210° @ Cruise and 180° @ Stop? What's Going On?

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A high stall speed torque converter will dump tons of heat into the radiator at cruising speeds. An auxiliary trans cooler can help with this. But my $ is on the lower house collapsing at highway speeds. RRR is right on (as always) for getting more coolant to flow and this can't happen if the lower hose is sucked closed.
 
DEVIOUSDUSTER said:
No seal on the bottom of the hood. I have an AAR/Stinger fiberglass hood that uses low tension springs and rubber bumpers. Latched with Eddie Motorsports hood pins.

Do you have a picture of what the seal or flaps should look like? Never thought this would be the issue.
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Is there a gap under the hood that air can recirculate from the rear of the radiator, through that gap, and back through the radiator?

You may try a towel or something like a pool noodle if there is a gap, to see if this helps.
 
68gtxman said:
A high stall speed torque converter will dump tons of heat into the radiator at cruising speeds. An auxiliary trans cooler can help with this. But my $ is on the lower house collapsing at highway speeds. RRR is right on (as always) for getting more coolant to flow and this can't happen if the lower hose is sucked closed.
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Spot on 68GTXMan. I can definitely feel the heat coming up through the floor. (And I used FatMat pretty generously all over the interior) I'm using a custom built Dynamic Converter - stall is around 3200-3400 RPM. I have the auxiliary cooler mounted in front between the grille and radiator (located closer to the driver's side headlight so it doesn't block any airflow directly through the radiator.)

I'm banking on the hose - but I have yet to get the new part. I really like the pool noodle idea as well for the air dam between the radiator and engine bay! (I think they make rounded black insulation foam for use around residential water pipes, which might be the way I go) The foam padding used on roll bars would probably work too. The fiberglass hood doesn't have provisions for the stock rubber style and I don't want to drill into it. With a little Polak ingenuity we'll get something to work.
 
DEVIOUSDUSTER said:
I really like the pool noodle idea as well for the air dam between the radiator and engine bay! (I think they make rounded black insulation foam for use around residential water pipes, which might be the way I go) The foam padding used on roll bars would probably work too. The fiberglass hood doesn't have provisions for the stock rubber style and I don't want to drill into it. With a little Polak ingenuity we'll get something to work.
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This is what I did for awhile until I got tired of having to put the foam in place all the time.

I ended up drilling holes in the factory locations and using a new factory style hood seal.
 
Lots of great ideas and info here... I just installed some 3/4" plumbing pipe insulation on top of the radiator support on my car to see if that helps, as I am having the same issue of higher temps at hwy speeds. Also ordered a lower hose spring.
I have a 4000-4400 stall convertor and I am sure that's not helping! I also have a tranny cooler mounted out front.

Anyways, thanks to all those who contributed! Here's a photo of my make-shift hood seal. It's a perfect fit and a cheap way to test to see if it helps!
 

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Thanks for the visual MobileCustoms. Cheap and simple - I like it!

I just purchased the lower radiator hose spring from that Ford Mustang website.

...I feel dirty
 
I think all the bases have been covered here. Please keep us posted on what ultimately solves your problem. Good Luck !
:happy1:
My top 3 choices would be Too much Total Timing, Too lean @ cruise or lastly too small of a radiator.
 
Still need an answer on the carb and what's been done to it so far. Lean engines run hot. Just because it's good at idle doesn't mean it's good at highway speed
 
Might just be the radiator. The stock ones with a hi effeciency core seem to cool as good or better than the universal aluminum ones. Holley carbs usually run rich at off idle and cruise.
 
fklskv said:
Still need an answer on the carb and what's been done to it so far. Lean engines run hot. Just because it's good at idle doesn't mean it's good at highway speed
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Sorry for the delay. Holley 750 DP with mechanical secondaries
 
mguner said:
Are you running a thermostat? The system does require some restriction to keep the heads from cavitation.
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DEVIOUSDUSTER said:
Sorry for the delay. Holley 750 DP with mechanical secondaries
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I noticed you said "fiberglass hood" in one post. does it have a scoop? if it does, and it isn`t sealed to the carb., hiway speed air pressure from the scoop can pressurize the engine bay and actually stop air from flowing thru the radiator. had two hotrods do this, and also a friends 500' crate motored p/u.
 
famous bob said:
I noticed you said "fiberglass hood" in one post. does it have a scoop? if it does, and it isn`t sealed to the carb., hiway speed air pressure from the scoop can pressurize the engine bay and actually stop air from flowing thru the radiator. had two hotrods do this, and also a friends 500' crate motored p/u.
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Interesting....fighting the same issue .
Was leaning towards my valves not sealing. Going to do a leakdown test, but that's another possible cause to explore since I have a functional scoop not sealed to the carb. Thanks for the insight.
 
famous bob said:
I noticed you said "fiberglass hood" in one post. does it have a scoop? if it does, and it isn`t sealed to the carb., hiway speed air pressure from the scoop can pressurize the engine bay and actually stop air from flowing thru the radiator. had two hotrods do this, and also a friends 500' crate motored p/u.
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Interesting point. You're right - it is stock style fiberglass flat hood with a dual snorkel hood scoop. The center is cut out to the shape of the base of the scoop so as to let as much fresh air in as possible. (Spectre ExtraFlow air filter where the cover is also a filter) It's not sealed to the carb.

Might put some foam block in the scoop just to see if it makes a difference. Thanks for the suggestion.
 
I believe the solution has been found!

Drum roll please....

Lower radiator hose spring

I tried making the seal with the lip of the hood and the radiator support but she still got hot. Tried blocking the hood scoop - same results.

I put the lower radiator spring in from CJPonyParts about 2 weeks ago and it's really made a difference. Cruising to shows now I never go over 200. Did 60 miles of interstate highway this last weekend at 65mph and it stayed right at 195. Feels good not have to constantly watch the gauge as much as before. (Still do - only out of habit though)

...It's just too bad that Summer is coming to an end. I'm finally enjoying the fruits of 5 years of labor.

Thanks for the help everyone!
 
Glad you found it!
Plugging the scoop did nothing for mine. Hose is not collapsing.
Gonna do a leak down test but it's so damn hot here and I am just disgusted with it right now.
I think I have an intake leak based on the fact the idle goes up 200-300rpm when it gets hot, but nobody has told me that sounds correct. After 10 yrs building and 2 yrs chasing overheating and other bugs, I am burning out and barely want to look at the car.
 
Some of you guys might want to check your valve lash or preload. I have an older mechanical rocker arm set up with the iron arms and adjustment screws in my 360. My engine would always get a bit hot, so after going through a few things I decided to check the preload for ***** n giggles. I dont know if the lifter plungers decided to act differently after some miles were put on the car, but I took almost two turns out of all of the adjusters to get the preload to a better adjustment. Temps are down and I have more manifold vacuum. Might be something to consider.
 
[quote="Dart67";1970930308]That is one of the most important pieces of the cooling system.

It keeps the hot engine bay air from being drawn back over the top of the core support and recirculated through the radiator.[/quote]

Happen to mine, hot air being re circulated at idle. I used a piece of foam rubber from the home Depot to seal it
 
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