1972 Ford Maverick, fresh 393w, dished pistons, 9.75:1cr, built C4, 3,000 stall, 3 row champion radiator, electric fan, 180 thermostat. 650 holley double pumper. Plugs read rich at cruise, and full throttle (shutoff/coast to stop). MSD 6AL2 w/ timing at 32 total @3000, 14 at idle.

So i've been having a lot of trouble with keeping this motor cool. Probably has 50 miles on it, and wants to run over 200. I don't let it get past that, and when I stop it doesn't seem to want to cool down.

Bumped the timing back to 14 idle, 32 total @3000. (was 16 and 34 can adjust anything below total w/ the msd box, as distributor is locked out, and the timing curve is programmed w/ a computer) Took the hood off, and drove around. Still wants to go over 200. Probably 2 miles of driving 35, then another 2 miles of hwy (speed up to 55mph, 3 stop lights), then limping it home another 2 miles trying not to overheat. Took the pulley off and made sure that I did have the correct waterpump, etched "Gates 43272" on the pump snout. Which is a reverse rotation water pump.

Both heads read 200-ish with an IR thermometer. Radiator reads 190-ish at the top, 160ish at the bottom. Trans cooler reads 165ish at the top, 145ish at the bottom. Transmission pan reads 175ish (but that's also right by the headers/exhaust, car was too low to get a reading of the center of the pan.) This was with the gauge in the car reading 200ish.

Doesn't seem to want to cool down to 180 after getting to 200 while stopped and idling. Let it idle for probably 5 minutes when I got home, taking temp readings, and still stayed at 200ish.

Fans are oriented correctly. Coolant system builds pressure (have tested the 16 psi cap in the recent past). New motorcraft thermostat, tested, working.

Don't believe there's air in the system. Headgaskets should be oriented correctly, know I double checked that when I put the heads on, plus you can see both "tabs" of the headgasket sticking out. Plus you'd temp readings would be high.

 

check lower radiator hose. Makes sure it has a spring inside so it doesnt collapse.

As for timing, Your idle is fine, but your cruise rpm need to be at or higher than your wide open. So figure out your cruise rpm and put it at 38ish. If it was me I would have idle at 25, low load cruise at 38-42, wide open 34 if this is a map based timing curve.
If its rpm based only, 25idle and 34 by 2000rpm.

low cruise timing can cause high engine temps.

 

Addressing the rich plugs. The top of the porcelin near the electrode getting black is cruise. Down inside the plug and the bottom of the porcelin is WOT.

What is your idle and cruise afr?

 

RPM based timing only. I can adjust it to 25/34@2000 and see what happens. Car has slip tube headers, that can't be welded as they go around the cross member, therefor no AFR gauge (and no one makes headers for a 351w in a maverick besides crites). I'll look at the plugs closer, i was just judging by the top of the porcelain.

Edit: Also, no spring in the lower hose, but it doesn't collapse.

Greatly appreciate your help and insight!

 

So I adjusted the timing (and idle metering screws) as you said, and drove it around for a long while in town (30-45minutes). 35-45 mph stop/go, which is 1500-1750rpm ish. Engine temp was around 200 the whole time. Never got to 210, never got below 190. Ambient temp was about 85 all day, and sun was just on the horizon when I got home, temp was about 80.

I know it doesn't mean much, but attached is a photo of a plug I pulled after getting home. WOT plug looks the same though. I honestly thought the photo was better when I took it, I'll try to get a better one when it's daylight out tomorrow.

I know that 200 is okay, but also I live in a state that we frequently get a week of 100+ weather, and I'd like to still drive the car, also plan on a roots blower, and A/C. So if I can't keep it cool now, I definitely won't be able to then.

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More timing will tend to cool the engine down. That combo will probably want to cruise at 45* or so.

 

If your radiator has a 30 degree drop, that's pretty typical of a decent setup. I wouldn't assume that the t stat is going to be exactly 180, there's so many junk parts out there now. If it maintains 200 I wouldn't worry much. I actually wouldn't worry at 220 as long as it's consistent.

 

I agree on the thermostat. Would you mind posting a pic of your cooling stack?

 

45 degrees seems like a ton, unless you mean w/ vacuum advance, which I do not have.

I'm hesitant to say thermostat is bad, as I watched it open at 180 in hot water. Also the car runs 180 if I just start it up and let it idle, but also unsure if it would ever cool down to 180 after a drive. It did cool from 210 to 200 after getting gas, but that doesn't mean a ton.

Attached are photos of the plug, one on the black background (car fender) is wot shut off. Other one with the engine in the background is just from my drive last night, getting home.

And radiator stack uploaded too. E-fan wiring is good, runs, and blades oriented correctly.

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What is the cfm rating on the fan, who is the mfg? Looks pretty light duty?

 

Zirgo 3000 cfm

 

They is no way that fan pulls 3000cfm.

Plugs are pig rich.

That tranny cooler/fan in front of radiator is killing flow.

Hard to tell by your picture but it looks like detonation on the strap??

 

Agree,plugs way too rich.

That shroud is killing airflow,not enough when driving,and the fan can't pull enough when running.

 

No detonation, probably just dust on the plugs brushed against wiring pulling it out. If you're speaking of the "weld splatter" looking stuff in the 2nd photo. That wasn't there when I blew them off and reinstalled them.

I knows it's rich. But I thought rich helps with cooling and lean runs hot. Or is there a point where too rich causes overheating?

Don't see how the trans cooler would be the root cause when people run condesers and intercoolers infront of the radiator with no issue. Have also driven with hood off to, and still runs warm.

I'm not an expert on fans, original fan from champion was supposed to be like 2600cfm, the 3000 zirgo I bought blows just as hard.

I could cut holes in the corner of the radiator, but the photo distorts how much area isnt covered. You can google champion 3 row for a maverick and see better photos.

I appreciate the help, and sorry if I come off as rude or not listening, I just need some more explanation, and typing on mobile it's hard to write everything I'm trying to say.

 

Rich/lean isn't going to effect your coolant temps in a big way. That flat shroud cuts the airflow down to only the size of the hole for the fan, the rest of the rad getting not enough air. The hole in the core support to the left of the rad isn't helping also.

 

I see a combination of things that are not helping cooling: Your trans cooler has a pusher fan, but it looks like it is pushing into the blocked portion of the shroud. The trans cooler itself is not an issue, but it has no way to flow air efficiently. Like Brian said, the flat shroud is blocking most of the radiator airflow. The shroud needs to be spaced out and the fan can be set under it. Look at the way derale sets up their fan shrouds: #ad


The fans are inboard on the shroud, those black sections are flaps, they close when the fan is pulling air, but when your vehicle speed is high they open to allow flow through the radiator. I think with your setup as it is now I would just completely delete the "shroud" and keep the fan flush mounted to the radiator, use some foam tape to ensure it gets a good seal against the radiator. That will probably fix 90% of what you have going on. Those fans are sort of "self shrouded" and that will get you a lot more airflow when moving.

If you had a shroud that could breathe on the radiator I wouldn't worry about the open sections off the side of the radiator, but if you are struggling with cooling at speed look at blocking them off with some sheet rubber or aluminum.

A better fan or even a clutched mechanical fan would help a bunch with what you have going, but I think you can make what you have work.

 

Ohhh okay, your explanation makes a ton of sense! Thank you very very much for taking your time to type all of that out! I'll see what I can do and get back with results.

 

So looking it over. The transmission cooler is about 1" off the radiator, but is in line with the fan itself. Maybe that's an issue, as usually radiator stacks are almost, if not touching each other.

I can try to fab up something like that derale, but unsure how big of fans I can put on there. Currently it's a 16" fan, no space vertically, and maybe 1" on each side, so maybe two 10" fans at best. And then speed flaps ofc. Wiring/alternator is sufficient.

Or I might be able to fit a steel fan (w/o clutch) on the WP and use the factory fan shroud? Maybe, unsure w/ the serpentine belt WP being deeper than v belt, and a 3 row radiator, may not have enough space to put a fan. Fan clutch would definitely not fit.

Or just start with removing the shroud and flush mounting the fan. I just hate those plastic fan mount kits, seen them rub holes in the radiator tubes a few times. Although that was with a cross flow radiator, still hesitant. Could just make mounting straps if that does work though.

And also consider filling in the voids on the side of the radiator.

Lot of thinking out loud there, but just weighing my options and want opinion on what the best use of my time is.

 

If it is running hot at idle, usually the fan is too small.

If it runs hot while driving, the radiator is to small.

First thing I would do would be to move the tranny cooler setup away from the path of the radiator. Just tie wrap it safely for now.

Check voltage at fan compared to battery. What is the voltage drop? Low voltage will lower flow.

Running two 10" fans will not flow much at all. You will be better off running one of the largest fans you can fit. How big of a diameter can you go? What diameter fan are you running now?

The fan mounted on a shroud needs to have clearance from the radiator.

 

Voltage should be 12+, all new wiring, but I can verify and get back to you.

Was going to move trans cooler, just a lot of work, no where to place it. But I will do so and get back, it's free.

Fan is 16", largest I can fit vertically. A lot of people run a ford Taurus fan, but I didnt want the hassle of two speeds, and believed 3000 cfm rating of my fan.

Thanks for the suggestions, I will get back to you!