VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Engine rebuild gone bad

I reassembled my 1926 engine and the first “running” (if you can call it that) went miserable. Sparing a long-winded description of the activities, I had the head rebuilt, new valves, valve guides; ground the head flat, new springs. I also rebuilt the carb and dialed-in the timing. I squirted each cylinder with a healthy dose of oil (perhaps my biggest mistake). Lastly, I honed the cylinders with a bead honer, removing the glaze. The engine started with great difficulty, and upon extremely hard, and upon starting it spewed a white and blue smoke. Upon examining the plugs, they were wet with oil, gas water mixture. Upon draining the oil, it was a foamy white, smelling of coolant. By guess: I blew a head gasket when I put oil in the cylinders, creating an over pressure situation. However, I am concerned that something else could be going on. Any suggestions?

Hi 3rd owner.

Just a few questions.

Did you use a new head gasket and apply a coating?

I assume you torqued the head according to the specs?

How much oil did you put in the bores?

I agree it does not sound too good, but I would do a compression test first up.

If its not a head gasket, it could be either a broken piston ring or a massive crack somewhere, which I would doubt.

Good luck

Let us know how you get on.

Cheers

Ray

Ray,

I used a new gasket and I torqued the bolts, inside-out, in small increments, 60-65 ft-lbs. I used a copper coating, applied thin, just to keep gasket in place. I put about a half-shot ( 1 oz) of oil in each cylinder. I am going to pull the head and replace the gasket. The head was purchased on eBay, and looked good upon receipt. I fear a cracked head, but I do believe it's the head gasket. Do you think a compression check will reveal anything?

Dave

If you have a failed head gasket, a compression test will highlight which cylinder is the culprit.

Cheers

Ray

I will check and report back.

Dave

Hi,
Fair chance it is a cracked head.Been there and done that and I wish you well in finding a good head.

They normally crack inside the exhaust port and the cracks are not real visable.They also crack externally in the middle of the head.
Very hard to repair as the carbon is burnt out of the cast iron and they crack where you can not see or weld.

Cracked head is not what I wanted to hear, as the head I replaced was cracked. However, it is off and tI will have it magna-fluxed.

You need to pressure check the head. Magnaflux will only find the cracks that are visible not the ones in the runners or passages.

Is a pressure check a common service or do I have to improvise?

Dave

I have plugged all of the ports with an expanding rubber plugs and will devise a method of plumbing my air compressor to the gooseneck. I will place the head in a tub of water and pressurize. Bubbles will reveal any cracks.

That should work. I use rubber stoppers and/or a plate or flat surface, "C" clamps and rubber pad to seal the block side of the head. Depends on what year head which of them I use. Have made up a "T" with radiator outlet hose, pressure gauge and valve with adapter to my air hose. I have found that with 10-15 psig I can hear the leaks. Have never immersed the head in water but have used soapy water to squirt into passages if I have a suspicion of small leak or to verify the location when I hear one.

To all: yup, head was cracked, inside, multiple places. I going to hav the previous head stitched at the small crack above the exhaust manifold, it never leaked. Live and learn. Thanks to all, I really appreciate this chat board.

Sorry to hear that,

But at least now you know.

Cheers

Ray

If its any consolation, I had a crack on the face of the head, middle water jacket, about 3/4 inch long. drilled and plugged it myself. 39 years later no problems.

Thats too bad. I think I am going to be dealing with the same problem with my 26'.