Problems with one cylinder on a 20/2

[JohnF]

Jens;

I have found that the pony pump I (used to) use for transferring cleaned veggie to my Biodiesel reactor quickly lost its "oomph".  A quick check of it shows that the impeller (plastic) has been severely damaged by either the veggie or what is in it.  It still made all the appropriate noises, just didn't deliver - sorta like a politician.....

[billswan]

jens

I know biodiesel is hard on some types of fuel lines veg oil may be too?

The pump may be bad because of the veg oil like adev and john f  addvise.

Check your lines and your pump.

Billswan

[bschwartz]

I've been using a Walbro diaphragm pump in my mercedes and my 6.5 Chevy Suburban for 2 years with no issues.  They provide 5-12 PSI (depending on model).  Noisy clacking things, but they have served me well.  I don't know how the seals would deal with bio, but 100% SVO hasn't slowed them down.

[rl71459]

bschwarts

What walbro pump is it?

Rob

[bschwartz]

It is an FRB5.
I didn't purchase from this company, but here are the specs.
http://www.fuel-pumps.net/frb51.html

-Brett

[rl71459]

Thanks

[AdeV]

how do peristaltic pumps stand up to continuous usage - does the tubing not need regular replacement on these ? I like the idea !

I don't know, is the honest answer. The only one I've actually seen in use is used to bleed brake lines. Whilst googling (because I couldn't remember the name "peristaltic", I came across a few references to them being rated for continuous duty, and the line lasting for "millions" of cycles...

One thing that did occur to me; they may be self-regulating as regards downstream pressure - because there'd be some leak-back past the moving "thing" in the pump; so maybe you'd be able to avoid a return pipe & regulator; however, the only low-cost examples of peristaltic pumps that I can find really do provide miniscule amounts of liquid (4.2ml/minute was what one of them quoted).

Edit: Thinking about it, they use peristaltic pumps for heart bypass and dialysis machines; I'm sure it must be possible to get both the pumps, and replacable piping for those, relatively cheaply; is there such a thing as hospital surplus?

[billswan]

jens

That is one big ass pump, 8 to 11 PSI and 45 gph my gosh isn't there a smaller pump out there somewhere?

It says industrial but don't you think that is a little bit to big for your oid? Divide the GPH output by 10 and that would be to much!

If all your fuel line is in good shape inside (no collapsing liner) and you are sure it is the pump you now are using why not take it apart to see what makes it tick. It might be fixable.

Billswan

[billswan]

Now that is weird, I only saw your reply by accident. I normally just click on 'read new posts since last visit' (or whatever) and your post never came up.

Jens

Jens
Have noticed some glitches in the software like you note above, thought it was just me or my computer.
Have also noted others making mention of other problems. Wounder what is up?

Still think you should give the pump you have, a look see, maybe it can be modified to pump the veg oil perhaps a heaver spring or a internal relief or possibly a new oring of some other type of rubber and it may fix the problem. Aren't you the least bit curious why it doesn't keep pumping and jams up?

Billswan

[veggie]

Jens,

I would like to respectfully challenge your diagnosis.
180 Deg. F veggie oil is very similar in viscosity to dino-diesel.
The theory of the plunger grabbing or sticking due to viscosity would only be valid if you think the temperature of the oil is cooling before it reaches the pump. If that is the case, perhaps some additional heating is in order (heat wires around the pump ??).

If you can tolerate the exhaust odor, run some dino for a while and see if the problem pops up.

Just a thought...
Veggie

[bschwartz]

Jens, I think you will be really pleased with the performance of the pump.  They tolerate a lot of extremes.  My single tank Mercedes pump works in the winter pushing COLD (30 degree F) veg from the tank, and the pump on the suburban sees oil after it's been heated to around 160.  As you are just trying to get fuel to the injection pump with no real need for pressure, the Walbro will click away happily for years.

[bschwartz]

If it isn't too inconvenient, run it as a pressure pump.  These are always recommended to be run as close to the tank as possible.  They push MUCH better than they suck.

[bschwartz]

Why is it easier to pull a rope than to push a rope?
Is it easier to blow water through a hose, or to suck it?
I guess with the racor, if you use suction, it is impossible to pressurize it beyond atmospheric, and to much pressure could cause a leak (around seals, not necessarily external).  With the pump, only atmosphere will fill its small cavity for pushing, and at the end of a long run of fuel line, not much (particularly oil) flows quickly enough to fill that spot.  As you don't need any real pressure (unlike a vehicle engine), I don't think placement will really matter.  We also aren't talking about a 10 foot run like under my suburban.

[vdubnut62]

Most electric pump manufacturers  will void the warranty if the inlet is not filtered.
Ron