1952 Chevy with Small Block overheating

[48fordf1]

I have a 52 panel truck with a camaro subframe, new Chevy crate 350 rated at 260HP, with a holley projection 2d fuel injection. Its coupled with a TH400 transmission and a3.23 rear end, with 205/75 R15 tires. It runs down the road at 60 mph at 2500 rpm. Additionally it has a Walker Z series radiator with a 16" electric puller fan with about 3000 cfm i also have a condenser fan.

When I pull a small camper (1500lbs), it will want to run up to 220F without air running. I have taken my mechanical advance and vacuum advance from about 47 degrees to about 30, in addition to the 10 degrees BTDC it idles at, but it still runs hot. I have a rich/lean indicator that stays in the green.Additionally, it gets about 8mpg. I was thinking with fuel injection I would get about 15.

I purchased a aluminum 3 core radiator, but dont want to install it and it not make a difference.

Anyone have any ideas i can check. I have a limited distance between my waterpump pulley and radiator, so a thick fan wont fit.
Thanks

[xaircav]

Is the Walker radiator inlet and outlet sized for a V8? (1.5" upper and 1.75 " lower) When I ran my 283 with the six cylinder radiator the slightest bit of stop and go would cause temps to soar. With a two row aluminum Champion I pulled a parade float at a crawl on a 90+ day. Good article in the June issue of Street Rodder about cooling in general and aluminum radiators in particular.

[Wrenchbender Ret]

I think the aluminum radiator is the answer. Also try a heavy duty therm. About 1/3 of the new thermostats we get are defective.

[Donaldo]

What temp thermostat ae you using ?

[nvrdone]

Id check the thermostat first. Even remove it & see what happens
Ive got a 327 with a water pump driven fan & a 180 deg t'stat.
The radiator is an original I had re cored many years ago & it doesn't run hot even towing a 21' ski boat that is 4200 # on the trailer

[joedoh]

do you have a trans cooler in the rad? add an aux if so, your coolant temps will go down dramatically. if you arent running a trans cooler, add one before the TH400 gives up.

check your fuel map, if you are rich the exhaust temps will be sky high and mileage will SOOK. you can run it at night with a camera taped under the hood, the manifolds will glow red under load if your fuel map is rich

[48fordf1]

It is a V8 radiator with a 180F thermostat. I tested the thermostat with a heat gun and it does open properly. I do have the transmission plumbed to the radiator, as well as an external oil cooler.
Before I put in a new crate motor, the old smoking motor ran the same thermostat and new radiator, with the same trans and rear end. I got the same results with the worn out, 12mpg motor. I bought a new high flow water pump with this motor to try and eliminate this problem.
I see no way any air can miss the radiator going down the road. I had ordered a 2 row, 1" tube radiator, but they sent me a 3 row aluminum instead. Once I try it, I own it. Guess I could sell the walker radiator for a discount and get some money back, provided the aluminum works. Is it possible that 2500 rpms at speed is too much. I was thinking not. I know a 700R4 would help, but I don' t think my TH400 is the problem.
Thanks for all the replies.

[joedoh]

Originally Posted by 48fordf1

I do have the transmission plumbed to the radiator, as well as an external oil cooler.

I still think this could be your problem. going up hill and towing like you say in your first post, your trans temps will be much higher than the 180 of the thermostat with just the small in rad trans cooler, it will get transferred to the coolant.

[48fordf1]

I just mounted 4 small 9" fans on the back of the radiator. Manufacturer states they are rated at about 2200 cfm each (seems far fetched.). I am not able to get just 2 good size (12-16") fans in there due to width of radiator, and clearance to water pump. These 4 fans let me miss my water pump pulley and pretty much cover the radiator. However, its still warming up going down the road with a load.
A couple of weeks ago, I moved the air cooled trans cooler from infront of radiator to under the splash fan. It is still piped into radiator cooler, might just have to remove it from radiator and mount a small fan on it just to make sure it doesn't miss any air flow under the splash fan. Then pull the trailer and see if its the transmission is heating it up.
I have to admit, its kinda hard for air to get up to the top of the radiator on these trucks without a fan putting/pulling it up there. But, all 4 fans have it covered.

Im gonna remove the condenser fan (pusher) in front of everything and see if its block an excessive amount of air flow at speed. If it will stay cooler at speed, then I can see if the other fans can cool the condenser as well.
Thanks for the replies.

[NEWFISHER]

Have someone else tune it. Im betting timing and fuel delivery. You have the rest of a mechanical cooling system covered.

[MARTINSR]

The first thing I look at with something like this is air movement, is there enough room for air to get through the radiator and OUT of the engine compartment? So often people make mods that you don't think are closing off air flow but do. For instance, when the fender liners had to be modified for the Camaro clip, do they now close up areas where air use to escape the engine compartment? The air that escapes is equal to the air that enters your radiator. If you were to block off the exit the air that enters the grille simply doesn't go thru the radiator and it would exit out the sides of the grille, it has to have somewhere to go. Electric fans can block air too, were shrouds made for the fan that now block air from going thru the radiator?

These are REAL common issues with modified old cars, air needs to go THRU the radiator and exit. Look at this as much or more than some internal problem with the engine referring to timing and all that, look at the air movement thru the radiator.

Brian

[48fordf1]

I have often thought that when someone had modified the inner panels, I actually was thinking they had cut too much away and there was too much interference and turbulence coming from underneath the truck to allow the fan to push it through the radiator. I had thought about making some rubber skirts to cover up some areas, but I haven't gotten that far yet.

I thought tuning might have a part in it, but, I got the same results with the old motor with a Edelbrock carb. Plus, the EFI runs like a champ, idles great, great throtte response, and I installed the O2 sensor to close the loop.

It is a '52, but it does have a '54 grill. I can't picture the '54 grill creating much more flow problems than the '52 would.

Anyone think a high flow thermostat will make a difference. Summits just up the road. Thanks for the inputs on troubleshooting.

[mr48chev]

I have to go along with Newfisher. Something isn't right with the timing and or the fuel delivery on it.

Air flow could be an issue but that is usually an issue on these trucks at slow in traffic speeds where you are sitting more than moving. Even with 120 louvers in the hood my truck would run along the highway at 55 with the mechanical gauge at 183 with a 180 thermostat but the minute I got in slow traffic the needle headed to the top of the scale. On mine I don't have enough fan for slow speeds.

Have you got the correct water pump for the belt system you are running? That seems to be an issue when swapping engines. The "new" engine may have a pump for a Serpentine belt system that isn't comparable with V belts.

Personally I don't think the radiator is the issue unless it is old and full of crud.

[48fordf1]

I found the original box for my water pump and verified with Summit that it was a belt driven (not serpentine) pump, so my rotation should be right. I believe I had purchased a new thermostat, might try a high flow one from them.
I have made many changes to timing, but it doesn't seem to have much of an effect on temperatures.
The Walker radiator is fairly new as well.
I did talk to Holley at lunch about the fuel injection. I told them I reduced fuel pump pressure from about 18-13 because it seemed too rich. He pretty much said that since the EFI is rated for 275 HP and my motor is a 260 HP, it should really be up near 18-21 psi. So, maybe it is running way too rich because its not adequately atomizing the fuel, which might becausing some heating issues. I will adjust pressure up to about 20 this evening and retune according to their manual and see what happens.
I still lean towards cooling because I have the same symptoms I had with the old carburated motor. With the size of a radiator for this year chevy, its kinda hard to get two large fans on the puller side of the radiator without some radiator mount modifications/fabrications.
Thanks for all the replies.

[MARTINSR]

Originally Posted by 48fordf1

I found the original box for my water pump and verified with Summit that it was a belt driven (not serpentine) pump, so my rotation should be right. I believe I had purchased a new thermostat, might try a high flow one from them.
I have made many changes to timing, but it doesn't seem to have much of an effect on temperatures.
The Walker radiator is fairly new as well.
I did talk to Holley at lunch about the fuel injection. I told them I reduced fuel pump pressure from about 18-13 because it seemed too rich. He pretty much said that since the EFI is rated for 275 HP and my motor is a 260 HP, it should really be up near 18-21 psi. So, maybe it is running way too rich because its not adequately atomizing the fuel, which might becausing some heating issues. I will adjust pressure up to about 20 this evening and retune according to their manual and see what happens.
I still lean towards cooling because I have the same symptoms I had with the old carburated motor. With the size of a radiator for this year chevy, its kinda hard to get two large fans on the puller side of the radiator without some radiator mount modifications/fabrications.
Thanks for all the replies.

Ok, let's go with the evidence at the crime scene. If it was doing the same thing with another motor, it had different everything from water pump to timing and it was over heating, about the ONLY thing it can be is the rad or air flow.

Are the fans blowing in the right direction? (YES, they can often blow or suck with a wiring change!) When does it overheat at idle or at cruising speed? How about posting some photos of the system and engine compartment?

Brian

[Highsider]

What would accidentally installing a "reverse flow" water pump do?
I never heard of such an item, until I saw a spec for an aluminum water pump, stating it was a "standard flow direction".
Feel free to explain.

[48fordf1]

Alot of Serpentine belt systems have the pump rotating in the opposite direction, so if installed and a standard pulley system was used to run it, flow would be in reverse. How much that would reduce cooling or what problems it would cause, I can't say. I double checked the part number against their catalog, so I'm pretty sure its correct. I had never heard of or thought about it until I was doing some research for this problem.

[48fordf1]

Mainly when driving at cruising speed. And yes, I'm a maintenance tech by profession, so direction of rotation is the first thing I check when I install one. It is on the back side of the radiator and wired as a puller. Right now, The radiator is covered with fan. I initially had a shroud from Walker around the fan, but removed it because it didn't help me out at all, just made it harder to work on.

[MARTINSR]

Well I have an easy test for you, remove the fan assy and go take it for a drive. Above 20 mph or so that fan is doing nothing what so ever. If you get up to cruising speed fast enough (don't get caught in traffic getting to the freeway) you can drive it without a fan and see if the added air movement THROUGH the radiator helps. I can't believe how much of the radiator gets covered with some of these AM fans and shrouds. If the air can't get through, it can't cool the water in the radiator.

If it's only at low speed or idle that is largely the fan that is getting that done. Cruising speed the fan dos nothing.

Just remove the fan and go drive it, quick test and you know one more bit of info to help you.

Brian

[Iceburgh]

I had a similar issue but running a 383, FI, 3:50 gear and a 400
at speed I am fine.
If over 85 a slow or pulling a hill it will get up there.
I mounted a 7" pusher high on the rad under the hood release and pull it in when needed.
Stays at 195 now.
But pull it on before t gets there.
It wont cool but will maintain

[fabguy]

This is a long shot but here is how I fixed my heating problem BY ACCIDENT. I replaced my harmonic balancer. Yes that was the culprit. It appears the timing marks are different in the earlier years than the later. I am assuming that when my engine was built they used the early balancer on a later crank. Anyhow, I replaced it and my new timing mark was corrected by almost 12 degrees. For me it was an expensive lesson but a really cool one, as since I did this work the truck runs a constant 160 degrees. I did replace the thermostat, hi flow water pump. This might not be what your problem is , just saying that this what fixed mine.

Mike

[Donaldo]

I'd try putting a 194' thermostat in as it sounds like the coolant is not staying in the radiator a sufficient time to cool - so you are just circulating hot coolant once the thermostat opens.....

[dubie]

Have you tried using a coolant additive like Water Wetter to bring the temp down?

[dwcsr]

I think you have an air flow issue most 16" fans are so restricted in the back I can't imagine how they can every say they get 3K cfm. If its a Zirgo its no where near 3000. If you have a pusher and a puller you have slowed the are flow significantly. Its a simple idea , if cool air can't get in hot air can't get out. Aluminum does not cool better than copper brass metallurgical properties don't allow it, its just cheaper and lighter and almost anyone can make one and weld it without expensive tooling.

If you can fit a Taurus fan in there try that. Stand it on end with the fan up at the top and cut several 2" holes in the shroud on the lower section and screw a flap of rubber over them. This allows air flow at speed but will suck closed when the fan is on at a stop or low speed. This cools off AC cobra's with 428's and they have a far smaller compartment than a AD.

If it were the transmission pushing heat into the cooling system enough to heat up the engine you'd have a trashed tyranny in short order. Transmissions don't like to be over heated.

Your timing /fuel is not the issue because you have had this with an entirely different engine unless you used the same carb and it is excessively lean. The only similar pieces are engine compartment and radiator opening. Take the fans off entirely and run it on the highway if one close enough and see what happens. It may just cool down as you go faster, This would prove restriction of air flow is the issue.

[48fordf1]

I did initially use the original harmonic balancer from the old motor. However, i ended up purchasing a new one. When I installed it, it seems my timing had changed from 12BTDC to 7BTDC, almost as if the marks were different. I could play around with that alot more and see what happens.
I do have "Purple Ice" in it, but I have to say, it didn't do anything.
I will try removing fans first, and see what happens. I think instead of just a timing light, I will try and tune it by using a vacuum gauge and see if I get a different result, maybe timing marks are way off. (It sure does run great and start good though).
Have to check on the taurus fans. I looked at alot of fans, and there are not alot of options for this small a core in a radiator. Thanks for all the ideas.
Will try somethings when I get home today and see what happens. I thought after I got a "street rod" instead of an original flathead ford, all my overheating problems would be over. I only thought I spent alot of money on them.