Pete M Posted April 4, 2021 Share Posted April 4, 2021 wait, unless shortening the intake tube is what does it? I'm a little fuzzy on all that. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 4, 2021 Author Share Posted April 4, 2021 I bet if you either bent that vent tube up or cut it back a little, you might yield another gallon or two in an 18. Link to comment Share on other sites More sharing options...
Pete M Posted April 4, 2021 Share Posted April 4, 2021 the little tube is the vent, and it's already pretty dang short. Link to comment Share on other sites More sharing options...
dzlmnche Posted April 4, 2021 Share Posted April 4, 2021 I can’t believe the timing of this thread!I’ve been researching extending the range in my Mercedes diesel swapped LWB with the 16 gal tank. I may have to put some thought into how to trim that tube.I am guessing the only difference between the 16 and 23.5 gal sending units is the length of the float... I don’t suppose anyone has a 16 and 23.5 gal sending unit to compare? Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 4, 2021 Author Share Posted April 4, 2021 Just now, dzlmnche said: I can’t believe the timing of this thread! I’ve been researching extending the range in my Mercedes diesel swapped LWB with the 16 gal tank. I may have to put some thought into how to trim that tube. I am guessing the only difference between the 16 and 23.5 gal sending units is the length of the float... I don’t suppose anyone has a 16 and 23.5 gal sending unit to compare? Lol I also did the research for that too: Sending unit identification - MJ Tech: Modification and Repairs - Comanche Club Forums Link to comment Share on other sites More sharing options...
dzlmnche Posted April 4, 2021 Share Posted April 4, 2021 Lol I also did the research for that too: Sending unit identification - MJ Tech: Modification and Repairs - Comanche Club Forums Are you local to CT? I owe you some beer. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 4, 2021 Author Share Posted April 4, 2021 Just now, dzlmnche said: Are you local to CT? I owe you some beer. Lol I am not. All the way out in AZ. I plan at least merge the two posts so that way all the info is together. Link to comment Share on other sites More sharing options...
Torq_Shep Posted April 5, 2021 Share Posted April 5, 2021 I will get measurements on that tonight. Been super busy with house repairs... Link to comment Share on other sites More sharing options...
Rad_Comanche Posted April 8, 2021 Share Posted April 8, 2021 Where is that plate ID you mentioned located on the tank? I was actually just looking at my 86 to see if it was a 16 or 23.5, since my sending unit is wonky. Good to know the 86 filler is also a different shape too. Excellent research on both the tank and send units! Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 8, 2021 Author Share Posted April 8, 2021 8 minutes ago, Rad_Comanche said: Where is that plate ID you mentioned located on the tank? Looking at the tank head on. Mine is to the left of the sending unit: My ID tag: Mine is correct and is the original tank. My MJ was built 11/15/87. Tank was built 11/10/87 with denotes of being 16 here's the 18 gallon one I snapped a pic of before I sold it: This one was made 12/03/86 which makes this tank from an early SWB 87. Link to comment Share on other sites More sharing options...
Pete M Posted April 8, 2021 Share Posted April 8, 2021 are the 16 and the 23.5 the same outside dimensions? Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 8, 2021 Author Share Posted April 8, 2021 Yup they are! Just measured my 16 and 23. Link to comment Share on other sites More sharing options...
Pete M Posted April 8, 2021 Share Posted April 8, 2021 so one would just need the different sending unit and tocut off that vent tube to gain a ton of gas capability? or skip the sending unit and just have a "full" tank for a long time before it started registering on the gauge. this seems too easy... Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 8, 2021 Author Share Posted April 8, 2021 Remember, its AMC. Why make two different tanks when all ya gotta do is add a longer vent tube to lessen the amount of gas that goes in. But that being said, youd have to let the tank sit for a while before you start modifying the vent tube. Just with sparks and fumes and all that. But yeah I think it is that easy especially since the 18 and 23 share the same sending unit. I really need to get all this info in one thread lol. Link to comment Share on other sites More sharing options...
Rad_Comanche Posted April 8, 2021 Share Posted April 8, 2021 2 hours ago, eaglescout526 said: Looking at the tank head on. Mine is to the left of the sending unit: My ID tag: Mine is correct and is the original tank. My MJ was built 11/15/87. Tank was built 11/10/87 with denotes of being 16 here's the 18 gallon one I snapped a pic of before I sold it: This one was made 12/03/86 which makes this tank from an early SWB 87. That answers that question! It is backwards and upside down, but this confirms I have a 16 gallon tank, original to my truck at that. Following for possible modifications for that vent tube... Link to comment Share on other sites More sharing options...
Pete M Posted April 8, 2021 Share Posted April 8, 2021 wait, how can they share the same sending unit if "full" is different for each? Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 8, 2021 Author Share Posted April 8, 2021 18 minutes ago, Pete M said: wait, how can they share the same sending unit if "full" is different for each? Well if you think about it they have different amounts they take but in reality it just depends on the float arm length. The catalog shows the 18 and 23 to be the same part number which I’ll have to get a pic of. Like the 16 has a shorter float arm which means it will get to “full” faster. But the longer arm for the FSU means the float will get to the top and read the same regardless of the tank it’s really in. 23 minutes ago, Rad_Comanche said: That answers that question! It is backwards and upside down, but this confirms I have a 16 gallon tank, original to my truck at that. Mine was upside down. I just spun the pic to show what it says. Link to comment Share on other sites More sharing options...
gogmorgo Posted April 8, 2021 Share Posted April 8, 2021 12 hours ago, eaglescout526 said: But that being said, youd have to let the tank sit for a while before you start modifying the vent tube. Just with sparks and fumes and all that. Use some heat-resistant hose and run another vehicle’s exhaust into it for a half-hour or so. That or purge with CO2 if you’ve got some handy. Link to comment Share on other sites More sharing options...
JustEmptyEveryPocket Posted April 8, 2021 Share Posted April 8, 2021 14 hours ago, eaglescout526 said: let the tank sit for a while before you start modifying the vent tube Could you get a tubing cutter in there? No sparks and they are fairly compact. Also, seems like the float arm would be easy to modify if you knew what length was needed. Cut it and use electric pixies to melt in extra length. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 8, 2021 Author Share Posted April 8, 2021 3 minutes ago, JustEmptyEveryPocket said: Could you get a tubing cutter in there? No sparks and they are fairly compact. Also, seems like the float arm would be easy to modify if you knew what length was needed. Cut it and use electric pixies to melt in extra length. See I thought about that and I’m a skinny guy but my arm gets all the way to my forearm and I can barely touch the filler tube. You could get to that tube with those cutters probably with no problem I went and measured this the other day for a fellow. The 16 gallon float arm from float to first bend is ~2 3/4” of an inch. Mean while the 23 and 18 is 5 1/2” from float to first bend. Link to comment Share on other sites More sharing options...
eaglescout526 Posted April 17, 2021 Author Share Posted April 17, 2021 First post updated. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now