Hitchhikingmike's Explorer

So sounds like the Taurus fans arent all that great. Ive hear this a few times that the Taurus fan failed after being installed on an EX. Ive been thinking about buying a universal fan, maybe a slimline one.

As far as the Overdrive pulley for the alternator, wouldn't the two just cancel each other out?

Thanks for your help mike

It's a matter of rotational mass and parasitic drag.

When you have a smaller rotational mass on the crankshaft it slows down the belt and winds up under driving the rest of the accessories on the belt drive to varying degrees.

Granted by running an overdrive pulley on the alternator will decrease gas mileage some, but it will bring the alternator back up to regular power with fewer rotations of the pulley. All the accessories create parasitic drag on the engine. When the alternator is over driven it still needs to create less drag than the original belt drive system or it will cancel out the UDP on the crankshaft. But since the alternator is generally not a high drag problem to begin with, increasing the size of its pulley shouldn't adversely affect gas mileage.

Actually the electric fans in the Taurus with the 3.8L engines push more air than any other aftermarket electric fan you could find else where. It is also the same fan used in the Ford MachVIII, which is also known to have the most powerful electric fan you can find. Remember too, I pulled my fan out of a '95 Taurus that probably saw most of its life in the heat of the Dallas area. They don't last forever. Once I put a new motor in it it will be just as reliable as any other aftermarket fan.

As the alternator ODP (over drive pulley). No it will not cancel out gains from the crank shaft UDP (under drive pulley). Unlike the rest of the front engine accessories, increasing the speed of the alternator does not increase the rotation resistance. The rotational resistance in the alternator only increases with more amperes are being drawn from the alternator.

MrQ is partially correct. To over drive the alternator, I will be replacing the pulley for one of smaller diameter.

To under drive the crank pulley is to decrease the diameter and to under drive the accessory pulleys would be to increase the diameter.

To over drive the crank pulley is to increase the diameter and to over drive the accessory pulleys would be to decrease the diameter.

I know it is a little confusing. But if you think for a while about it, you'll arrive at the same conclusion.

Dang your right. I wrote that very late at night, so I blame tiredness for my stupidity.

Yep, my brain hurts a little more now hahaha. But I believe I understand what you are saying. Thanks for all the clarification!

MillerTimeX17, I just took a look at your registry, you have done quite a lot of work yourself on your 3rd gen. Your's looks really good with the body lift and tires

The overdrive alternator pulley, electric fan, and hyden fan controller are all installed. The efan works beautifully. I have the fan controller set to turn the fan on at about 198 degrees Fahrenheit and unless the A/C is on, the air flow through the front end is so good that the fan never turns on at speeds of 30mph or greater. The fan only turns on once I am stopped for a few minutes to keep the engine cool.

I left my camera at my dorm room 50 miles away, I will take photos and post them along with a write up once I return later this week.

If you are still interested, on the way back home from my recent road trip (250mi. one way) I averaged 21.5mpg with 3 people and our gear loaded with an average highway speed of 65mph. That also includes about 30 minutes of stop and go traffic driving around the UTAustin college grounds too. Maybe if we didn't drive around the college we could have gotten 23mpg. All in all I still consider the mpg for the trip decent.

I also still had the fan clutch in during this last trip.

Sounds like you are getting that MPG up, Mike. I am really interested in that efan set up.

The Ram has an electric fan AND a mechanical fan on the engine. Dunno why...

Looking forward to pics.

The fan controller and so far my wiring job has held up great, even in the huge down poor of rain I have had for the past couple days. However I have decided that I am not done yet. Right now the fan is only wired up for one fan speed, hi speed. I have decided to put a switch on my dash to manually switch between low and high speed. I will probably make a trip to the metroplex electronic circuit store Thursday or Friday to pick up some more relays, diodes and switches to make it happen. I probably won't be finished and get around to posting the pics until next week once I am hopefully finished.

Alternator over drive pulley is now installed:





When I first installed the pulley, I noticed that it seated too far out from the alternator. This caused the belt to slide half way off of the power steering pulley when the engine was started. This was resolved by taking the pulley back off and trimming the back side down with a metal file so that the pulley sat closer into the alternator.

Voltage has now returned back to normal. At engine start up voltage is in the high 13s. An electric fan cannot be run with just the crank UDP, an alternator pulley must be installed to restore the voltage to support the efan.

The pulley was shipped to my door for a bit less than $40 including shipping and tax.

Did you have to change the belt size again?

No, I purposely purchased a size one inch smaller than was necessary with the UDP pulley after I installed the UDP to anticipate having to install the alternator pulley at a later time. So after the UDP was installed I purchased a slightly tighter belt than required, and the tension was tight. The tension in the best has now been restored to normal now with the alternator OD pulley installed.

MrQ said:

The Ram has an electric fan AND a mechanical fan on the engine. Dunno why...

Click to expand...

Cool. I bet the electric fan comes on with the A/C for better cooling in the cab.
With that set up, I also bet that engine is built up from the factory so that it can pull a massive load in the summer time up a steep grade without even getting hot I'm sure.

I'm sure that dodge is built for extreme cooling capabilities if its rated to pull close to 4 tons.

But no tranny cooler and only a 1 core radiator...

As far as I am concerned, without upgrading those two items, I will definitely not be towing anything more than 3-4k. Its a base model and was not setup with a towing package from the factory, which I am pretty sure would include the thicker radiator and better transmission cooling.

Update: all the modifications I have made appear to be netting me great mileage. My scanguage has been reporting an easy 25.5mpg on the highway with just the weight of myself inside cruising at 65mpg.

I plan on making a highway trip to do some winter camping after this semester of school ends. I will use this opportunity to gather highway mpg data.

Meanwhile, here is a picture of what I have been up to lately

Nice job! I was right around 24-25 on the highway before I went back to the clutch fan, lifted, and bigger tires

For all the bad talk the SOHC engine gets, it really is a great engine in the 3rd gens. All the problems were ironed out by the '02 production year. Since the pushrods were eliminated there is much less inertia mass in the valve train allowing the engineers to design the cam profiles to a higher tolerance. There are many explorers on the 3rd gen section of the forum with well over 200k on their original SOHC engine.


Only trouble I've had with mine is the idle air control clogging with carbon:

A lift and tires will do that to an ex Ronin8002 . At least you still have the potential to go back to great efficiency.

I got the itch to go see some snow. So with an Explorer packed with five people and gear off we went on a 1700 miles trip to the mountains. Can you guess what I was up to?



The driving conditions were not ideal for gas mileage. Average speed on the highway was about 78-85mph, going 75-80mph through the mountains and the cruise control set on 90mph most of the time through the state of New Mexico while cruising at 75 all through Texas. The little SOHC was hauling balls all the way down the road. Tire snow chains were also on for about 60 miles too.







So with the Explorer packed to the gills, the average fuel economy for the trip was 17.5mpg, but we were in a hurry to get there and back, so the average mileage did not come as a surprise.

Found the source of an old oil leak

I was just under my truck replacing the rear differential oil when I thought I would check out an old engine oil leak again I've had. I've randomly replaced seals but the leak never stopped, I assumed it was my rear main seal leaking. 2000StreetRod (Dale) suggested I check the oil filter mount to engine seal. Upon initial inspection it looked dry, but upon further scrutiny I found oil above the upper pan and on the block itself, higher than the pan gasket or rear main seal, ruling out those seals as culprits. I took off the exhaust manifold for continued inspection and sure enough, the filter mount is the culprit.



I removed the header to remove the oil filter mount to replace the seal on the engine block side. The seal had shrunk and became brittle due to the engine heat. I replaced the seal.

I am thrilled now as I believe I have fixed my long sought after oil leak. I had been loosing about half a quart ever 10k miles. My SOHC should now be oil leak free once and for all! Sometime soon I'm going to buy a brush on a wand that I can use to scrub off all the old oil cud off the block and pan.

I spent some quality time with the explorer this week. I spent about ten hours with Meguire's Ultimate compound, clay bar kit and an Autozone cheap orbital buffer and Meguire's NXT 2.0 synthetic wax. First I washed the truck with dish detergent to remove any old wax left on the body and got to work. Here are the results:

before (looks like sand paper)



after


There are now zero swirl marks and all light scratches have virtually disappeared! An almost mirror like finish!