Merrill's 4G64 DOHC.

[Merrill]

So many years ago, I owned a '88 Mighty Max and absolutely loved it. It was my first truck and definitely miss it. The person I originally bought it from really ran it down to its last limb and one day the engine locked up and I had to get rid of it. I always wanted another one but for some reason I never bought one.

I have a long history of racing and back in the day before I started building performance parts and race cars, I was a Mini Trucker. Bag, drag, hop, and body drop - all me, all day. I decided I needed a new race car (or truck in this case), and need a new shop truck, so I chose to build the Mighty Max I wanted to build waaaay back when I had my first one (except a little more modern). I have no plans to bag and drag since most track officials frown upon throwing sparks down the straight away.

The original plans have always been a 4G64 DOHC build, high boosted, and well built to our standards. We were tossing the idea around of using the existing 4G64 that comes in the Mighty Max since the deck casting is exactly like the 4G63 DSM. You can bolt the head straight on and call it a day.

The only problem (more like "what annoys me" most) is the lack of tuning and support. It's old, and so is the technology behind it. After a bit of research, and a stroke of luck, I located a 4G64 out of a Montero Sport which has the "newer" style block with the deck casting like the 4G63 Evo heads. It also uses the same sensors which means I can easily plug in an Evo ECU and tune it easily as well as adding a ton of tuning mods. The engine support for the Evo, in my opinion and experience, is far greater than the DSM.

Modern 4G64 modders are turning to Hyundai cylinder heads because they are almost exactly the same as the Evo. The CC's are slightly larger, but this is a 2.4, so it matches better. I have built a couple 4G64/Hyundai DOHC engines already and absolutely love the minimum cost for the high potential. I have a couple extra heads laying around the shop, and they are a Dime a dozen anyway so I made a call to a buddy of mine at the yard and snagged up the engine and transmission from a '99 Montero Sport 2WD 2.4.

Here is was after pulling it:
20140117_153738[1].jpg20140117_155218[1].jpg

After getting them back to the shop, I tossed them in the washer for tear down and inspection
20140118_122347[1].jpg

Now, for the life of me, I couldn't figure out why an extremely clean looking (internally) engine ended up in the yard. I didn't see a any holes in the block, no signs of a collision, and everything was straight and normal. I figured I just scored. After tearing down the transmission, I found out that the first gear synchro grenaded the shaft collar in addition to cracking off about half of first gear. That's why it was in the yard. Oh well.... I'll rebuild it eventually. The interesting thing is the Model number has the same coding as some of the DSM transaxles =, so maybe I can put together a custom gear set for it. I'll mess with it later.

So the engine was stripped and disassembled followed by a quick shot of paint. Once the block and a couple other parts came out of the oven, it was time to mock-up.

20140119_154738[1].jpg20140119_154746[1].jpg

Just like the DSM's take mods to fit, so does this one. Obviously the first issues are going to be the intake and exhaust being on the opposite sides. To my knowledge, there is no manifold that will bolt on easily. Only 2 intake manifolds I know that fit this engine are the Evo, and the Hyundai/Kia versions (Sonata, Optima, Santa Fe). Both manifolds will face the firewall just like the DSM swaps, but they are easy fixes just like the DSM swaps. I'll just build a SMIM for it once I get it in the truck. The exhaust is the same issue. No manifolds will just bolt right up and let you roll. I'm boosting this engine, so again, once I get it in the truck, I'll build the turbo manifold for it and all the other stuff.

If you look at the mock-up pic on the left, you'll notice the 2 tubes leading around the back for the heater. Notice the top tube runs right up to the outlet of the head. This will have to be modified to fit better (for me). The tube wrapping around the back pops out on the other side and has a port for the throttle body thermal valve. I don't need a functioning thermal valve for cold idle, so it will be deleted.

This is how I did it:

Here is what they look like for fitting to the Montero Sport
20140119_192441[1].jpg20140119_192453(0)[1].jpg
All I did was rotate the right side 90 degrees, and cut out the left side
20140120_145652[1].jpg20140120_145707[1].jpg
Here it is complete and ready for a fit check
20140120_145718[1].jpg

That's one problem solved.

Next up is the issue of this being a FWD engine, and I am mounting it to a RWD block. The Montero Sport has its thermostat located on the lower radiator hose/inlet tube, and the Hyundai's thermostat is located on the back side of the head. I don't need 2 thermostats, and I really don't want to run a water pipe to the back of the engine, so I decided to delete the rear housing.

This engine still needs an outlet for coolant and a place to install an upper radiator hose. The fine folks at Mitsubishi conveniently located a freeze plug right at the front of the head so there will be my exit. Very simple - pop the freeze plug out, and add a 1.5" aluminum tube.

20140120_145507[1].jpg20140120_155916[1].jpg20140120_160340[1].jpg

Once I get it in the truck, I will trim it down and build some stainless hard hoses for the cooling system.

Next up is the valve cover. I personally love the look of exposed gears and belt. The timing covers are not the same, so I won't be using it. I also need to modify the ventilation system to accept one of our catch cans. Seeing "DOHC 16 Valve" on the valve cover is cool, but pointless. If you pop the hood and see 2 bright gold cam gears, it's obviously a DOHC lol. First I had to weld the factory PCV and Vent holes shut. I also got rid of a screw hole I don't need while I was at it.

After a soak in the hot tank to remove the factory coating, I took a grinder to the lettering

20140119_151251[1].jpg20140119_153028[1].jpg

Next is the mounting tabs for the upper timing cover
20140119_151257[1].jpg20140119_153034[1].jpg

Then a couple welds followed by smoothing
20140119_181552[1].jpg20140119_183540[1].jpg

Then a quick sand blast to clean it all up
20140122_140007[1].jpg
I shot it with a coat of primer after that. Once I get the engine assembled I will add the new fittings for the ventilation system and give it the final coating. That pretty much wraps up the head Mock-up.

I'll have more later...