263 in 1950 Super w/dynaflow

I have written before about my overheating problem. I did lots of flushing experiments this summer and did not solve the problem. I also checked the impellors of the water pump. The problem does not appear to be the radiator or the pump.

It is possible that the water jacket has junk in it. It does not drain very fast from the block (and I had to clear it out with air to get it to drain at all).

However, I am also very afraid that I have a bad head gasket (or worse head problem). I am not seeing water in the oil. Also, no white smoke comes out the exhaust when the car is warmed up.

This is what I am going to do:

1) get combustion leak tester and see if combustion gas is getting into the radiator.
2) if head gasket ok then I am knocking out the freeze plugs starting with the rearmost one.
3) if combustion leak noted then I am pulling the head this winter and while it is off, I will knock out the freeze plugs anyway, and also pull the radiator (again).

Do people agree that if the combustion leak tester shows any indication of combustion gas in the radiator that my problem is definately the head? In other words, is there no such thing as an insignificant small leak that would be unimportant in trouble shooting this problem (like there is no such thing as being a little bit pregnant). It is an old engine and I will pull the head if I have to but I don't want to do it if it is possible for a problem to be small and not the cause of my overheating problem.

The overheating symptoms are this:

Starting from cold the engine slowly warms up and after 30-40 minutes it readlines and blows steam out the overflow (exactly when the needle reaches the top of the gauge).

Rebecca

forgot to add, I ran the engine with the radiator cap off and I did not notice any bubbles. If I was getting combustion gas contamination would I not see bubbles?

Rebecca

Yes, a head gasket leaking into the cooling system will definitely show up as bubbles in the radiator. From your description, it sounds like nothing more complicated than crud in the water jacket. I had an old Dodge that, although not overheating, had so much crap in the jacket that when I opened the cock on the side of the block to change coolant, nothing came out until I removed the cock and poked around in there with a coat hanger!:jeez:

Yes, a head gasket leaking into the cooling system will definitely show up as bubbles in the radiator. From your description, it sounds like nothing more complicated than crud in the water jacket. I had an old Dodge that, although not overheating, had so much crap in the jacket that when I opened the cock on the side of the block to change coolant, nothing came out until I removed the cock and poked around in there with a coat hanger!:jeez:

I sure hope this is what is wrong in my case. I did have trouble getting stuff to drain from the cock until I blew some compressed air in the cock. Now it drains slowly.

I plan on knocking out the freeze plugs and if I see junk in there (I hope I do) I will try and unblock it with a coat hangar. However, I will still need some kind of very powerful flush to clean it out after that. I already tried the prestone stuff. it did nothing (but it might have been too plugged).

I will proceed with my plane (test head first, then hopefully just proceed to clear out the water jacket).

Rebecca

From all the posts I have read, the coat hanger, and high pressure water and air, lots of scraping and perhaps take that new water pump off while flushing so you do not get junk in the seals and bearings.:car:

yes do take off the water pump to prevent it from getting gunk in it. The best thing I found for cleaning is some 1/4" copper tubing. Mate it up to a regular water hose and it can be bent to go all around the insides of the block water passages, I had a ton of stuff come out of my block, rust , dirt, chunks of rust and it definitely helped my engine run cooler.

I forgot to mention making an adapter so I could attach a 1/4" copper tube to my air compressor hose. I mashed the tip slightly in order to make a smaller outlet. This increases the air blast. Then I bent the end to angle the blast into the water jacket. After the first flush I used this to break loose a lot more junk which came out with subsequent flushing. Not exactly professional, but as my mother used to say, 'Poor folks have poor ways!':waving:

I read your posts and then went back and reread your original posts on overheating and I'd say that you do not have a head gasket problem. I'd say that you are probably on the right track with crud in the cooling system. Late timing was touched upon in the other thread and was my original thought but some other things come to mind. Such as running a little lean from a vacuum leak or a carb problem. When you put compressed air into the drain hole to get it to drain you could have put some crud into suspension in the coolant that has now been drawn into the radiator and is plugging some of the tubes. You say that the radiator was boiled and flow tested but you didn't say that the tanks were taken off and the core was physically "rodded out" to make sure that all passages were open. I don't have much faith in "flow tests" on a 50+ year old radiator. Lastly, and I'm sure this is a long shot, I went to your website and looked at the pictures of your car. I like it by the way. Did the radiator shop paint it or did you? If you did it, what type of paint did you use? Did you use paint specifically for radiators or did you use chassis black or rattle cans? Believe it or not but the type of paint on a radiator can have a huge effect on it's ability to cool properly. Regardless of what type of paint that was used you could try stripping it off and see what happens. Flat black is better for heat radiation, that is true, but paint that is causing a heat dam is worse than not having a black radiator. Just some thoughts, good luck.

I'd like to make a suggestion. Start the engine go for a short ride to get it to operating temperature. Shut the engine down, and immediately try to get your hand between the fan blade and the radiator and feel for cold spots. If you find cold spots, thats where the radiator is clogged. This method works every time! I also agree your engine has issues with build up in the water jackets. If you remove the frost plugs to give it a good cleaning, try to hook up to your hot water heater for hot water. Hot water always works better with the crud build up. If you have a shop vac, use that as well after the block drains. Coat hangers work also, to help move the crud around. After you're done, put two bottles of rust inhibitor in the cooling system. Then add your anti freeze, and distilled water. I hope I've help turn more lights on.

> in the coolant that has now been drawn into the better for heat radiation, >that is true, but paint that is causing a heat dam is worse than not having a >black radiator. Just some thoughts, good luck.

the radiator put that paint on. I had bought a can of eastwood radiator paint (thinner for better heat disspation) but they had painted it before I had a chance to do it myself. I agree that it looks like the wrong stuff.

I am will re-visit the radator (more crud in there since I started flushing experiments>).

Rebecca

On my '46 320, I recall the majority of coolant flows from the block to the head thru a single hole at the back of the head. It is very likely there's some rust and scale blocking the passages.

One thing that is found to remove rust and scale is to drain all the coolant from the system (block, radiator and heater), then fill it up with DISTILLED water and a bottle of Red Line Water Wetter. Drive a few hundred miles, and do this again, but this time you can use tap water. We accidentally found this phenomenon in a racing application. If you live in warm climate, you don't really need antifreeze at all. Water Wetter will reduce your temperatures and works best with straight water. Using antifreeze with WW will compromize the effect to some degree.

And, like someone suggested, check for vacuum leaks. Nothing can cool a lean-running engine. I have experience on that department.

By the way, I browsed thru your pics, which you seem to have a tremendous array, and you have done some nice work there. Good luck!

Hi, You are going through exactly what I did during the summer.After blowing the original 248 ,I also replaced it with a 53 -263 engine.Finding it to overheat after 30 minutes and following a lot of well intentioned advice,I changed the water pump,replaced the head gasket and flushed the system.The rad was rodded out before I put it in.Guess what,still overheated.However,before putting it into to storage I took it out on the highway and it overheated immediately and cooled down when I came off the highway.I believe that a lot of contaminent migrated into the rad after the engine replacement.When I had the head off I removed at least a can of sludge with a turkey baster.I now believe this junk got into the rad .The car is now in storage,but I believe I will have the rad redone in the spring.If this fails to solve the problemn.(1940 Buick Super Coupe For Sale)
Ray

Don't forget that when you have finished poking around in an engine block to loosen crud, it is wise to run some kind of filter between the block and top radiator inlet to arrest bits and pieces.
You can buy these things at radiator repair shops, or just make some.
Cut about 6 to 7 inches off the bottom of stockings, and remove top radiator hose. Now poke the stocking into the radiator through this hole, leaving 2 inches outside.
Roll this over the inlet neck on the radiator (a la condom style)
C'mon, we're all adults here !!!
Then replace the radiator hose so that you capture the stocking in between and do up the clamp. Now all the gunk should get caught while still allowing water through. Initially though, check this every few days, then weekly as you will be surprised as to how much crap is in there.

By the way, I know Molasses works a treat to remove rust, but has anyone ever run a mix around their engine for a while to deal with rust ?
As long as there are no aluminum components in the system, I can't see that there would be a problem.

Cheers