Fuel Vapor Separator - Design Opinions Wanted

[procomsignathid]

I'm thinking of 3D-printing some unobtanium parts, starting with the fuel vapor separator (P/N 77193-6011-2A). I have access to a printer that can do both nylon and HDPE, which I think would work for this part in terms of resiliency to fuel vapor.

Couple questions...

• Would this part be of use to folks?
• If so, would you prefer an accurate reproduction in terms of shape, or do you care what it looks like?

I have a few mockups I've put together in Fusion 360 so far, let me know if you dig it, and if so, if you like option A or B best!

Option A (faithful reproduction):

Option B (designed for easier 3D-printing):

Here's an idea of what it looks like on the inside (the latter version):

 

[GA Architect]

Nice work on a part I could use.

 

[charliemeyer007]

I still have my OEM 72 unit. Gas/alcohol resistant/proof plastic printing a must. Plug and play for fit and function would be more important to me as neither is OEM. Both look nice to me - Cheaper is better, choice is always good too.

 

[jembourbe]

As long as the gross dimensions and ports work in the place of the factory units, I could care less what it looks like. If you can see it when installed, your cruiser is missing some parts

 

[ijonesinsp]

I literally snapped one of the ports off the body of mine yesterday putting it back in place...

 

[procomsignathid]

I literally snapped one of the ports off the body of mine yesterday putting it back in place...

Ah bummer! I had the same problem when putting mine back in, which is what set me down this path in the first place. As a temporary bodge I used a section of a ballpoint pen cap and a lot of JB weld to get it back together, but I'm pretty sure it won't last. Basically any replacement, even in good condition, is going to be swapping 50-year-old plastic for 50-year-old plastic.

 

[ducktapeguy]

Just a suggestion if you go with option B and not worried about being a faithful reproduction. Since the weak point of these vapor separators are the ports, design it with a thicker boss around the ports can take a standard threaded brass fitting instead of a making it all one piece. Even with newer material the weak point is still going to be where those ports connect to the body

 

[procomsignathid]

I like that suggestion! It would be easy to beef it up with additional material w/o doing the brass fitting, do you have a link to something in particular?

EDIT: Are you thinking something like this?

 

[ducktapeguy]

Yes that's what I describing. Just adding material might not work because the weak point will always be right where the port exits from the hose, that's where most of the stress is going and where the material is thinnest. Changing to a brass or stainless port moves the stress point up to the body where you can add as much material as needed.

 

[procomsignathid]

Going with a reputable source on these might price folks out is my guess, I'll look for some chinesium equivalents. Here's what I found at McMaster:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[65swb45]

Ah bummer! I had the same problem when putting mine back in, which is what set me down this path in the first place. As a temporary bodge I used a section of a ballpoint pen cap and a lot of JB weld to get it back together, but I'm pretty sure it won't last. Basically any replacement, even in good condition, is going to be swapping 50-year-old plastic for 50-year-old plastic.

50yo plastic that has been stored in a warehouse for 30 years is not the same as 50 yo plastic pulled from a vehicle sitting in a field.

I have over a dozen good used ones available for sale.

 

[65swb45]

Yes that's what I describing. Just adding material might not work because the weak point will always be right where the port exits from the hose, that's where most of the stress is going and where the material is thinnest. Changing to a brass or stainless port moves the stress point up to the body where you can add as much material as needed.

THAT is an excellent idea!

 

[procomsignathid]

So it looks like 1/8" NPT (or 1/4" NPT) to 1/4" (1x, upper) and 5/16" (3x, lower) hose barbs will work to be compatible with the OEM part (6.3mm and 8mm diameter, respectively). Brass fittings are pretty easy to come by, but I'm hearing brass is no-bueno for fuel systems as it leeches zinc. Stainless steel seems to be the way to go. Been finding a lot of fittings in the $7-10 range that I think would fit the bill.

Looks like it would be about $40 in fittings alone, but it would be a pretty bomber setup.

 

[charliemeyer007]

I never had any trouble with brass and fuel fittings. But $2 each for stainless steel

https://www.amazon.com/Ceaeso-Stainless-Hose-Barb-Air%EF%BC%8Clead-free/dp/B0CYP94T4B

 

[procomsignathid]

I never had any trouble with brass and fuel fittings. But $2 each for stainless steel

https://www.amazon.com/Ceaeso-Stainless-Hose-Barb-Air%EF%BC%8Clead-free/dp/B0CYP94T4B

Fair point on the Amazon, I had limited my search to other areas, I found these but wouldn't be surprised if they were made in the same factory.

 

[charliemeyer007]

To me having a thicker tapered base to screw into is the ticket to the superior design/build. Brass barb at Home Despot are like $5 each in the 1/4-1/4 size

 

[ducktapeguy]

My own experience I have used brass fitting for fuel systems with no issues, the amount of zinc or other material contained in a fitting is negligible compared to the amount of fuel in a tank. These parts will normally never see direct contact with gas anyway, and they're not under any type of real load, so I don't think it would be an issue to use cheap no-name fittings off amazon.

The reasoning behind making it compatible with standard NPT fittings is you don't have to provide the fittings, just the body. People can source their own fittings locally

 

[procomsignathid]

That all makes sense. I could see this as "buy your own fittings" vs "include brass or SS fittings for $X or $Y". Thoughts on 1/8" NPT vs 1/4"?

 

[charliemeyer007]

Its your project, do it your way. Plug and play is a very good selling point - I really hate when I buy something and then need to buy something else to make it fit/work

 

[charliemeyer007]

What is the hose size its going to fit into? I don't mind a little forcing to make fit it - way better than trying to get an undersized unit to seal properly by crushing it with the clamp.