302 cooling issue

[Bo Boulware]

I have a 69 Bronco with a 302. C-4 trany and AC and Fie Tech I started with a new aluminum radiator the stock fan and a good shroud I fought overheating and finally took it to a reputable shop. They felt my radiator was plugged up so put a new radiator in. No help. Then an electric fan. No help. Took it to a second shop and they found the timing was off. Seamed to help but not in temperatures over 90 deg. I have read threads on here about similar problems. I’m thinking of putting one of the high volume water pumps on and changing thermostat to a Robert Shaw 180 deg. Anyone have any input if I’m going in the right direction? Not sure what kind of electric fan they installed but it doesn’t look to me like it covers enough of the radiator and they said it doesn’t need a shroud with the electric fan. But that also concerns me. My temperature runs about 210 when driving and if at slow idle climbs fast.

 

[1969]

Keeping Engine Cool With AC

Just finished a build on a 76 Ranger I have built several Broncos over the years but we wanted this one to have AC so I bought a kit from Classic Auto Air. Drove the Bronco around without AC with success keeping it cool (granted not in 98 degree weather). Now that I have the AC finished it's...

classicbroncos.com

Check out this thread that is currently being discussed and similar to your situation.

I would start with ditching your electric fan and converting to the explorer serpentine front dress to get a good fan clutch and fan.

 

[Timmy390]

Couple of things.....

FiTech or any EFI is going to want more heat than 180. Most EFI systems if not all, run a 192 or 195 stat. With a 190ish stat 210 is normal. My rig runs 210 to 220 (electric fan kick on hight at 220) even on the hottest of days.

Are you using the FiTech temp sensor? What temp does FiTech show?

Dash gauge or aftermarket?

Trans cooler?

Big tires? What gear ratio?

My aftermarket guage swings in temp fast sometimes. Took me a while to get used to it. I run a cheap ebay aluminum radiator and 17 inch electric fan (the one wild horses sells).

Tim

 

[Bo Boulware]

Thanks I will follow that thread also. I do have large tires and I’ll have to check gears. My Fie Tech gauge runs hotter than my stock gauge. Maybe I’m getting worried to soon but I feel it just keeps getting hotter. I try to shut it off before 225 or so. It boiled out once.

 

[Timmy390]

Well boiling out is an issue for sure.

Do you have a recovery/expansion tank or is it just open?

I run this fan. My SN95 ECM controls it.
https://www.wildhorses4x4.com/high-...MIje2rjf-ZhwMVuyrUAR2Y1AHEEAQYASABEgIZ8vD_BwE

Tim

 

[73azbronco]

you need a 190-195 thermostat for the efi. It won't make it boil over any more than what you have now.

What is the engine condition, new 302, old 302? Compression test? Vacuum at idle? Air conditioning?

I would use a stock water pump, hi flows have not proven themselves in the EB.

Use a good stock copper oem style rad. Mine is, and cools a 347. I also use the explorer serp stuff, but completely stock cooling is fine with a good running 302.

 

[Brush Hog]

Two things I found on mine when it was running hot: First was brand new radiator cap was bad right out of the box and wasn’t sealing causing boil over. Second was I had it running way too lean. Now it runs at 190 all the time no matter the outside themp. Used to creep up to 220+ at slow speed/idle. I run a Tom’s aluminum radiator and a metal clutch fan with a shroud. No efi.

 

[Bo Boulware]

Tried to find my gear ratio but guessing 3:50. Running 33 X 12.5 tires. Has a seal 16” electric fan. Says 1290 cfm.

 

[Timmy390]

3.50's and c4 is not optimal. It's generating some heat due to the bigger tires. I like an external cooler if sticking to the 3.50's but it's not a must.

My electric fan is an inch bigger and flows 2400 cfm at high speed or 1800 cfm at low speed. When my temps hit 220 sitting in traffic the fan goes to high and I can watch the temp guage drop.

I'm not saying throw money at a new fan but 1290cfm seems inadequate to cool a V8......and you have A/C too....at a minimum IMO you need more airflow and I like 2 speed fans.

Tim

 

[Bo Boulware]

When you say the transmission is generating heat I started thinking. When I had the exhaust put on they ran one of the exhaust pipes right along side the transmission or transfer case. I commented to him about heating my oil and he said it would be fine. Could that be some of my issues? Is there a temp the trany oil should be that I could check?

 

[Timmy390]

When you say the transmission is generating heat I started thinking. When I had the exhaust put on they ran one of the exhaust pipes right along side the transmission or transfer case. I commented to him about heating my oil and he said it would be fine. Could that be some of my issues? Is there a temp the trany oil should be that I could check?

The stock rear gear ratio, C4 and stock size tires are all designed to work together. When you add bigger tires and don't change the rear gear, it causes the C4 to work harder. Now with 33's it's not that big a deal but it's more than likely running a touch hotter than stock. If it were mine and I didn't plan on changing gears I would probable run an external trans cooler. Heat kills automatics. The exhaust being close is not causing your overheating issues.....but it might be raising the temp slightly of the trans fluid.

99% of the cooling issues are airflow related. Most overheating posts deal with temps being normal while driving but increasing when stopped which is related to airflow.

JMO but you have a fan that's marginal in CFM and only has one speed. That fan is trying to pull air through an A/C condenser and a radiator both of which are restrictions to the flow thus dropping the overall CFM.

As to the shop telling you no shroud is needed for an electric......Yes and no. Lots of factors involved. I've heard the arguments for both. I ran a shroud with my setup and then removed it with no noticeable difference. THAT SAID.......the Taurus fan is arguably the best most efficient electric fan ever made and it has a shroud. Has monster flow too.
https://www.summitracing.com/parts/...MI9ZPhxdCchwMVgTLUAR1F9w4CEAQYASABEgJ7V_D_BwE

Tim

 

[Bo Boulware]

So, do you recommend the Wild horse fan or the Taurus fan? Its sounding like I need to put a stronger fan on just need to decide on right fan. Are there any fitting issues with the Taurus fan that you know of?

 

[Timmy390]

So, do you recommend the Wild horse fan or the Taurus fan? Its sounding like I need to put a stronger fan on just need to decide on right fan. Are there any fitting issues with the Taurus fan that you know of?

IF I was going to go mechanical fan, I would do the Explorer front dress. Most consider it the best cooling mechanical fan for the Bronco.

As to electric, I would have gone Taurus but I had not room. I run the front dress off a 1996 E350 van and it's TIGHT......The WH fan was the only fan that would fit and it barely fits. Plus it was a name brand and moved lots of air.

Good read about the two options above
https://classicbroncos.com/forums/t...xploder-mech-vrs-tauras-electric-fans.256487/

Might also go to "google" and in the search bar put classic bronco taurus fan site:classicbroncos.com

This will bring up a large amount of info on the Taurus. I don't recall what everyone is using for a controller. My ECM does that for me.

What size alternator you running? 2 speed fans mean more amps.....

Tim