Hei & Electric Fan Upgrade On Dauntless V6

So thought I would share a few points from my recent upgrade to HEI ignition on my 1970 CJ5 with the Dauntless 225 V6. First off had I researched this project a little more I would probably have gone with either the Petronix ingnition or the DUI HEI setup. I ended up with the CRT HEI setup which requires grinding on my intake manifold and shaving parts off the HEI cap. Its an overall very tight fit with little options on where the vacuum advance port ends up. In my application the vacuum advance port left me virtually one option and that was pointing straight at radiator. My next hurdle was now the port hit my flex fan. I tried various spacers with no luck. My solution was to install an electric fan. I went with the 16 inch version from Summit (part# 555-52105) and it was also a tight fit but works well with ~ 1/2 clearance off water pump pulley and it cleared the vacuum advance. My next problems came when I started it up to set timing. Motor runs great with new HEI setup but it quickly overheated before fan kicked on. To make a long story short if you run this setup be sure you have the following installed.

* 15psi radiator cap (this is what's called for but mine had a 12psi)
* 180 deg thermostat
* 185 deg on / 175 deg off sending unit to electric fan
* MAKE SURE ALL AIR IS BLED OUT OF COOLING SYSTEM, this will drive you crazy if not done

In the end the new setup works well but yet to be tested in the California heat. Personally I would prefer the mechanical fan but just could not get it all to fit. One thing I would recommend is the fan instructions say to wire the relay power to a keyed power source. I ended up moving it to constant power so the fan will still run even with engine off so it cools things down when I park. Pay attention when you order fan as they have two kits. The one I got had a sending unit with 200 deg on / 195 off and I had to order the correct sending unit.

I also had to fabricate a "T" for the sending unit to the fan relay as there was only one port on my manifold. Picked the brass fittings up at my local Ace hardware. You can see this his quite a bit higher than the intake and here is where the air bubble in the system caused me headaches as the sending unit was not contacting the coolant so make sure you bleed out the system well!

 

I changed out the fhead in my cj6, in favor of a 225 oddfire. Didn't really have enough room for the mechanical fan either. The new aluminum radiator that fit the spot, Champion I think, had a elec fan come with it as part of the pkg. Didn't pay any attn to the cfm rating on the fan. When running at road speed, all was good. When running at trail speed, not so good. The oddfire got too hot. Started looking for a better fan and settled on this one ,https://www.summitracing.com/parts/flx-118/overview/. The cfm rating was the highest I could find, in a physical size that I could fit in the spot. Also choose to go with this adjustable relay to turn on and off the fan,GM Adjustable Thermostat Temperature Control Switch for 12v Electric Cooling Fan | eBay.. Now even on hot days, the fan can cool enough to make me comfortable with the engine temp, even at trail speeds. Of course in VA 80-90* is considered hot. I sure hope your setup works for you.

 

3b I looked at that fan as well but was concerned with how loud it would be. Curious as to your opinion on that

 

You can definitely hear the fan, but I don't think it is "too" loud. It is not bothersome in a drive thru fast food joint or similar. Actually it is comforting to hear it turn on and especially comforting to hear it turn off, knowing that the engine is comfortably cool.

 

OH and I run a 7lb cap.

 

Correction, I ordered my fan from Jegs, not Summit

 

I've been running electric fans for years. My motor required a 195 degree thermostat. My temp sending unit for the fans turns it on at 210 degrees and shuts it off at 195. The reason for this is so the electric fans don't run all the time.
And with my extra capacity radiator. My fans don't run most of the time. The only time I notice them running is when I am on the trail driving slow. Or in heavy summer traffic. I do have a switch to control the fans. This turn the fans on manually. I only use this when I'm trail driving or needing extra cooling.

 

If you utilize a switch to turn control your electric fan, you may want to incorporate an indicator light or lighted switch to remind you it is on. Good luck