Cooling Fan Mod for AX Options

[Borderline]

Over the years my car has become a dedicated AX car with only a few miles driven on the road just to make sure everything is functioning properly before an AX. The issue is that it takes sooo looong to warm the engine before running. Usually I wait for the engine oil temp gauge to move a little off the peg before my first run, but that means the oil is barely warm. So my plan is to remove the stock oil cooler (yes I have been using the air blockoff mechanism to help warm the engine) to reduce the oil mass and help with warming. The second part of the plan is to remove some blades from the fan so that it doesn't push much air at idle speed but still will cool the engine at speeds above 3k rpm. The question is how many blades to remove and which ones. Anyone have any experience in this department? I've searched back several years and found a couple threads showing some modified fans that they were planning on testing, but have never seen any results. Any suggestions?

[Chris Pincetich]

I wonder what would make a TIV overheat faster, having no cooling fan or no oil cooler? With no fan, more horsepower (IMG:style_emoticons/default/beerchug.gif)
Be careful with that engine (IMG:style_emoticons/default/shades.gif)

[Randal]

Over the years my car has become a dedicated AX car with only a few miles driven on the road just to make sure everything is functioning properly before an AX. The issue is that it takes sooo looong to warm the engine before running. Usually I wait for the engine oil temp gauge to move a little off the peg before my first run, but that means the oil is barely warm. So my plan is to remove the stock oil cooler (yes I have been using the air blockoff mechanism to help warm the engine) to reduce the oil mass and help with warming. The second part of the plan is to remove some blades from the fan so that it doesn't push much air at idle speed but still will cool the engine at speeds above 3k rpm. The question is how many blades to remove and which ones. Anyone have any experience in this department? I've searched back several years and found a couple threads showing some modified fans that they were planning on testing, but have never seen any results. Any suggestions?

First I'd build a fixture that measured the amount of actual air flow with the fan at different RPM.

Once you know the flow you can cut every X number and then measure it again.

Pretty soon you're going to know what each vane cut is worth at each RPM.

With that knowledge you can probably make some good judgements on how many vanes you want to cut and then try in the field.

Right, you might want to pick up a few fans for the experiment.

Or better yet ask Bontempi how many vanes he ran in his race 4. (IMG:style_emoticons/default/smile.gif)

[Borderline]

Over the years my car has become a dedicated AX car with only a few miles driven on the road just to make sure everything is functioning properly before an AX. The issue is that it takes sooo looong to warm the engine before running. Usually I wait for the engine oil temp gauge to move a little off the peg before my first run, but that means the oil is barely warm. So my plan is to remove the stock oil cooler (yes I have been using the air blockoff mechanism to help warm the engine) to reduce the oil mass and help with warming. The second part of the plan is to remove some blades from the fan so that it doesn't push much air at idle speed but still will cool the engine at speeds above 3k rpm. The question is how many blades to remove and which ones. Anyone have any experience in this department? I've searched back several years and found a couple threads showing some modified fans that they were planning on testing, but have never seen any results. Any suggestions?

First I'd build a fixture that measured the amount of actual air flow with the fan at different RPM.

Once you know the flow you can cut every X number and then measure it again.

Pretty soon you're going to know what each vane cut is worth at each RPM.

With that knowledge you can probably make some good judgements on how many vanes you want to cut and then try in the field.

Right, you might want to pick up a few fans for the experiment.

Or better yet ask Bontempi how many vanes he ran in his race 4. (IMG:style_emoticons/default/smile.gif)

That's why I posted the question here, Randy:) I figured someone had tried something already. Those threads I found in my search were from 2007!!! My first thought would be to remove half of the fins.

[wndsrfr]

The fan is a centrifugal pump, just like any centrifugal water pump and it's power consumption is directly related to the mass of fluid it is moving. If you throttle the fluid, it'll use less power.
Simplest solution that occurs to me is to use the flaps in the fan outlet housing tin to throttle the flow with a manual throttle cable that can be locked. Disconnect the thermostat bellows (I'm guessing that you've already done that to maximize the flow) and rig the throttle cable into the cabin somewhere handy between the seats. That way you can monitor head temp when driving on the street and not overheat by manually opening the flow when you want.
If you've got a thermostat set up in your oil cooler plumbing it'll not open 'til 180F, so oil is going to warm up just as fast as without it, but you could shortcut the plumbing there to eliminate the flow to the front cooler without having to remove it.
All that said, I'm concerned that trying to hurry up the warming process you may put stresses on the engine castings that may bring you grief......tread carefully!

[Borderline]

The fan is a centrifugal pump, just like any centrifugal water pump and it's power consumption is directly related to the mass of fluid it is moving. If you throttle the fluid, it'll use less power.
Simplest solution that occurs to me is to use the flaps in the fan outlet housing tin to throttle the flow with a manual throttle cable that can be locked. Disconnect the thermostat bellows (I'm guessing that you've already done that to maximize the flow) and rig the throttle cable into the cabin somewhere handy between the seats. That way you can monitor head temp when driving on the street and not overheat by manually opening the flow when you want.
If you've got a thermostat set up in your oil cooler plumbing it'll not open 'til 180F, so oil is going to warm up just as fast as without it, but you could shortcut the plumbing there to eliminate the flow to the front cooler without having to remove it.
All that said, I'm concerned that trying to hurry up the warming process you may put stresses on the engine castings that may bring you grief......tread carefully!

thanks for the input wndsfr, I'll try to be careful not to thermal stress the engine but waiting 15 to 20 minutes for the oil temp gauge to move is kind of rediculous.. OBTW, I don't run a front oil cooler and have switched over to 5W-30 oil because the temps hardly ever get up to a proper operating temp (~200F). I have been using the stock flaps with a cable control similar to what you described and it doesn't seem to help much. I was thinking that removing some blades from the fan would help warm the engine up faster and still supply adequate cooling at engine speed above 3K rpm. I just don't know how many to remove.

[J P Stein]

Bill:
Like you I wanted to see the oil temp move off the peg before making a pass.
I was pretty consistent about it, but not always able.

After *7 years* I tore down the motor....I felt it was getting a bit slack. Found some scoring on the cyl walls....no wonder the leak down test sucked on a couple holes. I also found the ring gaps were too tight. Pick a reason for the scoring. The rest of the motor was just fine.

Personally, were I you, I'd find something else to worry about......like your need for another 100 HP. (IMG:style_emoticons/default/biggrin.gif)

[Borderline]

Bill:
Like you I wanted to see the oil temp move off the peg before making a pass.
I was pretty consistent about it, but not always able.

After *7 years* I tore down the motor....I felt it was getting a bit slack. Found some scoring on the cyl walls....no wonder the leak down test sucked on a couple holes. I also found the ring gaps were too tight. Pick a reason for the scoring. The rest of the motor was just fine.

Personally, were I you, I'd find something else to worry about......like your need for another 100 HP. (IMG:style_emoticons/default/biggrin.gif)

Hey JP, I'm working on the HP part! I just found some issues with the engine and thought I'd address the "cooling" issue at the same time. Cylinders 1 and 2 have bad leak down numbers and at the last dyno session I had lost 1/3 to 1/2 of my torque at the bottom end. It sounds like both intake valves are not sealing very well. I still have to pull the heads and check it out, by I'm thinking that long periods of idling may have allowed some particle build up on the valve seats not allowing them to seal.

Anyway, that's how I got to this point. The plan is to go with a 78mm stroker crank with my 103mm piston will bring it up to 2.6L......That should warm up the oil (IMG:style_emoticons/default/biggrin.gif)

[J P Stein]

My best advice, if you're sticking with a T-4, is go buy Randal's motor.
He has more bucks in it that I had in my whole freaking car......well, in my conversion to a 2.7L.....which was not hot enough for the pointy end of XP.....I needed another 100 hp also.
His T-4 seemed reliable and makes good /usable power.

[yeahmag]

I'm not sure if you run a dry sump or not, but I'm considering heat sheets or the like for mine. Something like this:

http://www.mcmaster.com/#heat-sheets/=ufqqwp

[Borderline]

My best advice, if you're sticking with a T-4, is go buy Randal's motor.
He has more bucks in it that I had in my whole freaking car......well, in my conversion to a 2.7L.....which was not hot enough for the pointy end of XP.....I needed another 100 hp also.
His T-4 seemed reliable and makes good /usable power.

Yeah, we've talked about it and I've seen the dyno curves....very impressive and yes there is a ton of money in that engine. I'm surprised nobody has picked it up yet. One of the issues I have with that engine is it is very complicated, fuel injection twin throttle bodies. I like to keep things simple so I can understand them. I also think that with a 2.6L I can make more TQ and HP than his 2.4L for less money. You're right though, that engine of his has everything and was done right! (IMG:style_emoticons/default/biggrin.gif)

[ChrisFoley]

I have a 120V heating rod inside my dry sump tank which I can use to get the oil up to about 120F before starting the engine.

[Borderline]

I have a 120V heating rod inside my dry sump tank which I can use to get the oil up to about 120F before starting the engine.

Chris, are you running the stock cooling fan? I have a friend with an electric heating for his V8 and has a generator mounted on his trailer. He keeps it running until he's ready to take it off the trailer. A little more work than I'm ready for.

I've been meaning to thank you for getting the new headers to me in such a timely manner. I wish I could post a fantastic dyno sheet showing what an improvement they made, but I found that after 4 years of AX'ing my motor is a little tired. the only thing I can say for now is that the new headers gave more torque at the top end on the tired engine than the old headers gave when it was fresh..........did i say that right? Anyway, thank you. They look great and the car is very quick even with a tired motor.

[ChrisFoley]

Chris, are you running the stock cooling fan? I have a friend with an electric heating for his V8 and has a generator mounted on his trailer. He keeps it running until he's ready to take it off the trailer. A little more work than I'm ready for.

I'm running my horizontal fan.
I haven't ever worked with modified stock fans, but I know that when road racers remove fins they generally have a 6" pipe to provide cooling air from the front of the car.

Since oil temp is your concern, I suggest not involving the air cooling system except to remove the stock cooler from the airflow.

[Borderline]

Chris, are you running the stock cooling fan? I have a friend with an electric heating for his V8 and has a generator mounted on his trailer. He keeps it running until he's ready to take it off the trailer. A little more work than I'm ready for.

I'm running my horizontal fan.
I haven't ever worked with modified stock fans, but I know that when road racers remove fins they generally have a 6" pipe to provide cooling air from the front of the car.

Since oil temp is your concern, I suggest not involving the air cooling system except to remove the stock cooler from the airflow.

That sounds like a reasonable approach. Though I can't resist the temptation to experiment. Maybe I'll pick up a second fan to modify slightly and try testing it on the dyno (IMG:style_emoticons/default/biggrin.gif) Thanks.

[McMark]

Bill i have a fan for you ready to go. Pm me your address

[Borderline]

Bill i have a fan for you ready to go. Pm me your address

PM sent. thanks Mark! (IMG:style_emoticons/default/biggrin.gif)

[McMark]

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