Radiator spews after 10 miles

[fiddlybits]

Ok, I'm baffled. (which means I won't slosh)

Today I took the car for her first long drive. I have been running a 10 mile circuit but today I planned a 25 mile double loop for a total of 50 miles. The road is mostly level with gradual grades and posted at 55 mph the entire way. Temperature outside was 52 when I departed.

I was maintaining a solid 55 without full throttle and everything sounded happy. Everything went great until mile 11. Then I started getting water spots on the windshield and about a mile later I had water blowing past the gasket in the motometer and all over the windshield. Then, as quickly as it had happened, it stopped. (I did ease off the throttle to about 45 for a minute)

I had a 4 way stop that took a minute and then I was back at 55 and everything was fine again. (Note: during all this time the motometer only showed a half inch of red and I did check that it is working)

About 9 miles from that stop the same event happened again and I happen to be at a historical marker so I pulled in. The water level was running just below the overflow and was 170 degrees. Puzzled, I headed for home.

Arriving home I IR'ed the temp on the block and the hottest spot I could find was 185. The water level was at the same place and when it cooled only took a pint to bring it to the overflow. (I'm using the overflow as a gauge while I figure the car out. I know that, cold, that that level is too high and will blow water out as it warms up.)

Other things that I've checked:
Timing is correct.
Power is solid and never changed.
Mixtures seems to be right as tailpipe is light brown.
I was running full advance and the GAV was set about 1/4 open.
Radiator is fresh and IR temp is equal on all tubes.
Water pump has the modern seals and stainless shaft.
Fan is aluminum 2 blade.

Everything seem normal except these "eruptions". It's like a ball of gas builds up and then lets loose.

Anyone seen anything like this?

[RonC]

Your water might be getting pumped by the water pump faster than it can drain through the radiator tubes. In addition your motor meter cap gasket is not sealing. I would replace the gasket and monitor the water level.

[Bob C]

If you have the water up to the overflow you have to much water.
If you have a baffle run it with the water just to the bottom of the baffle.

Bob

[roadster]

I had something like that
I replaced the motometer with a plain cap
no more problem.
Good luck

[Mitch//pa]

well just reading your story i do 2 things different
1. i only fill the rad tank to baffle level or just below when cold. not to the top of overflow tube as you mentioned.
2. i never run full advance, usually around 9:00 ish.

[Tom Wesenberg]

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Do as Bob said and it should be fine. If it still overflows you must have some blocked tubes. Last summer I had some tubes blocked by flakes of rust. The car didn't overheat until the top tank filled and sent coolant out the overflow pipe. Then the coolant was too low and the engine overheated.

I removed the radiator, turned it upside down and backflushed it with a sump pump. This removed the rust flakes. I did the same backflush to the block using the sump pump, and got about a cup of rust flakes out.

I am now ready to go drive it again after the snow melts and the road salt gets washed off.

As Mitch said, I also never run full advance, but about 1/2 to 2/3rds. down.

[Kurt in NJ]

When I fill the radfiator it is onlt till i can see it just above the baffle ---if it is filled any more it spits it out, you should try not adding any coolant and see where the level stabilizes.
i always run with full advance,the owners instruction book tells you to use it for high speeds and have never been able to make it ping with gasoline that was good (I have used "contaminated" and stale gas in the car)

My 40 year old repro motormeter gaskets are getting tired, if I overfill the radiator it will spit some

Check your overflow tube to see if it is clogged ---there is a mud wasp around here that likes holes that size./

[mshmodela]

I had a similar issue but at way less miles.. My quail lower gasket and upper were not sealing... A new lower one I purchased, but and new upper one I hand cut from a thick washer so far all fine with short stop and go city 35mph driving.

[ryanheacox]

I had a problem similar to yours. Under at high speed and climbing hills, the radiator would spit. Not sure why but after switching the anti-freeze for regular old water, the problem stopped. Now I start each season I drain out the anti freeze and put in distilled water. What are you running for coolant?

[antiquepa]

Had the same problem when I used antifreeze., had'nt used antifreeze since 2002 and had no more problem, I do put antifreeze when I store it for winter..I would try pure water w/rust inhibiter,,worth a try!!

[Mike V. Florida]

Originally Posted by fiddlybits

About 9 miles from that stop the same event happened again and I happen to be at a historical marker so I pulled in. The water level was running just below the overflow and was 170 degrees. Puzzled, I headed for home.



Anyone seen anything like this?

as the water is still in the radiator and the water was 170 and the block was 185 I think it is just finding its own level. With a non pressurized system and the temps you mention and the water leaking out the cap, I would check the overflow tube for a blockage and replace the cap gasket.

[Purdy Swoft]

I had trouble with the gaskets with the quail cap on the coupe. I finally fixed it with new gaskets and high temp silicone sealer. I have less problems with an original Style cap. Usually the radiator filler neck gets damaged when the flip top style caps are used.The water pumps, if not modified will pump more water than anything but a new old stock radiator can flow. when thgis happens, the water will find a place to escape. I grind the tips of the pump impeller. Snyder has recommended this for years and it really helps. It probably leaked less a 45 mph because the lower the rpm the less the water pump will pump. I run plain water and water pump lubricant in the summer. There is no advantage of running antifreeze in summer with an unpressurized cooling system. These cars are nearly 100 years old and can't be compared to newer cars with pressurized cooling systems with better head gaskets and way more head bolts. I have run at speed with full advance for 54 years with no bad effects. Running with retarded spark labors the engine and makes it run hotter, plus it loses power. You are really right on running full advance. You just don't want to lug in high gear with full advance. Some don't know what lugging means. Its not l;ikely that you would ever lug an engine in low gear. Lugging happens in higher gears when speed is allowed to drop and strains .the engine.

[PC/SR]

Are you using a thermostat?

[FL&WVMIKE]

NO MATTER WHAT, put a new gasket in your radiator cap !
It should not leak - NO MATTER WHAT !
From the sounds of it, you do not have a heating problem, just a leaking radiator cap.
MIKE (mikeburch)

[justcruisin68]

i'm not the smartest, but if the rad. cap is sealed tight, wouldn't that make it
a pressurized system?

[dlfrisch]

I had the same problem. I have a vented radiator cap so when it puked, it made a mess. I learned - keep the coolant or water down to the baffle plate and it will or should be Ok. Even with 100% anti freeze coolant. I did have a little radiator spit, through the cap again, so I installed a 160 degree thermostat and temp. gauge. All has been good to this point. Temperature holds at 160....165 degrees. I have been out and run 45 - 50 mph up and down small hills and did over 100 miles. No problem.

[Bob C]

Originally Posted by justcruisin68

i'm not the smartest, but if the rad. cap is sealed tight, wouldn't that make it
a pressurized system?

No, the radiator will vent through the overflow tube.

Bob

[machine girl]

water flowing to fast.

[fiddlybits]

Thanks for all the suggestions.
Did some experimenting today.
Started with adding soap to the water in the system and running the car up to temp a few times, followed by a thorough fresh water flush. (3 times). This was to start with a fresh cooling system. Final fill was with distilled water like it has been. (Again, all the way to the top of the overflow as I want to know how much water is displaced from cold to running temp.)
Removed the new gasket, that I had just bought and installed, from the motor meter and replaced with slightly thicker O-ring therby obtaining a positive seal. (it thinking this is 80% of it.)
Then, just to monitor things I attached a hose to the overflow and ran it down the side of the car, into the window and stuck the end in a gallon jug on the floor. (it looked "interesting")
Then went for a drive.
Everything behaved as expected. As the engine warmed up, water flowed in to jug. Nice and even flow with no sudden burps. (Traffic was not letting me hold 55 so I am going to run test again tomorrow)
Got home and had to take care of some chores and when I got back to the car I was surprised by something that had not crossed my mind. The jug was empty! (Guess I got a good seal on the cap)
30 minutes later the car had a coolant recovery tank hanging from the radiator support with the overflow from that going inside to the jug for a test tomorrow.
I'll add the water wetter when the tests are satisfactory.

[Mike V. Florida]

Originally Posted by fiddlybits

Then, just to monitor things I attached a hose to the overflow and ran it down the side of the car, into the window and stuck the end in a gallon jug on the floor. (it looked "interesting")
Then went for a drive.
Everything behaved as expected. As the engine warmed up, water flowed in to jug. Nice and even flow with no sudden burps. (Traffic was not letting me hold 55 so I am going to run test again tomorrow)

Next time empty the water out and drive it again and see if more water goes to the jug or if it has found its level.

I had the same "problem" as you when i first got my car. I noticed though that i was adding the same amount of water each time it "overheated". I now top it off every few months as I cannot see the water level beneath the baffle.