53 New Yorker

1940 Buick Special engine oil circulation question

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Posted (edited)

Hello Buick friends,

 I'm wondering if I should see oil squirting out of the ports on the rocker arms when the 1940 straight 8 engine is running, but I have the valve cover off?

I just started the car for the first time in 15 years of sitting...  and I have oil pressure at the filter inlet line and the line leading to the side of the head, but I'm not getting oil squirting out of the valve train.

 I changed the oil, but haven't put a new filter in yet.

Any advice or suggestions would be greatly appreciated.

Cheers

Edited by 53 New Yorker
another thought (see edit history)

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I've also read in the shop manual a note about a small open ended screen where the oil lint to the rocker assembly arm is attached to the cylinder head.  it says this screen can be removed by using a wood screw as a "puller" device. 

 Is it wise to remove this screen?  Where would I get a replacement?

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Posted (edited)

Most of us pull that little filter at the front of the head, where the oil line goes in and never look back !!!

The line comes from the bypass oil filter anyway so it is "clean" oil.

 

Mike in Colorado

Edited by FLYER15015 (see edit history)

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Hello the fitting in the head has a very small hole to help restrict oil flow,might want to remove and clean out it and line , that old oil gets really gummy ,if you really feel adventurous,you may also want to drop the oil pan to clean it and oil pump pick up screen, probably be amazed of all the sludge in it. I had a 41 Packard that the oil screen was so plugged that it collapsed luckily it could still pull oil .hope this helps.Gary

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Still NO oil squirting out of the little holes on the top of the rocker arms!

Someone beat me to taking out the little screen in the front of the head...  but I did have to clean a little gunk out of the passage.

 The restricter is clear... and I have really good oil pressure up in that fitting to the cam.  Plenty of oil flowing down the valve lifter rods, but no oil spurting out of the ports on the top of the rockers....

 

 Anyone have any idea what could be the problem?  Am I thinking way too much into this...?  I would think the oil that is supposed to squirt out of the top of the rocker arms is what should bounce of the inside of the valve cover, and fall on the valve springs/stems and lubricate them... yes?

 

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It does not squirt out. More like bubble out, so the valves are not overloaded. There are no valve stem seals.  If there is oil to the pushrods, I think enough oil is getting into the rocker arm.  Try cleaning the hole on top of the arm, using a piece of wire.

 

  Ben

 

 

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Hello again,the oil to the rocker arms just sort of flows out around the the arm and push rods it’s not a high pressure flow .As the rocker shaft carries the oil through to the arms with holes in line with them, as long as there is a flow of oil to all of the arms and getting supplied may be ok.

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Exactly as Ben Bruce said posting at about same time.

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Thanks Guys...

 Ben, I'll try the wire trick...   I saw a video post of a fellow who was starting up his 1940 for the first time, and the oil was pulsing out of those hole... this is why I thought my engine should be doing the same thing, and it isn't.

 I will have to follow up on this later... as I've just taken the fuel pump off for rebuilding...  I do not want to run the engine with the fuel pump missing.

 BTW... where can I find the modern replacement number for a new oil filter?

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I have used the wire trick and I have also used an old fashioned air pump (football needle valve type) and blown back ward from the head through that oil line. Most of these cars did not use detergent oils years ago and that line gets gummed up.

 

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Depends on the RPM. At low idle of 600 there should be flow but no squirt. People typically adjust the valves at 600 RMP. At 1200 RPM there should be squirting. At 2000 RPM there should be a real mess.

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I did a partial rebuild on my engine some years ago.  Cleaned and re-used the existing rocker arm shafts and rockers.  With this configuration, the oil squirted out at idle.  Pretty messy during a valve adjustment!

 

When I re-did the engine using a much nicer shaft and much better rockers, the oil just barely flows out of the rockers.  I decided this was as it should be.  Why?  Because the oil has to flow around a portion of the annulus of the shaft OD and rocker ID before it gets to the outlet port.  On my worn shaft, the wear was so bad that the rocker could wobble a bit on the shaft.  With my newer parts, the fit is quite close - I can see how the flow is supposed to be minimal.

 

Jeff

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