Overheating and Water Pump Questions

[jon6.0]

I have a 7MGTE in my 85 4-Runner rock crawler. I just put a 2-row aluminum 31x19 radiator with a 26x17.5 core in the back of the bed with a shroud and 2200 cfm fan. To get to the back I needed about 20 feet of piping and the radiator fill cap is above the back seat.

It will idle and go slow all day long and stay at 200F-210F.

When I speed up to 60mph it heats up to 230F-240F. I haven't driven it farther than 8 miles to figure out if it will get hotter.

I have driven it both with the top on and without the top on.

Is it possible the water pump isn't pumping the coolant fast enough or with enough flow since I added all the hard piping to get the radiator in back?

Or is my fan to small at 2200cfm and I should get a dual fan 4000cfm unit?

 

[IJ.]

I'm guessing the pump is cavitating trying to push that head of water at higher engine speeds.

You might want to try an electric booster pump in series set to only come on above xxx temp.

 

[jon6.0]

I'm guessing the pump is cavitating trying to push that head of water at higher engine speeds.

You might want to try an electric booster pump in series set to only come on above xxx temp.

Where would I get a booster pump from?

 

[IJ.]

I use a Davies Craig EWP 110 here to help out in summer traffic and it works well in that configuration, ie: either pump can flow through the other depending on which is pumping faster.

 

[jdub]

The last 10 days of 110 deg temps aren't helping

 

[jon6.0]

Well I just got back from another test drive. Took the top off, folded down the back seat, and left the windows down. It was dusk so it was only 103F.:aigo:

Went right up to 230 and stayed there a while then started creeping up some more toward 240.

So I left it in 5th and went 1200rpm. That was about 30 mph and it started cooling right down.

Based on this I believe the pump is indeed cavitating and I need a booster pump.

What are the stock spec's of the water pump? What pressure and flow?

 

[jon6.0]

I use a Davies Craig EWP 110 here to help out in summer traffic and it works well in that configuration, ie: either pump can flow through the other depending on which is pumping faster.

What does 110 lph equate to in gph?

 

[jdub]

28.95 Gph
But, I don't think IJ specified lph in use...that is max flow for the pump.

 

[jetjock]

29...

edit: beaten by the dubster

 

[jon6.0]

DOH! The Davies pump is 110 Liters per Minute. Not per hour.

http://www.hrpworld.com/index.cfm?form_prod_id=747,587_3529&action=product

 

[jetjock]

It's still 29

 

[IJ.]

Cracking up laughing here

[thumb]http://ij.supramania.com/assembly60.jpg[/thumb]

 

[jdub]

Seemed a little low :biglaugh:

 

[jon6.0]

Cracking up laughing here

[thumb]http://ij.supramania.com/assembly60.jpg[/thumb]

Did you remove the impeller of your stock water pump like the Davies-Craig website says or are you just running it in series?

 

[IJ.]

I run it in series as each pump will flow through the other depending on which is pumping faster Jon.

 

[jon6.0]

I run it in series as each pump will flow through the other depending on which is pumping faster Jon.

Cool. Thanks. They are definitely the cheapest option. I looked at Summit and Jegs and the Meziere and others are $350-$450. Looks like next payday I'll try one out.