The Ford Barn - View Single Post - No. 7 Cyl never gives evidence of a power stroke on '46 Flathead

ronchamblin · 07-24-2017, 08:54 PM

Well .... first, thanks for all the input from you Ford persons. I have to say that all that troubleshooting was done under the assumption that the engine rebuilder assigned someone experienced with old flatheads to rebuild my '46 flathead, which is in an otherwise original '34 Ford 4-door sedan.

All the testing, as describe above, caused me to finally remove the intake manifold to check the valve adjustments. I discovered that the No. 7 cylinder exhaust valve never closed, as it had a zero clearance. Therefore, during the intake stroke, the air into the cylinder came from the exhaust manifold instead of from the intake manifold. That explains why I never had a wet plug. The valves should be .014" and .016". I discovered several at .065", and at least one had no clearance at all. Apparently this fellow had no clue about these lifters, which have to be adjusted via the cap screw in the top.

Upon informing the rebuilder of my discovery, he said that "People make mistakes". I suggested to him that in the future, if he is not sure of a workers abilities, he should at least check the work to ensure perfection. I took me about four hours to set the valves properly. The engine runs good now.

Again, thanks to all you fellows for the great input on the problem. One assumes rebuilders know about proper valve adjusting.

07-24-2017, 08:54 PM	#64
ronchamblin Junior Member Join Date: Aug 2013 Location: Jacksonville, Florida Posts: 13	Re: No. 7 Cyl never gives evidence of a power stroke on '46 Flathead Well .... first, thanks for all the input from you Ford persons. I have to say that all that troubleshooting was done under the assumption that the engine rebuilder assigned someone experienced with old flatheads to rebuild my '46 flathead, which is in an otherwise original '34 Ford 4-door sedan. All the testing, as describe above, caused me to finally remove the intake manifold to check the valve adjustments. I discovered that the No. 7 cylinder exhaust valve never closed, as it had a zero clearance. Therefore, during the intake stroke, the air into the cylinder came from the exhaust manifold instead of from the intake manifold. That explains why I never had a wet plug. The valves should be .014" and .016". I discovered several at .065", and at least one had no clearance at all. Apparently this fellow had no clue about these lifters, which have to be adjusted via the cap screw in the top. Upon informing the rebuilder of my discovery, he said that "People make mistakes". I suggested to him that in the future, if he is not sure of a workers abilities, he should at least check the work to ensure perfection. I took me about four hours to set the valves properly. The engine runs good now. Again, thanks to all you fellows for the great input on the problem. One assumes rebuilders know about proper valve adjusting.