So having recently purchased the car and not knowing history here is what I do know. Recently completely re-wired the car and new MSD6 and radiator etc. The engine ran a little rough and was not totally smooth when I bought it. I did notice a little white puffs coming out the tail pipe but the guy said it had not been moved in a month and was just started. As I have completed other things and now can run the motor at length I noticed a little water forming on the floor of the garage as I was testing things. I whipped out my trusty vacuum gauge and went to work with my timing light. Figured its not been tuned or timed in awhile. I went to work to start the timing and adjust the carb etc.. I got everything close but could never get it to really smooth not a twitchy vacuum gauge. So after trying to adjust the everything a let it run and drove around the block a couple times. I don't think the neighbors cat will every be quite the same.. After changing my shorts I went back out and started to fiddle again. After about an hour I shut it off for the day and let it sit over night. The next morning I went out checked water in the radiator again and it was down about one to two quarts. Filled it up and fired it up and it ran but still water in the driver side exhaust. So I kept after it for most of the morning letting it idle and tried to see if I could ever get things to smooth out. An hour later water still dribbling out the exhaust and still not running right. Time to pull the spark plugs and check those. They all look reasonable 7 looks a little fouled and like its got a miss. So lacking further information I figure head gasket maybe so I take it all off look at the heads and look overall fine. So I move on pull the heads and the gasket looks fine. Now my dilemma replace motor, just replace head gasket and put it back together, is it time for a new motor? Pistons look good fouling on number 7 which is what the spark plug told me. Cylinder walls look good hone marks are visible and the motor looks like a recent or semi recent build in the last 5 or ten thousand miles. I can not see anything obvious and everything looks good otherwise... Is it time for a new motor?


PS No oil in water and no water in oil... Just water dribbling out the exhaust at about a quart or two per hour based on spirited driving..

 

You're going to want to examine the cylinder walls closely and check for cracks. Coolant could get sucked in and blown out the exhaust without affecting the oil. Too bad you didn't mention anything sooner. You could have tried running the engine with the radiator cap loosened, which would have lessened the pressure in the water jackets and possibly affected how much or little water might be getting sucked in. Engine looks recently rebuilt, what oversize is stamped on the top of the pistons (030, 040, 060, etc)?

 

I did run it cap off and give or take about the same results... I have investigated it further and been looking closely at the heads and taking a ton of measurements of things. I am the kind of guy that wants to know why something is doing what it is doing. Use to take things apart as a kid all the time.. Did my first motor work back in the 70's and just never lost the knack for it. The heads are aluminum, Procomp, pistons stock 4.0 inch bore and checked the cylinder measurement's. Everything is right at 4.01 to 4.05 inches. The heads however were put on with incorrect sized gaskets from everything I have measured. The heads require a gasket of 4.150 to 4.185, .030 crush depth. I think as it appears the gasket rings actually sat right on the edge of the head and although fit the cylinder are to small for the heads. This would account for tiny amounts of water to slip in to the cylinder and would blow out the exhaust and not getting below the pistons to mix in the oil. Its all I can figure out so far and did not seal properly on number 7 cylinder. probably not a good seal anywhere but failed at number 7. So I have another engine on its way and I am going to rebuild this one with the proper gaskets..

 

Head gasket shown is correct size, but, may not be the correct material for alum.
Cleanest cylinder is the leaky cylinder.
Be sure to have heads pressure tested - could have an internal leak.