Water pump pulley ratio high RPM offroad

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Plato2k5

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Hey there!

I have a 88 Jeep wrangler on 42s with a Mopar 360LA that has a turbo.

I have ALWAYS fought running hot while running at Silver Lake Sand Dunes in Michigan. It never gets hot at idle or driving down the road or in stop and go (its not a DD so hardly EVER happens). Regardless, it only ever gets hot (will clim past 225) from hitting the hills at wide open spinning around 5-5500 RPM. Go up the hill, down, go up another hill, go down, up another...etc. So its not one looooong duration of high RPM. Its just back to back runs.

I have a good aluminum radiator, electric fan with shroud that covers the entire rad, Flowkooler high flow mechanical water pump.

I have fought this from day one when I put this together (non turbo) 10 some years ago. I have tried various radiators, water pumps, and fan configurations. Always has done the same thing.

I JUST started looking into the water pump pulley in relation to the crank.

First off my Crank has 4 V belt ribs. So I assume this engine originally had smog pump and A/C???

The water pump pulley is SMALLER compared to the Crank. Is it possible I am just over spinning the pump causing cavitation at the high RPM? Once I just cruise around the dunes it has a chance to cool??

I see March performance sells a set of V belt pulleys for a high flow water pump that is a 1:1 ratio.

Any Ideas??
 
I use 1-1 on my dirt car. turn 6200-6500. what I have found is you need airflow and water flow. I would do the 1-1 pulleys with a good mechanical fan ( high pitch 4 blade ) with a good shroud. very few electric fans have the airflow you need.
 
mod5v said:
I use 1-1 on my dirt car. turn 6200-6500. what I have found is you need airflow and water flow. I would do the 1-1 pulleys with a good mechanical fan ( high pitch 4 blade ) with a good shroud. very few electric fans have the airflow you need.
Click to expand...

I unfortunately cannot do a mechanical fan. For one, space :( and two, the engine is offset to the passenger side to clear the front drive shaft so the fan would not be in the optimal spot.

Since its a jeep YJ, my radiator core dimensions are 18" x 18".... leaves A LOT to be desired. I really don't want to have to custom fabricate a grill to accommodate a bigger rad...but if I need to, I will. The fan that I have now is a 3,000 puller. Seems EVERYONE runs this style fan and NEVER has any issues what so ever in their V8 jeeps. I just never bothered to look at the pulley sizes.

I think another issue is the hot air has no way to escape from under the hood since its crammed with stuff. So airflow cannot get in.

I'll start with a 1:1 pulley and go from there. Appreciate the feedback.
 
Electric Water pump, restriction ring, twin electric fans.

Eliminates al guesswork.

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Ahhhhh, and instead of a T-stat, there is a washer installed with a sized hole for your application.
Gotcha!
Missed that, thanks.
 
Plato2k5 said:
Hey there!

I have a 88 Jeep wrangler on 42s with a Mopar 360LA that has a turbo.

I have ALWAYS fought running hot while running at Silver Lake Sand Dunes in Michigan. It never gets hot at idle or driving down the road or in stop and go (its not a DD so hardly EVER happens). Regardless, it only ever gets hot (will clim past 225) from hitting the hills at wide open spinning around 5-5500 RPM. Go up the hill, down, go up another hill, go down, up another...etc. So its not one looooong duration of high RPM. Its just back to back runs.

I have a good aluminum radiator, electric fan with shroud that covers the entire rad, Flowkooler high flow mechanical water pump.

I have fought this from day one when I put this together (non turbo) 10 some years ago. I have tried various radiators, water pumps, and fan configurations. Always has done the same thing.

I JUST started looking into the water pump pulley in relation to the crank.

First off my Crank has 4 V belt ribs. So I assume this engine originally had smog pump and A/C???

The water pump pulley is SMALLER compared to the Crank. Is it possible I am just over spinning the pump causing cavitation at the high RPM? Once I just cruise around the dunes it has a chance to cool??

I see March performance sells a set of V belt pulleys for a high flow water pump that is a 1:1 ratio.

Any Ideas??
Click to expand...
What transmission are you running? Manual or auto?
Do you have a coolant expansion/recovery tank connected to the radiator?
 
512Stroker said:
What transmission are you running? Manual or auto?
Click to expand...
I run a 47re. Also fuel injected. 4.56 gearing. There is a small trans cooler infront of the rad. I need to move that so I get 100% cool air flow across the rad.

Now I do run the sand dunes in 4 low. Not sure if that matters...but again, I think I might be spinning the pump to fast.
 
Plato2k5 said:
I run a 47re. Also fuel injected. 4.56 gearing. There is a small trans cooler infront of the rad. I need to move that so I get 100% cool air flow across the rad.

Now I do run the sand dunes in 4 low. Not sure if that matters...but again, I think I might be spinning the pump to fast.
Click to expand...
You can divorcee the trans totally from the cooling system.
Run a separate trans cooler with its own electric fan and remove the trans cooler you have now from in front of the radiator. A hot tranny can add a lot of heat load to your cooling system that you do not need.
How about a coolant recovery tank? Do you have one?
 
Plato2k5 said:
I run a 47re. Also fuel injected. 4.56 gearing. There is a small trans cooler infront of the rad. I need to move that so I get 100% cool air flow across the rad.

Now I do run the sand dunes in 4 low. Not sure if that matters...but again, I think I might be spinning the pump to fast.
Click to expand...
I dont believe you are spinning the pump to fast.
Your radiator size is killing you.
 
512Stroker said:
You can divorcee the trans totally from the cooling system.
Run a separate trans cooler with its own electric fan and remove the trans cooler you have now from in front of the radiator. A hot tranny can add a lot of heat load to your cooling system that you do not need.
How about a coolant recovery tank? Do you have one?
Click to expand...

I do plan on doing that. I do not run the built in tranny cooler on the rad. I do have a remote cooler for the trans with a fan... problem is...where do i put it!? If this was a car, this would be easy. But I go through mud/water/sand/dirt. I was at drummond island in October and I had my 42" tires buried in mud/water. Only place I can think to mount it is inside somewhere.

I do have a recovery tank. Its not very big thought.
 
512Stroker said:
I dont believe you are spinning the pump to fast.
Your radiator size is killing you.
Click to expand...

Guess I'll pull it into the garage this winter and start cutting and welding. Just crazy that every other V8 swap wrangler never has cooling issues.
 
Plato2k5 said:
I run a 47re. Also fuel injected. 4.56 gearing. There is a small trans cooler infront of the rad. I need to move that so I get 100% cool air flow across the rad.

Now I do run the sand dunes in 4 low. Not sure if that matters...but again, I think I might be spinning the pump to fast.
Click to expand...
Have you tried running in 4 high range? That would drop the pump rpm?
If it gets hot in high range its not your water pump rpm.
 
512Stroker said:
Have you tried running in 4 high range? That would drop the pump rpm?
If it gets hot in high range its not your water pump rpm.
Click to expand...

I don't...because trans will get hot lol lol. plus my stall is wrong, gearing is wrong...can't get into the RPM needed to climb. Never ending battle!!!!

I think you hit the nail on the head stating the rad is toooooo small. I just was hoping for a simple easy and quick fix :( But, I might as well just go all out and do it rite.
 
Plato2k5 said:
I don't...because trans will get hot lol lol. plus my stall is wrong, gearing is wrong...can't get into the RPM needed to climb. Never ending battle!!!!

I think you hit the nail on the head stating the rad is toooooo small. I just was hoping for a simple easy and quick fix :( But, I might as well just go all out and do it rite.
Click to expand...
Check out Griffin radiators they have a 2 row 1 1/4 inch core design that would realy help.
I have used a couple of them and they did the job very well, plus they are made in the USA.
 
512Stroker said:
Check out Griffin radiators they have a 2 row 1 1/4 inch core design that would realy help.
I have used a couple of them and they did the job very well, plus they are made in the USA.
Click to expand...



^^^^^^^^^^^^^^THIS^^^^^^^^^^^^

More cores are NOT better. Your pump isn't Turing too fast either.

Up the radiator size and if you can get two 1.25 cores do that.

Then you'll be pooping in tall cotton.
 
Ok thanks! I will look into them. I know there is a lot that goes into a radiator that I definitely overlook.

Thanks for the help all!
 
Also, my radiator is a dual flow. I know there are some pros and cons to that. Any reason to go back to a normal flowing?
 
yellow rose said:
^^^^^^^^^^^^^^THIS^^^^^^^^^^^^

More cores are NOT better. Your pump isn't Turing too fast either.

Up the radiator size and if you can get two 1.25 cores do that.

Then you'll be pooping in tall cotton.
Click to expand...

But pooping in short cotton offers a better view
 
Plato2k5 said:
The fan that I have now is a 3,000 puller. Seems EVERYONE runs this style fan and NEVER has any issues what so ever in their V8 jeeps. I just never bothered to look at the pulley sizes.
Click to expand...
if everyone else runs a certain setup without a problem, what's different about your setup?
 
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