Pet cock filters.

[Agemax]

As there has been a few threads lately enquiring about petcock fuel filters and they do not seem to be available new, i thought i would try and design a easy,cheap alternative.
as my own filter has been missing for a few years now it would be a good time to get one sorted but there is one thing i need to know.......

can someone please measure the height of the main tank tube and the reserve tube? measure it from the flat mounting surface of the petcock where it sits flush with the tank.

thanks.

 

[tom203]

My old petcock (likely stock original) has res/ pr pickup 5mm up from mounting surface. The main tube is about 85mm up. I replaced this with a petcock that had much lower main tube- about 25 mm lower if I remember right.

EDIT; those measurements should be main tube up 80mm, and res/pr 2mm up

 

[Agemax]

My old petcock (likely stock original) has res/ pr pickup 5mm up from mounting surface. The main tube is about 85mm up. I replaced this with a petcock that had much lower main tube- about 25 mm lower if I remember right.

thanks Tom, i will keep the reserve tube the same but debating on whether to make the main tube shorter so you have a greater volume before hitting reserve but i suppose it doesn't really matter, the owner can decide on the height, bigger main tank/smaller reserve or even smaller main tank/bigger reserve............ the choice is endless really

 

[tom203]

I made correction. My original petcock had too high a pickup (at least on my "L" tank ) at 1/3 tank, the carbs would starve for fuel going down a long hill, new one is better.

 

[Agemax]

would anybody happen to know the mesh size (in microns) of the stock Suzuki pet cock filters?

 

[BigD_83]

would anybody happen to know the mesh size (in microns) of the stock Suzuki pet cock filters?

Off the top of my head, no, but if you give me a day, I can throw one in the SEM, and give you a measurement by the end of the day tomorrow

 

[Agemax]

Off the top of my head, no, but if you give me a day, I can throw one in the SEM, and give you a measurement by the end of the day tomorrow

that would be great, i have a few leads on different filters that could fit but knowing what the OEM mesh size is would help me get close to what is needed.

thanks BigD

 

[BigD_83]

Fiter Mesh Measurements

Fiter Mesh Measurements

As promised. Looks to be about 70μm mesh. The bright bits? That's rust:

 

[bwringer]

As promised. Looks to be about 70μm mesh. The bright bits? That's rust:

Now THAT is the finest misapplication of science that I have seen in a good long while... :clap: :clap: :clap: :clap: :clap:

 

[Agemax]

wow, thats great. the filter i plan on using has a choice of either 50 mesh (297 micron) 60 mesh (250 micron) or 100 mesh (149 micron).
as a calculated guess i opted for the 50 mesh so i think it should be ok but as they are cheap enough and the same price then i could always go to the 60 mesh if needed.
i think 100 mesh would be too fine.
thanks for the info BIGD.

 

[BigD_83]

No worries...

note the BIG chunk of rust in there measures out around 70 x100 μm. I was a little surprised at how small some of that rust is, but I guess I should not have been, given the amount of rust one can find in the bottom of carb bowls.

I guess it is a good thing there a couple of places for the rust to settle out, but with the constant movement, it would appear we are constantly chucking rust through the combustion chamber.

I'm going to have to cut open one of the sintered inline filters to see what the pore diameter and porosity is really like.

 

[BigD_83]

wow, thats great. the filter i plan on using has a choice of either 50 mesh (297 micron) 60 mesh (250 micron) or 100 mesh (149 micron).
as a calculated guess i opted for the 50 mesh so i think it should be ok but as they are cheap enough and the same price then i could always go to the 60 mesh if needed.
i think 100 mesh would be too fine.
thanks for the info BIGD.

Agemax,

are you concerned about clogging the filter if you go finer?

EDIT- the stock mesh pitch works out to be 200

 

[Agemax]

Agemax,

are you concerned about clogging the filter if you go finer?

EDIT- the stock mesh pitch works out to be 200

that was a concern. the filters are stainless and washable but do we really want to add cleaning the petcock filter as a "regular" maintenance activity.
i suppose it depends on the condition of the tank inside. my tank is brand new so i could get away with a coarser filter whereas a rustier tank would require a finer filter, but then require more frequent cleaning.

bye the way, this is the conversion chart i am working against....may be right or wrong but it gives a good general idea.......

http://www.showmegold.org/news/Mesh.htm

 

[BigD_83]

My math was a little different, but by that conversion chart the stock measure would be around 230 mesh.

My math: 8 grids/mm x 25.4mm/inch = 203 grids/inch.

Just my 2 cents, but my experience with sintered filters says that cleaning requires a strong detergent and ultrasonication.

I have some inline with one piece of equipment to filter liquid carbon dioxide, and they have a [EDIT- 0.5 μm] pore size. They get used maybe twice a week, and are pretty clogged up after two years. Even though it is (mainly) biological material, it still requires both detergent and sonication to get them even remotely clean again, but certainly not like new.

I applaud any effort to make the filters more robust, and cleanable.

Best of luck in the pursuit.

 

[Agemax]

My math was a little different, but by that conversion chart the stock measure would be around 230 mesh.

My math: 8 grids/mm x 25.4mm/inch = 203 grids/inch.

Just my 2 cents, but my experience with sintered filters says that cleaning requires a strong detergent and ultrasonication.

I have some inline with one piece of equipment to filter liquid carbon dioxide, and they have a 50 μm pore size. They get used maybe twice a week, and are pretty clogged up after two years. Even though it is (mainly) biological material, it still requires both detergent and sonication to get them even remotely clean again, but certainly not like new.

I applaud any effort to make the filters more robust, and cleanable.

Best of luck in the pursuit.

i'm confused now. earlier you say the stock filter is roughly 70 mesh (210 micron) now you are saying it is 230 mesh (63 micron).

are you recommending using a finer or coarser filter?

 

[BigD_83]

Sorry Agemax,

I was multitasking, and in my mind I had another measurement of 0.125" (1/8") from somewhere, and I had just taken 8 and multiplied it by 8 to get a pitch of 64/inch. That is obviously not what is going on here.

Let me try to clear it up:

My measurements have the stock pore size at approximately 70 micrometers, not 70 mesh). The pitch or mesh size includes the bars between the holes. If you look at the last image, there are 8 holes+bars every mm, which works out to about 200 holes per inch (200 mesh).

Does that make sense?

 

[Agemax]

Sorry Agemax,

I was multitasking, and in my mind I had another measurement of 0.125" (1/8") from somewhere, and I had just taken 8 and multiplied it by 8 to get a pitch of 64/inch. That is obviously not what is going on here.

Let me try to clear it up:

My measurements have the stock pore size at approximately 70 micrometers, not 70 mesh). The pitch or mesh size includes the bars between the holes. If you look at the last image, there are 8 holes+bars every mm, which works out to about 200 holes per inch (200 mesh).

Does that make sense?

right, i got you. so 200 mesh = roughly 70 microns.
so the stock filter is a 70(approx)micron filter.
if i am using a 50 mesh filter then that is too coarse for the job.
the best i can get with the filters i have chosen is 100mesh, approximately half the mesh filtration it should be............?

is that right?

 

[BigD_83]

You've got it!

I also need to make another correction. In my explanation in Post #14, about my inline filters. Your question made me wonder if I had quoted the right size. I was in fact, off...I have edited the inline filter size above (re:liquid carbon dioxide)...it should have been 0.5 micron.

 

[Agemax]

0.5 micron is pretty small haha......
right, as i always refer to microns, but you guys prefer mesh (and i have a conversion chart handy) i will stick to referring to filters in "MESH" size from now on......

so...........will a 50 mesh filter be to coarse or do you think it will ok?
i am going to proceed with them anyway at the moment as that is the ones i have ordered but once i know they fit properly and will work then if anybody else wants to make their own they can decide themselves what size mesh they want to use.

 

[BigD_83]

I, too prefer to use pore diameter, but I routinely use both references in the work I do, depending on the application.

I think 50 Mesh is really coarse, given the size of that huge particle in the middle of the shot. I could see a bunch of those floating downstream and causing havoc.

It'd be worth investigating what happens to rust in the combustion chamber, and what happens to the combustion chamber due to rust. Does it contribute to ring/seal failure?