VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1935 - 207 engine block water drain.

What does the water flow look like coming out of engine with the thermostat out? Have you back flushed the engine with a garden hose?
Do you have proper air gap at the top of the radiator to allow the water to "fan out" inside? Or is it full to the top?
During the flushing did you get any rust chunks?
There are still a lot of questions here.

Thanks for asking! As she sits right now the radiator was serviced last winter. Repairs were made to the tank and it was rodded out.
I then flushed out the engine both ways. All was clear. I found the baffle behind the water pump was missing. I installed one and replaced the water pump. After all that the issue changed from low speed heating issues to higher speed cruising heating issues. Now I can drive her all day at low speeds without problems. Yesterday I took her on the parkway for 5-7 miles and she got hot so I got off and continued for another 5-7 miles on back roads. She was running about 5-10 degrees higher than before we got on the parkway. Nothing boiling over. She sat for 3 or 4 hours at the car show. We left and she did the same thing.
Today I opened the radiator petcock and green water came out which should not be as I added 3-4 gallons of fresh water yesterday while on the road that must have blown out of the over flow. There was no boiling over the top side. I assumed all the anti-freeze would be gone after adding so much water yesterday. The 160 thermostat was replaced a few times.

My next thoughts are that the rad cap is not holding pressure. I would check that before going farther.

Older gas stations had this simple tool for checking rad caps to see if they hold pressure. Maybe napa or pep boys or ?? other automotive parts tools sellers.

my radiator has had the top rad cap/ornament holder removed , hole filled and replaced with an 90 degree elbow slightly lower down on the top tank , soldered in and a 15 pound cap applied.

It hopefully might be as simple as the rad cap not holding pressure.

mike lynch.........

The pressure is constantly being released through the overflow tube....the cap doesn't hold pressure.
Possible causes of overheating.
Water pump packing sucking in air (bubbles).
Radiator core restricted. Cleaning seldom helps, a new core is the only fix.
Cracked head or bad head gasket.
Too lean of a mixture or incorrect timing could be the cause (not common)
From what I have read 1935 Standards had a "running hot" problem - fix is installing a 1934 Master core and modifying it to fit.

See "new radiator" thread below.

Thanks all. A recore is not an option as my tanks are weak. So if I tackle pulling the radiator again I should replace it. I see Wizzard, the Brass Works, Walker, and Griffin now make replacements. I won't let the car get that hot again.

I went through the same thing. After buying a new radiator, it still ran hot! Finally pulled the head. (I had flushed the block both ways several times until I did not get any rust out.) To my amazement I found rust chunks blocking the holes between block and head in the gasket area! Had I done this first I would still be running the old radiator. It is a toss up but that is my two cents worth.

Well at this point I might as well pull the head too. I have flushed it on several different occasions both ways. Never any foam in the water or water in the oil. Thanks I appreciate all the help.

While I had the head off...I took it to the head shop and had it magnofluxed for hare line cracks around the valves. Guess what? Yep, it was busted. I got a head that was good and put it on!

I have a 981 head that is already rebuilt. It need my shaft and lifter assy. from my head. I am reluctant to put a good compression head on a "not rebuilt" engine. Especially since she runs so well.
I am re-thinking doing the head at the same time as the rad. replacement so I can diagnose where the problem lies.

Update. The "direct fit" radiators are direct if are sporting a small block V8. I will take the original radiator to be check again to be sure it is the culprit. My hopes were that the over flow tube was clogged or crimped. Not the case. So if the radiator comes back good I will start digging into the engine. Again, she runs so well though.

If you are running a Non-pressure system and fill it up like a pressure type system it will over flow until it reaches proper level. The radiator must have "head space". That is an air space between the top of the radiator and coolant level. This space does two things. First allow for the expansion of coolant when it becomes hot and secondly to allow the "internal fan" to properly fan out the water as it makes the turn into the top of the radiator. This baffle spreads out the coolant over the tubes in the top tank. Proper coolant level is often misunderstood along with overflow on these models.

Although I don't have a '35, I have run into a couple of heat issues that I think are worth mentioning.

1. I used to have a 1958 panel truck that was overheating. I had the radiator cleaned and rodded, which helped but did not solve the problem. I was told that even though water flowed freely through the radiator, the old core was just not transferring as much heat as it should (the fins separated from the tubes). A new core attached to the old tanks solved the problem. So, good water flow does not necessarily mean good cooling.

2. In prepping a 1928 engine to run after sitting 40+ years, I pulled the head just to 'look things over'. I found that the previous owner had used some kind of sealant on the head gasket. Not a crime unto itself, but he put so much sealant on that the water holes between the block and head were SEVERLY restricted. Glad I pulled the head for find this error.

Hang in there and keep us posted. With all this mental exercise, you might never get dementia!

Cheers, Dean

Thanks all! I was blowing out as much as a gallon or more at each "stop to cool down" I made. I found the over flow tube to be clear. If the radiator proves to be operational, it's on to the engine. There is a great rad shop 40 minutes away who specializes in old stuff. I have a date with them.
As frustrating as it may get. All will agree it's all good.

I would suggest that if you are going through that much water that you have a look at the head gasket. On the newer engines that is almost a 100% guarantee, on the older engines less so 90% maybe.

Although not 100% sure BUT IT SOUNDS LIKE BLOCKED UP WITH RUST. If you are blowing that much water after shut down. It can not circulate right.

Or has the incorrect head gasket.

I am loosing the water as I drive. Not much after shut down. She gurgles and blows pressure when I pull over.
Went to Cap-A-Radiator today. The radiator is running at 30-40% on the flow rate. The tank is too bad to be a candidate for a core transplant. So it is onward for the Griffin Rad install, boo hoo. I have not located one 34-35 radiator anywhere.
We are going to pull the water pump for a repack and a look see inside. The "direct fit" rad sits nicely in all the brackets. I have to modify the hose connectors with aluminum elbows. Then we will tenderly check the grill shell and fan blade space for fitment.

There is an ad in the Generator and Distributor Magazine (The Vintage Chevrolet Club Of America's official magazine.) that has radiator works in there who can build you one.

Found it. Thanks

She lives! Left the engine in the car. Pulled the water pump and side freeze plugs. My mechanic used a commercial high pressure power washer. I spent hours poking and prodding everywhere I could. Power washed again. Then he scoped inside the block with his camera. We agreed the block was not near as bad as the head when we started and now even better.
We flushed and flushed, reverse flushed again and again. Water clear, we re-installed. Ran it flushed it. Re-torqued and ran it, flushed it. She has not gone over 155 degrees in stop and go as well as 4 - 5 exits at 55 mph. I expected much worse in the block and wonder why the head was so bad. End of the day, she lives and runs better than ever.
Thanks for all the help!!!

Nothing like one of those gas powered washers to shake the rust out, regular tap water pressure can vary all over the map....maybe 80 pounds pressure at tap

washers......1200 + pressure . Takes the paint off you car to if not carful !!!!!!!!!!!!!


glad you got the fix........HAPPY MOTORING ONCE AGAIN
mike

Thank you. She's on top of her game.

Good for you! That is the way to go! That is what I had to do. I keep a "rust preventative" in there with the fluid all the time. I am proud for you!

Thank you. You guys are what keeps our cars on the road. I can't believe the difference with the 981 head. It is nice to watch the road instead of my temp gauge. I spoke to an engineer at Griffin Radiator. They will modify their "direct fit" to accept our radiator hose size and direction. He said in 10 years with the company there has never been a request for this radiator with an original motor application. Go figure!