Temperature issues

[TheGreatPumpkin]

Hi all. Car is running hot on the highway. Example: 3000rpm, 70mph, 14:1 AFR, hits 230 according to my Autometer gauge. Car is a BBF 466, 9:1, mild, headers, Ford Motorsports water pump, Griffin rad, 180 tstat, fan switch is 200 on, 185 off.
Just got back from a drive, haven't checked coolant level. My timing is 15 initial, 10 vac @ 15inhg, 21 mechanical by 3300, 36 total, 46 maximum possible at cruise but at 3000rpm it's less than that. What's going on here? Too rich? Too much timing or too little? I'm leaning towards "too rich" but I'm kinda stumped.

[hoodeng]

Too much fuel typically won't make it run hot, too lean can, retarded timing can make it run hot ,too much advance will ping. If it is at 14:1afr that is not rich as far as i know.
Is this a recent build or developed over time?

[Ken_Parkman]

I have had an electric fan system cause highway overheating; excessively restrictive to airflow if the shroud forces all the air to go through the fan or fans.

[Geoff2]

This^.

[TheGreatPumpkin]

That's interesting about the fans. Mine has dual Spals that came with the rad, and has the little flaps on the back of the shroud to let air pass. BUT I have fog lights and a license plate mounted under the bumper that might actually be blocking some air. It's a recent build on an older short block with no known cooling issues with the same heads and a single plane, single carb intake, mech fan on stock pump, similar bolt on parts etc. Sitting at idle, the fans cycle and it never gets above 195. Hopefully that helps narrow it down?

Edit: this is the radiator, says 1734 total cfm for dual 12in pullers, which doesn't seem right. All of Spals 12in fans seem to be between 1200 and 1600cfm each.
https://www.griffinrad.com/load_details ... id=8-00087

Front of car:

Screenshot_20220820-061045.png

[Dan Timberlake]

I wonder if a temp sensor could be added to the outlet side of the radiator, in an adapter to in the lower rad hose, for testng porpoises.

A modest chin spoiler or a belly pan under the engine might lower under-hood pressure at highway speeds, relieving too high pressure on the engine side of the radiator.

In one of the trilogy Smokey tells a story about engine bay pressure being pretty high, and completely wrecking the Rochester FI ability to control fuel delivery properly
I got a kick out of the story. First because Smokey was monitoring engine bay pressure 1957. Second, what he did to correct it while testing at speed, and third what happened the moment it was corrected.

[TheGreatPumpkin]

I wonder if a temp sensor could be added to the outlet side of the radiator, in an adapter to in the lower rad hose, for testng porpoises.

A modest chin spoiler or a belly pan under the engine might lower under-hood pressure at highway speeds, relieving too high pressure on the engine side of the radiator.

In one of the trilogy Smokey tells a story about engine bay pressure being pretty high, and completely wrecking the Rochester FI ability to control fuel delivery properly
I got a kick out of the story. First because Smokey was monitoring engine bay pressure 1957. Second, what he did to correct it while testing at speed, and third what happened the moment it was corrected.

I'm very into that type of experimentation - i have an infrared temp gun but i left it at the shop. Gonna try the chin spoiler. Was gonna put it on a while ago anyway but just didn't prioritize it

[chimpvalet]

There is plenty of benefit to be had in minding how air flows after passing through the radiator. Shrouding to eliminate airflow getting into the engine bay via bypassing the rad is a valid strategy, and some sort of belly pan can assist airflow extraction at speed. Just some thoughts that might pertain to a car which cools fine at idle but gets hot at freeway speeds.

Cheers
Steve

[TheGreatPumpkin]

I topped off the coolant and ramped up the timing curve, leaned it out a tiny bit, didn't go over 210... Progress

[hoodeng]

^^^^^^^^
A,ha! Points about location ,air feed and flow are also relevant. Can you get it onto a dyno?

[TheGreatPumpkin]

LA traffic back from the show, stop and go, was forced to stay in the too-rich rpm range, but basically ran at 215-220. That's on me for screwing with the tune yesterday. Still better than before

I guess I COULD get it to a dyno but I'm not sure it's necessary. I might also be depressed about how much power it truly makes

It seemed to really respond to the timing change and mixture, and they were small changes. I'm confident I have enough cooling capacity, just need to optimize the stuff you all mentioned!

[Walter R. Malik]

Hi all. Car is running hot on the highway. Example: 3000rpm, 70mph, 14:1 AFR, hits 230 according to my Autometer gauge. Car is a BBF 466, 9:1, mild, headers, Ford Motorsports water pump, Griffin rad, 180 tstat, fan switch is 200 on, 185 off.
Just got back from a drive, haven't checked coolant level. My timing is 15 initial, 10 vac @ 15inhg, 21 mechanical by 3300, 36 total, 46 maximum possible at cruise but at 3000rpm it's less than that. What's going on here? Too rich? Too much timing or too little? I'm leaning towards "too rich" but I'm kinda stumped.

One head gasket might be installed backward.
Also, That water pump needs to be turned fast. At least 1 to 1 with the crank, not under-driven; sometimes faster than the crankshaft RPM.

[David Redszus]

Possibilities:

1. Coolant is crap.

2. Radiator tubes are plugged with sludge.

3. Radiator fin to tube solder joints loose.

4. Radiator fins plugged with debris.

[TheGreatPumpkin]

Possibilities:

1. Coolant is crap.

2. Radiator tubes are plugged with sludge.

3. Radiator fin to tube solder joints loose.

4. Radiator fins plugged with debris.

I'm 99.999% sure the head gaskets are on correctly, I recall checking it multiple times during installation because I didn't want to be that moron that messes it up.
I'll check the pulley ratio.

#1 is possible
#4 is possible

[F-BIRD'88]

With the non factory fog lights at the bumper you've definatly turned it into a "Bottom Breather" like a Firebird.

Needs a big chin spoiler under the rad support.
Move the fog lights apart or back or eliminate.
Be sure that there is a steel wire coil spring in the bottom radiator hose. As when hot can collapse.

Combined with the fan shroud a lit of air is not passing thru the radiator at speed.