Head gasket follow up

[JtownJoe]

Finally got the head off my 30' Tudor today & there was plenty of evidence of coolant in # 3 cylinder & an area of the gasket appeared damaged between the cylinder & water jacket area near the exhaust valve on #3. I will still examine the port & valve area closely but if all is well there that should solve the blown gasket issue. But another puzzling discovery is that #4 piston has almost no carbon build up as compared to the other ones. (Looks almost new) for a 4 year old rebuild, I have always noticed that there seemed to be little, if any, difference when I pulled that plug wire when running, but all others would slow down the idle. This seems to bear out my suspicion that #4 was firing weakly if at all. I had same 100# compression in that cylinder and of course switched plus & even p[lug wires in the past with no changes noticed. With the head off I verified that the valves are opening & closing correctly & I know it had great spark, any other ideas??

[BILL WILLIAMSON]

A totally clean piston top is a SURE sign of a coolant leak into that cylinder!!!! Bill W.

[mll1446]

Jtown joe, was your engine running fine prior to this discovery any knocks or misses? I have similar issue

[Mitch//pa]

if #4 was not firing as strong and the piston / combustion chamber are clean then you were getting coolant into that cylinder

[ford3]

BillW is correct, a perfectly clean piston top and cylinder indicates a water leak, also an easy and quick way of finding a suspected water leak is start by pulling spark plugs till you find one that is absolutly white and free of any carbon, a good indicator of a water leak into that cylinder

[green30coupe]

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Originally Posted by ford3

BillW is correct, a perfectly clean piston top and cylinder indicates a water leak, also an easy and quick way of finding a suspected water leak is start by pulling spark plugs till you find one that is absolutly white and free of any carbon, a good indicator of a water leak into that cylinder

Originally Posted by BILL WILLIAMSON

A totally clean piston top is a SURE sign of a coolant leak into that cylinder!!!! Bill W.

Bill W. and ford3 are both right on target. Cylinder misfire and a clean cylinder = coolant leak into cylinder.

Ed

[JtownJoe]

Ran fine for last three years & then started to use coolant with no visible leaks & then started to miss badly but I ruled out head gasket problems when I got perfect compression readings on all 4 cylinders but looks like that was a miss leading indicator & I was getting water in the compression chamber anyway. I didn't do the holding compression test that might have shown that the pressure was leaking into the water jacket instead of holding the pressure.

[JtownJoe]

Thanx guys, for all the replies, I didn't know that was the an indicator of coolant leaking into the cylinder & if I don't find any cracks on a close examination of the block & intake & exhaust ports I'll be back in business with a new Fel-Pro gasket from Bratton's.

[Mike Peters]

Joe: Be sure to retorque that new head gasket. Run it for no more than 10 minutes and retorque those head bolts. , again after first spin around the block, etc. I put one together this summer and had to retorque 5 or 6 times before it finally stayed put,(stopped losing torque". Eventually those head studs will "set" in.
mike

[Art Bjornestad]

There is an exhaust gas test kit that shows if exhaust gas is getting into your cooling system. Perhaps someone can supply the name.

[BILL WILLIAMSON]

Originally Posted by Art Bjornestad

There is an exhaust gas test kit that shows if exhaust gas is getting into your cooling system. Perhaps someone can supply the name.

It's brand name is "BLOK-CHECK" Bill W.

[JtownJoe]

I'll look for that BLOK-CHECK, Thanx again guys!!!

[BILL WILLIAMSON]

Originally Posted by JtownJoe

I'll look for that BLOK-CHECK, Thanx again guys!!!

Also, Joe,
Quick test for water in the oil: Hold dipstick on a 45 degree angle with a drop of oil hangin' on it, heat the drop with a match or a lighter. Yellow, smoky flame, O.K. If it sparkles & spits like a sparkler, you have WATER in the oil!!! Bill W. (Buster T., The Dog, reminded me of this trick!)

[glenn in camino]

Try a different distributor cap.

[Special Coupe Frank]

Joe,

Is your engine set-up with the original style armored cable to the distributor and proper clamp and stud on #8 head-stud/nut ?

There were (at least) three different cable clamps (all with different thicknesses) & co-ordinated studs ( longer than the rest of the "short" studs). If the clamp is missing, or a "long" stud is used with a "thin" clamp, the head nut can "bottom"out" on the stud threads before it fully clamps the gasket, allowing leakage between cylinders #3 & #4, eventually resulting in gasket failure.

Went through this on my '28...

[juke joint johnny]

Originally Posted by BILL WILLIAMSON

Also, Joe,
Quick test for water in the oil: Hold dipstick on a 45 degree angle with a drop of oil hangin' on it, heat the drop with a match or a lighter. Yellow, smoky flame, O.K. If it sparkles & spits like a sparkler, you have WATER in the oil!!! Bill W. (Buster T., The Dog, reminded me of this trick!)

Bill !! that's another clever Homespun solution !!!
Thanks for that
I reckon that Buster T is a lot smarter than a lot of people What say You?

John Cochran

[john in illinois]

Joe,when a gasket leaks,it is always a good idea to check flatness of the head.

John

[JtownJoe]

I am running a FS Distributor & have a spare cap to try & I'll make sure of the clearance on the shoulder of the new Grade 8 studs & nuts. Thanx for the tips!!