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Discussion Starter · #1 ·
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 and 1 for the filter making it a 7 quart system - and they would be right based on the year of their GTO and/or the dipstick pulled from their engine. This conflicting info deals with the 1965-67 model years.

With the introduction of the 400CI, all Pontiacs seem to use 5 quarts in the pan and 1 quart for the filter. I have not compared the 389 to 400 heads with regards to oil return holes/passages which may have been redesigned when the new 400CI engines/heads came out, and thus the fix for the extra oil that was being held up in the top end of the engine.

A service bulletin was issued by Pontiac in 1966. It clearly states that the oil capacity is 6 quarts in the pan and 1 quart in the filter. GTO owners will tell you that their dipstick clearly says 6 Quarts at the fill line. Yet when a 5-quart dipstick is set side-by-side with a 6-quart marked dipstick, they are identical in length. There is no difference in the pan, they are all seemingly the same. Hmmm, so what gives?
I believe it was a PY forum member who stated that he had talked with Milt Schronack of Royal Pontiac fame and Milt said that Pontiac was replacing a lot of 1965 GTO engines under warranty and it was found that the engines were being burnt up due to lack of oil. The owners were pushing the engines hard and at the upper RPM's much of the oil was being pumped up to the top end and not leaving enough in th pan to oil the bottom end - especially if the oil level fill level had been allowed to get low. So Pontiac issued a service bulletin to fill all engines with 6 quarts plus 1 quart for the filter. They also used a dipstick having the 6-quart fill mark. This extra quart helped keep enough oil in the pan and prevent the engine from running out of oil and burning up.

So this bulletin and change was for 1966, but owners of 1965 and 1967 GTO's have also found the 6-Qt stamped dipstick. It is quite possible that when the car was brought to a dealership to be serviced and the oil/filter changed, the 5-Qt dipstick was replaced with the 6 Qt stamped dipstick so as to protect Pontiac from having to cover warranty engine work.

So it boils down to that Pontiac used a 5 quart pan and a 1 quart filter for 6 quarts, but increased the pan fill on their earlier cars to cover them from having to do engine warranty work due to those individuals who ran their engines hard, or raced them, and burned up the bottom ends due to low oil levels.

Pic #1 is the Pontiac bulletin.

So how high is the fill level of oil when it is in the pan? Nobody seems to know. BUT, now you do!! I used my 1973 factory pan having the oil baffle to see just what the oil level is within the pan. The pan was made level for this test. I filled and measured for 3 Quarts, 4 Quarts, and 5 Quarts. Keep in mind that this is at rest and once the engine fires up, oil gets pumped through the engine and the 5 Quart fill level will drop.

I will have a few follow up topics covering the factory oil baffle and my hand at extending the 1973 baffled oil pan in the photos for more oil capacity and adding the extended oil pump pick-up tube/screen to match. Got it all done and it was a ton of work, a lot of hours, and I would not recommend anyone doing this as I can assure you it would be easier and much simpler to just order an aftermarket oil pan having the additional oil capacity. Me?, I'm cheap, can do the fabrication work, and wanted to keep with "old school" practices that were done when a good aftermarket pan wasn't available or it was too expensive for the average car guy - like me when I was younger. (y)



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Discussion Starter · #2 ·
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 and 1 for the filter making it a 7 quart system - and they would be right based on the year of their GTO and/or the dipstick pulled from their engine. This conflicting info deals with the 1965-67 model years.

With the introduction of the 400CI, all Pontiacs seem to use 5 quarts in the pan and 1 quart for the filter. I have not compared the 389 to 400 heads with regards to oil return holes/passages which may have been redesigned when the new 400CI engines/heads came out, and thus the fix for the extra oil that was being held up in the top end of the engine.

A service bulletin was issued by Pontiac in 1966. It clearly states that the oil capacity is 6 quarts in the pan and 1 quart in the filter. GTO owners will tell you that their dipstick clearly says 6 Quarts at the fill line. Yet when a 5-quart dipstick is set side-by-side with a 6-quart marked dipstick, they are identical in length. There is no difference in the pan, they are all seemingly the same. Hmmm, so what gives?
I believe it was a PY forum member who stated that he had talked with Milt Schronack of Royal Pontiac fame and Milt said that Pontiac was replacing a lot of 1965 GTO engines under warranty and it was found that the engines were being burnt up due to lack of oil. The owners were pushing the engines hard and at the upper RPM's much of the oil was being pumped up to the top end and not leaving enough in th pan to oil the bottom end - especially if the oil level fill level had been allowed to get low. So Pontiac issued a service bulletin to fill all engines with 6 quarts plus 1 quart for the filter. They also used a dipstick having the 6-quart fill mark. This extra quart helped keep enough oil in the pan and prevent the engine from running out of oil and burning up.

So this bulletin and change was for 1966, but owners of 1965 and 1967 GTO's have also found the 6-Qt stamped dipstick. It is quite possible that when the car was brought to a dealership to be serviced and the oil/filter changed, the 5-Qt dipstick was replaced with the 6 Qt stamped dipstick so as to protect Pontiac from having to cover warranty engine work.

So it boils down to that Pontiac used a 5 quart pan and a 1 quart filter for 6 quarts, but increased the pan fill on their earlier cars to cover them from having to do engine warranty work due to those individuals who ran their engines hard, or raced them, and burned up the bottom ends due to low oil levels.

Pic #1 is the Pontiac bulletin.

So how high is the fill level of oil when it is in the pan? Nobody seems to know. BUT, now you do!! I used my 1973 factory pan having the oil baffle to see just what the oil level is within the pan. The pan was made level for this test. I filled and measured for 3 Quarts, 4 Quarts, and 5 Quarts. Keep in mind that this is at rest and once the engine fires up, oil gets pumped through the engine and the 5 Quart fill level will drop.

I will have a few follow up topics covering the factory oil baffle and my hand at extending the 1973 baffled oil pan in the photos for more oil capacity and adding the extended oil pump pick-up tube/screen to match. Got it all done and it was a ton of work, a lot of hours, and I would not recommend anyone doing this as I can assure you it would be easier and much simpler to just order an aftermarket oil pan having the additional oil capacity. Me?, I'm cheap, can do the fabrication work, and wanted to keep with "old school" practices that were done when a good aftermarket pan wasn't available or it was too expensive for the average car guy - like me when I was younger. (y)



View attachment 137479
Here are the levels of the oil in the pan as measured from the bottom and the depth from the top of the oil pan rail to the oil level. I don't have photos of the 1-quart or 2-quart levels, just the measurements. You will see photos of 3, 4, & 5 quart fills.

Pontiac Factory Oil Pan with Oil Baffle - Measurement of oil levels based on quart capacity - 5 Qt pan. Pan bottom has a taper - 7 3/8 Front to 7 " Rear.

1 Qt Oil - From top of pan rail to oil level - 6"
Depth of oil at oil level to bottom of pan - 1 3/4"

2 Qts Oil - From top of pan rail to oil level - 5 1/2"
Depth of oil at oil level to bottom of pan - 2 1/2"

3 Qts Oil - From top of pan rail to oil level - 4 7/8"
Depth of oil at oil level to bottom of pan - 2 3/8"

4 Qts Oil - From top of pan rail to oil level - 4 1/8"
Depth of oil at oil level to bottom of pan - 2 7/8"

5 Qts Oil - From top of pan rail to oil level - 3 3/4"
Depth of oil at oil level to bottom of pan - 3 1/4"
Oil level depth above baffle and across front of pan extension - 5/8"
 

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Discussion Starter · #3 ·
Here are the levels of the oil in the pan as measured from the bottom and the depth from the top of the oil pan rail to the oil level. I don't have photos of the 1-quart or 2-quart levels, just the measurements. You will see photos of 3, 4, & 5 quart fills.

Pontiac Factory Oil Pan with Oil Baffle - Measurement of oil levels based on quart capacity - 5 Qt pan. Pan bottom has a taper - 7 3/8 Front to 7 " Rear.

1 Qt Oil - From top of pan rail to oil level - 6"
Depth of oil at oil level to bottom of pan - 1 3/4"

2 Qts Oil - From top of pan rail to oil level - 5 1/2"
Depth of oil at oil level to bottom of pan - 2 1/2"

3 Qts Oil - From top of pan rail to oil level - 4 7/8"
Depth of oil at oil level to bottom of pan - 2 3/8"

4 Qts Oil - From top of pan rail to oil level - 4 1/8"
Depth of oil at oil level to bottom of pan - 2 7/8"

5 Qts Oil - From top of pan rail to oil level - 3 3/4"
Depth of oil at oil level to bottom of pan - 3 1/4"
Oil level depth above baffle and across front of pan extension - 5/8"
3-Quart Fill

Metal
Blue Yellow Art
 

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Discussion Starter · #7 ·
I didn't want this post to get lost in the forum as it kinda relates to the pan fill levels. And I spent 200 hours and a $100,000 government grant to come up with the answer. ;)

 

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I made this same post in your thread about the heads.

The E-heads have a much more restrictive oil return back to the pan. I added an extra drain to try to help this situation. I don't have a picture of the drains in the heads, but I've attached a picture of the drain line I added to my engine.

Auto part Engine Automotive engine part Vehicle
 

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Discussion Starter · #9 ·
I made this same post in your thread about the heads.

The E-heads have a much more restrictive oil return back to the pan. I added an extra drain to try to help this situation. I don't have a picture of the drains in the heads, but I've attached a picture of the drain line I added to my engine.

View attachment 138224
Good info as I have not seen any other info on the E-heads but read there were some oil drain issues. I suspect this would only apply to a race type use engines and not a street engine? I'd hate to pay what they get for the E-heads and then have to modify as you have for the street. :(
 

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It should be fine for the street, but at high RPM the heads don't drain well enough. They just have small drain holes, no open passages. Just two holes if I remember correctly. If you wanted to check the valves after a race, oil would probably go over the edge of the head and onto the engine. You have to wait a bit before taking off the valve cover off.
 

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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 and 1 for the filter making it a 7 quart system - and they would be right based on the year of their GTO and/or the dipstick pulled from their engine. This conflicting info deals with the 1965-67 model years.

With the introduction of the 400CI, all Pontiacs seem to use 5 quarts in the pan and 1 quart for the filter. I have not compared the 389 to 400 heads with regards to oil return holes/passages which may have been redesigned when the new 400CI engines/heads came out, and thus the fix for the extra oil that was being held up in the top end of the engine.

A service bulletin was issued by Pontiac in 1966. It clearly states that the oil capacity is 6 quarts in the pan and 1 quart in the filter. GTO owners will tell you that their dipstick clearly says 6 Quarts at the fill line. Yet when a 5-quart dipstick is set side-by-side with a 6-quart marked dipstick, they are identical in length. There is no difference in the pan, they are all seemingly the same. Hmmm, so what gives?
I believe it was a PY forum member who stated that he had talked with Milt Schronack of Royal Pontiac fame and Milt said that Pontiac was replacing a lot of 1965 GTO engines under warranty and it was found that the engines were being burnt up due to lack of oil. The owners were pushing the engines hard and at the upper RPM's much of the oil was being pumped up to the top end and not leaving enough in th pan to oil the bottom end - especially if the oil level fill level had been allowed to get low. So Pontiac issued a service bulletin to fill all engines with 6 quarts plus 1 quart for the filter. They also used a dipstick having the 6-quart fill mark. This extra quart helped keep enough oil in the pan and prevent the engine from running out of oil and burning up.

So this bulletin and change was for 1966, but owners of 1965 and 1967 GTO's have also found the 6-Qt stamped dipstick. It is quite possible that when the car was brought to a dealership to be serviced and the oil/filter changed, the 5-Qt dipstick was replaced with the 6 Qt stamped dipstick so as to protect Pontiac from having to cover warranty engine work.

So it boils down to that Pontiac used a 5 quart pan and a 1 quart filter for 6 quarts, but increased the pan fill on their earlier cars to cover them from having to do engine warranty work due to those individuals who ran their engines hard, or raced them, and burned up the bottom ends due to low oil levels.

Pic #1 is the Pontiac bulletin.

So how high is the fill level of oil when it is in the pan? Nobody seems to know. BUT, now you do!! I used my 1973 factory pan having the oil baffle to see just what the oil level is within the pan. The pan was made level for this test. I filled and measured for 3 Quarts, 4 Quarts, and 5 Quarts. Keep in mind that this is at rest and once the engine fires up, oil gets pumped through the engine and the 5 Quart fill level will drop.

I will have a few follow up topics covering the factory oil baffle and my hand at extending the 1973 baffled oil pan in the photos for more oil capacity and adding the extended oil pump pick-up tube/screen to match. Got it all done and it was a ton of work, a lot of hours, and I would not recommend anyone doing this as I can assure you it would be easier and much simpler to just order an aftermarket oil pan having the additional oil capacity. Me?, I'm cheap, can do the fabrication work, and wanted to keep with "old school" practices that were done when a good aftermarket pan wasn't available or it was too expensive for the average car guy - like me when I was younger. (y)



View attachment 137479
It should be fine for the street, but at high RPM the heads don't drain well enough. They just have small drain holes, no open passages. Just two holes if I remember correctly. If you wanted to check the valves after a race, oil would probably go over the edge of the head and onto the engine. You have to wait a bit before taking off the valve cover off.
I am now more confused then ever. I have a '67 with headers and thinner oil filter. How much should I use with an oil change? Thanks!
 

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Discussion Starter · #13 ·
I am now more confused then ever. I have a '67 with headers and thinner oil filter. How much should I use with an oil change? Thanks!
READ THIS POST!!!!!!

 
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