Cooling fan conversion

[KeeponDragon]

I have this "challenge" with wanting to improve or modify things. And it's usually stuff that qualified folks spend months tweaking to ensure it's reliability.
Do I know better then them?
I dont believe so.
So I guess it's a case of "because I can, I will"
My 03' Tundra has almost 370k on it now. No idea how long a thermostatic fan clutch is supposed to go for.
So I spent some time, made a plan, collected parts, made a part, and this weekend, decided to do the install.
My main concern was being able to return it to OE, should my bright idea not be up to task. So far, I've only had to clearance the hub knob on the water pump. Conveniently, I placed the electric fan right in line with the pump. Because Oops.

The coolant temp switch goes in here. I machined this out of a piece of solid stock.
Then welded the bung into it

The electric unit is a little smaller than the belt driven one, but the speed it moves air should be a good offset.

It's a good fit. Tucks in nicely.

I managed to get a 3 or 4 mm gap between the motor n water pump snout.

The main objective here, besides saying I did it, was to free up some of the remaining horsepower this engine still makes...
Guess I'll find out

 

[6.5 Fan]

Looks like a good fit, hope it works for you.

 

[slow-poke]

One thing to consider is how much the rubber mounted engine will shift forward under braking. 3mm does not seem like a lot of clearance. Looks like the part on the RHS will be rotating so might act a bit like an angle grinder if it shifts forward.

I do like electric fans.

With 370k sounds like its just broken in, good for another 100k or maybe two. Go Toyota Go!

 

[Former Member]

You can go with 2 fans which offsets the interference points giving you the clearance you need. Additionally it allows for a 2 stage cooling to optimize engine temps as required. Single fans be it clutched or electric are on or off.

Going electric also reduces fuel consumption and increases available power.

 

[Janger]

Good idea. Any noticeable difference?

Does your taco have cruise control? Mine is a bit intermittent.

 

[KeeponDragon]

You can go with 2 fans which offsets the interference points giving you the clearance you need. Additionally it allows for a 2 stage cooling to optimize engine temps as required. Single fans be it clutched or electric are on or off.

Going electric also reduces fuel consumption and increases available power.

Initially this was my plan. I had harvested a dual setup from an Audi turbo car. But out of two setups, only one fan worked.
So I went with this single, two speed from a Volvo 5 cyl turbo.
The fan switch is a 2 speed variety from a VW, (because I know those from owning a lot of them), first stage kicks in at 90', the 2nd at 115'.

 

[Susquatch]

A very small percentage of people can feel an electric fan engage and disengage, but most people cannot. Almost everyone can feel an A/C clutch though.

More fuel economy and more power from an electric fan is very subjective. Depends on ambient temp as well as frontal speed and the vehicle size. It actually takes more power to run an alternator to run an electric fan than a mechanical fan, but that isn't true for an electrically clutched fan. However, if the frontal speed is high enough, no fan is needed at all. In any case, the benefit is much less than driving with eggs on the pedals. Basically, learning to drive any given vehicle efficiently provides the biggest opportunity to improve that there is.

Something that most people never think about is the opportunity for savings that large vehicles with big engines presents. A 10% improvement on 15L/100km truck is a whole litre and a half. A 10% improvement on 5 L/100km car is just a half litre. Plus it's way easier to get that improvement on the truck.

Obviously, this ignores the fact that the truck burns a lot more fuel than the car, but the incentive to improve it is a bigger reward. If you need a big vehicle for whatever reason, consider improving how efficiently you drive it. Start with a raw egg in a sock on the accelerator and the brake pedals.

 

[KeeponDragon]

Good idea. Any noticeable difference?

Does your taco have cruise control? Mine is a bit intermittent.

I took it for an uphill rip last night, kept the rpms up to try and stress it out, temp gauge stayed at the half mark. Half is about where the clutch fan would keep it, so that at least tells me it's working. Revs did seem a little peppier.

It's funny you called my truck a Taco...as it is an older Tundra. But, it is about the same size as todays Taco's...
The current Tundra is way and above larger then my truck.

 

[KeeponDragon]

One thing to consider is how much the rubber mounted engine will shift forward under braking. 3mm does not seem like a lot of clearance. Looks like the part on the RHS will be rotating so might act a bit like an angle grinder if it shifts forward.

I do like electric fans.

With 370k sounds like its just broken in, good for another 100k or maybe two. Go Toyota Go!

Well, it "seems" pretty secure in there. When the fan engages, either high or low, it sucks itself towards the rad, maybe 5mm. But it IS pulling away from the hub snout on the water pump.

The engine, a 2UZ-FE 4.7L V8, is a real workhorse. Iron block, aluminum heads, runs ok on regular, better on premium. Rated at 230hp.
The valve train is still within spec too. I checked it about 3 months ago. Figured for sure, after that kinda mileage, I'd have to make adjustments. Nope. This is my first Toyota. And after 8 yrs, it owes me nothing. Definitely keeping it.

 

[KeeponDragon]

A very small percentage of people can feel an electric fan engage and disengage, but most people cannot. Almost everyone can feel an A/C clutch though.

More fuel economy and more power from an electric fan is very subjective. Depends on ambient temp as well as frontal speed and the vehicle size. It actually takes more power to run an alternator to run an electric fan than a mechanical fan, but that isn't true for an electrically clutched fan. However, if the frontal speed is high enough, no fan is needed at all. In any case, the benefit is much less than driving with eggs on the pedals. Basically, learning to drive any given vehicle efficiently provides the biggest opportunity to improve that there is.

Something that most people never think about is the opportunity for savings that large vehicles with big engines presents. A 10% improvement on 15L/100km truck is a whole litre and a half. A 10% improvement on 5 L/100km car is just a half litre. Plus it's way easier to get that improvement on the truck.

Obviously, this ignores the fact that the truck burns a lot more fuel than the car, but the incentive to improve it is a bigger reward. If you need a big vehicle for whatever reason, consider improving how efficiently you drive it. Start with a raw egg in a sock on the accelerator and the brake pedals.

I won't bullshit anyone, I like the loud pedal. But not all the time, as that just gets expensive. Either in fuel consumption or paying the traffic tickets. 95% of the time, I feel like I drive pretty soft on the throttle.
Will I pick up any mileage with this project? Don't know yet.
But after last nights test flog up a hill, my butt dyno may have felt a bit more oomph, not as much labour to do it.
I can say, I feel pretty certain that the rev's come up a bit faster, without the rotating mass bolted to the front of the engine.

You hit the nail on the head though, with the tradeoff of alternator load to run the motor. When the fan kicks in at idle, there is a noticeable drop in rpms. But no different then if the AC clutch were to engage.

Like I stated before, I did this because I wanted to. Not out of necessity, but want.

 

[slow-poke]

Plasticine is great for checking clearance on something like this. Little dab in the right spot, find a hill, zip down and get into the brakes and then inspect.

 

[Janger]

Oh you have a Tundra not a Tacoma. My error. 8 years old and 370K? That's a lot of driving! Is it a work vehicle?

@Susquatch driving with eggs on pedals?

 

[Janger]

Dry cut saw - home made

@KeeponDragon - I'd like to see your home made dry cut saw.

 

[Susquatch]

@Susquatch driving with eggs on pedals?

It's just a behavioural cue. An egg would never survive my paws. The idea is to avoid fast acceleration and fast braking.

I actually got pretty good at efficiency driving. But a young fellow in my group could drive rings around all of us. We sponsored a fuel-a-thon competition for auto journalists in the Maritimes. We gave them a one day course with instrumented vehicles, then they each picked a car that was filled with a metered quantity of fuel. My engineer took which ever car they didn't want. He was still driving ages after the last one quit. Made a believer out of all of them.

The hairy guy with big feet wasn't allowed to drive.......

 

[KeeponDragon]

8 years old and 370K? That's a lot of driving! Is it a work vehicle?

Nope...I've owned it for 8 now. It's an 03'. Might be a typo up top lol.
I've put roughly 80 of that on myself. Been a great truck.
I'll just keep fixing it until I can't anymore. It's still cheaper than the cost of newer vehicles.

 

[Tecnico]

It's just a behavioural cue. An egg would never survive my paws. The idea is to avoid fast acceleration and fast braking.

SNIP!

The hairy guy with big feet wasn't allowed to drive.......

Unless I’m trying, my right foot is my biggest enemy. I don’t try much around town - LOL! I just like how responsive this thing is. Oh, it’s a Golf R It gets such good mileage without trying that I don’t!

That said I’m surprised at the difference just putting it on cruise control makes. Now before you say it just keeps you from stepping on it I thought the same until I set the computer to display MPG and held the pedal still on level ground which is what cruise would do.

The instantaneous MPG is always higher with cruise and I think there must be a different control map for when the car knows it won’t have to compensate for my size 12s at any instant. Probably leaner and more boost & spark advance. @Susquatch does that make sense?

I can beat it at it’s own game on the highway if I really try by coasting and in and out of cruise but that’s a little more work. It came in handy one dark winter night in the middle of nowhere in NB when I pushed my gas stop a little far…

D

 

[Susquatch]

The instantaneous MPG is always higher with cruise and I think there must be a different control map for when the car knows it won’t have to compensate for my size 12s at any instant. Probably leaner and more boost & spark advance. @Susquatch does that make sense?

You didn't say what year your golf is. But almost all modern engines control spark advance and fuel mixture based on an engine map. The maps define optimum performance under all conditions of operation. While modern engine controllers do know that cruise is engaged, it does not change what part of the map is used. The mere fact that you can beat it with extreme attention to detail tends to validate that. For most people, cruise control is the easiest way to get better economy. So congrats to you for being able to better that.

Also, without getting into too much detail, governments would frown on that essentially calling it a cycle beater if it did do that. That's not to say it's inherently a bad idea, especially if it reduced emissions, just that it would not be considered legal.

Lastly, the instantaneous fuel efficiency display really isn't truly instantaneous. Even instant is a bit of a rolling average. The average is also usually weighted by the rate of change. A true instantaneous display would drive you bonkers.

 

[Tecnico]

You didn't say what year your golf is.

Lastly, the instantaneous fuel efficiency display really isn't truly instantaneous. Even instant is a bit of a rolling average. The average is also usually weighted by the rate of change. A true instantaneous display would drive you bonkers.

My Golf R is a ‘19.

There are 2 display modes, long term average and “instantaneous”. The instantaneous mode would be what a layman would call real time but probably as you say it is a rolling average of the last few readings etc. with a sub second refresh so it looks instantaneous and the eye can follow it.

@KeeponDragon sorry for the threadjack!

D