Oil pump exploded view

[Ben Bruce aka First Born]

A thought has been in my head for awhile. Need to get it out to reduce the overcroweded condition.

We often get a question about oil pressure/oil pumps relating to our Straight Eight engines. We get various answers. One that comes up is "is there a gasket for the bottom plate" to the oil pump? So can anyone with a parts book or whatever it is called post an exploded view of same?? Should put that question to rest.

Thanks

Ben

[NTX5467]

(Trying to "reason" this out . . .)

Once, a Holley Carb engineer stated that "Gaskets are there to make up for sloppy machine work" at a carburetor seminar I attended. In a way, that makes sense. BUT I also know that surfaces can become "un-flat" with time and heat cycles even if they were perfectly flat when they were first machined.

If you look at the later-1950s Chevy parts books (original printings rather than the later editions!), there were exhaust manifold gaskets as many of the "head set" or "engine rebuild gasket kits" have in them, yet by the middle 1960s, there were NO such gaskets on production vehicles . . . Chevrolet or otherwise, generally.

In the case of an exhaust manifold to cylinder head gasket, they might have initially perceived to be necessary due to the heat expansion issues of those two bolted-together parts. Letting the manifold "slide" a little as it expanded sooner than the cylinder head did from "non-running" to "fully operational" engine heat levels. It might well be that when Chevrolet started to use "heat washers" under the exhaust manifold bolt heads, plus the "locks" on the bolt heads, they didn't need the prior exhasut manifold gaskets? Plus, from what I'd seen (at that time) of those exhaust manifold gaskets, they would not have lasted very long in some vehicles!

But if an exhaust manifold bolt gets 1/4 turn loose and a "sound" resuts, it's not big deal, if there wasn't a gasket. If there had been, the gasket would have been "blown out" (as the less expensive header gaskets were known to do!) and needed replacement. But in the case of an oil pump, I'd "vote" for the need of a thinner paper gasket between the end plate and the main housing . . . with proper torque sequence of the bolts.

Respectfully, I don't think it would really matter if it was a Buick DynaFlash 8 or any other engine, for that matter. I'd personally like to see a gasket there, for good measure, at least. And, I'll readily admit I've never seen a DynaFlash 8 oil pump . . . just going off of "gut suspicions".

Just some thoughts,

NTX5467

[Aaron65]

Running the gasket lowered my hot oil pressure significantly. I removed it and oil pressure returned to an acceptable level. I think the gasket might be there to add clearance if need be. I don't have numbers, as I was using the dash gauge, but I do know that with the gasket in there, I was down to 7 psi on my mechanical gauge at hot idle (and not summer freeway hot either, just normal 20-30 minutes or so running hot). At a 35 MPH cruise, my dash gauge was 1/3 to 1/2 way in the normal band. Now, without the gasket, it's near the top of the band. The shop manual gives a clearance range for the end plate to gears...and it turns out that's pretty crucial.

Edited June 11, 2013 by Aaron65 (see edit history)

[Ben Bruce aka First Born]

It would be crucial!

Clearance is supposed to be .004, I believe. The gaskets that come with the sets are WAY thicker than this. The more clearance, the less pressure. That is why I was asking if someone had an exploded view. It should show gasket or no.

Ben

[1953mack]

....."is there a gasket for the bottom plate" to the oil pump? So can anyone with a parts book or whatever it is called post an exploded view of same?? Should put that question to rest.....

No gasket shown.

The only mention of any gasket relating to the oil pump assembly in a Buick Shop Manual is....."attach pump assembly to crankcase, using the proper gasket which is of thin fiber. Tighten the two attaching screws evenly....."

Al Malachowski

BCA #8965

"500 Miles West of Flint"

[1939_Buick]

Try this page 75A from 1928-52 parts books (but may not upload)

Edit: beaten by post above by less than 1 minute

1928-52 Master Parts Book pg 75-A.pdf

[Guest shadetree77]

Hmmm...I'm pretty sure I put a gasket in there. It just so happens that my oil pan is off right now allowing easy access to the oil pump. I did notice a significant drop in hot idle pressure after I re-built that pump. Only at an idle though. It seemed to be fine going down the road. Pressure is supposed to drop at idle though. Wonder if I should remove that gasket? Thoughts?

1939_buick, you wouldn't happen to have that entire parts manual scanned would you????

[1939_Buick]

1939_buick, you wouldn't happen to have that entire parts manual scanned would you????

No. Have scanned the approx 50 page's with images and a few other odd pages of part numbers.

These are often on ebay and available from other resellers: well worth buying

Also the 1942 shop manual is very good

Edited June 11, 2013 by 1939_buick (see edit history)

[Aaron65]

Hmmm...I'm pretty sure I put a gasket in there. It just so happens that my oil pan is off right now allowing easy access to the oil pump. I did notice a significant drop in hot idle pressure after I re-built that pump. Only at an idle though. It seemed to be fine going down the road. Pressure is supposed to drop at idle though. Wonder if I should remove that gasket? Thoughts?

Remove it...after a long drive on a hot day, you'll have almost no idle oil pressure.

[Ben Bruce aka First Born]

No gasket shown.

The only mention of any gasket relating to the oil pump assembly in a Buick Shop Manual is....."attach pump assembly to crankcase, using the proper gasket which is of thin fiber. Tighten the two attaching screws evenly....."

[ATTACH=CONFIG]197353[/ATTACH]

Al Malachowski

BCA #8965

"500 Miles West of Flint"

Thanks, Al

That answered my question. Is as I thought. Now, if I could only remember!!!

Ben

[Barney Eaton]

If the pump turns freely without a gasket do not use a gasket. If it binds or will not turn (with cover installed) something is wrong.

Here are a couple of videos that help explain oil pumps for the rookies.

different type of pump but he shows how to check end clearance. Edited June 12, 2013 by Barney Eaton (see edit history)

[FLYER15015]

Thanks, Al

That answered my question. Is as I thought. Now, if I could only remember!!!

Ben

Ben,

I print out a lot of these pictures and staple them to the shop wall.

Spend a lot of time looking for the picture that shows to what i'm trying to do.

Get led off in another direction looking at all the pictures and forget what I started on.

But it keeps me busy................

Mike in Colorado

[Guest Rob McDonald]

beaten by post above by less than 1 minute

But, hey, yours shows up bigger on screen, which helps the old eyes. What a wonderful place this is, where an arcane question about a 60 year-old car is answered within minutes, with pictures!