Oil pump shaft radial play

Buick oil pumps are done by feel imo,...never once have I measured anything on one,..eye ball the gear stick out,..shim it till it has a nice mild drag on it when torqued,....then continue with life

 

Alluminum grows like crazy. I would bring the cover up to the operating temp and remeasure. You might just get the squeeze you're looking for..

 

Exactly one reason why measuring is pointless,...it grows ,...the gears never sit parallel to the cover,. etc etc,...I do use the thrust plate always,..as it acts as a girdle in my mind to help with expansion and just simply from experience

 

Sure, but it sounds like you are referring to the shaft axial play, the "up-and-down" movement. I am concerned with the shaft radial play, the shaft "side-to-side" movement.

 

If it spins smooth it's fine,..if you can move it laterally,..it's garbage,..the one pictured is mostly certainly garbage,...one would have better luck honing the cover and sleeving the shaft imo,..but that's a waste of time still imo

 

I've had a couple that were tight to the cover,....sand paper with the gear chucked in a drill fixed that

 

Why not contact the folks who made the cover you're measuring?

Neither TA nor Melling have any input on the manufacture of the Proform cover.

 

Why did not I think about that.... Question sent to them as well.

 

...and they still haven't replied. I just called ProForm and they did not know what this clearance should be. However, they told me that Finish Line Motorsports is the supplier and designer of this ProForm cover and they should know. No one at the Finish Line phone support today knew, but apparently a guy named Bob who was out of office today should know. Let's see if they will reply to an e-mail I sent.
https://www.finishlinemotorsports.com/

 

Now the engine is back together again!

As for the tolerable radial shaft play, I don't have any final answer there yet. I spoke with someone who builds Buick race engines and they said that 0.004" (0.1 m.m) of radial oil pump shaft play would be too much for a race engine but for a stock street application that should be no problem at all. I measured the actual bore on the old cover using telescopic gauges and a micrometer. Although it felt quiet loose, most of the bore wasn't more than 0.0031" (0.08 m.m.) larger than the shaft. As it is worn to an hourglass shape it was a bit larger right at the start of the bore. The brand new Proform 69510 cover definitely felt tighter but not rock steady and it measured 0.002"(0.05 m.m.) of radial shaft clearance. So in the future I will not estimate shaft clearance using an indicator dial if I don't have too, the estimate seems to easily become very exaggerated as people in this thread pointed out. This new information put me on the verge to actually install the old cover, but the new cover felt so nice in every respect and I already had it home so it went on. As far as I can tell the Proform cover is a precision and quality product.

The front cover seal was easy to start to seat using an hydraulic press. The tool I had on was too small so I used a piece of plywood. As I had no support under the slanted front part of the cover it started to tilt after a while. As it had already gotten a good start I could quiet easily finish the job with a wooden mallet though.


Like many others, I choose to go with the Melling booster plate. They cheaped out on this and made it out of machined cast iron. I choose to remove some scaling/burs with a file to be 100% sure the gears would spin freely.



Something really nice with the booster plate is that you get a way to actually measure the final axial play. A drawback is that I had to compress the gasket before final mounting. I could get a 0.05m.m. (0.002") feeler gauge in a bit.


To try and get a more complete picture I also tried to estimate the axial play using a dial indicator. I held the cover as steadily as I could and tried to move the shaft axially as straight was possible. The tip of the indicator was as close to the center of the gear as possible in order to reduce the effect of the gear tilting.


Both measurement methods have their inaccuracies but I think I landed at around 0.04 m.m. (0.0016") of axial play. By having the information from this thread, I felt confident this should be fine: https://www.v8buick.com/index.php?threads/oil-pump-clearances-and-oil-pressure.326597/

I packed the pump with vaseline to be 100% sure it would prime. Then I primed it using a re-ground old screwdriver and an electric drill according to tips here on the forum. I was a bit uncomfortable doing this, the pump was a bit hard to spin at first with vaseline in it. It primed up after just a few revolutions though. After this I could prime it again to above 2 bars (30 psi) easily using just a screwdriver by hand It also held pressure for quiet some time. The new distributor was a bit hard to get in first time. I took it out, removed the gear and gave the shaft ends 2-3 strokes on each side with a file. I don't know if this was the issue, but after this it went in.

I had a mechanical pressure gauge hooked up and at first startup cold idle oil pressure was 3-4 bars (45-60 psi). After a while it dropped to maybe 2 bars (30 psi). It was a temporary install with a rubber hose so removed before it got actually hot. Wasn't really worried anymore pressure would be too low I have an electric oil pressure sensor mounted, and some time ahead I will put in the gauge to do some long term monitoring.


I happen to have a high volume oil pump, Melling K-20J. I know it is recommended against by many, but it was the only one I could find around here. It didn't say online it was high volume when I ordered it but I found out after when I already had it opened at home.

I did paint the oil pump adapter read before it went back on.

 

Just don't rev when cold or run thicker than 10w-30 oil with the HV pump and you will be OK.