Guest rusty1951 Posted November 23, 2008 Share Posted November 23, 2008 Is there a gasket between the oil housing and the cover plate? Mine was missing one and the rebuild kit came with a gasket/ Would removing the gasket increase oil pressure? Link to comment Share on other sites More sharing options...
Aaron65 Posted November 23, 2008 Share Posted November 23, 2008 NO NO NO! It will lower your oil pressure drastically! They didn't come with a gasket and the gasket will take it out of spec...You will be wondering why you are getting only 5-7psi hot idle if you put in the gasket. It took me a lot of thinking and work to figure out, so learn my lesson!!!! DO NOT USE A GASKET!!!!!!!!!! Link to comment Share on other sites More sharing options...
Guest rusty1951 Posted November 23, 2008 Share Posted November 23, 2008 Thanks. I wonder why the kit came with a gasket that fits perfectly. Who knows? Why is there a very small hole (1/16) or so in the pipe between the screen and the oil pump housing? Link to comment Share on other sites More sharing options...
Aaron65 Posted November 24, 2008 Share Posted November 24, 2008 It's for a cotter key to hold the pickup tube in there...don't forget to put one or your pickup will fall out!!! Link to comment Share on other sites More sharing options...
Aaron65 Posted November 24, 2008 Share Posted November 24, 2008 By the way...ckeck the clearance between the pump housing and the gears with a straightedge and some feeler gauges to make sure the clearance is in spec. Maybe they include the gasket in case you need to machine the housing square... Link to comment Share on other sites More sharing options...
Guest rusty1951 Posted November 24, 2008 Share Posted November 24, 2008 Thanks for your help. I had not thought about the gasket to take up clearance if machined. The gasket is pretty thick. Who knows? Link to comment Share on other sites More sharing options...
Aaron65 Posted November 24, 2008 Share Posted November 24, 2008 I determined the gasket to be somewhere between .002 and .003 inches thick...I believe outside range of clearance is .004, so it doesn't take much to see how the gasket could pull the pump out of specs...I used a bit of loctite on the screws to hold the plate on and bolted the pump up... Link to comment Share on other sites More sharing options...
JoelsBuicks Posted December 1, 2008 Share Posted December 1, 2008 The gasket is for the other side of that plate, not the gear side.Joel Link to comment Share on other sites More sharing options...
Guest rusty1951 Posted December 8, 2008 Share Posted December 8, 2008 I installed new gears for the pump and a NOS cover. I tighten it all up and was unable to turn the shaft (the one that connects to the distribitor) without using a large screwdriver and a hell of lot of force. I then installed the gasket that came with the rebuild kit. It turned easy. There is just barely play in the shaft (up/down). Any ideas for here. Link to comment Share on other sites More sharing options...
JoelsBuicks Posted December 10, 2008 Share Posted December 10, 2008 Does the old plate show much wear? I wonder what would happen if you used the new gears and old plate? My oil pump had a gasket between the plate and the pick-up "shroud" but no gasket on the gear side. Perhaps it starts out with a gasket which can later be removed if needed?Joel Link to comment Share on other sites More sharing options...
Guest simplyconnected Posted December 10, 2008 Share Posted December 10, 2008 The gears should rotate easily with NO slop. The pump needs good metal-to-metal fit for the oil to act as a seal, and lubricate the parts. It's hard enough to turn a free pump (picking up oil) with a drill motor.I have never seen a gasket used between the rotors and the plate. (The gasket wouldn't last too long.) This is the area that sees the most oil pressure of the whole system. All parts are precision-ground and bolted securely. Link to comment Share on other sites More sharing options...
Aaron65 Posted December 11, 2008 Share Posted December 11, 2008 There is a gasket that comes in these rebuild kits, and the only place for it to fit is between the plate and the gears. It's very thin, but thick enough to make an oil pressure difference. Like Joel said, I might try the old cover with the new gears...definitely check the clearance between the gears and the pump body with a straightedge and a feeler gauge...we're talking thousandths of an inch here, so feeling movement in the shaft isn't accurate enough...even a loose pump will feel tight when checked in that manner...with that being said, the pump should still turn freely by hand when it's sitting in your hand. Link to comment Share on other sites More sharing options...
Guest simplyconnected Posted December 11, 2008 Share Posted December 11, 2008 What's the confusion? Your main bearings have between a half to one and a half thousandths (.0005-.0015") per inch of crank journal clearance. Certainly, two ground and hardened oil pump surfaces could easily be in that tolerance without gaskets. Why would anyone need a gasket if the oil drips right back in the pan? Link to comment Share on other sites More sharing options...
Aaron65 Posted December 11, 2008 Share Posted December 11, 2008 You don't want any air getting in at the pump body though...there obviously needs to be a good seal there, but like you said earlier, it's a machined surface, so a gasket really isn't needed. Link to comment Share on other sites More sharing options...
Guest rusty1951 Posted December 11, 2008 Share Posted December 11, 2008 I took the pump to the machine shop and the new gears stick out .0015 and the gasket is .007.I took a feeler gauge and between the gears (new and old) was .0015 and .002 was a distint no go.I installed the old plate which has a faint wear pattern and used new gears. I can spin with my hand but is slightly tight but not excessive, is more than just a drag.I think that maybe the way to go is new gears and old plate. Sound reasonable???? Link to comment Share on other sites More sharing options...
Guest simplyconnected Posted December 11, 2008 Share Posted December 11, 2008 Does your machine shop have a surface grinder? They usually do. You can grind the new gears (or old plate) to give .0015" clearance when assembled sith no gasket. That would satisfy everything at once. They shouldn't charge you much to take a thousanth off, and it should only take five minutes to do. A surface grinder is the most precision machine there is. Link to comment Share on other sites More sharing options...
Aaron65 Posted December 12, 2008 Share Posted December 12, 2008 Yep, machining is really the only thing to do...., as .0055" clearance is going to be too much. Link to comment Share on other sites More sharing options...
Guest Hector Posted December 12, 2008 Share Posted December 12, 2008 Just a thought.The manufacturer should have a spec or dimension for the gears end play,for example,on my 350 Buick the end play spec is .002"-.004".When I replaced my gears I stacked two Felpro gaskets to end up with a total of .003" end play.There are also different thicknes shim material that is offered for the 350 and 455 Buick engine,I don't know if there are some out there for the straight eights.I know that the 350 and the S8 are very different animals but the end cap on the oil pump is something that you want to set as per the manufacture's specs for it to work correctly.More than just clearance between the gears and the plate,you want a specific range to shoot for.You may want to post a question at inliners.org I've seen some Buick chatter there in the past.Good luck. Link to comment Share on other sites More sharing options...
Guest rusty1951 Posted December 12, 2008 Share Posted December 12, 2008 I forgot a zero in what I wrote. The distance that the gear stick out is .0005 sorry. Link to comment Share on other sites More sharing options...
Guest simplyconnected Posted December 12, 2008 Share Posted December 12, 2008 It should be recessed by about a thousanth, Rusty. Too tight is worse than too sloppy. Flush is too tight. Link to comment Share on other sites More sharing options...
Guest rusty1951 Posted December 14, 2008 Share Posted December 14, 2008 I want to thank everyone for their help. This is what I am going to do. I installed the old plate with new gears and no gasket. It was tight (sort of) for about 180 degrees of turning. I then placed oil in the pump (tablespoon or so) and then tried. It turns nice and free and does not seem to bind. Much better that before. I can feel no up/down movement with the shaft unlike with the gasket installed. There was a play that could be felt. Once running I will update on my oil pressure. thanks Link to comment Share on other sites More sharing options...
Guest simplyconnected Posted December 14, 2008 Share Posted December 14, 2008 You're doing the right thing by changing gears, Rusty1951.You should see good oil pressure at idle speed, for a very long time. Most restorers take the oil pump for granted, unless a problem appears. This is the heart; all oil gets squeezed through your pump before it gets to the filter. The pickup screen isn't very fine and it passes anything that will fit through. My gears had witness marks of nasty steel pieces that were gobbled-up and spit out. I had no idea until I pulled the gears out and looked. Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted January 1, 2009 Share Posted January 1, 2009 Hi rusty. Havent heard any thing from you for awhile. How is your project progressing? Ben Link to comment Share on other sites More sharing options...
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