Thought I'd share some progress. Been busy the last few weeks so this stalled a tad but got a bunch of stuff done today. Block was standard bore, worn about .003-.004 at the top (152k miles!). Got it bored and honed out .020 over. All of the core plugs were rotted and once removed, revealed tons of block sealer. Had to scrape out the crud with a long screwdriver through the head surface water jacket holes and flush, flush, flush with water.

The heads are a mess. One head was cracked and welded, the other is cracked and needs to be welded. Whoever touched these heads before apparently never bothered to check spring pressure/installed height as the valves were obviously bouncing off the seats. Valve guides are fine and none have dropped (though I thought the 91's had the clips to keep them from falling). It's a wonder this thing ran at all.

Frank, I know you gave me the spec for head decking, but where do you measure from? The valve cover surface to the head surface? I want to measure these before I go through the trouble of welding the one and putting new valve seats in. I'm almost tempted to go to the yard and pull a set off a 3.0 equipped Caravan, rebuild them and use the Montero's cams and cam gears.

Hoping to start assembly next weekend (at least the bottom end).

I'd go to a DIY yard and pull heads from a Caravan or Diamante SOHC. I'm not sure if the Caravan cams are the same, so if you go this route, swap the Montero cams into the new heads. You also might need a couple of longer bolts for the valve covers since one boss on the Caravan head is lower than the Montero. I wouldn't use the Diamante cams unless you're prepared to degree them.



Yes....... 3.310" is standard spec... no more than .008" milling total head + deck.... check for warp.

Look close at the decks for etching.

I probably don't have to tell you to clean those deck hole threads and watch the clamping range of the bolts..... torque to 80 lb-ft. Head studs are available if you want a solid clamp, but the bolts work fine for a N/A engine if you're careful.

Spring pressure is 74 lbs at the installed height of 1.591" - limit 1.630". I assume that's the spec for a new spring - all of them will lose pressure after a few miles. Mine all measure about 60-65 lbs and I didn't change them.

Frank

Wow, where has the time gone. This took way longer then it was supposed to but the engine is finally done and running. A whole bunch of things totally stalled the project but over the past month it was picked back up and finished. Some interesting DOH moments:

Used the wrong bolt on one of the valve covers and bottomed it out in the cam tower before it clamped the gasket to the head...hehe, boy that can leak a lot of oil once it's running! <img src="/forums/images/graemlins/shiner.gif" alt="" />

Speaking of getting it running...I totally forgot the distributor cap #1 spark tower is not located directly above it's spark contact on the underside of the cap, so pointing the rotor to the #1 tower results in a lot of misfiring. Thank god for McMontyV and his manuals! Once I realized what I did, I reset the distrubtor and had it running inside of 5 minutes.

We had the injectors cleaned and flow tested at a local NJ shop. $15 per injector and they were in decent shape. This thing runs great, pulls hard and is very quiet when running. Gotta love a fresh engine!

Some cell phone images:

The 91 RS as purchased for $250.00

Bottom end going together (My brother's 67 Mustang Fastback in the background)

Engine back in it's home.

Almost done!

Success! A cold Guinness and some roasted peanuts at the local watering hole. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Only thing that still needs to be replaced are the two small coolant lines that connect to the throttle body but I can't find them anywhere (and the ones on there are barely holding). Anyone have some part numbers on these guys? I found some small brass 90 deg. elbows coupled with some regular straight hose, I could make my own, but then there's two more connection points to worry about.

Good deal! <img src="/forums/images/graemlins/kewl.gif" alt="" /> A fresh 3.0L does make a big difference.

You should be able to get those hoses from a dealer. They are part of a recall package that added a throttle plate heater to eliminate throttle blade icing. You can by-pass them if you need to and just leave the 2 tubes open. If you need to change anything to make it work, the tubes are removable and the ports can be tapped for pipe threads:



Those brass barbs I used are not the best for automotive use, though - they tend to tear the hose on removal. If you can find the automotive type with a single smooth ridge it'll make removal easier and preserve the hose.

Frank

Frank, his throttle body doesn't look like that, but then his is a '91. On his the IAC and hot water items are switched (the IAC is under the TPS). One hose comes straight in under the TPS, the other comes out the opposite side of the TB and 90's towards the lower intake. I thought the recall only affected vehicles made before 1990? I eventually found them under CAPS though it took some hunting. Ones called a Throttle Body Feed Hose, the other " " Return Hose. They were $10 and $14 bucks from Mentor Mitsu's online order page. I also ordered a new Speedometer cable as his squeaks bad, even after numerous attempts at greasing, oiling (with Speedo removed, rear jacked and idling in gear to spin the cable) plus the needle bounces (when connected) which makes me think it's frayed, bent or otherwise damaged.

Overall this thing is coming along with the only remaining thing I would do is replace all four shocks with some new KYB's.