[Tom Vaught]

1) You can take a spring and cap from any normal Pontiac Oil Pump and swap the parts with the 80 psi spring cup and spring. I used to buy the 80 psi spring cup and spring from Melling for about $4.00 and convert the stock 60 psi pumps to 80 psi pumps.
So going the other way, if you have your old pump laying around should work unless the pump had 150,000 miles on it.

2) Pure street vehicle I would run the 60 psi pump parts too.

3) The hardened Driveshaft is a good idea if you run the 80 psi pump but I have never seen a stock 60 psi driveshaft fail in normal usage. Not Racing stuff with thick oil.
Maybe if you got a chunk of material inside the gears of the pump from a crappy oil pick-up design.

4) I would run the later oil pan with the baffle welded in the pan. Helps on right hand turns off freeway ramps.

Tom V.

[Steve C.]

Concerning the parasitic loss from a 80 lb pump. This from Jim Butler on the subject....

"We've never seen a noticeable performance loss from the added load," says Butler. "Racers will sometimes run a 60-psi pump to reduce parasitic drag and free up a few horsepower. While that's acceptable in a dedicated race engine that's frequently torn down, it's certainly not something we recommend for all engines."

Curious, anyone have testing data with the difference in power/torque loss on a engine between the two pumps ?

https://www.hotrod.com/articles/hppp...-observations/


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[SusieQ]

Good stuff guys.

I like the idea of switching the spring to convert it to a 60psi. That's a big help if I decide to go the 60psi route. I was thinking I had to buy an entire new pump.

I'll look into the cost of the spring and then make a decision on what I'm going to do.

The collective wisdom is that the 80psi isn't necessary, and would "probably" be fine, or "shouldn't" cause any problems. I'm not a big fan of doing things that have disclaimers such as "probably and "shouldn't," especially when there's no clear advantage, so I'm leaning towards changing that spring.

An added advantage going with the 60psi is I don't really need to spend money on a hardened driveshaft.

Thanks again guys!

[Jay S]

The first time I ever tried an 80 psi pump the new engine started and ran then quit. Pulled the distributer cap off and the rotor wasn’t turning. Pulled it out found nothing wrong. Pulled a valve cover off and the valves were not moving. Found that the key on the cam sheared. Replaced the key and it start up an ran, when we rev’d it up the cam key sheared again. Grrrrr...20 some years later I can smile about it. We weren’t back then. We pulled the engine and put in a 60 psi spring and never had any trouble after that. Not saying it will happen to you. But Pontiac didn’t exactly overbuild the cam gear or the cam drive.

[Mister Pontiac]

One last idea I haven't seen mentioned yet is simply wrapping safety wire around the pickup tube, and tying it off tight to the body of the pump. In my old aircraft mechanic days, we used safety wire on everything. I saw the opportunity with the Pontiac oil pump pickup years ago, and have done it a few times since with no issues.

Wrap the wire tight around the outlet tube right next to where it presses into the pump body, pull it taught around the body of the pump a couple turns, and then twist the safety wire tight. Even though the wire may have a little 'give' over time, it won't give enough to allow the pickup to come out of the pump. Haven't seen this method fail yet, and requires minimal effort and zero cost for the piece of mind. Probably the simplest 'fix' I've seen too.

In lieu of welding or drilling/tapping/screw install, just another idea that has been successful for me.

Hope that helps.

[Steve C.]

Seek data on HP loss with a Pontiac 80 lb pump vs a 60 lb pump, I suggest hard if not impossible to find. If you find documented information post it. I have a inquiry in to a oil pump engineer very familiar with Pontiac oil pumps, if I get a response I'll pass it on for interest.

In the meantime, for interest.... a Chevy big-block’s oil pump can draw well over 10 hp at 7,000 crankshaft rpm. Use a grade or so thicker in viscosity and that can go up another 5 hp. On the other hand, pay attention to the system’s efficiency and you can divert as much as 10 hp from what the oil pump absorbs and put that to good use at the rear wheels of your vehicle. That from a book.

Would one feel 10 hp in the seat of your pants on the street with your 7000 rpm Pontiac engine..

Side note, my talking points here within this thread were not to suggest the OP should use or require a 80 lb oil pump, period. For the most part it is just to elaborate that using one in some situations will not harm a Pontiac !
Nor is it a evil as some suggest

Onward thru the fog.................


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[SusieQ]

grivera...it's all good. I'm open to different opinions so I appreciate the input. I'm just letting you know the direction I'm going in. I'm curious to see if there will be any new insights shared regarding the copper gaskets.