94 SR 3.8 DOHC Project

[Justice R]

My wife and I recently Picked up this 94 SR from a friend of mine. He bought it off Carlos AKA Cap510 AKA Mr Pajero_Montero A few years ago. The rig broke down on him a while back and appears to have jumped time. Since we moved out of state im no longer around to assist with the repairs so he sold it to us cheap. The plan is to make it into a reliable and capable long range off and on road cruiser camp rig. The SR is rust free had a straight body so I figure it’s worth saving. I’ve always wanted to make a 3.8 DOHC since reading about Charlie‘s rig that he build about 15 years back and documented on the wire. Anyways, we towed it back here to NM from CA and got to work.

 

[Justice R]

The front of the engine was already disassembled and I could see that the timing was off by a few teeth and the water pump was seize. We pulled the engine out and went to look for a 3.8.

 

[Justice R]

We went to local pull and pay, and found a couple 3.8’s both MIVEC which I really didn’t need MIVEC heads, but the cost is the same regardless. So the heads will be set aside for later. We found a 09 Galant Raliart and pulled the engine.

 

[Justice R]

Tore the old 3.5 down and found that the pistons had indeed kissed the valves, the heads otherwise were nice and clean, hoping that the guides are ok and I can go through them replace the bent valves, clean them up replace the seals and do a basic valve job.

 

[Justice R]

Disassembled the 3.8 and everything looks good. Cross hatch still visible in cylinders, no rust in coolant passages. Haven’t removed the pistons and crankshaft yet, going to measure everything and hopefully just get away with new bearings, deglaze the cylinders and a re-ring.

 

[Justice R]

We’ve been spending a lot of time in the yard getting all the pieces to needed to fit. The 3.5 DOHC is a strange animal with a lot of one off parts. Right now I’m doing mock ups to ensure everything fits. Water pump is different and looks like I’ll need to use the more common SOHC pump so we got a thermostat housing off a sport in the yard. Oil pump is different and there is gapping at the front of the oil pan with the new style 3.8 oil pump. Looks like I need to find a 3.5 SOHC gen 2 or 2.5 oil pan somewhere or machine a wedge of aluminum to fill the gap. Rear of pan is perfect and all but 2 bolt holes on the sides match. for some reason when resizing photos here they get turned sideways..

 

[MontySquareo]

nice! I've always been interested in putting 3.8 mivec heads on a 3.5 block, and just having a switch or button to engage the mivec solenoid. I'm not sure if it would work though.

 

[Justice R]

Yea. I set the Mivec heads on the old 3.5 block just for fun. Appears that they fit just fine. you'd have to mount the cam sensor somehow, I’ll have to look at it closer after I finish this DOHC build. Maybe they’ll go on my 99 someday.

 

[CharlieNorth]

Nice to see another of this build being done,
It might just be me but I would not take the 3.8 lower end apart. The original engine has better parts and tolerances than any shop will give you.

 

[Justice R]

Nice to see another of this build being done,
It might just be me but I would not take the 3.8 lower end apart. The original engine has better parts and tolerances than any shop will give you.

Yea, I’ve considered that. I’m not sure how many miles are on this thing which is why I was considering refreshing the bottom end. Maybe I’ll take a peek at some of the bearing surfaces and see how they look first.

 

[CharlieNorth]

Pull one rod cap and look at it, Unless it has been run out of oil recently I doubt it would be bad. Even going back to my 71 Colt that I autocrossed and ran track events routinely seeing the oil light on. After a decade I pulled the bearing caps and put them back on. I did not change any parts. The factory parts are the only ones I would use and I think there is very little chance of anything being wrong.
Oh, I still drive a 72 Colt with original engine, Yes I pulled the head off years back to port it. No other work will be done while I own it, no need.

 

[Justice R]

Pull one rod cap and look at it, Unless it has been run out of oil recently I doubt it would be bad.

I’ll do that and report back. Just returned from the junkyard with more parts. Can’t seem to find the right oil pan though. Might have to go down to el paso…

 

[Justice R]

Found some stuff in the local pull and pay….Notably a nice 96 SR. Got as much off that as we could. Took the front bumper since the 94 is missing it and the front skid. Just set in place for the time being..





The elusive Mitsubishi flashlight my wife found in the 96SR in the junkyard.



The 96 also had perfect butterflies which were deleted from the manifold of my 94 so we grabbed it as well.



Mocking up the assembly. Looks pretty good. Had to use SOHC thermostat housing and related pipe as the 3.8 uses a different water pump, this water pump came from a 3.0 sport and bolted right up. Seems all the SOHC water pumps interchange from 3.0 up tom3.8. The upper pipe looks like it’s going to need a spacer or a little grinding to clear the cam gear And will need to be tapped for 2 additional sensors. The 94 has 4 water temp sensors/switches where the later models had only 2.

The only major piece I’m missing is an oil pan off a 3.5 SOHC. This one from the 3.5 DOHC bolts up nicely but the front does not match up at the saddle on the passenger side as you can see the gapping there. Tomorrow I’m going to put the water crossover on the back and check the water tube fitment. I’m confident that it will all work at this point. And then take it all apart for a good cleaning.

 

[CharlieNorth]

If you do not have it already, the 3.0 DOHC timing belt is what I used.

 

[Justice R]

If you do not have it already, the 3.0 DOHC timing belt is what I used.

Yea, I’ll be ordering a 3000GT timing belt for it soon.