Overheating and vapor locking

Hi Issac,

Nice car.

Where do you have your timing set? I have battled a number of older cars and overheating and come to find out, it was the idle was the issue. Basically, it is running too rich and gets hot quick.

The last one was my father in-laws 1956 Lincoln Mark II and it did exactly what yours does. I bumped the timing up and overheating stopped.

Main reason I would look at this is because it seems like you addressed everything in the cooling system.

If this doesn't pan out, your only option may be putting a high speed electric fan on it or even a pusher fan in front of the radiator. However, before going there, get an infrared temperature meter and check all around the engine and make sure you don't have a restriction.

Let me know what your timing is set at and we can go from there.

https://www.2carpros.com/articles/how-to-use-an-infrared-temperature-meter

Hi Kasekenny1,
Thank you for the suggestion, would that entail using a timing light and shining it on the engine marks? I’m not a very experienced backyard mechanic. Please let me know and thank you.

Yes. This is exactly correct.

Here is a video that takes you through the entire process. They get very detailed but the important thing you need to follow is how to set the light up, how to check the base timing (idle/initial), then how to adjust the timing by moving the distributor.

One important thing when setting your base timing is to remove your vacuum line from the distributor. This is the vacuum advance and will effect your setting so you want this unhooked.

Once you set your base timing, the advance will take care of itself. I suspect that your base timing in low which is causing your total timing to be low which is why you are overheating while driving down the road.

There are video on the internet of guys setting timing on your engine but they were pretty amateur so I didn't want to recommend them on how to do it. However, feel free to look at them to show where all these components are on your specific engine.

https://youtu.be/UYGU7mTwsZc

Hopefully this helps. Please let me know if you need more assistance with this and I will help how I can. Just a tip. If you don't feel confident doing this, then I wouldn't attempt it by yourself. You can probably find any senior mechanic and ask them to show you how to do it and I am would think they would. They may charge you to do it but I am sure they wouldn't mind teaching you if you ask. At least, I know I would and I am sure there are others that will as well.

I had the distributor checked and it was loose, so it was tightened down and re-timed. The overheating is okay, if the car is driven locally, it is when the car is driven on freeway speeds that the temperature gauge goes to 240-250 and then if I get caught in stop and go traffic or stopped at a long light, it heats up more and causes vapor lock, then I have to get to the side of the road and let it cool 30-60 minutes before I can restart it.

Okay. These are a little harder to figure out because they happen when driving down the road so checking it out is clearly not that easy.

What we need to do is, get it hot (before it vapor locks) and use an infrared temp gauge and see where you have a hot spot or if it is even all around the engine and cooling system. You will want to measure the engine block and cooling hoses and radiator.

Normally, these issues are caused by a restricted radiator or kinked hose. Basically, when the engine gets hotter if the coolant is restricted, it can't cool the engine quickly enough. At a lower RPM it is okay.

Let's check and see if you have a hot spot and go from there. Thanks

https://www.2carpros.com/articles/how-to-use-an-infrared-temperature-meter

Hi Kenny,

Keep in mind I have done the following:

My car runs about 240 during highway drives, when I slow down to get gas the car heats up and then vapor lock occurs. I have replaced the radiator to a four core, water pump to a high flow, replaced the thermostat to I believe a 160 or 180 degree or less in an attempt to keep the car running cool. Flushed and replaced the antifreeze. I also replaced the clutch fan, with a new one. The car still runs hot and continues to vapor lock when running slow or in bumper to bumper traffic. I need help!

Also, I haven't tried the infrared yet. I don't know where a restriction could be, since I have replaced everything that I could think of and I plan on doing the infrared soon.

Okay. We need to go back to how the engine is tuned and running. The engine may be running well but if the cooling system cannot keep the engine cool then it is most likely tuned to rich. I mentioned it earlier but I fight vapor lock on my father in laws 1956 Mark ii. The cooling system is not the issue, but when I bump the timing up a little it runs better and cooler.

Where is the base and total timing set? I know you had it checked but I am wondering if you can advance the timing and see what happens with the vapor locking?

I get how it can be frustrating because you have gone through the entire cooling system but again, I don't think it is a cooling system issue.

At this point, the only other thing you could do is add a pusher fan on the front of the radiator to keep the system cooler.

The carburetor needed to be re-jetted. It runs cooler until it is run on the freeway at 60-75 mph, then it runs up to not quite 240. It does cool down when running 50 and lower, just after coming off the freeway. Any suggestions?

Isaac

What RPM are you running at when the temperature gets that high?

I'll have to get back to you on that one. Also, would a shift kit in the transmission be a problem? I had a shift kit put in just after I noticed that the car would overheat. it's just a shot in the dark.

Okay. It depends on the type of shift kit. Normally they don’t change shift points they just make the shift points more firm.

Let me know the RPM and we can go from there. Thanks.

Okay, 3000 at 65 mph.and 3250 at 75 for the 240 degrees.

That is why you are overheating at that speed. That is too high for a cruise speed. The water pump can’t move the coolant fast enough to keep up with the heat generated from that RPM.

What gearing do you have in the rear end?

Unfortunately you may to to reduce the gearing so you can be at a lower RPM at higher speed or drive slower.

The original gear was 2.41, but I wasn’t able to find the original gears, so I had to go to 3.42. I think that’s what it is.

You nailed it. Unfortunately, driving slower is probably going to be the only option until you can locate another set. The fortunate thing is you probably won't get any speeding ticket.

Is there anything else I can do?

I talked to the reared guy and he told me that the gears are okay and shouldn’t cause the overheating.

There is nothing wrong with the rear end. It’s just causing you to run at a higher RPM when going 70 MPH. It is doing what it is supposed too.

Running at a constant 3000+ RPM the cooling system can’t keep up. When running at a slower speed the RPM is lower and it doesn’t overheat. This is why the vehicle wasn’t built with this high of a gear.

At this point your only options in my opinion are to drive slower so the RPM is in the range it would have been with the smaller gear. Or put a pusher fan on the front of the radiator to try and move more air to cool the coolant faster so that you have colder coolant going through the engine at that constant high RPM.

What about the radiator? The radiator is 4 core, would this cause the overheating?

Yes it will if it is clogged up how does the coolant look? This guide can help:


https://www.2carpros.com/articles/engine-overheating-or-running-hot


Please run down this guide and report back.

I have replace all the cooling: water pump, radiator, clutch fan, 160 degree theromstat. The radiator was the original radiator, until it was replaced with the 4 core radiator. I'm wondering if the 4 core isn't letting enough air through to cool the water in the radiator down.I don't think the lower hoses have the wire spring in it though and I read that it should have the wire in it.

4 core radiators are meant for very high horse power vehicles. Meaning in excess of 1000 hp. The idea is there are more rows of coils so that the coolant will have longer in the radiator and come out colder so that it can cool an engine that is able to produce that much hp. I would not think this is the issue. However, it is too much radiator for this vehicle.

However, you premise is basically what I am thinking your issue is. Running at that high RPM the coolant isn't getting cold enough so an auxiliary fan on the front of the radiator that pushes more air when the engine starts to overheat would solve it.

Before you do that, here is what I would suggest, get an infrared thermometer and when the engine starts to over heat, pull off the road ASAP and start measuring around the engine and cooling hoses to see what the temp is. It should be within 5 degrees all over the engine except for the lower hose. This should be much cooler since this is just coming out of the radiator. If it is not, about 10 degrees or more then the radiator is not cooling it enough.

So, would I use the pusher fan with the clutch fan on the car? Also, what brand of pusher fans are good ones or what do you recommend?

You can't really make a wrong choice with these but here is a link to a pretty common product. Clearly, I don't endorse this company but there are pretty popular.

Here is a video from them that I think answers your questions. However, this is to be used in addition to your existing system. Let me know if you have more questions. Thanks

https://youtu.be/7QO5zHJmtYY

If the heater core is clogged, could that be the reason for the overheating? When I turn the heater on, there is little to no heat that comes out.

Very good possibility unless you have a heater core bypass. I don't show one but if you have one, then if it gets clogged it routes the coolant back to the system so that it doesn't cause this issue. Check your inlet hose to the heater core and see if there is a "T" on it that goes to the outlet. If there is then you have a bypass and you are correct that it is probably clogged which is why you are not getting heat. However, it is just routing the coolant back to the engine so it is unlikely that it is causing your issue.

If you don't have one, I would suggest testing this by creating one. Just disconnect the inlet and outlet hose and get a connection piece and put them together so that it bypasses the heater core and then drive it.

Let me know what happens. Thanks and good thinking trying the heat. I never would have thought of that with it being summer an all. Thanks