radiator fans?

[JeepcoMJ]

the 2.5 MJ I have that is the donor of the engine for my 2.5 xj has a aftermarket fan. it's really nice...but it is solid mounted to the waterpump pully (where the old clutch operated fan would be).

 

I'm concerned that this will keep the engine too cool as it runs all the time.

 

do you guys think it will be a problem? I have a stock clutch operated fan, but don't particularly care to use it as it's ugly. this one is black with chrome blades...bad reason I know...

[TNT]

Your thermostat determines how cold it runs. A solid mounted fan will probably eat up about 3-5hp more then a stock one will.

[JeepcoMJ]

ok. I'll figure out how to mount it to a clutch cause I want it in there lol.

[Pete M]

You could go with an electric and gain a few ponies. :D

[JeepcoMJ]

true. do you think the 4.0 spare fan would be enough?

 

or I probably need bigger...

[87manche]

2.5 use the same rad as the 4.0?

if so, I'd think two stock 4.0 fans could do the job, as that's a pretty large radiator for a 4 banger.

if not, the mechanical fan is something like 2000 CFM, so you'll need a 16" or so E fan to replace it.

[Pete M]

Yeah, for a single fan I'd recommend a quality aftermarket if possible. But if you've got an extra stocker lying around, you could try it and see. :brows:

[JeepcoMJ]

different rad. from a 4.0

 

I think the headers are the same though...so I could put a 4.0 rad in it :D

 

but I'm not gonna since I have a HD 3 row rad to put in it.

[87manche]

different rad. from a 4.0

 

I think the headers are the same though...so I could put a 4.0 rad in it :D

 

but I'm not gonna since I have a HD 3 row rad to put in it.

in that case I'd stick the largest E fan I could fit under the shroud on it and call it good.

[Oizarod115]

You could go with an electric and gain a few ponies. :D

 

you know what man, i have electric fans an i'd bet the increased load from the alternator eats up any ponies i gained. cause at idle a flip of the switch is usually good for a 100rpm drop

 

however... a flip of a switch and i'm up to however many horses i gained from ditchin the clutch fan

 

oh and i'm runnin a 4.0 with a stock e-fan and another small car e-fan and i stay at 210 perfectly, maybe 215 on REALLY hot days, but if i idle for long enough it'll come on down to 205ish anytime

 

and my truck has always had cooling problems i've never really seen it run below 190 after fully warmed up

[Pete M]

You might need to upgrade your alt then. I've got a 170 amp unit (you won't need that much) and the engine doesn't do anything when I kick on both of my electric fans at the same time. If you've got an old 60 amp unit, then you might be straining it.