HELP OVERHEATING 322ci 1938 La Salle Engine!

[jos1270]

I have a 1938 La Salle that is overheating. I will let you guys know all I have done and hope that someone can help me. First of all I have flushed out the radiator and engine block. The radiator was leaking and had it re-cored with a 20-30% more efficient core but is still overheating.

I was told by a friend that maybe it could be that the water pump is pulling the water out of the radiator to fast and not letting it cool down enough. So he told me to put a few washer in the radiator hoses that run to the radiator. I figured he would was right, because in the winter it never warms up all the way. So maybe it's moving the water so quickly that it does not let it get hot. And in the summer it gets pretty hot. So I went ahead and put a Asher on each side of the engine block but it still overheating. I'm not sure if the holes on the washer may still be to big.

Another thing I was told could make it get hot is that the carburetor is running lean. So I tried to richen the fuel mixture. But still hot. I'm not sure if I need to do something to the carburetor to add more fuel because I opened up the carb all the way but it didn't seem to run any different.

I also went ahead and cleaned the exhaust manifolds and got Jet-Hot high performance to re-coat  them their ceramic coating.

Lastly I have been told that that their may be two other causes that could make get hot. Combustion leak into the cooling system, either by head gasket failure or a crack in the engine block, which I'm hoping it is not either of them. Or it could also be the engine timing. I have no idea of how I could check either of this things out. Would I have to take the engine apart to tell if it's a engine block crack or head gasket, or is there a different way? Also I have no idea how many degrees it has to be for it to be timed right. Does anyone have any specs not the timing for 322 flathead La Salle engine?


Jose Luis Aranda Espinoza

[Wayne Womble 12210]

The radiator flow deal is a MYTH. Take those washers out.

[Glen]

How is your thermostat?  Do you even have one?  The original thermostat opened or closed the shutters in front of the radiator. 

How do you know the engine is over heating?  Are you checking the temperature with a thermometer? Or are you only going by the fact it is spitting out water from the over flow?  If you are going by the water coming out of the over flow it will do that if you fill the radiator to the top.  When the engine warms up the coolant expands.  Also make sure you have the proper radiator cap and it is working properly. 

Next get an infrared thermometer (non contact).  They are cheap from Sears and many other stores.  With the non contact thermometer check the temperature of the lower radiator hose and the upper hoses to see if the radiator is cooling the coolant. 

A common problem with these engines is an accumulation of rust a other crud in the coolant passages in the block.  That needs to be cleaned out. 

[Steve Passmore]

All the advice from Glen is top notch. Buy a manual, all the timing details are in there.

Agree fully with Wayne, complete nonsense. take the restrictions OUT. More flow and faster means cooler engine.

One other thing it could be. What thickness of core did they put in your radiator?  It should be as close to the original 4" as you can get.       My 36 was re-cored by a well established company here who said they can no longer get the 4" thick cores so they fitted a 75 millimeter core saying it was 20% more efficient with the cooling, with the cooling yes, but NOT the flow.     After 5 miles the top tank pressure would gradually push most of the water out and it would boil.  They were adamant the flow was sufficient, I was adamant it was not and made them under duress find a 93mm core and fit that. They said I was wasting my money and theres no way it would make any difference. To their total disbelieve it cured the problem completely.
Two small a core restricting flow is akin to having a blocked radiator.
Be wary also of them fitting two cores one behind the other to gain the thickness. this has happened to Ty Stinson in Maryland and its giving big problems. These cores are not designed to have another directly behind it and he has massive over heating problems.

[joeceretti]

Mine was overheating as well and was caused mainly by too thin of a core. I am lucky and have a custom rad shop very close to my house. The man who has been there for years and learned from his father made me a custom core to the exact specs of the original and my engine runs as cool as it should. During warm weather the rad shutters aren't really needed. They are more for colder weather to keep the engine from running too cool. As far as water flow, the impellers in these water pumps are not the most efficiently designed and at a very slow idle the temps can get too hot. If I let it sit and idle at 320rpm it will slowly creep up to the red line. If I bump my idle up a touch, water flow, and air flow, increases and it slowly settles down to just about the center of the temp gauge. Does your car still have the manual dash controlled throttle connected? You can leave your idle down nice and low for as quiet an idle as you want and over ride with the manual control by slightly increasing the idle until your temp is correct. Don't use it as cruise control, that's not what it was meant for and is dangerous when used this way.

[jos1270]

Glen: My La Salle has no thermostat. It actually doesn't even have the shutters it use to have back in the day. I believe who ever had it before me took them of thinking that that by taking the shutters off it would cool it off more. I know that it is overheating because i keep a close eye on the temperature gauge. In the summer the gauge has climbed all the way to where the red starts. Although i never thought of actually getting a infrared thermometer. I'm going to have to try that.

S. Passmore: Where can i find a manual? I wouldn't mind buying one. About the radiator, I just checked the size, and guess what? It is a 3 inch core. The thing is that in 50 to 83 degree weather it does good. I have taken it as far as 1:30 away from home and it stays pretty good. It tries to climb when I am at a stop light, but once i get going it starts going back down just a little and stays in the middle of the temp gauge. Now from 84 degree weather and up it starts climbing and gets scary. What i forgot to mention is that went ahead and put an electric fan with toggle switch. Every time it starts getting warm in 85 and above degree weather, i turn it on to help it. But it eventually gets hot enough that it scares me. At that time I pull over and let it cool down and don't pull it out in hot weather.

Joe Ceretti: The water pumps seems to be good. I am not mechanic so I'm not 100% sure that its at its best. I went ahead and took the water pump apart cleaned it up and greased up too. About the dash controlled throttle, I have no idea if its still on it. I'm guessing no, because i have pulled and pushed every button that i can see on the car and nothing makes the idle go up or down, unless its somewhere that cant be seen.

49er: I have tried different things on that suppost to get rust and crud out with out taking the heads off. I have yet to do that. And i will probably do it to see if the heads are OK.

[joeceretti]

Hot days, overheating at idle.

Increase your idle a touch. Advance your timing in tiny increments (Make sure the engine is hot to test this) and drive, under full throttle. When the timing is set perfect you will get a tiny bit of preignition pinging for the first ten seconds of acceleration. After ten seconds ease off on the throttle for a second and the reapply. If it still pings then you have advanced too far, back it off a bit.

To say it another way. 10 seconds of preignition pinging was considered normal by the engineers. You need to find that point. Advancing the timing AND increasing the idle will help your problem a whole bunch.

Finally, you say it climbs to the edge of the red... it doesn't go into the red? Red is overheating, below the edge is not. I understand when it gets close to the red you are nervous, you can burn up a valve which is a costly fix.

Adjust things a bit like I explained and I am confident that you will not ever get so close to the red that you panic.

EDIT: You should think about adjusting your idle so that at idle the generator gauge shows just a touch on the negative (discharge side) or right on it. Also, the throttle control on a 38 is the pull knob directly to the right of the ignition key. What do you have there? Where does whatever you have there connect?

EDIT2: I know that idling there is higher than what the specs say BUT the specs consider that you have a throttle control on the dash to counteract any overheating or undercharging at idle. The operator would normally have the pull knob to adjust the idle as needed to keep things running without burning up. Fix your throttle control and then you can set your idle back nice and low and thusly adjust as needed while driving depending upon the current conditions.

[jos1270]

Joe Ceretti: Thank you very much for the info. I will try to mess with the timing. By any chance would you happen to know to what degree the timing has to be set at? That way I advance with more confidence and know that I am not going to far. I am new at this so I want to take as many  precautions as I can. To the right of the ignitions switch I have the fog lamp switch. The throttle control was taken off at one point before I got the car.   

P.S. Is it a sure thing that the radiator core has to be 4" thick? Im trying to find out on google the size of a radiator for a La Salle, but cant find anything.

[joeceretti]

I don't know the size of rad on the lasalle.

For the timing, the amount depends on the amount of sharp edges and carbon inside the cylinders. Start with the timing set to zero, lined up dead center on the tdc mark. Advance about an eighth of an inch.... Drive... No preignition...advance anorher eighth of an inch... Hard throttle... No preignition... Advance... Do this until on hard throttle you get a little bit of preignition pinging on hard throttle and then no more then after ten seconds it settles down. If yo go to far, retard the timing. Find your sweet spot. This must be done with the engine hot, not just warmed up.

You will get the most power and the best fuel economy this way. It will also run coolest.

If you want the car to run smooth and silent, set it to tdc and it should make no pinging sound but will be underpowered and will eat fuel.

[Wayne Womble 12210]

 Judging from the symptoms, in cool temps your radiator is just sufficiant enough to cool the engine back down when the speed goes up. But it is obvious that the fan/air speed over the radiator is deficient because it heats at idle. However, indications are that the radiator is not sufficient at higher temps to cool the engine at any speed. It takes three things for cooling to happen, water flow, air flow, and a good radiator.  All totaled,  the indications are that the radiator is marginal. It will not cool at idle for lact of air flow, and it will not cool at speed because of low cooling capacity.  Assuming good enough water flow, you need a radiator.

[C.R. Patton II]

Hello Jose

Glad to read you are receptive to the great counsel you are receiving from these guys.

[jos1270]

Wayne Womble: thank you for the info. But I have a question, I am guessing you are trying to say that I need a new radiator? I re-cored  the one I do have. You think I need to go ahead and still get a new one? I paid $1,000 to get a new core. I don't really want to pay that or even more and lose the $1,000 I already payed. I fell like that would be throwing money down the toilet. I want to try to find out a different way if possible if not then I'm going to dish out more money to get a new radiator.

I have another question. I have read on other forums that people have made the holes bigger on the heads to get more water flow to run from the top of the heads to the radiator. Do you think this will help?

Thank you again Wayne

C.R. Patton II THANKS FOR CHECKING UP ON MY PROBLEM. 

[Steve Passmore]

Jose,  The manuals are available on ebay all the time as re-prints.

You should not be guessing what Wayne is trying to tell you.     Your radiator core is NOT wide enough, Period.  The La Salle core should be 4" the same as Cadillac as both engines have the same of everything regarding the water system.   All the flatheads I have owned up to 48 have 4" cores. If you have the correct radiator you will have a 4" top and bottom tank also.

No matter what else you try you will not cure this overheating with an undersized core. No extra fans will help as the water from the block can't get through there fast enough for it to do any good.     
Holes in the head to increase the flow will do no good when the capacity of the core can't cope with what it already have.      Read my last post. Been there, done that.         Like me you have to bite the bullet and get the correct core.         
Believe me, if Cadillac thought back in the day they could have managed with 3" of core and saved themselves even $1 on each car they would have done so.  Everything on the car is there for a reason and is the minimum required to do the job efficiently.

[joeceretti]

These cars are on the edge of overheating when everything is correct. Anything below spec will push them over the proverbial edge.

[las39]

Do you still have your two lower air scoops? Are they 90° and straight ?
Another way to assist cooling is to turn on your other radiator (the Heater). 

[gary griffin]

Mo is correct, if your engine is overheating turn off everything that is loading it  including A C and turn on your heater to full heat.  The objective is to disperse heat instead of generating more heat. I have done this a couple of times in my life and it got me to a place that I could solve my problem. Very uncomfortable to turn the heat on in the summer but less uncomfortable than being stranded or ruining an engine. Think of your heater as an auxiliary radiator in overheating situations.

[jos1270]

S Passmore: thanks for the info and i guess i am going to have to bite the bullet.

Joe Ceretti: thanks!

Las39: what do you mean lower air scoops.

Gary Griffin: thanks for the advice.

[joeceretti]

You are welcome. Increasing your idle should help some until you can get the rad replaced. More idle will keep the water flow up while you are waiting at lights, etc.

I feel your pain. You should really look around more. I got mine custom built, using as many parts of the rusted out old frame as possible and it is a work of art for $600 Canadian dollars.

[las39]

S Passmore: thanks for the info and i guess i am going to have to bite the bullet.

Joe Ceretti: thanks!

Las39: what do you mean lower air scoops.

Gary Griffin: thanks for the advice.

These two unpainted pieces encircled in yellow circle, lead air over the front end to engine. These are thin metal and usually rusts away, and results in escaping cooled air downwards away from engine.

[jos1270]

S. Passmore: A 93mm core would be about the same as 3.5 inches, wont it? I just talked to person who does radiators and told him i needed a 4 inch radiator and he said that a 3.5 inch is what he could do. I also just looked up on google and it said that 93mm=3.66 inches. Am i correct?

Joe Ceretti: I wish i would be $600 instead of $1500 that i am going to be charged. 

las39: yea i think it does have those plates. But im going to make sure to see if it does have it.