Keeping a 318 Cool for Lemons

Hey guys so our Lemons car is having a little overheating issue at our last race. We ended up having to run our electric fans the whole race and it was hard to keep temps under 220.

For that race we have a 3 core radiator with an ac water pump as our car was an ac car to begin with. Pretty sure it was a 6 blade when I swapped it out as the old one was making a horrible noise. Our heater core line is just looped with about 14 inches of coolant line as the heater core is long gone in this car. We have two electric fans mounted to the radiator. They could be boxed in a little more but the idea was to run no fans. These are a pull style. At the time it had a new 180 degree thermostat with just water in the cooling system. It does have a spring in the lower rad hose. Rad cap is a 1.1 Bar unit. Will say it was HOT at our first race and we were running in 95 Degree weather with a good 60% humidity which is a cool day in South Carolina in September. As for the rev range on the car. Most of the time it was 3-5k rpm. More of shifting at 4500.

So we plan on doing some testing and have done a few mods. Including.

- Fixing a lot of bent fins on the rad. Probably 20% were bent and doing full blockage.
- Flushed the whole cooling system to get the nasty water out.
- Broke the thermostat and made it into a restrictor plate.
- Adding water wetter to the coolant system over straight water. No coolant allowed.
- Going to box the top of the radiator in to get the air going threw the radiator.

So question is we are racing for 8 hours a day and looking to do full 24 hour race with the car next year. We want it to keep it running cool and maybe even without the fans help. So I had a couple questions. One is there a good water pump to use. Our car had a 6 balde but the bearing was bad. I had a new chrome looking one in the back of the car that we swapped on. Maybe this one is not up to the task. Or maybe are the racers using the non a/c 8 blade unit. Is there a high volume pump people like to use?

I also herd that some people will wipe the heater core circuit out 100%. Our intake manifold would be easy as its threaded and we could just plug it. What would we do on the water pump side. Could bend it shut and weld it up. Not a fan of caps as they like to fail.

What about under driving the water pump. Maybe the pump is happy 2-4k rpm but when you start spinning it higher it could be cavitation?

So for you guys who might do long stint on a circle track or dirt track. What are you tricks to keeping the engine cool? Next race is in Barber in February. Would like to keep the car cool. I know this is different than more people who street drive or drag race. But still got a problem to solve.

96Formula6sp said:

What about under driving the water pump. Maybe the pump is happy 2-4k rpm but when you start spinning it higher it could be cavitation?

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you may be on to something here...im sure others with more knowledge will chime in.

Underdrive may help, running one on my 535, me personally I don’t really like the 3 row radiators, by the time the air hits the last row it’s hot and probaly not doing much if anything at all, 2 row with 1-1.25” tubes. Aluminum pump housing, high volume pump, can try the water wetter for additional help I’ve never used it. Hard to keep an engine cool with that long of a duration.

If the heater core is gone than eliminate the heater circuit. All keeping it in a loop is doing is providing a potential area for air to seep into the system, and creates another hose that can blow if the car does overheat. I believe the water pump on the Ram 250,s 360LA motors are high volume pumps. 6vane. The parts stores tag them as Heavy duty.

96Formula6sp said:

Hey guys so our Lemons car is having a little overheating issue at our last race. We ended up having to run our electric fans the whole race and it was hard to keep temps under 220.

For that race we have a 3 core radiator with an ac water pump as our car was an ac car to begin with. Pretty sure it was a 6 blade when I swapped it out as the old one was making a horrible noise. Our heater core line is just looped with about 14 inches of coolant line as the heater core is long gone in this car. We have two electric fans mounted to the radiator. They could be boxed in a little more but the idea was to run no fans. These are a pull style. At the time it had a new 180 degree thermostat with just water in the cooling system. It does have a spring in the lower rad hose. Rad cap is a 1.1 Bar unit. Will say it was HOT at our first race and we were running in 95 Degree weather with a good 60% humidity which is a cool day in South Carolina in September. As for the rev range on the car. Most of the time it was 3-5k rpm. More of shifting at 4500.

So we plan on doing some testing and have done a few mods. Including.

- Fixing a lot of bent fins on the rad. Probably 20% were bent and doing full blockage.
- Flushed the whole cooling system to get the nasty water out.
- Broke the thermostat and made it into a restrictor plate.
- Adding water wetter to the coolant system over straight water. No coolant allowed.
- Going to box the top of the radiator in to get the air going threw the radiator.

So question is we are racing for 8 hours a day and looking to do full 24 hour race with the car next year. We want it to keep it running cool and maybe even without the fans help. So I had a couple questions. One is there a good water pump to use. Our car had a 6 balde but the bearing was bad. I had a new chrome looking one in the back of the car that we swapped on. Maybe this one is not up to the task. Or maybe are the racers using the non a/c 8 blade unit. Is there a high volume pump people like to use?

I also herd that some people will wipe the heater core circuit out 100%. Our intake manifold would be easy as its threaded and we could just plug it. What would we do on the water pump side. Could bend it shut and weld it up. Not a fan of caps as they like to fail.

What about under driving the water pump. Maybe the pump is happy 2-4k rpm but when you start spinning it higher it could be cavitation?

So for you guys who might do long stint on a circle track or dirt track. What are you tricks to keeping the engine cool? Next race is in Barber in February. Would like to keep the car cool. I know this is different than more people who street drive or drag race. But still got a problem to solve.

Click to expand...

I have always been a fan of more cooling capacity than the engine can create. One day after a bit of an overheat, I decided to engineer more available cooling capacity at a reasonable cost. I purchased two Buick heater cores from Rockauto at $34 apiece and two 5" Spal fans for about $22 apiece. The cores were 4" x 24" and 1 1/2 thick. They ran side by side and were looped together in series by placing the inlet/outlets on opposite ends. The lines that fed them were the original heater core lines ( I didn't need the heater so they were blocked off with plugs) which is cooling directly from the engine block without a thermostat controlling temperature. The fans were originally constant but the extra cooling was so great, I had to add an inline sensor and cooling controller. I run a 22 rad on a BB 512 stroker, 630 HP, and the cooling is amazing. Adding up the extra cooling area I get 192 sq. in. more of cooling surface, my rad is only 396 sq. in. total. They mount down in the front of the cross member on a slight angel beneath the front main pulley and the rear of the units is slung from the stabilizer bar with two brackets that have loops in them Removal is a matter of undoing two front bolts, tipping it down and lifting the loops off the stabilizer bar. The attached hoses allow the unit to almost drop to floor level. I used to run a 180 thermostat and engine temps were in the 210 range on a hot day. I now run a full flow 160 thermostat (the engine barely surpasses that temp) and allow my rad fan and lower core fans to regulate the engine cooling temps via a dual Dakota Digital controller. I have never surpassed their set point of 190 degrees even on the hottest days standing still in traffic at 950 rpm's.

MarPar said:

you may be on to something here...im sure others with more knowledge will chime in.

Click to expand...

Yeah got to look around to see what is around. My normal track day car is a Miata. I just threw a bigger rad in it as the 16mm one just could not keep up anymore. Moved to a 52mm and had zero issues. Granted the car is a 2001 vs our 1972 Rust Bucket Dodge

1967coronet440 said:

Underdrive may help, running one on my 535, me personally I don’t really like the 3 row radiators, by the time the air hits the last row it’s hot and probaly not doing much if anything at all, 2 row with 1-1.25” tubes. Aluminum pump housing, high volume pump, can try the water wetter for additional help I’ve never used it. Hard to keep an engine cool with that long of a duration.

Click to expand...

Yeah not to worried about it. Its an all aluminum rad that came with the car. So not going to change it unless there was a big issue. Even if the third row is not doing anything it probably can't hurt. A new radiator for the car is around $300. Something we do not want to spend unless we have to.

aeon280 said:

If the heater core is gone than eliminate the heater circuit. All keeping it in a loop is doing is providing a potential area for air to seep into the system, and creates another hose that can blow if the car does overheat. I believe the water pump on the Ram 250,s 360LA motors are high volume pumps. 6vane. The parts stores tag them as Heavy duty.

Click to expand...

Yeah, Looks like we are going to try get that hose out of the system. Not to worried about the hose as its new and a high quality silicone piece. But still I think the idea would to take it out of the system. Still need to find a way to make temps from to the 190-200 range with no fans. Doing a test day in two weeks. Might swap the water pump before hand.

Water Wetter

Yatzee said:

I have always been a fan of more cooling capacity than the engine can create. One day after a bit of an overheat, I decided to engineer more available cooling capacity at a reasonable cost. I purchased two Buick heater cores from Rockauto at $34 apiece and two 5" Spal fans for about $22 apiece. The cores were 4" x 24" and 1 1/2 thick. They ran side by side and were looped together in series by placing the inlet/outlets on opposite ends. The lines that fed them were the original heater core lines ( I didn't need the heater so they were blocked off with plugs) which is cooling directly from the engine block without a thermostat controlling temperature. The fans were originally constant but the extra cooling was so great, I had to add an inline sensor and cooling controller. I run a 22 rad on a BB 512 stroker, 630 HP, and the cooling is amazing. Adding up the extra cooling area I get 192 sq. in. more of cooling surface, my rad is only 396 sq. in. total. They mount down in the front of the cross member on a slight angel beneath the front main pulley and the rear of the units is slung from the stabilizer bar with two brackets that have loops in them Removal is a matter of undoing two front bolts, tipping it down and lifting the loops off the stabilizer bar. The attached hoses allow the unit to almost drop to floor level. I used to run a 180 thermostat and engine temps were in the 210 range on a hot day. I now run a full flow 160 thermostat (the engine barely surpasses that temp) and allow my rad fan and lower core fans to regulate the engine cooling temps via a dual Dakota Digital controller. I have never surpassed their set point of 190 degrees even on the hottest days standing still in traffic at 950 rpm's.

Click to expand...

Interesting idea of adding some more coolers. Our current fan setup is on or off. No controller minus the driver. I had had terrible luck with fan sensors. Granted will say that cruising the car has no issues. Got into a full course yellow where speeds dropped to 60mph and temps were around 190 right away. Even with the fans turned off. 2 Laps of racing later they were back into the 210-220 range with the fans running. Will say we were in our parade and water temps keep creeping up. Ended near 225 when I could shut the car down. Wondering if this water pump is an issue. Might go get one from the parts store and shove it in this weekend. Granted might need airflow threw the rad. Front of the car has nothing on top as the stock hood latch was ditched as the cable was bad. The bracket left as well as we just did some nice hood pins.

360/4spd/4.10’s, 450+hp.
Things I have done to cool the engine for extended trips were;

22lbs. Radiator cap
Shroud
MP Viscous fan (5 blade unit moves the most air)
MP - HP water pump
New radiator, aluminum, 3 row. More rows the merry. Don’t ever think otherwise. 3rd row not doing nothin, LMAO, hogwash at its finest!!!!!

In another car, the pervious owner said that needed a radiator, but! In the summer when the engine heat temp rises, just put on the heat. It cooled the engine down perfectly. Granted, it was a bit “extra” warm in the car, but, what is a kid to do working min. wage back in the day. Barley afforded the insurance.

Thinking about your issue I recalled a scenario from Fast and Loud last night where AK was racing Pikes Peak Hill climb and he was having overheating issues. The solution was to cut holes in the hood to allow heat out of the engine compartment. Not sure if the Lemons rules would allow this but it might be something to consider. It makes sense that allowing heat to escape from the engine compartment would help. Not only does it allow heat to escape but it increases the velocity of the air moving through the radiator and over the engine itself resulting in more efficient cooling.

Put the biggest 2 row radiator with 2-1.25 tubes in it. Cut some holes in the hood to help the hot air escape, also if using the electric fan stuff, you will need 35-5000 cfm to keep it cool. Or you could use a 7 blade mechanical fan with shroud. The rules for Lemons state that you must use only water in the cooling system, but I know people that use Water Wetter and they don’t have temperature problems.

rumblefish360 said:

360/4spd/4.10’s, 450+hp.
Things I have done to cool the engine for extended trips were;

22lbs. Radiator cap
Shroud
MP Viscous fan (5 blade unit moves the most air)
MP - HP water pump
New radiator, aluminum, 3 row. More rows the merry. Don’t ever think otherwise. 3rd row not doing nothin, LMAO, hogwash at its finest!!!!!

In another car, the pervious owner said that needed a radiator, but! In the summer when the engine heat temp rises, just put on the heat. It cooled the engine down perfectly. Granted, it was a bit “extra” warm in the car, but, what is a kid to do working min. wage back in the day. Barley afforded the insurance.

Click to expand...

-Need to check the rad cap. Might only be a 16psi unit.
-For the fan we are running two electric fans on the rad. Car has no clutch fan off the water pump.
- I think the rad is pretty new and flowing well. So no need to upgrade it. Really its 4 races old.
- No heater core or fan unit for that. It was all ditch years ago.

aeon280 said:

Thinking about your issue I recalled a scenario from Fast and Loud last night where AK was racing Pikes Peak Hill climb and he was having overheating issues. The solution was to cut holes in the hood to allow heat out of the engine compartment. Not sure if the Lemons rules would allow this but it might be something to consider. It makes sense that allowing heat to escape from the engine compartment would help. Not only does it allow heat to escape but it increases the velocity of the air moving through the radiator and over the engine itself resulting in more efficient cooling.

Click to expand...

So good news? The hood was cut by older owners. Car has to have a hood at all times in lemons. Guess they tired that out and it may have helped.

5.7 hemi said:

Put the biggest 2 row radiator with 2-1.25 tubes in it. Cut some holes in the hood to help the hot air escape, also if using the electric fan stuff, you will need 35-5000 cfm to keep it cool. Or you could use a 7 blade mechanical fan with shroud. The rules for Lemons state that you must use only water in the cooling system, but I know people that use Water Wetter and they don’t have temperature problems.

Click to expand...

So hood has been cut. Never checked our fans. They look like two units off a land rover discovery(at least that is what they look like). They seem to flow enough air. As for the rad not thinking it is an issue. Working on boxing it in this weekend to help air get threw it. As for the water wetter it is legal at the drag strip where they only want watter. We are going to add that into the system.

So over the weekend we boxed in the rad some more. Making some side panels to help feed air into the rad. We have thought about cutting the lower valance as its blocking around 20% of the rad. But for right now everything seems to be working. Took on a test drive and with the restrictor plate we are seeing temps around 160. Granted this was just cruising around and not wide open throttle like on track. Going to Barber this weekend to test it out.

So test day went well. On track temps were just under 160. It was a cold day being in the 40s with rain pretty much all day. If we were running it in the race a cardboard box might help with some blockage to get a little more heat in the engine. Did notice that if the car idled it would get up to 210 really fast. Say 1-2 mins when making our driver change. So sounds like maybe a 160 thermostat and a new D250 360 water pump. Hopefully this solves everything.