Gen 2.5 3.8 Swap

[ChargerX3]

Jeff is correct. My MIVEC is an 07' so it has the long acuator like yours. It will poke through your firewall unless you modify it. I picked up an actuator from an 08' and blocked off the crossover to the other head because i wasnt going to tap it for the rest of it to work. This way it still works, but now clears the firewall.

Pics for reference.

 

[1BadM6]

Thanks for that ChargerX3. Where did you locate your actuator. I've done quite a bit of searching and while I can find the solenoids everywhere I cannot find the actual housing. I'm also confused as to why you plugged the oil line to the other head. Doesn't that oil become pressurized to activate MIVEC on the right head? Thanks for the response and the great pics.

Dwight

 

[ChargerX3]

I found it in one of the eclipse forums. Some kid wanted the older style so we traded. I plugged the line because I already have an actuator on the other head. I would have had to drill my other head and swapped the opposite side of the head to work. I wasn't going to pull my heads to do all that work. It to mention I would require new timing covers that I don't have.

Also notice the cover I have on my cam angle sensor? It points straight up. Yea just remembered I forgot to install the proper montero unit that sits at about 2:00 instead of 12:00. Also change the cog inside to the matching montero unit. This is all applicable if running a flashable 98 montero ecu.

 

[Atrais]

I'm confused.

So you swapped actuator housings on the left head, but the actuator on the right head was never an issue? Is that correct or am I missing something?

 

[Jeff V.]

The actuator on the left head (the one with the red cover) is on the front of the engine by the timing belt.

The actuator on the right head is the one that was swapped for the lower profile model.

 

[Atrais]

The actuator on the left head (the one with the red cover) is on the front of the engine by the timing belt.

The actuator on the right head is the one that was swapped for the lower profile model.

Ah, got it. Have you got it running yet?

 

[Jeff V.]

I'll let Charger talk about that. I'm just helping with some of the ECU and wiring issues.

 

[Atrais]

Cool. I"m trying to decide between this and a 6g72tt swap. I like the simplicity of N/A but if I'm going to take the 3.5 out something more powerful is definitely going back in.

 

[ChargerX3]

Motor is installed and running! Working through some minor wiring including MIVEC control and staring the tuning process.

TT route would be fun but you had better be good at fabricating up some exhaust manifolds. The other big obstacle is finding somewhere to mount an adequate sized heat exchanger.

 

[Atrais]

Nice! Are you using an external MIVEC controller or were you able to flash a ROM that can control it? I was told the '98 Montero ECU didn't have enough maps to add in a MIVEC control one as well....

I was wondering about the manifolds on the 6g72tt, will they for sure put the turbos in a bad spot (I honestly don't know)? Though fab'ing up some manifolds wouldn't be the end of the world. As for a heat exchanger: with the type of driving I do in this thing I'd probably just go water to air to keep the charge piping short and in the engine bay. Then I could locate the system's heat exchanger where ever. The easiest route would be a supercharger on a 74 or 75, but I'd probably end up having to ditch the mechanical fan and make up some kind of belt drive off the crank pulley to run a decent sized belt/supercharger. However I like the mechanical fan setup, and with the amount of crank pulley/bolt issues that the 6g has I'm wary of making the stack up on the crank pulley longer.

 

[Jeff V.]

I was wondering about the manifolds on the 6g72tt, will they for sure put the turbos in a bad spot (I honestly don't know)?

Here's the problem with the stock 3S turbo layout.

The red circles show the approximate location of the turbos. This is how it would sit in the truck if you were looking at it from the front. If this was in the car, you'd be looking through the drivers side fender. The turbo on the right side is normally up against the firewall in the 3000GT, and so it's mounted high to clear the chassis cross member. The one on the left is mounted low to let the hood slope down. So you'd probably need to relocate the left side (passenger/ right side in the truck) up high to clear the frame rail.

The turbo that ends up on the drivers side of the truck would have the exhaust outlet facing forward. So you'd either need to either have the downpipe exit out and then wrap back down under the engine, or relocate that turbo as well. The flanges are triangular, so you can't just spin them 180*. Left alone, the compressor inlets would be facing the firewall in the truck.

Anything can be done with enough determination, skill and money, but it sure won't be easy. If you're going to custom build all the manifolds and piping anyway, just boost the engine you already have. Or look into that company in Australia that has a kit to install a TRD supercharger on the 6G74.

I've got a spare 6G72-TT in my garage. If I ever get around to doing the 6G74 swap in my truck, maybe I'll take an afternoon to mock up the TT engine just for fun. It's not a Montero, but it should give people a general idea of how it would sit.

 

[Swank Force One]

TRD supercharger on a 6g74? You have my attention.

Edit: $7500. Hard nope.

 

[Jeff V.]

I'm constantly surprised that nobody has made an aftermarket lower manifold to allow you to bolt up the plentiful GM V6 superchargers.

 

[coffeegoat]

It's been discussed, for example see here. And it's actually been done before by this guy. But it's certainly not an easy approach.

The tricky part is managing the fuel side, there isn't enough capability in the stock fuel injector system to manage the extra fuel (also fuel pump). The electronics is also pretty challenging apparently, needing either a new ECU or a piggyback system to manage the fuel, do tuning, and avoiding catastrophic knocking.

I was really interested in giving it a shot but as soon as I dug into the ECU and fuel issues I decided it was way out of my depth. From my perspective it would be interesting to do an increased electrification approach to add power as well increase economy - investigate a high efficiency brushless alternator (with shutoff), switch to electric coolant fans, etc. Basically try to meld insights from the hypermiler world with those in the high-power world...

 

[Jeff V.]

Charger is using mostly 3000GT electronics and fuel for his 3.8 engine. There's absolutely no reason those concepts couldn't be applied to a boosted Montero application. The wiring would be even easier on a Gen 2.5 or later Montero because those weren't based around the older 12V engine with it's distributor.