Motor Mounts

Peter B wrote:
Steve D'Antonio has mentioned this in articles in PMM - what about the known fact that filters actually work better - ie do what they are meant to do a bit more efficiently, when they have been in use for a while, and are actually 'partly clogged' with the stuff they are filtering out...?

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I think Steve D'Antonio comes up with this stuff just so he has something to write about so he'll get paid.* I don't deny his experience (I guess) but from what I've read of his stuff I think he has elevated armchair theorizing to an art form.

I think I'll stick to the advice and practices of the aviation, automotive and marine engine mechanics and engineers I know personally.

All filters do work better as they get an accumulation of stuff , that serves as a pre filter and lessens thev work load of the filter medium.

Water is an exception from junk , and a filter that is partially water blocked is best changed as it is now smaller..

FF wrote:
All filters do work better as they get an accumulation of stuff , that serves as a pre filter and lessens thev work load of the filter medium.

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You've got the right statement for the wrong reason.* Sure, a filter that is crudding up with stuff will capture more stuff on the exterior because that's where the stuff accumulates.* But this "lessens the work load of the filter medium" business*is not a good thing, it just means the surface of the filter is getting all crudded up so less stuff is pasing through it and the filter is that much closer to slowing or shutting down the flow of fuel or oil or whatever.*

A dirty filter is a dirty filter.* The flow of fluid through it is not dependent on where the crud is.* Exterior or interior, the point is it's gathering crud and so getting closer to being clogged.

Like I said, great armchair theory, not much relevance to reality.

No, it's not just armchair theory. Put it this way...the filter first captures larger particles than the actual micron pore size rating, as it were, but over time these accumulated larger particles actually tend to reduce the pore size to, in effect, something smaller, so more efficient at capturing even smaller stuff than the filter was rated for. This is all at the microscopic stage at this point, so hardly even visible if inspected other than faint discolouration, but there, none-the-less. We are not talking solid crud type contaminants here, but Marin, as you have said yourself in the past, really cruddy, dirty fuel, with significant contamination, is now thankfully largely only a bad memory for most of us in the parts we travel. Result being filters can now last a lot longer - best monitored by a vacuum gauge for the really fastidious. I don't bother - I don't do enough distance. I've had my filters replaced twice in 10 yrs, mainly because I thought why not, the mechanic is working on her, so may as well. In each case they were barely discoloured and the motor was never missing a beat, even at top rpm.
Maybe it is worth adding, I don't have a fuel polishing system. My primary filter performs that function, as the tanks both drain from the bottom, and I never have them more than half full, yet only drain ~1 teaspoonful of water a year from the bottom of the primary filter, and it also was barely discoloured at each change. So much for the condensation theory - at least in our climate. Am I just lucky? I think not...I am just not a lucky person. I've never won anything - sorry - I lie - I did once win 2 mugs for being closest to the pin on the par 3 during the annual Drs v's Chemists golf match in about 1980. Still got them actually - used one this morning for my coffee...so I guess that says I'm careful.

In the 13 years we've had our boat I have never found water in our filters, ever. And our tanks are full, half full, mostly empty, completely empty, the whole gamut all year long. Our tanks all gravity feed from their lowest points into the day tank, which feeds the engines and generator from its lowest point.

However in Hawaii, where I often flew multiple days in a row, every airplane on the line ALWAYS had some water in the bottoms of the tanks in the first preflight of the day even if the plane had been flown multiple times the previous day and had the tanks filled to the tabs (so not all the way full) each evening.

And I still don't buy the "partially clogged filter does a better job" theory. I'm not going to say categorically that it's wrong, I just don't buy into the concept.

Marin wrote:And I still don't buy the "partially clogged filter does a better job" theory. I'm not going to say categorically that it's wrong, I just don't buy into the concept.

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******* Glad you said it, Marin. I was thinking it but didn't have the guts to say it.

SeaHorse II wrote:Marin wrote:And I still don't buy the "partially clogged filter does a better job" theory. I'm not going to say categorically that it's wrong, I just don't buy into the concept.

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******* Glad you said it, Marin. I was thinking it but didn't have the guts to say it.

*I didn't say "partly clogged" Marin.* I thought it was plain I meant 'used, in the sense of 'doing it's job', and which does improve it's filtering capacity for a time...up until it 'begins to get clogged' obviously, then the function starts to degrade, but easily detected by a vacuum gauge.* Now play fair.* You don't like to be mis-quoted either, I've noticed.*

At least we agree on the fact that a bottom draining fuel system is better than a lot of money spent on expensive fuel polishing systems, and Walt agrees with that also I suspect.*


-- Edited by Peter B on Thursday 26th of January 2012 03:06:17 AM

Peter B wrote:
*I didn't say "partly clogged" Marin.* I thought it was plain I meant 'used, in the sense of 'doing it's job', and which does improve it's filtering capacity for a time...up until it 'begins to get clogged' obviously

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Okay, but if the fuel filtering gets better as the filter picks up crud, then it would seem to me a better solution would be to use a finer filter to begin with. Maybe this is why our diesel shop and the people I know at Northern Lights/Lugger all advised us when we got the boat to use 2 micron filters on everything.* Which is what we have been using for the last 13 years.

If a partially clogged filter does a better job then I had better start using the filters that the people around this marina throw away.....like hell!!!!
A clean filter does a better job than a partially blocked filter every time...no bull**** batman


-- Edited by Tidahapah on Thursday 26th of January 2012 03:50:26 AM

"A dirty filter is a dirty filter. The flow of fluid through it is not dependent on where the crud is. Exterior or interior, the point is it's gathering crud and so getting closer to being clogged."

When the filter IT SELF is plugged , partially clogged , it will pass less volume, time for a replacement.

Collecting big crud on the SURFACE of the filter does nothing to block the flow to the filter , its BIG CRUD!

Most rec. boats change filters by calender , not by volume passed or restriction gauge readings.

This is fine , tho not as efficient in, dollar coats .

But if it saves a single tow home , "Pri$less".

FF wrote:


Collecting big crud on the SURFACE of the filter does nothing to block the flow to the filter , its BIG CRUD!

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*Right.* But this notion that big crud on the surface of a filter makes the filter more effective is a false economy, I think.* What it means is that the filter is doing its job.* If you depend on the filter surface collecting big crud to make the filter do its job properly, then it would seem you're using the wrong filter.


-- Edited by Marin on Thursday 26th of January 2012 01:12:05 PM

If you have a floscan you can't use a 2 micron filter.

*It will cause bubbles in the fuel flow giving bad readings.

*A 30 mocron in the racore is what is recomended.

The 2 micron at the engine filter is fine as the flow scan is installed before the motor filter.

SD

skipperdude wrote:
If you have a floscan you can't use a 2 micron filter.

*It will cause bubbles in the fuel flow giving bad readings.

*A 30 mocron in the racore is what is recomended.

The 2 micron at the engine filter is fine as the flow scan is installed before the motor filter.

SD

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* * * * Absolutely correct!

SeaHorse II wrote:skipperdude wrote:
If you have a floscan you can't use a 2 micron filter.

*It will cause bubbles in the fuel flow giving bad readings.

*A 30 mocron in the racore is what is recomended.

The 2 micron at the engine filter is fine as the flow scan is installed before the motor filter.

SD

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* * * * Absolutely correct!

*And I caught flak for using a 30 micron on my Racor?

dwhatty wrote:
*And I caught flak for using a 30 micron on my Racor?

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******** When was this?

SeaHorse II wrote:dwhatty wrote:
*And I caught flak for using a 30 micron on my Racor?

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******** When was this?

In this thread. Bottom of page.*


-- Edited by dwhatty on Thursday 26th of January 2012 04:54:08 PM

AAh but is that your only filter?

If so a 30 may not be small enough.

If you have a floscan you can't use a 2 micron filter.

It will cause bubbles in the fuel flow giving bad readings As stated.

*I was refering to a boat with a floscan.

SD

skipperdude wrote:
AAh but is that your only filter?

If so a 30 may not be small enough.

If you have a floscan you can't use a 2 micron filter.

It will cause bubbles in the fuel flow giving bad readings As stated.

*I was refering to a boat with a floscan.

SD

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Is that my only filter? No. I use the Cummins branded on-engine filter as well. Don't know the micron of it. Does that count?

dwhatty wrote:

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Is that my only filter? No. I use the Cummins branded on-engine filter as well. Don't know the micron of it. Does that count?

* * * * I use the exact same set up and for the many thousands of hours I have put on my engine, It has never failed me. :cynic:

Exactly the point I was making in some ways earlier in the thread. The bad thing about using 2 microns all round is then only the primary filter is actually doing anything, and will pick up all the crud, and block up earlier, while the secondary filters are not really doing anything much. The whole idea of having 30microns on the primary is that it takes out anything above that, yes, and even some smaller stuff as it ages, thus only smaller particles get through and are caught by the secondary filters, of which I have two on the Lehman 120. This progressive increase of filter efficiency is the secret to the whole deal, and makes each filter justify their existence, and give their maximum life at the same time. If you use 2 microns throughout, you could at least save the changing of the secondaries to a much longer engine run time, and change just the primary regularly, because it is doing all the work.
So David (dwhatty) was right, and Walt agrees, so that's not bad consensus.

This is all a far cry from motor mounts..but what the heck.

There is no right answer to fiters.* All they re designed for (singles or systems) is to keep crap out of the engine.* As long as you have a small enough media between the tank and the necessary parts...then thats all that's important.

In all my years of recreational and professional boating...I've only had a few engines quit because of filters.* On diesels... the one or two times...it wouldn't have mattered how great of a filter system you had...the first filter setup would have plugged quickly and needed to be changed in a short amount of time.

The only thing that would have changed that is... a filter vacuum warning system (and all that might have done is have me change the filters 10 miles closer to land that without the vacuum guage).

So the bottom line is clean fuel and clean tanks...on a rec boat you should be able to see or pull a sample of fuel at the bottom of your tank regularly or you are rolling the dice.* I like sight guages for that very reason.

With very*clean fuel, you can run hundreds if not a thousand hours on a single 2 micron filter and your engine doesn't give a hoot how fancy your filtration setup "might" be.

If you have a floscan you can't use a 2 micron filter.

That may be true for a suction fuel system , but we ran over 10,000 miles with a pair of 1000series Raycore and the 2 micron.

The difference is our filters are gravity fed .

It might be also that our 6-71 flows a huge volume of fuel , rather than the minor fuel pumped by Bosch style pumps.

Peter B wrote:
Exactly the point I was making in some ways earlier in the thread. The bad thing about using 2 microns all round is then only the primary filter is actually doing anything, and will pick up all the crud, and block up earlier, while the secondary filters are not really doing anything much.

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*I thought the only reason to have filters at all is to keep crud from reaching the injector pump and injectors, period.* Seems to me the earlier the crud gets caught, the better.* If the primary filter gets everything, I say terrific.* The other filters are just along for the ride and to catch anything the primary might miss.

But my obvjective is to stop everything right off the bat.

Now if a person has dirty tanks, or the fuel in the local region has a reputation for being contaminated, then I can see the logic of using progressively finer filters simply to avoid having to change the first one all the time.* But that's a situation designed to fix a flaw in the boat's (or the fuel dealer's) fuel system.

But we have (or had when we got the boat) brand new tanks, a brand new fuel system, and the fuel dealers in this area don't seem to have any issues with fuel contamination.* So we're not trying to fix a contamination problem with our filters, we're just trying to make sure nothing gets to the injector pump that should't get there.*

Based on our experience so far, a single 2-micron filter would be all we'd need if we were willing to live without a backup, which we aren't.* The Racor element is never dirty, there is never any water in the bowl, the vaccuum gauge on each egine's fuel system has never read anything other than zero except in tests to make sure they're working, and this over the last 13 years.* I'm sure there is crud that I can't see on the filter element, but what's there is is not apparent.

So unless there is a contamination problem with* the fuel, in which case I would think the proper cure would be to eliminate the reason for the contamination, I see no value in having a progressive set of filters.* Get it all as far away from the pump and injectors as practical and have a filter or two between the primary and pump as a backup is the way I look at it.

So how many micron motor mounts do most of you use? I have found there to be no correlation between motor mounts and fuel filters, oil filters or cigarette filters.

Touche´Carey. We have wandered off thread a bit here...as usual...but sometimes it leads to interesting places...

I had to go back six pages just to see what I missed!!* How did you guys get so far off the topic?

Skipperdude:

That is the most unusual motormount system I have ever seen.* From the pictures, I'm assuming it bolts all the way through the stringers?* Like you say, they've worked sucessfully for a long time and the metal certainly looks beefy enough to support a 3208.

Thanks for sharing

Larry B

*

"I would think the proper cure would be to eliminate the reason for the contamination,"

The most common reason for contamination is a cheap box for fuel, instead of a proper , easy to service fuel tank.

The first purchaser didn't know to demand it , and you are stuck.

I would prefer if we used 1 micron double filters on the raw Virginian tobacco , 5 micron on the hill side stuff from North Queensland.
But bugger just a dunny roll on the main engine fuel would be good.
I will in future just buy my fuel from someone who has processed the fuel himself, loaded it in clean s/s tanks and taste tested before it came on board my boat.
Cheers
Hunter Valley wines are still some of the best