New 351w Running Hot

[blade]

I have an 85 mustang that I switched from a mechanical fan to electric only. After installing the electric fan my car would overhaeat at idle. The fix was sealing between the shroud and the radiator with some high density foam. There wasn't a large gap probably about a quarter inch.

 

[nvrstuk]

I have an 85 mustang that I switched from a mechanical fan to electric only. After installing the electric fan my car would overhaeat at idle. The fix was sealing between the shroud and the radiator with some high density foam. There wasn't a large gap probably about a quarter inch.

Many won't believe or try to fix the small things that make the difference!

 

[Madgyver]

Delta PAG 18" brushless fan with a custom mad built shroud solved my cooling issues on my 393Clevor. ECM set to come on at 200* and turn off at 190* with a 180* thermostat. Ram air will shut ECM off where fan is not needed.

 

[cldonley]

Here's a pre-welding pic of mine. 1" body lift, explorer radiator. My fan exceeds the size of the radiator on all four sides. Planning to use the little close out plate that came with the kit and the piece cut out of the shroud base to make close outs, have it welded, then use high temp RTV to seal the shroud to the radiator.

 

[BtheFelix]

There is a ton of great advice in this thread, but one thing I didn't see is the brand of the radiator you're running. FWIW, I had serious issues running hot and went through much of the same to try and resolve my cooling. Come to find out, I was running a Howe radiator that looked good inside and out but was the real issue. The Howe radiator was in it when I purchased my Bronco so I don't know its real history. I installed a Champion Radiator and now mine runs too cool with a 165* thermostat. Good luck in your journey.

 

[nvrstuk]

Radiator design is critical. Without being too critical, the Champion cuts corners in several areas in engineering design for efficiency BUT IT WORKS!!

I had a custom Ron Davis built. It is a coveted brand by many and an apples to apple comparison with the SAME shroud, same fan, same wp, same hot 93deg summer back to back days and the RD could not keep my engine cool at freeway speeds as the temp would climb up.

I slapped in an Oreillys replacement for a Ford Granada from '76 for a 351W and from that day and the rest of its life on my "temporary radiator" it never got above t-stat for 4 yrs.

The RD sucked. It had epoxy to help keep the joints strong and we think that made the difference. Epoxy does not transfer heat/cold well at all.

I run Griffin now. 1 1/4" tubes, 2 row. Cools 600 hp in 115deg record heat crawling or cruising at 75mph

 

[DirtDonk]

My fan exceeds the size of the radiator on all four sides.

But it’s also recessed entirely into the shroud.
That is generally considered not the most efficient. However, given the design of the fan and the full coverage of the shroud, it may still pull a lot of air through the radiator.
Before you do anything permanent, you should test it extensively (or have you already?) and see how much air it pulls through under all conditions.
What fan and clutch is it?

Planning to use the little close out plate that came with the kit and the piece cut out of the shroud base to make close outs, have it welded, then use high temp RTV to seal the shroud to the radiator.

I would say negative on the high temp RTV.
First, you don’t need high temp in this situation.
If this area ever gets over 300°, you have a lot of other problems!
Second, and more importantly, you definitely do not want to glue the shroud to the radiator and make it a real chore to remove in the future if you need to.
And third, the same results or better can be accomplished with different materials.
Perhaps some sort of a foam or rubber seal would be better?

 

[ba123]

There is a ton of great advice in this thread, but one thing I didn't see is the brand of the radiator you're running. FWIW, I had serious issues running hot and went through much of the same to try and resolve my cooling. Come to find out, I was running a Howe radiator that looked good inside and out but was the real issue. The Howe radiator was in it when I purchased my Bronco so I don't know its real history. I installed a Champion Radiator and now mine runs too cool with a 165* thermostat. Good luck in your journey.

Sure you don't mean those the other way around? I've heard about a TON of issues with the Champion and not a single one with the Howe.

Delta PAG 18" brushless fan with a custom mad built shroud solved my cooling issues on my 393Clevor. ECM set to come on at 200* and turn off at 190* with a 180* thermostat. Ram air will shut ECM off where fan is not needed.

+1 for the Delta PAG. I don't have mine done yet and I went with the 16" but the fan seems like a monster and pretty sure I'll be happy with it after testing. I did find a cheap shroud that I'm slightly modding to work for me and should be perfect for my space.

 

[Timmy390]

Radiator design is critical. Without being too critical, the Champion cuts corners in several areas in engineering design for efficiency BUT IT WORKS!!

I had a custom Ron Davis built. It is a coveted brand by many and an apples to apple comparison with the SAME shroud, same fan, same wp, same hot 93deg summer back to back days and the RD could not keep my engine cool at freeway speeds as the temp would climb up.

I slapped in an Oreillys replacement for a Ford Granada from '76 for a 351W and from that day and the rest of its life on my "temporary radiator" it never got above t-stat for 4 yrs.

The RD sucked. It had epoxy to help keep the joints strong and we think that made the difference. Epoxy does not transfer heat/cold well at all.

I run Griffin now. 1 1/4" tubes, 2 row. Cools 600 hp in 115deg record heat crawling or cruising at 75mph

My nice champion american eagle radiator with 1 inch tubes just crapped the bed. popped a hole in the lower right side. Due to lead time and price, I took a chance and installed a cheap aluminum from ebay. Been testing it for a few days in 100 plus air temps here in AR. It runs a couple degrees hotter but so far so good. The ebay radiator is not as thick and didn't have the correct mounting but I mad it work.

Running 210-220 with 195 stat......been pulling a 12 foot utility trailer......fan kicks on high at 220 and she starts to cool.....

Tim

 

[ba123]

My nice champion american eagle radiator with 1 inch tubes just crapped the bed. popped a hole in the lower right side. Due to lead time and price, I took a chance and installed a cheap aluminum from ebay. Been testing it for a few days in 100 plus air temps here in AR. It runs a couple degrees hotter but so far so good. The ebay radiator is not as thick and didn't have the correct mounting but I mad it work.

Running 210-220 with 195 stat......been pulling a 12 foot utility trailer......fan kicks on high at 220 and she starts to cool.....

Tim

Haha, I wondered about those cheapo ebay radiators. Almost bought one just to mess with the fan and shroud cause so cheap. Perfect for getting by until you can get what you really want but if it works, great!

 

[cldonley]

But it’s also recessed entirely into the shroud.

It is a bit too far. About half the fan blade angle at the top and almost the whole fan blade angle at the bottom. I have not tested it yet, but I'm planning to do so before finishing it up.

I would say negative on the high temp RTV.

My other thought on this is to apply a peel and stick foam insulation between the radiator and the shroud for ease of removal. But nothing's gonna go wrong, right?

What fan and clutch is it?

Stock 95 explorer 5.0 fan with heavy duty aftermarket clutch.

 

[nvrstuk]

Peel and stick foam insulation doesn't bond well to .012' thick alum fins! Ask me how I know. It does seal the gaps tho and that helps.

 

[cldonley]

Peel and stick foam insulation doesn't bond well to .012' thick alum fins! Ask me how I know. It does seal the gaps tho and that helps.

Mine overlaps onto the plastic tanks-maybe that'll work better?

 

[nvrstuk]

Gotta be better. Make sure you use a wax & grease remover to get rid of any mold release chemicals so it has a chance of staying in place till the shroud holds it in place

 

[cldonley]

Gotta be better. Make sure you use a wax & grease remover to get rid of any mold release chemicals so it has a chance of staying in place till the shroud holds it in place

I was concerned the shroud might chafe a hole in the tanks. The peel and stick would protect from chaffing and seal. Gonna have to try it.

 

[Ol'Blue]

Back at it. I found the PO had trimmed the fan down about 3/8" so figured that definitely would be the issue. (see pic) Ordered new stock style fan from Toms and threw it in. It was able to idle in 85* weather for about 10-15 minutes before the electric booster fan kicked on at 190* then climbed to about 210* before I shut it down before getting any hotter, so I still have some work to do.

With the new fan I still have about 5/8" to 1" gap depending on side. I have the shroud centered up as best I can.

The other thing I noticed is the air flow seams to fly off the edge of the fan and not back to the motor.

I got the radiator off a member here about 7-8 years ago and I think he said it was a Griffin and is 4 core, so Im hoping a new radiator isn't needed.

The shroud fits tight against the radiator, but I may try tapping it up anyway to see if there is improvement.

Im thinking the next step is a new shroud as suggested, get the gaps down to 1/2" and fan centered, but Im concerned I may have to toss the shroud if I eventually have to replace the radiator since size maybe different.

If shroud doesn't do it, next will be radiator damn then maybe 195* tstat as suggested.

The new fan "seams" to pull more air by feel, idles longer before heating up and looks good with the new motor so Im good with the $100 spent there.

 

[DirtDonk]

Did you try revving it up a little bit to see if that brought the temperature down? If so, what did it take?
All this heating up was with the hood open still?
I think we’ve talked about it before, but you are aware that 210 is nowhere near overheating. Correct?
In fact, it’s where many engines run today. And only about 10° over the thermostat you should probably be running.
I’ll have to go back but I assume you’re using a 180.

When the electric fan kicked in was it pushing air through the shroud any more efficiently?
Speaking of the shroud, it almost looks like your fan is too far in still. At one point on the side it looks about half in, half out. Which is great. But for the rest of the shroud, it looks mostly in.
Is that how it is, or is it just the angle of the picture makes it look that way?

 

[DirtDonk]

And what is your idle speed? Can you afford to raise it a couple of hundred RPM to improve fan and pump performance, or would that make it too high?

 

[Ol'Blue]

I did not try revving it up to see if it would cool.
Hood closed
I know 210* is not that bad but was hoping to see it below 200* at idle.
Maybe my expectations are just too high and I should just drive it for a while and see how it goes.
Yes 180* tstat
When the elec fan kicks in you can feel more airflow
You are correct on the fan in shroud. The top 1/4 its all the way in. On the passenger side halt way in and on driver side 3/4 of the way in. I didnt notice the driver side being in so far before.
Maybe next step is to cut that extension piece off the top and trim every side to half in.
Idle is already pretty high.
I have the WH 5.75 pulleys so maybe change size of motor pulley to increase the fan speed?

 

[ba123]

Like Paul said, 210 isn’t hot. +1 for revving it to see what happens while there. You’re standing still with a fan that’s controlled by engine speed. I wouldn’t shut off until maybe 217° if still climbing and if revving doesn’t help. 220° is probably the start of “hot” imo.

Oh, just saw you have a 180 tstat. Isn’t that too cool and won’t run right? Isn’t standard a 192-195 tstat? I know it is for the 5.0 and a quick search for a 351 finds the same thing.