427 oil filter fill

[Kenneth K.]

Good morning-

Does anyone know if the oil filter on the 427 was filled at the assembly line?

The reason I ask is the AIM on page J369 has an instruction to add 1.376 gals (5.5 qts) to the crankcase. It does not indicate to add any oil to the filter. I can’t find any reference in the AIM that instructs the assembly line worker to add oil to the filter. I find it hard to believe that GM would start the engine without any oil in the filter.

I recently filled a AC PF-1218 filter and it topped off at holding 0.5 qts. If the PF-1218 held the same amount of oil as the OEM filter then the crankcase from a dry fill would have a total of 5.0 qts. and the filter would have 0.5 qt. after starting the engine. I thought that the OEM filter held 1 qt. of oil. If it did then the crankcase would only have 4.5 qts. after starting the engine and filling the oil filter.

The crankcase retains abut 1/3 qt after an oil change. Then only 4 2/3 qt would be required to fill the crankcase without an oil filter change. Using the PF-1218 that holds 0.5 qts. then it would take 5 1/3 qts. to fill the crankcase with an oil filter change. Does this seem correct?

Thanks,
Ken

[Duke W.]

Oil along with coolant was added prior to the brief "hot fire" test at the engine plant, and I expect the filter was empty at this time. Once the engine fired oil pressure was checked along with timing and adjusted as necessary plus abnormal noise and visual leak checks. The actual run time of the engine was as little as about 30 seconds. If the engine passed the oil and coolant were evacuated and the engine was sent off for shipping. If not it went to the repair area.

I doubt if the oil in the filter was evacuated so that remained along with a fraction of a quart elsewhere in the engine. The OE cartridge filter holds about a quart of oil. I expect the PF 1218 is a spin on, and most modern spin on filters hold less oil than the old cartridge type.

So adding 5.5 quarts certainly would have filled the system (5 quart pan, plus about a quart for the filter)... maybe even slightly overfilled it. In any event, there was certainly enough oil in the engine to get through the shipping process to the dealer and dealer prep included checking the oil and adding as necessary.

If the oil filter is "right side up" like a vintage Chevy SB or BB, I think it's a good idea to pre-fill the filter, but a lot of cars have horizontal or "upside down" filters that you can't pre-fill. Upon engine start it takes a few seconds for oil pressure come up, but at idle speed there is very little load on the bearings and plenty of oil in them to withstand a few seconds of no new flow.''

It's nothing to be concerned about.

Duke

[Joe L.]

I expect the PF 1218 is a spin on, and most modern spin on filters hold less oil than the old cartridge type.



Duke

Yes, the PF-1218 is a spin-on type oil filter. It's a modern day version of the old PF-35. Of course, neither a PF-1218 or PF-35 was ever originally used on any Corvette but they can be used on any 1968-82 and most 1984-91.

[Gary B.]

Below is John Hinckley’s description of the hot test at the engine assembly plant. This is part of a longer document on the Camaro Research Group website. It sounds like there was no oil filter/canister fir the hot test.

Gary


“Hot Test

The engine was clamped in place and four quarts of oil were pumped into the fill tube opening, which was then plugged. Adapters connected the thermostat housing and water pump to a circulating water supply, a shunt adapter was screwed into the oil filter cavity, an oil pressure line was connected, a slave spark plug wire harness with its own coil and timing light connection was attached to the distributor and the spark plugs while a natural gas adapter elbow was attached to the carburetor pad and an air-powered starter was clamped to the harmonic damper, along with clamping exhaust manifold outlet adapters to the flex pipes that extracted the hot exhaust fumes.

The operators then fired the engine, checked for oil pressure and oil or water leaks, set the timing, tightened the distributor hold-down clamp and chisel-staked the reference mark on the distributor base and intake, and listened for any unusual noises. Oil and water were drained, all test adapters were disconnected, and the engine was hoisted out of the test stand and placed on another conveyor that took it to the shipping area. Engines needing further attention due to test discrepancies were set aside for repairs; when repairs were completed, those engines were re-tested and sent on their way.”

[Kenneth K.]

From all your comments it sounds like 4 qts. of oil was evacuated before the engine arrive on the assembly line. The oil filter must have been installed at the engine assembly plant since I can’t find any reference in the AIM that an oil filter was installed on the assembly line. The oil filter must have been empty when the engine arrived at the assembly line if a shunt adapter was screwed into the oil filter cavity at the engine assembly plant.

The engine would have about 1/3 qt of residual oil and an empty oil filter when it arrived at the assembly line. The assembly line worker added 5.5 qts. After starting the oil filter would have 1 qt and the pan would have 4.5 qts. plus the 1/3 qt residual. About 4.8 qts. in the pan.

I am trying to recalibrate my oil dip stick. I found one of Joe’s earlier posts that says all BBC take a total of 6 qts. I assume that is using the 1 qt. OEM filter and a total of 5 qts. in the pan (including the residual). If I am using a 1/2 qt oil filter then I would have a total of 5 1/2 qts. I changed my oil pan gasket and removed the 1/3 qt of residual oil so my pan is dry. I filled the PF-1218 oil filter (it took almost exactly 1/2 qt) and installed it. So then do I fill the crankcase with a total of 5 qts and make a Full mark on my stick?

[Joe L.]

I am trying to recalibrate my oil dip stick. I found one of Joe’s earlier posts that says all BBC take a total of 6 qts. I assume that is using the 1 qt. OEM filter and a total of 5 qts. in the pan (including the residual). If I am using a 1/2 qt oil filter then I would have a total of 5 1/2 qts. I changed my oil pan gasket and removed the 1/3 qt of residual oil so my pan is dry. I filled the PF-1218 oil filter (it took almost exactly 1/2 qt) and installed it. So then do I fill the crankcase with a total of 5 qts and make a Full mark on my stick?

Kenneth-----

I can tell you this much: in 1968 all Corvette engines changed to the PF-25 filter. This spin-on type filter was considerably shorter (and less capacity) than the PF-1218 and certainly much less than the cartridge filter used on 1965-67 big blocks. Nevertheless, the rated engine oil capacity for all 1965-74 big blocks was 6 quarts.

By the way, although several different part numbered oil pans were used on Corvette big blocks over the 1965-74 period, they were all virtually identical and had the same capacity.

[Kenneth K.]

Hi Joe-

Thank you for your response. As always I appreciate your help.

Interesting that the 6 qt. capacity didn’t change when GM went to the smaller PF-25 in 1968. Even more confusing is the Note #6 on page J369 in the AIM that says in the Revision Record box dated 9/15/69 that the amount of oil to add “Was 1.12 gal” (4.5 qts.). So in 1968 GM went to a 1/2 qt smaller oil filer and in 1969 added 1 qt more oil…

Would you recommend that I add a total of 6 qts. then start the engine and after the oil drains back to the pan make a Full mark on the stick? Or should I add only 5.5 qts. to account for the 1/2 qt smaller PF-1218 oil filter?

Thanks,
Ken

[Joe L.]

Hi Joe-

Thank you for your response. As always I appreciate your help.

Interesting that the 6 qt. capacity didn’t change when GM went to the smaller PF-25 in 1968. Even more confusing is the Note #6 on page J369 in the AIM that says in the Revision Record box dated 9/15/69 that the amount of oil to add “Was 1.12 gal” (4.5 qts.). So in 1968 GM went to a 1/2 qt smaller oil filer and in 1969 added 1 qt more oil…

Would you recommend that I add a total of 6 qts. then start the engine and after the oil drains back to the pan make a Full mark on the stick? Or should I add only 5.5 qts. to account for the 1/2 qt smaller PF-1218 oil filter?

Thanks,
Ken

Ken-----

Are you using an original dipstick and dipstick tube? If so, I would fill the filter with oil first, noting the volume added. Then add 5 quarts of oil. Start the engine, let it run for a little while, then shut it down and wait about a few hours. Last, note the dipstick reading. If not at "full", add whatever volume it takes to get to full. The 5 quarts + whatever you need to add to get to "full" is what you need to fill with after your next oil change assuming that you continue to use the PF-1218 and fill it prior to installation.

By the way, I would not use a "generic" dipstick and try to "calibrate" it. Just use an original or reproduction dipstick and tube. The oil fill does not need to be precise "to a gnat's ass".

[Owen L.]

I bought a repro tube from CC or Paragon or someplace several years back and it was about 1/2" longer than the stock tube I was replacing. That results in 1/2" shorter stick projection and would have required quite a bit more oil to be at the full mark.

Be careful about t******* the tube, because extra tube below the block flare is of no concern, but the tube length above the flare will change the projection of the stick (gauge in GM parlance) into the pan. What you need to know is the length of the tube above the flare.

edit: {apparently trim+ing is a dirty word }

[Kenneth K.]

Joe/Owen-

I have my original stick and tube but it is missing the bracket that attaches to the manifold bolt. I bought a replacement from CC and it appears to be a very good reproduction. I didn’t notice any differences in length or construction. The only difference I noted was the markings on the stick.

I installed the new tube and added a total of 5 qts of oil to the empty pan (no residual oil in the pan). Have not started the engine yet. The reading on the stick show it is low by a little more than a 1/2 qt. I then removed the tube from the manifold bracket and found I could insert the tube a little bit further down into the block flare before it bottomed out. The reading on the stick when it is fully seated down into the block flare shows it is a little overfilled. The tube at this depth is to low for the bracket to fit on the manifold bolt.

I was thinking the depth of the stick in the pan is fixed at the correct depth when the tube is bolted to the manifold. But since my original tube is missing the bracket I can’t confirm the bracket is fixed at the correct location to the tube on the reproduction from CC. If the bracket on the CC tube is to low then when bolted to the manifold that would explain why it is not fully seated down into the block flare and it is reading low. In this case it would take close to 5.5 qts to the Full mark (not including oil for the filter). If the tube is supposed to be fully seated down into the block flare then the bracket is to low to bolt to the manifold and it would take a little less than 5 qts to the Full mark (not including oil for the filter).

Any suggestions….

[Joe L.]

Joe/Owen-

I have my original stick and tube but it is missing the bracket that attaches to the manifold bolt. I bought a replacement from CC and it appears to be a very good reproduction. I didn’t notice any differences in length or construction. The only difference I noted was the markings on the stick.

I installed the new tube and added a total of 5 qts of oil to the empty pan (no residual oil in the pan). Have not started the engine yet. The reading on the stick show it is low by a little more than a 1/2 qt. I then removed the tube from the manifold bracket and found I could insert the tube a little bit further down into the block flare before it bottomed out. The reading on the stick when it is fully seated down into the block flare shows it is a little overfilled. The tube at this depth is to low for the bracket to fit on the manifold bolt.

I was thinking the depth of the stick in the pan is fixed at the correct depth when the tube is bolted to the manifold. But since my original tube is missing the bracket I can’t confirm the bracket is fixed at the correct location to the tube on the reproduction from CC. If the bracket on the CC tube is to low then when bolted to the manifold that would explain why it is not fully seated down into the block flare and it is reading low. In this case it would take close to 5.5 qts to the Full mark (not including oil for the filter). If the tube is supposed to be fully seated down into the block flare then the bracket is to low to bolt to the manifold and it would take a little less than 5 qts to the Full mark (not including oil for the filter).

Any suggestions….

Ken-----

Did you install seal GM #274244 on the lower dipstick tube before you inserted it into the pan orifice?

[Kenneth K.]

Joe-

I installed a small o-ring on the lower part of the dipstick. It came with the reproduction stick from CC and it looks like the o-ring that is on my original. Is this the seal you are talking about?

The picture of the tube below is the CC reproduction and you can see the o-ring on the bottom of the tube. It’s not very thick so it only took up about a 1/16” of slack. After I removed the bolt from the manifold bracket I pushed the tube down an additional 1/2” or more before it bottomed out. I had to slightly bend the bottom of the tube before it would slide in easily and bottom out otherwise I would have had to force it into the block flare which i didn’t want to do..

The other pic is GM 274244 from Chevrolet Performance on Amazon. They want $22 for it. This one looks thicker than the o-ring than came with the stick from CC. I saw other o-rings for the tube as low as $7 but they didn’t look as thick as the one from Chevrolet Performance.

Owen mentioned that he bought a reproduction stick from CC and it was 1/2” longer than his original. The stick I got from CC was the same length as my original but if the bracket was attached 1/2” lower on the tube the effect would be to raise the tube 1/2” which is the issue Owen experienced. The CC stick has a Paragon number so it is probably made to Paragon’s specs. I always had good luck with Paragon’s reproductions being accurate so it seems unlikely the bracket would be in the wrong position.

Ken
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[Joe L.]

Joe-

I installed a small o-ring on the lower part of the dipstick. It came with the reproduction stick from CC and it looks like the o-ring that is on my original. Is this the seal you are talking about?

The picture of the tube below is the CC reproduction and you can see the o-ring on the bottom of the tube. It’s not very thick so it only took up about a 1/16” of slack. After I removed the bolt from the manifold bracket I pushed the tube down an additional 1/2” or more before it bottomed out. I had to slightly bend the bottom of the tube before it would slide in easily and bottom out otherwise I would have had to force it into the block flare which i didn’t want to do..

The other pic is GM 274244 from Chevrolet Performance on Amazon. They want $22 for it. This one looks thicker than the o-ring than came with the stick from CC. I saw other o-rings for the tube as low as $7 but they didn’t look as thick as the one from Chevrolet Performance.

Owen mentioned that he bought a reproduction stick from CC and it was 1/2” longer than his original. The stick I got from CC was the same length as my original but if the bracket was attached 1/2” lower on the tube the effect would be to raise the tube 1/2” which is the issue Owen experienced. The CC stick has a Paragon number so it is probably made to Paragon’s specs. I always had good luck with Paragon’s reproductions being accurate so it seems unlikely the bracket would be in the wrong position.

Ken
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Ken-----

The GM #274244 is basically an o-ring of 0.48" OD, 0.35" ID and 0.07" in thickness. It remains available from GM for a GM list price of $10.89. Even that sounds like a lot for an o-ring. I seem to remember that once-upon-a-time the 274244 had a "square" cross section rather than the round cross section of a typical o-ring. However, the one supplied for the last many years is of round cross section. In any event, I think that a standard o-ring that's close to the specs I mentioned should work fine.

The developed length (i.e. the length measured over the slight curve) of a GM supplied dipstick tube is 12" from the bottom of the bracket to the top of the seating ring.

[Leif A.]

Ken-----

The GM #274244 is basically an o-ring of 0.48" OD, 0.35" ID and 0.07" in thickness. It remains available from GM for a GM list price of $10.89. Even that sounds like a lot for an o-ring. I seem to remember that once-upon-a-time the 274244 had a "square" cross section rather than the round cross section of a typical o-ring. However, the one supplied for the last many years is of round cross section. In any event, I think that a standard o-ring that's close to the specs I mentioned should work fine.

The developed length (i.e. the length measured over the slight curve) of a GM supplied dipstick tube is 12" from the bottom of the bracket to the top of the seating ring.

To Joe's point, you could buy a lifetime supply of the "square" cross section o-rings for about $22. I had a recent plumbing issue that was resolved with the help of this "square" o-ring selection. The 1/2"OD by 3/8" ID with a cross section of 1/16" should work. Hope this helps.

[Kenneth K.]

Joe-

The length measured over the slight curve of the CC reproduction dipstick tube from the bottom of the bracket to the top of the seating ring is very close to 11 1/2”. My original tube I believe also measures very close to 11 1/2”. Here is why I think that…

I examined my OE tube and there are very small spot welds on the U shape portion of the bracket that is connected to the tube. There is one spot weld on one side of the U of the bracket and 2 spots welds on the other side of the U on the bracket. I measured the distance of the single spot weld witness mark to the top of the tube on the original tube and compared it to the CC reproduction tube. Both spot welds are 1-5/8” to the top of the tube. Therefore its more than likely that the length from the bottom of the bracket to the top of the seating ring is the same on the original tube as the reproduction CC tube since both tube lengths are the same.

When the reproduction tube is bolted to the manifold the top of the seating sitsjust on top of the flare on the pan which puts the o-ring just inside the top of the flare. I took a closer look at the pan flare and it looks like when the stick is fulling inserted it would put the o-ring about 1/2” below the top of the flare.

I am really confused now. Why would both the CC repo and my original tube distance from the bottom of the bracket to the top of the seating ring be 1/2” shorter than….“a GM supplied dipstick tube is 12" from the bottom of the bracket to the top of the seating ring.” If I installed a tube that is 12” from the bottom of the bracket to the top of the seating ring the dipstick would still read the same as the shorter 11 1/2” OE/CC tubes?

Thanks,
Ken