Making 12 inch spal fans work??

Since I replaced my gravely sounding lucas fans, my car is still prone to overheating, blasting through the mountains, in high heat, particularly with the AC on.

The first photo shows the 12 inch fans peeking up over the condenser and i noticed that when they come on, they spent most of their air coming over the top, so i built the following shroud to both help support the fans and help direct the air through the condenser and radiator. Additionally, i installed more foam to "force" the air to go through the radiator, not over it, as well as an additional 1/2 inch at the spare tire compartment lip.

Tomorrow i am going to go through the mountains in 100 degree heat with the AC on, so this will be a trial voyage. Previously, it ran to 225 water and the ac was ineffective.

More info Sunday, if i am not too burnt out by the drive.

I have seen a few threads with radiators and full house shrouds, but this is easily do-able.

hth,
chris
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

You might want to consider replacing the missing foam that seals the gap between the top of the radiator and the bonnet, as well as beside the radiator. This will ensure all the air is forces through the radiator, rather than by-passing it.

Regards

Michael

 

Chris it just seems strange that even with this mod you still continue to run high temps. It appears to me that there is something else going on. I had only reached 220* with my 77 when the WP froze and blew the belt. I very rarely reach 195* in traffic with the AC on in the NE here. Even at 95* days so I find it difficult that the stock fans can't keep the car cool. Also I haven't replaced the missing foam yet but still have a hard time getting past the 1st notch on the temp gage. What is your oil temp running at. I would think that they would run the same as the WT. I think a 20qt system with a 3L motor should be sufficent enough to keep the car cool. I would start to look for another problem. I assume you verified that the gage and sending unit are working and used a heat gun to check for hot spots on the motor. Also using the bleed port to plug in another temp gage to verify rad temp. After that maybe an engine flush and verify timing , rich/lean , and ignition. Gota be more then fans. My 2 cents

 

Hi Mike,

No one locally had the correct foam. Subsequent to these photos, i installed a double row of foam to temporarily block the air for this test.

thanks,
chris

 

If you're running in the mountains you may be leaning out which will cause you to run hot.

 

Hi Steve,

I have replaced the thermostat during the major. WHAT A DIFFERENCE ! the car warmed up much more quickly and it ran at about 185 most of the time, only going higher when in 100+ heat. The old thermostat wasn't closing fully and would open a bit too soon, so it tok forever to get to temp and usually didn't. The temp sender was replaced at the same time.

I have replaced the cooler with a Mocal unit about the same surface area as stock, along with a 180 thermostat. all of the lines are -12 as well - So, the oil comes up to temp just slightly behind the water really nice, particularly in 50-60 degree northern califoania weather.

I had a bung welded to the top of the thermostat housing so i could install Verell's bleed screw and i could bleed the system at the engine as well as the radiator.

This ought to do it.

hopefully,
chris

 

The mountains are about 2-3000, not much - but it is a lot hotter inland at this time of year, 100+ At sea level, the LM-! is telling me that i am running around 12 mostly.

chris

 

These puppies really need to be fully bled. One thing I've noticed is that ceramic coating the exhaust really lowers operating temps.

 

I had an 80 GTBi which also overheated in bumper to bumper in the summer on the West Side Highway. I cut an exhaust outlet into the hood which made a HUGE difference. Ferrari took a look at what we had done and copied our exit vent on later cars.

 

Do you have a picture? I would sure love to see what it looks like.

 

These photo's will give you an idea of what we did. Mine was an 1980 car with a hood like the first photo. We cut in an exit vent
with ducting leading from the back of the radiator to the exit vent. Ferrari copied what we did on the later cars as per second photo.
Image Unavailable, Please Login
Image Unavailable, Please Login

 

also helps down force on the front .. . the P GT3's incorporated it

 

At speed the fans are not needed at all in fact they inhibit air flow at speed. Under that condition the car would cool better if you took them out.

Look elsewhere for your problem because it is not the fans.

 

I saw a lot of threads here about electric fans. But, when my fans starting shrieking like banshees last summer I refurbished one (you can take them apart and lubricate with 3-in-1 oil) and the other (trashed due to my clumsiness and brittle parts) I replaced with an identical Lucas fan. I wanted to stay original if I could. Those gyp Lucas fans even work in the deep south in the dead of summer -- plus you have the comfort of knowing you are riding with the Prince of Darkness cooling your way . You can get the Lucas fan from a Jag shop. The '74 XKE uses the same fan.

Seamus

 

Give that rad a rest! why don't you rebuild it. It has passed more water than niagara falls.

 

Chris, i went to home depot and got regular home a/c foam and cut it to match. the 3 cars i owned and did this too performed perfectly in the humid Georgia summers.

i think you need to have the radiator recored, as well as the heater core.

 

Chris,
What is the internal condition of your radiator? Has it ever been removed and cleaned out? I am wondering if it my be restricted or partially plugged inside from residue over the years.

 

I had thought about it being 30 years old and having unknown care - 30 k miles??? So, whent he lucas stuff started to fail, i read and followed a few threads to install 12 inch fans. I noticed that they stood three inches over the ac condenser and a hell of a lot of air was blowing over the top of the radiator, so i did the shroud thing.

I also applied foam to the hood over the radiator to keep the air going through the rad and ac cond. rather than over it and out the fender louvers.

Just to make sure the hot air wasn't coming over the "lip" into the spare compartment and possibly into the cabin, i installed another 1/2 by 3/4 bit of foam a that joint as well.

Since i was journeying into the hot country, i had a knowledgeable budy drag out his R-12 can and add a bit of freon to the system as well.

Completely blowing by the old rule of changing one thing at a time, i hit all of the above measures, as well as building a fairly tight shroud for the two 12 inch fans, so i can only report that the result was great. I could hold 70 mph through the hills, with ac on, in 100+ degree heat and the water temp hit 200 max, oil running 230 or so and the ac doing a great job. I often backed it off from max to mid-cool and ran #2 speed on the fan. I know i have a freon leak somewhere, but suppose that the cooling system is doing quite well.

Moving past that, i am wondering how well it might work if i did pull the rad and have it recored/rodded - or if it looked like this work wouldn't improve things, going to an aluminum radiator.

Basically, I want a trouble free cooling system in 100 degree heat, on the track. If it will do this without overheating, i will be happy. Routine driving/touring will be trouble free.

best,
chris

 

Thanks Michael,

You forget that i live beyond the redwood curtain - Ace hardware is the best i can do without having to go online. Speaking of which, anyone have a good site to score the wide/thick foam??

thanks,
chris

 

Dearest Hugh E. Rection,

I have little idea about the interior condition of the radiator. When i pulled the intake manifolds, along with a carbs, to match the gaskets and do a carb rebuild, i had a moderate amount of crud build up/pitting, possibly indicating that the block and radiator might not be deposite/corrision free. I have almost no experience with copper radiators, so am not sure how to interpret my findings.


Longingly yours,
chris

 

Hi Brian,

Is your avatar from the big labowski? One of my heros - or is that a self portrait?? You are probably right that the problem lies elsewhere, but i couldn't ignore the fact that all of that cooling air gong over the top of the radiator wasn't doing any cooling.

If this doesn't keep it cool on the track, the rad is coming out for a rod/recore/or aluminum replacement. Mixture and timing are good, new coolant/hoses/t-stat&sender. 12 inch ducted spalls coming on at the right temp - and no front plate

stupified,
chris

 

I am pretty sure this is a pic of him when he got arrested a while back.

The fans are a good improvement but your problem is at speed not in traffic.

Foam a good idea too but like others have said I think the radiator is suspect.