New 351w Running Hot

[Ol'Blue]

Unfortunately motor can’t be raised. Distributor is already close to the hood. Yes 1” BL. Fan farther away from radiator, might be able to squeeze 1/4” otherwise blades may hit belts and radiator hose. Current fan is 7 blade 17”. If I can get it centered and go to an 18” that should give me about 1/2” all the way around gap.

Which is the best 18” fan?

I have been playing with the mixture some while tuning and haven’t noticed a change in temps.

 

[DirtDonk]

Have you also tried advancing the base timing a little?
When you say you’ve messed with the mixture, do you mean the idle mixture adjusting screws? Or changing the Jets?
Mixture screws are good for smoothing things out, but rarely (if ever ?) help with a heating up at idle issue.

 

[Ol'Blue]

Have you also tried advancing the base timing a little?
When you say you’ve messed with the mixture, do you mean the idle mixture adjusting screws? Or changing the Jets?
Mixture screws are good for smoothing things out, but rarely (if ever ?) help with a heating up at idle issue.

Yes advanced base timing to ping then backed off 2-3*. I was around 13-15* base maybe more and went back to 8-10.

Just idle mixture.

 

[DirtDonk]

OK, timing looks to be in the normal range then.
Unfortunately, the idle air/mixture screws don't have a lot of effect on overall running. Just the idle, as they are designed to do.

I suppose you could do a simple test in your driveway.
If you have a fairly powerful floor house fan, sidle it up to the grille and see if your coolant temps go down with it blowing extra air through the radiator.
And by the way, the spot you have your fan sensor is where your coolant temp gauge sensor goes. The thermostat housing is typically where we put fan sensors.
Any reason you didn't use the normal spot for the gauge?

I don't know whether or not it has any real effect on the readings, but locations do matter sometimes.
Maybe others have tested their gauges in different locations?

Paul

 

[73azbronco]

looks like you could easily fit a 2 inch larger flex fan. That out 2 inches is the majority of your cooling capability.

 

[nvrstuk]

You need 3/4" MAX clearance from fan blade tips to shroud. Fan blades need to be 1/2 way recessed into the edge of the shroud.


Cooling issue only at idle usually means your fan isn't pulling enough air. A business card should be held atightly gainst the grill at idle. Keep working on fan placement.

302's/5.0's are easy to cool. 351's can be harder so something is obviously not quite right. Do not think a flex fan can pull the air that a stock 7 blade steel fan can- not even close. Stick with the OE, tighten up the shroud. Get ALL that stuff right and report back.

 

[gr8scott]

Which is the best 18” fan?

7 Blade Radiator Fan, SBF V8, 66-77 Ford Bronco

NEW OE-Style Radiator Fan for 66-77 Classic Ford Broncos. Fits 289, 302 & 351W V8 Engines. 7-Blades, 18 inch Diameter. This fan is made exclusively for TOMS OFFROAD and is a direct replacement of the factory original radiator fan. Just like the original with the exception it does not have any of...

tomsoffroad.com

EDIT: That fan plus this stat:

FlowKooler 330-195 FlowKooler Robertshaw Series High Performance Thermostats | Summit Racing

Free Shipping - FlowKooler Robertshaw Series High Performance Thermostats with qualifying orders of $109. Shop Thermostats, Mechanical at Summit Racing.

www.summitracing.com

 

[Bart]

New freshened up 351w roller and not crazy HP stuff. Running hot when not moving. 302 did the same thing but not as bad and would hold at 190* once the electric pusher would come on. Now Im running around 210* and would go higher if I let it.

Looking for advice to further improve the cooling.

Currently has flowcooler WP
Aluminum radiator converted to three pass
I believe its a WH fan shroud
Stock 7 blade fan about 1-3/4" from the radiator and roughly half into the shroud.
Speedway 180* high flow tstat
Spal pusher fan that comes on at 190*
Vented hood scoop
Trans cooler through radiator

Pretty sure I burped the system well enough and still tuning, playing with timing etc. but I don't think timing is causing the overheating. Placing a paper towel in front of the radiator at idle will not pull the paper to the radiator. I don't think I'm getting enough flow through the radiator. Not ready for the Explorer Surp/Fan just yet.


I plan to remove the small trans cooler you see in the pic of the grill. It covers about a third of the radiator and am sure it not helping engine temps. I was thinking of also trying to get the fan closer to the radiator but I would have to make some mods to the shroud or fan will hit. Also heard the flex fans can loose thier effectiveness. Was thinking of the WH 8 blade fan, but wanted thoughts.

Thanks,

By your pictures I see that the area between the grill and the radiator support is still open. My 351 W (.040 over) ran hot until I installed the radiator air dam. That dropped 20 degrees off it's temps. Before the air dam I'd have the hood up to cool it down any time we stopped. I even ran Moab one year without a hood. Now the vehicle will sit and idle all day long and maintain the temp of the thermostat I installed. I believe it was something in the 200 degree range. Engines live longer at that temp. Old school likes it down around 180 or less. That's hard on the engine. Whether it or not, you believe me on that or not. Get the air dam from W.H. or TBP and you'll be oh so glad you did. Beside you won't loose tools down the front. I don't have any trans coolant going through the radiator of any of my vehicles. 2002 F350 7.3 dually diesel, down to '57 Ford Fairlane 500. It doesn't help that a radiator is also trying to get rid of trans heat. BTW look at all newer vehicles and see that the area between the grill and radiator is also closed off.

 

[Ol'Blue]

Allright gents, I think I have my plan together:

Center up the radiator/shroud
Toms OE style 18"
Once I get the fan in hand. Check thickness and see if I can move it farther away from the radiator
Double check my sending unit wiring
Give Water Wetter a try too, couldn't hurt
I think I will try WH Air Dam. Its always been on my list for looks and function. I wish they made it one piece but it does look cool.
Also having the Pertronix distributor curve checked and possibly recurved. I heard they can have a lot of advance built in.
I may hold off going to the 190* tstat and see what operating temp after doing the above. I was reading that some were operating at 190 ish with the stat I have.

* It'll be 3-4 weeks before I report back. Heading out for vacation later next week.

Thanks for all the help!

 

[nvrstuk]

My .02? Do ONE mod at a time!

Since it only happens at idle how hard is it to narrow it down when only doing one mod, have an iced tea while letting it idle and repeat. Then you KNOW it was airflow or whatever. Knowing what the cause is/was is almost as important as having it working so the symptom won't be repeated later.

Have a great vacation!

 

[73azbronco]

Beside you won't loose tools down the front.

whats the fun in that? I still need to install my WH airdam. Just not enough damn time.

Like never said, try one thing at a time. shroud/fan first. Air dam. Then water wetter. Water wetter is not a solution, it just improves what you have 7-10 deg. They claim 20, i never saw that much.

 

[Ol'Blue]

Ok one step.......ish at a time and found some time to work on it before vacation.

I was able to center up the shroud around the fan. I still have about 1" gap between the fan and shroud. Yup too much. I also removed the trans cooler as previously mentioned. I also have a trans electric fan that hardly ever kicked on, now its kicking on soon but I can manage that.

No real change in radiator cooling as the booster electric fan still had to kick on at idle while drinking an iced tea.

I don't think this step is a surprise due to the excessive gap in fan to shroud, but still good to know.

While I had the shroud removed from the radiator, I was able to get a better measurement of my fan. It about 17-3/8" and looks exactly like the Toms OE style fan. I will call them tomorrow and ask them to physically measure their fan to compare.

Anyone know of a good 19" mechanical fan?

 

[nvrstuk]

Your fan dia is fine. Close the gap. I have 1/2" of clearance btw fan blades and shroud

 

[Ol'Blue]

Your fan dia is fine. Close the gap. I have 1/2" of clearance btw fan blades and shroud

With 1" of clearance, I need a larger fan or need to somehow shrink the shroud. Im I missing something?

 

[nvrstuk]

Retrofit the shroud

 

[cldonley]

I'm installing one of these right now. They have several sizes to fit different size radiators. I know others on here are using these too.

Aluminum Fan Shroud Kit for 26 Inch Radiator, Engine Driven Fan

These universal fit aluminum fan shroud kits can be built to fit many applications with a belt-driven fan. The adjustable collar will accommodate 15"-20" fan diameters. Measures 19-5/8" tall x 20-1/2" wide x 2-5/8" deep. Works well with Speedway 26" wide radiators Made for exact fit of many...

www.speedwaymotors.com

 

[nvrstuk]

That's what I have used for years on my serp setup.
Super simple & a very fair price

 

[Ol'Blue]

Back from vacation and back at it.

I was measuring for the aluminum fan shroud kit. How did you deal with the fact that the fan extends past the top of the radiator and to the passenger side? Did you weld in a filler piece?

Pictures?

 

[77BRONKOTN]

Reverse water pump?

 

[nvrstuk]

Back from vacation and back at it.

I was measuring for the aluminum fan shroud kit. How did you deal with the fact that the fan extends past the top of the radiator and to the passenger side? Did you weld in a filler piece?

Pictures?

Yes, you would need to pop rivet in a filler pc.

After it all works perfect then have someone TIG it in place.

I don't have that issue since my radiator has 50% more surface area and I have a body lift.

You will like the final results