making a jeep 4.0 stroker run cooler

[flexin91xj]

I'm building a 4.6 stroker for my '91 XJ and was wondering if there were any tips or secrets to making the engine run much cooler. I'm aware of high flow water pumps and powerful electric fans, but I'm wondering if there's anyway to modify the cooling passages and or ports to allow more coolant flow through the block over stock.
Is this possible?

[the_wrench116]

The head gasket is the limitation it has tiny little ports. Maybe to balance flow?

[Cheromaniac]

I'm building a 4.6 stroker for my '91 XJ and was wondering if there were any tips or secrets to making the engine run much cooler. I'm aware of high flow water pumps and powerful electric fans, but I'm wondering if there's anyway to modify the cooling passages and or ports to allow more coolant flow through the block over stock.
Is this possible?

Probably the most important item of all that's needed to make the engine run cooler is a good radiator, and a stock 2-row radiator or a Modine 2-row will do the job nicely. Don't go for a 3-row aftermarket radiator unless it's at least 1-1/2 times thicker than the stock unit 'cause the tubes tend to be smaller and you'll actually have less cooling capacity.
The fan(s) is the next most important item especially when idling or driving at slow speeds where there isn't enough ram airflow through the radiator. If you're going solely electric, I recommend that you keep the stock auxiliary fan on the driver's side and use the factory shroud from the passenger side to mount a second larger electric fan.

[flexin91xj]

I have a 3 row CFM all metal radiator with dual electric fans pushing 1300cfm in my '91 2-door and it works great. But my '91 4-door with the same 3 row CFM radiator had a flow kooler high flow water pump and stock fan and it never got above 160-170 degrees even when crawling. I think the high flow water pump makes all the difference! Im gonna go with the Hesco water pump cause they say it adds 8hp due the design of the propeller.
The CFM radiator is thicker than the stock unit but only by around 3/8 of an inch. Plus it was under $250 bucks including shipping.
Im just worried the stroker will produce a lot more heat than a mainly stock 4.0 and want to keep it in check. I might even go with bigger displacement if I can keep it cool.

[92tank]

my single row alum rad keeps mine plenty cool, with just a stock water pump.

[superj]

mine is fine with all stock cooling copmonents also. under 200 on the gauge

[gonridnu]

We have a copper brass 3 row radiator, a Hesco water pump, a late model auxilary fan, and a Napa fan clutch. Towed a Jet Ski to the lake last week in 90 degree weather at 70 mph and she stayed cool. If I work it real hard slow wheeling it needs to take a rest once in a while to recover but that's it.

[gradon]

Yesterday I installed the American Eagle two-1" core all-aluminum radiator and a new 195* Stant Super-stat. Today I was driving in ~100* with the AC on max and it was b/t 200-220*. It probably has to burp itself a few more times, but is an improvement from my stock single row w/plastic ends that I had to turn off the AC and turn the heat on when it was getting close to 3/4 temp a week or so ago. The water pump bearing is making noise so guess I'll have to replace that in the near future. I gotta do my research on Naxja, cause I recall a newer XJ has a better designed water pump.

[Cheromaniac]

The water pump bearing is making noise so guess I'll have to replace that in the near future. I gotta do my research on Naxja, cause I recall a newer XJ has a better designed water pump.

Make that the very near future 'cause if the water pump bearing is making noise, the start of a coolant leak is only a few days away. The '00+ OEM water pump has an improved impeller design that absorbs less HP than the earlier version so that would be a good replacement.

[wjtom]

stock radiator in a wj with the new napa water pump works fine.has to be the new one to get the good impeller!even with the 4.7 and 10.3 to 1 no problems at all.