EmTee Posted February 22, 2022 Share Posted February 22, 2022 So, I filled my new radiator with antifreeze today and started the engine only to discover oil leaking at a pretty good rate from this fitting at the front of the engine. It looked as though it had been leaking before, so while I had the radiator out I tried to tighten the fitting, which actually made things worse... So, I removed the fitting and the oil line to see what was going on. Looking into the opening in the head I could see what appeared to be a brass seat, however, it was much deeper than the flare on the pipe fitting could ever reach -- WTF...? I tried clearing the orifice to get a better look, but I couldn't see any way this thing could possibly create a pressure-tight seal. Finally, I decided to use an easyout to try to remove the brass seat. Oddly, once the easyout bit into the brass, I was able to pull it up to the threaded portion of the hole and with a little more tugging, I pulled this out of the hole: This was after I straightened it out. When I first removed it, it was collapsed to about half the length. There appears to be nothing to prevent that screen/filter from being pushed further into the opening as the fitting on the tubing is tightened. Again, I can see no way this thing could ever not leak oil as I found it. Finally, I created a spacer using about 1-inch of 5/16" tubing, which I cross-drilled to ensure oil flow. One end of the tube bottoms-out in the hole, while I fitted the end that interfaces with the tube with a brass seat to mate with the flare fitting on the tube. When installed, and the fitting tightened, I started the engine and confirmed that there was no oil leak. I also removed the valve cover and verified that oil was flowing through the rocker shaft and dribbling out of the rocker arms. So, it is 'fixed' for now, without the screen-thingy in the picture above. I'd like to know, however, how this fitting is supposed to be assembled and what part (or parts) that I'm missing in order to put it back as originally designed. Any insight is appreciated! 2 Link to comment Share on other sites More sharing options...
critterpainter Posted February 22, 2022 Share Posted February 22, 2022 I thought the fitting in the head was threaded for 1/8 NPT and an adaptor was used to fit it to the oil line. 1 Link to comment Share on other sites More sharing options...
EmTee Posted February 22, 2022 Author Share Posted February 22, 2022 That's what I would have expected, however, having found that screen in the hole makes me think there's some Buick-specific fitting that would go into the hole??? The brass flare fitting screws easily into the threaded hole, so I am thinking they are straight threads... Link to comment Share on other sites More sharing options...
Bloo Posted February 22, 2022 Share Posted February 22, 2022 What? Now I'm confused. The fitting must have been bottomed on something other than the screen, right? I don't see a flare seat there, nor any seat for a threaded sleeve fitting. @MCHinson @37_Roadmaster_C @Marty Roth @Gary W Link to comment Share on other sites More sharing options...
MCHinson Posted February 22, 2022 Share Posted February 22, 2022 The 1937 and 1938 are different as the 1937 screen is in the inlet to the rocker arms. That line and fitting was on the engine when I got the car. I removed the line, cleaned it up and then snugged it down when reinstalling the oil line. Did not see an oil leak in the limited time that I drove the car. Sorry I can't provide any additional insight into it. Perhaps @38Buick 80C can help. He is the resident 1938 320 engine expert. 1 Link to comment Share on other sites More sharing options...
buick looks fine for 39 Posted February 22, 2022 Share Posted February 22, 2022 Straight eights are notorious for sludge build up in the line from main oil gallery in the block to the head. The screen is intended to keep the rocker arm assembly from being plugged up and starving the rocker arms of oil. With new oils the screen probably is not as important as the 30s and 40s. Also, the screen is designed to seat deeply in the head. If you decide to reinstall a nos screen let me know, I have a whole bag full. I may also have a fitting as well Thanks Leif 2 1 Link to comment Share on other sites More sharing options...
38Buick 80C Posted February 22, 2022 Share Posted February 22, 2022 correct the screen should be there and deep in. to me it looks blocked likely causing excess pressure and thus the leak. I'd be interested in one or more of those NOS screens Lief. Link to comment Share on other sites More sharing options...
EmTee Posted February 22, 2022 Author Share Posted February 22, 2022 9 hours ago, buick looks fine for 39 said: If you decide to reinstall a nos screen let me know, I have a whole bag full. I may also have a fitting as well 56 minutes ago, 38Buick 80C said: I'd be interested in one or more of those NOS screens Lief. Lief, yes, please! I'd be interested in any of the necessary pieces that you're willing to part with. If you have a fitting and screen just PM me and let me know how you want to handle the transaction. Thanks to all who have commented. Link to comment Share on other sites More sharing options...
pont35cpe Posted February 22, 2022 Share Posted February 22, 2022 I could be wrong, if i remember correctly the brass fitting that screws into the head for the rocker oiling, has a smaller hole than the other oil line fittings. Link to comment Share on other sites More sharing options...
NailheadBob Posted February 22, 2022 Share Posted February 22, 2022 (edited) On 2/22/2022 at 7:27 AM, EmTee said: Lief, yes, please! I'd be interested in any of the necessary pieces that you're willing to part with. If you have a fitting and screen just PM me and let me know how you want to handle the transaction. Thanks to all who have commented. @EmTee You can look at the specifics for pipe group 1.917, connector & elbow 1.928, screen 1.930 in the master chassis parts book, if you need copies of this let me know. Looks like Connector, crankcase to cylinder head oil pipe #1337299 notations ( this fitting used for service when oil line screen is removed from cyl head) Part # 1302361 screen, is on e-bay by annbuickparts AND 2040 parts.com also has the screen. Bob Edit: Group 1.917 pipe, crankcase to cylinder head oil : # 152120 fits 1937 thru 1942 (H1942) connector (3/16") in cylinder head not sure what H1942 stands for. Edit: ADD #114962 sleeve, threaded 3/16" In crankcase & cyl. head. Edited March 1, 2022 by NailheadBob update (see edit history) 2 Link to comment Share on other sites More sharing options...
buick looks fine for 39 Posted February 22, 2022 Share Posted February 22, 2022 When I initially looked at the posted photo, I thought something was odd but I couldn't put my finger on it. This morning I realized you are missing a fitting my friend and that's the reason why your oil line is leaking. I believe the fitting is called crankcase to cylinder head oil pipe connector group 1.928 part number 1337299 1936-47 and most likely later. I should have that connector if you need one. Anybody interested in a screen feel free to drop a web mail to me. I'll charge any price that is reasonable to both of us plus shipping which shouldn't be much Thanks Leif 3 Link to comment Share on other sites More sharing options...
buick looks fine for 39 Posted February 22, 2022 Share Posted February 22, 2022 (edited) Something I forgot, I'll guarantee it too minus shipping Thanks Leif Edited February 22, 2022 by buick looks fine for 39 knuckle head misspell (see edit history) Link to comment Share on other sites More sharing options...
kgreen Posted February 22, 2022 Share Posted February 22, 2022 Something looked amiss with your line connecting directly into the head. I just checked a couple of my 320 heads in my garage and see that you don't have a female nipple: 2 Link to comment Share on other sites More sharing options...
buick looks fine for 39 Posted February 22, 2022 Share Posted February 22, 2022 yep, that's it 1 Link to comment Share on other sites More sharing options...
EmTee Posted February 22, 2022 Author Share Posted February 22, 2022 That's it -- I knew something had to be missing! Like I said, there's no way that fitting could be pressure tight as it was, yet somehow the leakage wasn't terrible until I tried to tighten it, which apparently crushed the screen enough that the sludge around it no longer slowed the leak. With the valve cover off I see there's a similar fitting at the other end of the galley that connects from the top of the head to the rocker shaft. Link to comment Share on other sites More sharing options...
pont35cpe Posted February 22, 2022 Share Posted February 22, 2022 That`s the fitting i was referring to. 1 Link to comment Share on other sites More sharing options...
Jolly_John Posted February 22, 2022 Share Posted February 22, 2022 (edited) Yes, pont35cpe, as you originally stated, this picture portrays the restrictor fitting (a smaller outlet hole), designed to cut down on the flow of oil to the rocker arm. I bet Leif might also have this SPECIAL fitting that EmTee needs! John Edited February 23, 2022 by Jolly_John (see edit history) Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted February 22, 2022 Share Posted February 22, 2022 @buick looks fine for 39, Leif, if you are willing it would be nice to know the orifice size for the head oil fitting. It is not a complicated part, but the orifice size is the critical issue. Many of us can make the part if needed, but a drill size or dimension for the orifice would be great. Thanks, Robin 2 Link to comment Share on other sites More sharing options...
buick looks fine for 39 Posted February 23, 2022 Share Posted February 23, 2022 I'll dig one out and take measurements. If anybody needs a nos screen I think $5.00 plus shipping is fair. Thanks Leif 2 Link to comment Share on other sites More sharing options...
buick looks fine for 39 Posted February 23, 2022 Share Posted February 23, 2022 Emtee needed a fitting and I wanted to make sure I had the correct fitting for him. To my surprise I had 2 fittings which seemed identical, but the orifice diameters were different. I then pulled a fitting out of a 1939 248 engine and the orifice diameter was 1/16th inch. After that I pulled a fitting out of a 1939 320 engine and the orifice diameter was 1/8th inch. I guess empirically it makes sense the larger engine would require more oil supply to the rocker arm assembly. I never realized this before. Thanks Leif 1 Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted February 23, 2022 Share Posted February 23, 2022 Leif, thanks for the information. I will do some digging as the difference in orifice size makes no sense from a lubrication engineering standpoint. The only difference between the 248 and 320 is a small difference in length. That has no bearing on the amount of oil needed to lubricate the rocker shaft, rockers and valves. I will look up the part numbers and see where the differences happen. I always like a good mystery. Stay tuned...... 1 Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted February 23, 2022 Share Posted February 23, 2022 The orfice size in my 1950 is, I believe, 0.060. Or about 1/16th inch. They ARE to reduce, per Buick info I have read, oil flow to the rocker arms to reduce flow to the valve stem. I have found the orfice on the inlet to the head s well as at the outlet under the valve cover. Without the reducer orfice, the valve train is FLOODED! I Know.😁 Ben Link to comment Share on other sites More sharing options...
DonMicheletti Posted February 23, 2022 Share Posted February 23, 2022 Many, many years ago, an old mechanic told me that when a Buick owner complained about low oil pressure, a commom "fix" was to pinch the oil line feed to the rockers. I always thought that that didnt make sense, but maybe it was because of there were no restrictive fittings on the line. In any case I thought it was a bad idea. Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted February 23, 2022 Share Posted February 23, 2022 (edited) Ok, some research... My parts book only goes thru 1941 so it is not complete for the strait 8 series. I am having trouble determining the part number, but by reading every line I think I have found the orifice fitting. EDIT:. Below info is wrong except for the screen info... Bloo helped and explained some fitting terms. We can not find the orifice fitting listed. We will continue looking. Buick calls it a threaded sleeve and it seems to be group number 1.928 part number 114962. This is confusing because that group is called an elbow, but the sleeve is listed in that group. My book is a copy and a bit hard to read, but it looks like it is listed as 3/16, which is LARGE, and listed for both the 248 and 320 for 1938, 39 and 41. No mention before 1938 and skips 1940. This seems very odd and I am thinking I am on the wrong part however, very clearly the parts book lists the in head filter screen as group number 1.930 part number 1302361 and it also is for both engines 1928, 39 and 41. HELP!! Could others with parts books have a look and see if I am nuts or correct. Either is a possibility 🙄. Edited February 23, 2022 by 37_Roadmaster_C (see edit history) Link to comment Share on other sites More sharing options...
EmTee Posted February 23, 2022 Author Share Posted February 23, 2022 I believe I read something about a 1/16" restriction in the line supplying the valvetrain in the '38 shop manual I have. That said, the ID of the tubing appears to be about that size. Also, I have NO restriction currently at the fitting where the supply tubing enters the head and oil is definitely not flooding the valvetrain. I also saw what I think is the same fitting we're talking about installed at the top of the head where the short, 90* piece of tubing that feeds the shaft is attached. That fitting presumably has the same orifice. Now, when I install the fitting and screen that Lief is sending to me, I'm assuming that the screen goes in first followed by the fitting. There's really nothing holding it, I guess the brass 'washer' at the inlet just fits into the bore and oil pressure pushes the screen into the bore until the closed-end bottoms out, correct? Link to comment Share on other sites More sharing options...
Bloo Posted February 23, 2022 Share Posted February 23, 2022 What I want to see is what the TIP of this fitting looks like (green). And what the seat in the bottom of this looks like (red arrow). 1 Link to comment Share on other sites More sharing options...
NailheadBob Posted February 23, 2022 Share Posted February 23, 2022 The master parts book I have is a 1950, it shows: connector, crankcase to cylinder head pipe part # 1337299 fits 1936 thru 1947 with comment (this fitting used for service when oil line screen is removed from cylinder head) , I believe there must be a inside size difference to restrict oil pressure flow when screen is removed to rocker arms. I will wait and see what your findings are. 2 Link to comment Share on other sites More sharing options...
EmTee Posted February 23, 2022 Author Share Posted February 23, 2022 3 minutes ago, Bloo said: What I want to see is what the TIP of this fitting looks like (green). I'll have to take a picture of it tomorrow, but it's basically a truncated cone, with the tubing extending out about 1/16" from the center. I'm expecting the fitting to have a matching concave flare (i.e., seat) that the fitting I have can fit into. 1 Link to comment Share on other sites More sharing options...
Bloo Posted February 23, 2022 Share Posted February 23, 2022 (edited) 7 minutes ago, EmTee said: I'll have to take a picture of it tomorrow, but it's basically a truncated cone, with the tubing extending out about 1/16" from the center. I'm expecting the fitting to have a matching concave flare (i.e., seat) that the fitting I have can fit into. That sounds like a normal "threaded sleeve" fitting. What size is the tubing? You would need a female threaded sleeve fitting, maybe with an orifice added? Any currently available ones, and most in the old days for that matter, go to pipe thread. Is that pipe thread in the head? What size? Edited February 23, 2022 by Bloo (see edit history) 1 Link to comment Share on other sites More sharing options...
EmTee Posted February 23, 2022 Author Share Posted February 23, 2022 (edited) I think the threads in the head are straight threads based on the fitting I currently have screwed in there, but I'm not positive about that. NPT would certainly make sense... I think the line is 1/8", but that's just from memory - I'll have to measure it to be sure. Edited February 23, 2022 by EmTee (see edit history) 1 Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted February 24, 2022 Share Posted February 24, 2022 Now that I know more about the fittings and terminology I think my parts book says the tubing is 3/16 and the fittings are "Threaded Sleeve". As I learn more I will share 😀. 2 Link to comment Share on other sites More sharing options...
EmTee Posted February 25, 2022 Author Share Posted February 25, 2022 I measured the oil line that comes from the main gallery and feeds the rocker shaft at the front of the head. It is indeed 3/16" OD, as 37_Roadmaster_C noted above. I also copied the paragraph from the shop manual that describes the 1/16" orifice at the input to the rocker shaft: This implies to me that the restriction is up at the rocker shaft input. This makes sense, as I said yesterday, I have no restriction in the line where it attaches at the front of the head below the valve cover and yet I do not have oil flooding the valvetrain. This makes me think the orifice in the fitting that I'm missing is not critical. I'll measure the hole in the fitting that Leif is sending me and report what I find. I decided not to pull the line apart to photograph the fitting I have in the head yet, as I really wanted to take the car on a 'shakedown drive' today and the line isn't leaking now and I didn't want to tempt fate... When I receive the other half of the connection from Leif, I'll disassemble everything and photograph both pieces and the new filter screen before I reassemble the connection as designed. 4 Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted February 25, 2022 Share Posted February 25, 2022 @EmTee, Reading that I agree with you about the location of the orifice. The only thing I wonder is if the orifice is indeed in the fitting that screws into the rocker shaft bracket OR is it in the bracket itself. More to think about and investigate.... 2 Link to comment Share on other sites More sharing options...
pont35cpe Posted February 25, 2022 Share Posted February 25, 2022 Fitting to head is 1/8" NPT. 1 1 Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted February 25, 2022 Share Posted February 25, 2022 As I said earlier, at least in later years, the orfice is at the top, right corner of the head. I have found them either at the inlet OR outlet. None at the shaft end of the tube, or pipe, as Buick calls it. Ben 1 1 Link to comment Share on other sites More sharing options...
NailheadBob Posted February 25, 2022 Share Posted February 25, 2022 @EmTee@37_Roadmaster_CI know Leif is sending you the fitting, but Dorman has a fitting # 785-456D Inverted Flare Fitting male connector-3/16 in. MNPT Bob 1 1 Link to comment Share on other sites More sharing options...
EmTee Posted February 25, 2022 Author Share Posted February 25, 2022 3 hours ago, NailheadBob said: Dorman has a fitting # 785-456D Inverted Flare Fitting male connector-3/16 in. MNPT Thanks - this P/N may be useful to others in the future! 2 Link to comment Share on other sites More sharing options...
37_Roadmaster_C Posted February 25, 2022 Share Posted February 25, 2022 (edited) 6 hours ago, pont35cpe said: Fitting to head is 1/8" NPT. Not arguing as I do not know, but if it is NPT then what seats the filter screen in the casting. A NPT male would not bottom out as it must tighten into the taper to seal. If it bottomed out there would be no guarantee of a seal. Just thinking and that is a bit dangerous 😇. Just to expand this a little... My thinking is that the fitting you mention as being NPT MAY be the service fitting mentioned above as this would seal without the filter screen top to seal the fitting. Again, just thinking more... Edited February 25, 2022 by 37_Roadmaster_C add information (see edit history) 2 Link to comment Share on other sites More sharing options...
Bloo Posted February 25, 2022 Share Posted February 25, 2022 (edited) 11 hours ago, NailheadBob said: @EmTee@37_Roadmaster_CI know Leif is sending you the fitting, but Dorman has a fitting # 785-456D Inverted Flare Fitting male connector-3/16 in. MNPT Bob 8 hours ago, EmTee said: Thanks - this P/N may be useful to others in the future! I don't believe this is the right piece. I believe this Dorman piece is for a double flare. We won't know for sure until we see a picture of what @EmTee has, but believe it is 99.9% established that the fittings Buick used are Threaded Sleeve based on @EmTee 's post quoted below as well as the verbage used in the Buick parts manual. On 2/23/2022 at 3:40 PM, EmTee said: I'll have to take a picture of it tomorrow, but it's basically a truncated cone, with the tubing extending out about 1/16" from the center. I'm expecting the fitting to have a matching concave flare (i.e., seat) that the fitting I have can fit into. Still at issue, as I understand it, are 2 things. 1) The location and size of the orifice and 2) Whether the missing fitting is a standard Threaded Sleeve female with tapered (NPT) pipe thread at the opposite end, and matching tapered (NPT) pipe threads in the head, and if so, how that was compatible with the screen. The screen appears to have a sealing lip that a tapered (NPT) fitting would never reach, because it would tighten and seal in the threads in the head before it bottomed on the screen flange. Threaded sleeve fittings may sometimes be referred to as "Double Compression" fittings or "Dole Fittings". Here are some old threads. Edited February 26, 2022 by Bloo (see edit history) 1 Link to comment Share on other sites More sharing options...
pont35cpe Posted February 25, 2022 Share Posted February 25, 2022 I have screens coming from Leif, went ahead and pulled my line and fitting, from my 248 engine. Fitting to head is 1/8"NPT, fitting has a .046 hole. I think the screen is designed to collapse in length, when screwing the fitting into the head. 3 Link to comment Share on other sites More sharing options...
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