Re: 1940 Custom Oil Canister and Low Compression

Posted by HH56 On 2014/10/26 14:04:57

You don't need a restriction if you only have a direct line to the lifters. The restriction was placed in the line going to the filter in those situations where you have both a direct line and a filter that dumps into the crankcase. After the plumbing change was made to add the direct line and have the filter return to the crankcase, it was found too much oil was going to the filter and still not enough to the lifters. The restriction was to limit what could go to the filter. The pigtail line to the lifters was wide open.

There is one other situation I remember reading of that might be worth looking into. There was what Packard called a jiggle pin on some engines that could loosen and fall out resulting in low oil volume to lifters. Can't remember the details or years. The site is moving so slowly for me right now it will take some time to find the article to remember if 40 might be one of the years.

EDIT: Found the article and 40 is one of the years with the pin. Since I believe you said your problem started somewhat abruptly, might be worthwhile to download and check out the article on low oil pressure. It starts on the third page.https://www.packardinfo.com/xoops/html/downloads/SC/SC-VOL20NO1.pdf