Return From Vettefest - Fingers Crossed

[Duke W.]

Re: Return From Vettefest - Fingers Crossed

Tim & Duke;

Duke, your mention of Madison brings to mind my days and friends in Wisconsin. My buddy, with whom I bought this car in 63, was there in Engineering school say late 60's early 70's - a fellow by the name of Denis H. Landry. In fact, he had the 63 up there for awhile and/or stored in his mom's garage in Jefferson while I was in SEA.

Stu Fox

I don't recall the name. I was there from fall '68 through the end of 1970 doing a MS at the Engine Research Center. I had a 283 Chevy on a dyno in the basement of the ME building that I ran to collect data to put into an intimidating set of differential equations trying to figure out what was going on inside the carburetor.

Sometimes if I struck out at the bars I'd take the SWC for wild ride around The Beltway.

I often wonder how I lived long enough to collect Social Security.

Duke

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Duke;

My buddy had a degree in mechanical, and was pursuing one in electrical. I was up there to participate in a study grant program as a subject of a brain wave scan. The study goal was to explore means to communicate with the totally disabled through brain waves (crazy I know). He said I came the closest to being able to flat line of any subjects he had studied. Of course I told him that was easy for me. He was also working on a full scale all electric car they were developing in conjunction with the M.E. guys. We drove it around the parking lot. I don't know if he ever achieved his goal to copy all the department's analytical programs or not. He loved it there.

Ron;

You make some good points. I believe most of the white smoke my son saw was from the coolant getting on the R.H. exhaust system. The blue/black smoke I'm not too sure about yet. There is no evidence of oil contamination, least wise not on the dip stick. About the only other easy avenue to look at for any telltale sign of coolant in the crankcase is perhaps the PCV valve line, or maybe in the fuel pump cavity. I lost a 305 block in 87 due to a porosity crack so I know what the greasy goop looks like.

Thanks Ron. We'll keep ya'll posted.

Stu Fox

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Just to toss out a little update. I spoke with some of my old Hot Rod friends and they offered the following theory;

Possibly a thermostat stuck closed causing a "Short-Block coolant overheat and purge". Suggestion is to check for bubbles in the expansion tank with engine running which may indicate a head gasket leak by an exhaust valve.

I value their opinion because they have blown up a lot of Chevy engines. Who better would know, right?

I will have time tomorrow (finally) to do a running test and will confirm one way or another what kind of mess I got here. Either way, I can speculate that I will never trust a Chinese made thermostat!

Has anyone else out there heard of this symptom?

Stu Fox

[Clem Z.]

Re: Return From Vettefest - Fingers Crossed

take off the goose neck and take out the thermo,remove the fan belts. with the coolant full enough so you can see it in the thermo housing in the intake start the engine and watch for bubbles in the coolant. if a head gasket has a leak you will see bubbles in the coolant

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Thanks Clem. Sounds like a more positive way to check rather than at the expansion tank. Besides, that darn Mr. Gasket thermostat has to go no matter what. I don't know why I used that any way. For 47 years I always used an OEM 160 degree, then I have to experiment in my (and the car's) old age. Stupid!

Stu Fox

[Gary C.]

Re: Return From Vettefest - Fingers Crossed

Stu, as Mr. Clem recommended a Robert Shaw thermostat is the only way to go. If they stick it's in the open position. JMTCW, Gary....

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Gary;

That's the part that puzzles me. This Mr. Gasket item appears to be a Robertshaw ripoff from China. Oh well, I'll know better when I get it out today. Now if only my wife would hurry breakfast so I could get started. Got to have some energy.

Stu Fox

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

I just finished performing the test for head gasket leak by filling the cooling system with water through the thermostat housing with the thermostat removed, fan belts removed. etc. as Clem recommended in his post this morning. The engine started and ran fine, and I let it go until it broke about 120 degrees or so on the gauge, water was just starting to steam and rise in the water manifold. Until it reached this temperature, there was only a little wave activity from the Duntov showing, but no bubbles. After reaching this temp, it would gurgle some bubbles that to me were more like release of trapped air pockets. The water turned slightly cloudy as if it was approaching boil. I shut it down then rather than have the water run over onto the intake manifold.

As this was my first use of this particular test method, I'm not too certain what to look for. The air that gurgled up came first from one side and then the other (from one head and then the other), or so it seemed. That's why I felt it was just release of trapped air, typical of when you fill an empty system.

Any ideas or comments would be appreciated. Right now, I'm of the opinion I should re-charge the system with coolant and install a new thermostat and cap. Then see how it acts. Oh yes, when the wife lets me have access to the stove, I intend to test the removed thermostat to see how it functions.

Stu Fox

[Joe C.]

Re: Return From Vettefest - Fingers Crossed

A cracked head or block, or a small leak of coolant into a cylinder or two are sometimes very hard to detect. A car can often be driven this way for quite a while until the problem worsens. Drive your car often for awhile and watch your coolant level. If it drops and you have no external leaks, then of course you have a problem. One more thing I can suggest, is to read your spark plugs, particularly on the bank that you suspect as having a problem. If coolant is getting into a cylinder, you'll see a clean plug. Of course, if the crack is in the exhaust port, you'll see nothing amiss.

If your head is cracked at an intake or exhaust port, you won't see exhaust gas bubbles in your coolant, but you will "use" coolant at a decent clip.

Sorry I can't give an easy answer here, but it looks like yours might be a very small breach somewhere (for now).

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Joe;

Thanks for your advice. We'll button it up and just see how it goes.

Stu Fox

[Domenic T.]

Re: Return From Vettefest - Fingers Crossed

Stu,
To add another test that is easily done would be to do the vapor test at your radiator cap.
If it detects carbon monixide the liquid that is in the bottle turns a different color.
You draw the vapor from your water thru the liquid. The aoto parts store should have one you can buy.

DOM

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Thanks Dom. Will check into that.

Stu Fox

[Joe C.]

Re: Return From Vettefest - Fingers Crossed

Stu,
To add another test that is easily done would be to do the vapor test at your radiator cap.
If it detects carbon monixide the liquid that is in the bottle turns a different color.
You draw the vapor from your water thru the liquid. The aoto parts store should have one you can buy.

DOM

Dom,
That is a great test, but it will only show a blown head gasket. The test he did earlier with the thermostat removed accomplishes the exact same thing.

[Domenic T.]

Re: Return From Vettefest - Fingers Crossed

Joe,
Actually, it will also show if combustion is being blown thru a crack in the block or a cracked head too.

DOM

[Stuart F.]

Re: Return From Vettefest - Fingers Crossed

Just a brief update; I tested the thermostat several times in a pan of water, running it up to 200 degrees and it would NOT open (it's a 180). I tried this twice to be certain I did it right.

My question is; if it was stuck closed from day one, why did it run normal before - holding just under 180 on the road?

Could the long idle period at the show where in hit 195+ cause it to fail?

Could an L-76 with a water pump bypass hose possibly run normal with a closed thermostat?

I received my new cap and thermostat today so will button it up and road run it to see how it acts.

Thanks to all for your advice. I'll post the outcome.

Stu fox