225 V6 overheating

I need some help with the cooling system on my Jeep. This last fall I did a 225 swap in my 3A, I used a Walcks radiator with the lower outlet moved to the other side. I am also running a electric fan on the back of the radiator. The jeep runs cool when the ambient temperature is below 70. Now that it is much warmer the jeep runs hot when climbing hills slowly. What has everyone else used for a cooling system that will keep the 225 cool when it’s 90+ degrees out? Thanks for the help. 

AKoller wrote: I had heating problems with my Dauntless to begin with in my 3A. I used the factory 3A radiator and had the outlet moved to the passenger side. I had a 15" flex fan. I made a shroud to help pull air through the radiator and that helped but still was running well over 200 when the ambient temperature exceeded 90 degrees. I ended up ordering a aluminum radiator from Summit. It was only $159 dollars and I never have had a cooling issue since. If you want, when I get home this evening I can get you the part #. You should still double check all your basics. Timing, fuel/air mixture both can be overlooked and cause a heating issue.

Below is a picture of mine. It fits in between the driver side frame rail and the factory battery mount. You can see my flex fan sits pretty low on the radiator but i have the electric pusher fan between the radiator and the grill.




The only time I've ever seen it come close to 200 degrees is if I'm lugging it hard on a hot day for an extended amount of time. I think I could completely solve the issue by either building a shroud to help pull air through or eliminating the mechanical fan and installing a 16", thermostat contolled electric fan that is rated at 3000 cfm or more.

On Sunday I drove it about 50 miles round trip at 55 MPH (which is about 2800 rpm with my gearing) to my parents house to get together for fathers day. It was 90 degrees outside and the gauge never moved over 165 degrees. With my factory radiator I would have been at 225 degrees.

I now need to install a 180 degree thermostat. I had installed the 160 degree thermostat when I was having heating issues.


Edited by AKoller - 20 June 2019 at 4:50pm

AKoller wrote: Below is a picture of mine. It fits in between the driver side frame rail and the factory battery mount. You can see my flex fan sits pretty low on the radiator but i have the electric pusher fan between the radiator and the grill. The only time I've ever seen it come close to 200 degrees is if I'm lugging it hard on a hot day for an extended amount of time. I think I could completely solve the issue by either building a shroud to help pull air through or eliminating the mechanical fan and installing a 16", thermostat contolled electric fan that is rated at 3000 cfm or more. On Sunday I drove it about 50 miles round trip at 55 MPH (which is about 2800 rpm with my gearing) to my parents house to get together for fathers day. It was 90 degrees outside and the gauge never moved over 165 degrees. With my factory radiator I would have been at 225 degrees. I now need to install a 180 degree thermostat. I had installed the 160 degree thermostat when I was having heating issues.

Here is the part # for the radiator I have from Summit.

Edited by Rich M. - 22 June 2019 at 5:13pm

I went through this scenario on my 3B over the course of 3 engine transplants-327, 350, and 381.  I originally set it up (ca 1973) with a vertical Chevy truck radiator.  That required a dropped front frame cross member.  It sort of worked----with the 327

I think you at least need a shroud so the fan can pull air through the radiator all over the surface, not just where the fan is. That and a bigger fan would probably solve the issue you are having.