It's on the road! Finally! Step one of my incredible 'Two Step Process' is finally completed. It's really strange to open the hood and see nothing different. It looks EXACTLY the same as the 3.0L except it's cleaner. Weird.

After running it for twenty miles in stop and go traffic in 85 degree weather up to 45 MPH I fired up my OBD II scanner to check out the computer - my primary worry with this swap. Fuel trim, O2 sensors, etc. are all reading what they're supposed to be reading. The next step will be testing at highway speeds - 70-75 MPH - and higher RPMs.

The only issue so far is the temperature dash gauge. For some reason it's reading higher than it should at a specific temperature. The sensors are the same for the 1997 3.0L and 2002 3.5L and the engine isn't running as hot as the gauge says so I suspect it may be due to the extension of the wire. At least that's my best guess at this point. ???

The extra torque is definitely noticeable. It doesn't accelerate much differently from a stop but it's easy to tell that the engine doesn't have to work nearly as hard to get 5500 lbs moving. I can accelerate in fourth gear up hill starting at 2000 RPM. With the 3.0L that was impossible.

Next step is the suspension and oil pan modification/whatever. Once the suspension is back where it should be and the pan is out of the way it'll be time to take it off road. Can't believe the 3.5L SOHC is that much heavier than the 3.0L SOHC. Hmmmm.

Edward

Is the crank good in the 3.0? I need one... Have one that the crank bolt shat the bed on...

Awesome! I think the 3.5 has bigger connecting rods and i think they're forged, could be where the extra weight comes from.

Hi, Hazy. Sorry, I didn't keep the 3.0L. Since I plan on doing the same 3.5L swap in my project '97 I didn't want yet another 3.0L sitting around that I had no use for. Scavenged all the the interchangeable parts and then gave what little was left to the shop. Figure I'll sell the one out of my project vehicle but that won't be until next year. Have to do the SAS and 3-link first.

Edward

Yea, the 3.5L has a longer stroke and slightly bigger bore. Don't know whether the rods and crank are forged. I still wouldn't think it'd make that much difference, but it did in this case.

We ended up putting in a new set of Skyjacker coils and that brought it back up to where it normally should sit. I like the Skyjacker coils a LOT better than the Napa F150 coils I was running. The handling hasn't changed at all but the front isn't nearly as choppy and it flexes better.

So, spring are in and the oil pan is modified. So far, so good. No leaks. Between the lift from the coils and dropping the bump stops 1" we didn't do anything too radical to the sump. This won't work on my new project Sport but it's good enough for this one.

Took it up for a test 'wheel over the weekend. The extra torque is great on the mountain highways! The 3.5L with the 5-speed manual transmission is GREAT!! Drives better than the same vehicle unmodified. The 3.5L hauls 5500 lbs. up and down the hills with no problem - 70 MPH on an 8% grade at 8000 feet. Not bad.

I can't tell any difference off road - with the 4:1 and doubler I could be running a B&S 2-cylinder and it wouldn't make a difference.

The 3.0L ECU seems pretty happy. LT fuel trim hangs at about +.75 average for highway driving. So far, lowest has been -1.5 and the highest +1.4. Nothing else in OBD looks any different than the 3.0L ever did.

Working on another problem now. With temps bouncing around 100-105 here in Denver I've got an overheating problem. It's not a problem with the engine itself, thank God. The cooling system either isn't up to snuff for the 3.5L or it never was even for the 3.0L but the ambient temperature hasn't gotten high enough to cause issues. Starts to run hot on long inclines on the highway and pushing the RPMs up between 3-4K on long steep inclines at less then 2-3 MPH in 85+ degree weather off road definitely doesn't work.

On email with half a dozen radiator companies and Spal. Started pulling stuff off the front. First to go was the ARB plate under the bumper. That helped slightly on the highway. Next will be the IPF bumper lights. That'll open up as much of the front as possible without pulling the bumper.

Next step will be a new radiator to replace the stock radiator. After that, if I still have problems, is the dual fan setup from Spal.

We'll see how it goes. Only have a month and three weeks before we leave for Moab and I still have to install the new PCS steering box. Still waiting for them to ship the new one back. Sigh.

Edward

I would not buy an aftermarket radiator. The tanks are made from foil. I'd put a 3 row core in there and you'll never have a problem. You might get away with just a rod out, but going from a 2row to a 3row is the best way. If you look at the bottom header, you should see a row of dimples if there's room for the 3row. My 3.5 had them in the SR. Bet yours is the same. If the core is not performing, all the fans in the world won't help. Do you have a fan shroud?

The stock radiator is in pristine condition inside. I'm religious about cooling system flushes. So, I know it's not corroded or blocked. I pulled the radiator a while ago and pressure washed the core. That helped. It took quite a while to get all the red Moab dirt out. I checked when we were swapping the engine and it's still nice and clean so that's not the problem now.

The stock Sport radiator is different than the Montero radiator. Only one row. Checked and the 3.5L and 3.0L are the same so that rules out changing to the 3.5L Sport radiator.

Based on what I can see - heating up on long assents at low speed and assent on the highway it appears that there's either not enough coolant volume being pumped through the system and/or the radiator just doesn't have enough surface area. The ARB bull bar blocks a lot of air flow on the highway.

I run the Ford Contour dual fans.



These fans move a LOT of air. It'll cool down 10 degrees in less than 30 seconds once the load is off even in 100 degree weather. As you pointed out, no fan will work if the radiator isn't big enough.

I've been talking to tech at Spal and their opinion is this: For crawling - the radiator just isn't big enough - especially with ambient temperatures pushing 85-90+. Hauling 5500 lbs up a steep incline at 3K RPM produces a lot of heat, there's zero air flow from movement and the radiator is just too small.

On the highway he thinks a good part is that there's too much stuff in front of the radiator blocking the air flow I'd normally get from driving. He suggested removing as much stuff from in front of the radiator as possible and go from there. He still thinks the radiator is too small, though.

He strongly suggested addressing the radiator first for both problems. Anyway, that's pretty much what everyone I've talked to says and it's what I've more or less deduced for my self.

Right now I'm looking at going with Griffin. 3.25" core - dual tube. Any input on alternatives/someone better would be welcome.

Edward

Edward,

Can't you add another row to the OE radiator? Would be far cheaper I'd think.

I spoke to three shops here in Denver a few years ago. According to them the tanks aren't thick enough to do anything with. I could have a double tube copper core built with the same tanks, but it wouldn't be any more efficient - in fact, it'd probably be worse. It's a 1.375" (or so) core and there's barely 1/4" extra space on the tanks front/back. I don't see any way to add a second row to the factory tanks....

Talked to Griffin a bit ago. Looking at their 2 row/3.25" core all aluminum radiator. They don't have a template for the Sport (of course) so I'll send them one of the stock radiators for a template.

Edward

Wow, then definitely not like the full size Monty radiator.

Also be sure to check if he flushes the new aluminum radiators to remove the residue left from the welding process. As I understand it from listening to the Drive Radio radio show / podcast (courtesy of your local CO Select Napa store association/network... see www.drive-radio.com), almost all aftermarket aluminum radiator builders do not flush out those contaminants which unfortunately will react with most coolant formulations. Long story short, it causes issues if it's not first flushed out. At least that's what the hosts of the show claim. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Update: I fired off an email when I was typing this earlier (~3:15pm) and the host of the show (Donny Seyfer) has already responded! NICE!!

He says the manufacturing process leaves behind fluorides which if mixed with your old coolant can create acids that will eat your cooling system. The new aluminum radiators should be washed out with hot water and soap prior to installation.

Alternatively a polyorganic antifreeze can be used w/out washing out the radiator so long as you remove all non-polyorganic antifreeze from your cooling system.

Either way you're gonna be washing something out. <img src="/forums/images/graemlins/lol.gif" alt="" />