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| | | Joined: Aug 2019 Posts: 242 'Bolter | | 'Bolter Joined: Aug 2019 Posts: 242 | Has anyone tried a new carter mechanical pump on their 235? There are two flavors I'm aware of from summit or rockauto: Carter 2118Carter 2999I have the 2999 and cannot figure out a good way to thread onto it. Both pumps are listed as 1/8-27 NPSF on rockauto... but I can't find any adapter that size. My fuel lines are 5/16 with 1/2-20 threads on their flare fittings. Right now I'm using a 1/8npt to 1/2-20 flare adapter, but the 1/8npt doesn't seal without the aid of JB weld. What thread sizes do you guys have on your fuel lines & pumps?
'59 Chevy Suburban, NAPCO
| | | | | Joined: Feb 2004 Posts: 29,771 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,771 | The 1/8-27 is known otherwise as "1/8" Pipe". It has a tapered thread, and requires some type of thread sealer to prevent leakage. I prefer to use a flexible, non-hardening sealer like Permatex Super 300. It was developed in the 1950's to seal aviation gasoline fittings, and it works better then the Permatex 3D, which is also a non-hardening brush-on sealer. It's best to avoid Teflon pipe tape on gas like fittings, as slivers of the tape can get into the fuel system and clog carburetor passages or keep float valves from working properly. The most common adapter fitting for fuel lines has a 1/8" pipe male thread, and a 1/4" or 5/16" "inverted flare" on the other end.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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| | | | | Joined: May 2015 Posts: 11,039 Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums | | Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums Joined: May 2015 Posts: 11,039 | What Jerry said.
NPSF = National Pipe Size Female (more commonly indicated as NPTF for National PIpe Thread Female).
Adapters are easy to find at nearly any FLAPS or Hardware store.
Another sealer would be "Gasoilia" made specifically for fuel and gasoline. Pipe threads will seal without a sealer, but you have to tighten them till your eyes bug out or the female fitting cracks. Without a sealer, you also run the risk of galling the threads. Bottom line is use a sealer (not JB Weld).
Kevin 1951 Chevy 3100 work truckFollow this saga in Project JournalPhotos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together. | | | | | Joined: Aug 2019 Posts: 242 'Bolter | | 'Bolter Joined: Aug 2019 Posts: 242 | My eyes are already bugging out due to how many types of threaded pipe joints there are  However, your replies helped a lot. Thanks!
Last edited by Ott3r; 01/12/2020 10:14 PM.
'59 Chevy Suburban, NAPCO
| | | | | Joined: Mar 2005 Posts: 1,513 'Bolter | | 'Bolter Joined: Mar 2005 Posts: 1,513 | What Jerry said.
NPSF = National Pipe Size Female (more commonly indicated as NPTF for National PIpe Thread Female).
Adapters are easy to find at nearly any FLAPS or Hardware store.
Another sealer would be "Gasoilia" made specifically for fuel and gasoline. Pipe threads will seal without a sealer, but you have to tighten them till your eyes bug out or the female fitting cracks. Without a sealer, you also run the risk of galling the threads. Bottom line is use a sealer (not JB Weld). Not exactly...NPTF threads are designed to work without sealers. The "F" stands for fuel and is designated a dryseal thread due to the root and crest of the thread being taller than standard NPT which is designed to be used with some type of sealant.
1952 1300 Canadian 1/2 ton restomod You Tube | | | | | Joined: May 2016 Posts: 268 'Bolter | | 'Bolter Joined: May 2016 Posts: 268 | NPSF= national pipe straight fuel.
NPTF=national pipe taper fuel
1949 gmc 1-ton | | | | | Joined: May 2015 Posts: 11,039 Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums | | Housekeeping (Moderator) Making a Stovebolt Bed & Paint and Body Shop Forums Joined: May 2015 Posts: 11,039 | Not exactly...NPTF threads are designed to work without sealers. The "F" stands for fuel and is designated a dryseal thread due to the root and crest of the thread being taller than standard NPT which is designed to be used with some type of sealant. I did not know that. Thanks for the info. So the OP needs to find a NPSF male adapter. Or will a NPTF adapter work?
Kevin 1951 Chevy 3100 work truckFollow this saga in Project JournalPhotos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together. | | | | | Joined: Aug 2019 Posts: 242 'Bolter | | 'Bolter Joined: Aug 2019 Posts: 242 | ok... i think i found something: https://www.mscdirect.com/product/details/53567848that is, assuming a nptf fitting will play nicer with my npsf pump than my current npt fitting.
Last edited by Ott3r; 01/13/2020 10:42 PM.
'59 Chevy Suburban, NAPCO
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