"Re: '36 Chevy PCV [Re: yar] #125760106/03/18 05:36 AM
P
Pre '68 Dave Offline
Shop Shark Joined: Jan 2001
Posts: 4,884
Snohomish,WA,USA
Here are a couple pictures of 235's I did."
Dave,
Thank you so much for that information. I duplicated your efforts although my project is a 1936 Chevy 207 engine. After installing the PCV valve to a modified draft/oil fill tube and connecting the PCV valve to manifold vacuum using the 1/8" female pipe threads in the manifold for the windshield wiper vacuum source I discovered that no vacuum was developed i the crankcase. To find the vacuum leak I applied about 5 psi pressure from my air compressor into the oil dip stick hole in the block and traced the sound of leaking air to the back of the engine, between the engine and flywheel. Because the engine is in the '36 pickup there is no direct view of that area so spraying a soapy liquid in there would make bubbles but their exact location would not be visible.
Because Chevy did not use a rear main seal until about 1940 the massive air leak is probably along the crankshaft - rear main bearing interface. Have you encountered that problem in the PCV conversions you've done on early Chevy engines?
It looks like the next step will be dropping the pan and hoping that when Egge Machine redid the main bearings they used shims under the caps to allow adjustment of the bearing clearances.
What do you think?
Thanks so much for your input.
