Re: 1940 356 engine problem

Posted by Bill Butterworth On 2013/2/2 21:53:28

OK, this is where we're at now. First of all, made a mistake in previous post, compressed air test showed possible leaking exhaust valve not intake valve. This turns out to be the case. Removed head and found mark on underside of head at the #6 exhaust valve location and #6 exhaust valve is bent! Bend, however, is towards opposite side of valve as mark on head so I assume valves like lifters rotate during normal running conditions? This is hard to believe as after many repeated measurements with a caliper I see a clearance of 0.005" plus the thickness of the head gasket. Measured the maximum open measurement of an exhaust valve face to the block face (.250") and the depth of the head combustion chamber casting from head face at the location of the exhaust valve at 0.30" plus approximately 0.004 or so of a compressed head gasket. Have no problem buying a new head but the thought that crosses my mine is there any way a hydraulic lifter can push valve higher under actual running oil pressure compared to oil pressure during testing? (Unable to load pictures of valve and head, message comes up that file size is too big.)