All of those would be very difficult to source if not included.

 

[Toasty]

Be cool if Leo posts up his 3.8 swap with info, maybe we can figure the dollar to horspower ratio.

 

[the_new_nomad]

Actually the 3.5 MIVEC makes more power, not just the advertised 10-15 extra horsepower either. That 3.5 is an all aluminum race engine and it probably makes 300+ horsepower and the hint at this is the "276" horsepower. That's the magic number in 90's Japanese race cars which means it's far exceeding what's advertised. Google "Japanese Gentleman's Agreement".
The 3.8 is less money, more common and it'll make you happy for sure. That 3.5 however is the legend, it is a race engine and it should be treated as such. It won't be cheap to maintain but you WILL have one haul ass Montero if you pull it off.

This was what interested me in the motor. If the motor is bulletproof and could be reliably tuned beyond a 3.8 perhaps with a small amount of boost for high elevations I have the resources to build some special. If nominal then I would go the easy route with a 3.8 instead. I don’t have the knowledge to do this on my own though and would need to find a shop to do the work.

Even something like the cracked timing cover, not sure where to start searching for that part. But I would think there must be some JDM Mitsu dealer that can source.

Any more thoughts? Does it sound like I’d be in over my head?


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[plh]

This was what interested me in the motor. If the motor is bulletproof and could be reliably tuned beyond a 3.8 perhaps with a small amount of boost for high elevations I have the resources to build some special. If nominal then I would go the easy route with a 3.8 instead. I don’t have the knowledge to do this on my own though and would need to find a shop to do the work.

Even something like the cracked timing cover, not sure where to start searching for that part. But I would think there must be some JDM Mitsu dealer that can source.

Any more thoughts? Does it sound like I’d be in over my head?


Sent from my iPhone using Tapatalk

Sounds like a nice dream. Being you can find a running 3.8l mivec for $800 or less....

And good luck finding any EVO 3.5l engine parts excepts for consumables & those common to others. Its more than 20 years old and there were not many made.

But if you have deep enough pockets that you can have someone else do the research, retrofitting and fitting, hit up Toasty. He is super qualified for this kind of thing.

 

[cr4x4cruiser]

Leo knows...
It ain't cheap...
C.A.R.B. is not your friend...
6G74 3.5L can easily be refitted to 3.8L [pistons/ crankshaft]...
6G74 3.8L DOHC would be far cheaper...
Bottom-end of 6G74 is stout - period...
Oh, yeah - that ECU...

#howmuchyougot

 

[Toasty]

I love the idea of a 6G74 DOHC bored out BTW.
Without specific knowledge of how to swap an engine yourself i think it's your best bet to just follow the footsteps of those who have already done it and do the 3.8 swap. Use a shop that has the experience and just buy all the things needed for the swap. Hopefully Leo will chime in and recommend the shop he used.

 

[evomaki]

I'm sure this has been covered someplace, but I have a few 3.5l and 3.8l questions. Are the bottom ends compatible? Will 3.5 heads bolt to a 3.8 block so as to have increased displacement and not MIVEC? Just trying to plan for the eventual need for some engine work, which is likely a ways off but curious. Is the 3.8l crank different, as in more stroke? Can the 3.5l block handle being bored out or are there issues about cylinder wall thickness? Can the 3.5 ecu handle a bit more displacement? Thanks!

 

[RyanY]

I can answer only one of your questions: The 3.8 is both bored and stroked compared to the 3.5, so the crank is definitely different.

Keep in mind that not all the 3.8 engines were MIVEC - the non-MIVEC swap is far easier than the MIVEC as it's essentially just a long block replacement.

Not sure that anyone has done the research to determine if the 3.5 SOHC and 3.8 SOHC heads are similar enough to be interchangeable. Josh at ADD is doing a 3.8 swap on his Gen 2.5 and has identified some coolant port differences between the heads, but I haven't heard anything more from him about it.