# PJ's oil pan tech



## 1968gto421 (Mar 28, 2014)

Reading Jim's oil pan tech (all 3) got me wondering about how much oil IS left in the bottom of the pan for the oil pump to access when the engine is "at speed".









Pontiac Oil Pan Tech - Fill Levels


The question of oil and filter capacity has been asked a couple times here in clarifying the correct amount. The confusing part is that some will say 5 quarts in the pan plus 1 for the filter making it a 6 quart system. BUT, another person may say that the correct amount is 6 quarts in the pan...




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After viewing Jim's extended sump story-









Pontiac Oil Pan - Making It Deeper


Not for the faint of heart! LOL I wanted to extend my factory oil pan, much like was done before extended/extra volume Pontiac oil pans were as available as they are today. I could have purchased one myself, but I like to fabricated and thought I would give it a try. Never again. LOL Was a...




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I got to wondring since Jim fabricates, he could build an engine test stand, put a Pontiac engine on it and modify the oil pan with plexiglass (or similar) sides and bottom for the sump part, run the engine and let us all know how much is actually left in the bottom for the oil pump. Yes, there would be oil spatter on the plexiglass but I believe he could determine what is left in the bottom. I'd do it but I cannot fabricate (no skills and arthritis in fingers). I believe Jim is fully capable of this project and could publish it if he wished.

Here's a fabricated test stand as an example: Thanks JIm!


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## 1968gto421 (Mar 28, 2014)

Forgot to mention, great oil pan arcles, JIM. Very well done. Thank you for all your work.


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## PontiacJim (Dec 29, 2012)

1968gto421 said:


> Reading Jim's oil pan tech (all 3) got me wondering about how much oil IS left in the bottom of the pan for the oil pump to access when the engine is "at speed".
> 
> 
> 
> ...


We are on the same page.  However, it'll be some time before I am ready to install my engine. I thought it would be cool to do as you say and put a sight glass on the side of the oil sump. But I would have to weld in additional fittings and when done with the testing, plug the fittings up as I would not feel comfortable with a glass sigh glass on the car. At work, when I move trailers around, we have a "yard switcher" that has an hydraulic system that raises & lowers the trailers so you don't have to manually do this each and every time. The hydraulic fluid is held in a square tank on the side of the switcher. It has a graduated sight glass that tells me the level of the hydraulic fluid that is in the system should I need to add some. Don't think my wheels were not turning looking at that sight glass everyday! LOL

That said, what I am going to do when I get a little free time is to take a Pontiac head I have, install a valve cover & gasket, then level the head off from front to back, and then tilt the head at the same angle it would be as if mounted on the engine.

Then I will use some colored water and with a graduated CC container I use, slowly pour the water in through the hole at the top of the valve cover until it leaks out. This will at least give me an idea of how much oil remains up in the head, then X 2 for two heads. Then I was thinking of measuring the 1/2" oil galley holes in length to calculate how many CC's each galley would hold. Then you have that area right after the oil filter adapter which has a little volume and I will try to measure that in CC's.

Keep in mind that once you fire up the engine, oil for the most part will remain in the pushrods and lifters so I am discounting those. You will have a little in the lifter valley area, but again, the amount will stay there even after shutting down the engine and you check the oil level. The valley area has drain holes at the ends, so the amount that would be captured in a running engine should not be much as it will run out fairly quickly. I enclosed a photo of my 455 block I prepped before taking to the machine shop just so you can see it in the left side back towards the distributor and there is one up front on the right side. That drain hole oils the distributor/cam gear.

Now I don't have the skills to begin to compute how much oil an oil pump will move oil through "X" number of passages at "X" RPM's. Another consideration would of course be bearing clearances, oil in suspension due to crank windage, flat tappet lifters - hydraulic/solid & bleed down rates, roller lifters, stamped steel rockers vs roller rockers, etc.. So there is obviously a number of variables at play that would only be answered if a site glass were used and RPM's recorded.

So my goal with my measurement will be to get an idea of what I believe is the amount of oil left in the top end and the main oil supply passages and then add a small amount to that number. Although not scientific as some might be able to do, it'll be interesting to have a general idea of how much oil, normal pan fill level at rest, and the amount of oil that will be used in the upper end. Then subtract that from the normal quart pan fill and it should provide a reasonable answer, ie 5 quarts - 1/2 quart leaves 4 1/2 in the pan once the engine is running, which may indicate a little overfill is OK as long as your crank throws aren't dipping into the oil or whipping it up and my oil pan oil levels show these levels. If the oil is somewhat over-filled on purpose in a stock pan, then that is indeed where I will recommend an windage tray and an oil pan with the oil baffle - either stock aftermarket, or add your own sheet metal baffle like factory with the dimensions I provided.

You may be thinking that the more RPM's you spin the engine, the more oil gets pushed to the upper end and may hang in there due to that area getting flooded faster than drain back. The oil pump will only put out some much as this is the purpose of the check valve otherwise oil pressure, and I suspect oil volume, would continue to increase as RPM's increase and you might find the oil fitler blowing apart or seals blowing out, and the pan running dry if the fill was allowed to get too low. I suppose another variable would be oil weight that was used. 10W-30 vs 20W-50 in my mind means the heavier oil would be slower to return, but this may not be as true with synthetic oils. Back in my time the big thing was to coat the inside of the block with glyptal red or rustoleum to cause the oil to return faster. But you seldom hear or see of this anymore. Here is a neat YouTube video test using glyptal red, and then different automotive chemicals on it to see how it reacts. Keep in mind that todays oils are reformulated and may have different chemical make-ups, so I would hate to see a chunk or sheet of it flake off and crap up mu oil pick-up screen. OK for racing where you tear your engine down regularly for inspection, but not what we do with a street engine.


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## 1968gto421 (Mar 28, 2014)

Thanks Jim, your thoughts are good and informative. I was curious about this after reading your oil fill levels tech. Made me think about my brother who occasionally takes his 454 '66 Chevelle down to Atlanta Dragway (Commerce, GA) and runs the grudge races for kicks ($). When he gets to Commerce he always adds a qt of oil to his engine worrying it will all hang up on the heads and lifter valley and his oil pump will suck air. He has a high volume pump and uses 20W50 so I guess his worry is justified to some extent. Next day he changes oil and cuts open his oil filter and refills with normal quanity of oil. As you know our Pontiacs have an "open" lifter valley while Chevs have a "closed" lifter valley so I reckon oil could hold up there on a BBC while draining back. I look forward to your cylinder head oil volume test to give some factual inffo on this. After reading your sump build article, I think I'll take Cliff Ruggles' advice and and get a Canton pan like his (go ahead call me chicken  ).


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## PontiacJim (Dec 29, 2012)

Your brother is probably wise in adding the extra quart for racing. Canton has some good pans and in different shapes - more volume and/or deeper. Just get the correct pan to match the stock pickup tube/screen or a matching extended one for a deeper pan. They will also have oil baffling which in my opinion is what is really needed above all.

I did the oil level demonstration just to see exactly what the oil levels were in both sump depth and from the crankshaft. I get irritated when people throw out info that is not backed up by facts or something tangible that others can see. So that is why I did it and then followed up with my extended sump oil fill levels. I too here all the info on how much oil is held up in the upper end, like its a quart, its a quart & half, it depends on the heads, it depends on the engine, etc.. Nothing really solid there. So I figured I would at least try to come up with some kind of fact based answer with regrads to the factory iron head even if it is not 100% accurate and only 80% accurate - at least there is a base to which can be used and known. Should be interesting to know what that is.

I liked the Canton pans, but it means more $money that I could save by first trying to extend my own pan - old school style. Was a lot of work and time involved and not for everyone. The pan is quite heavy with the extension. Purchasing an oil pan ready to bolt on is the way to go for 99% of the builds. I just had to be different! LOL


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