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Incompatibility with CAT air trap and Kingtech/Jetcat engines?

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Incompatibility with CAT air trap and Kingtech/Jetcat engines?

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Old 01-26-2016, 08:47 AM
  #51  
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Todd thank you.

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Old 01-26-2016, 09:25 AM
  #52  
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Todd, If the filter is clogged, of course shouldn't attribute the fault to the CAT, but the filter has low restrictions less than 4 PSI under 9.9V with Jersey filler pump, still wouldn't attribute the fault to the CAT.

The only theory that I could come up with is debris clogging port during filling, and I offered a different plumbing method to avoid this, which could apply to any UAT. And this scenario may or may not apply to the failure either. If anyone comes up with other possibilities let me know.

We are only reporting what we find, and making recommendations, it's all.

Good Luck!

Barry
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Old 01-26-2016, 10:52 AM
  #53  
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Originally Posted by Gaspar View Post
Hi,

I see that there are some misunderstandings about what the ecu does, the ecu don't shutdown the engine in the case of a clogged filter.
Thanks Gaspar, I did not think you shutdown on high pump voltage, I know JetCat doesn't, thanks for the clarification.

FWIW in this whole thing, I would say double and triple check these ARF tanks. In fact if I am ever forced to use one, I would saw it in half and fix it internally. I have seen cases of ARF tanks rinsed and rinsed repeatedly and then something still flakes off, of the internal seam or somewhere inside, who knows.

And rule one is to check your pump voltage (or PW or whatever it is called) after each flight. It normally does not jump up immediately, it creeps up as the filter(s)/UAT/CAT whatever get clogged. You get plenty of warning.

I would rather have a pure bubble trap and a filter as 2 separate items. I assume the CAT internal filter is helping to prevent bubbles, but the number 1 bubble I am afraid of is from the upstream header tanks sucking in a big blob of air under maneuvering, I am less concerned with micro cavitation, blah blah but that is just me.
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Old 01-26-2016, 11:23 AM
  #54  
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Matt the internal filter is a great bubble trap hence why its used, it also filters fuel naturally as do most other pickups.

I also make (plug plug) a clunk which uses the same filter system as the CAT for pickup, it works well and prevents any crud heading up those fuel lines...



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Old 01-26-2016, 11:56 AM
  #55  
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Originally Posted by marquisvns View Post
Todd, If the filter is clogged, of course shouldn't attribute the fault to the CAT, but the filter has low restrictions less than 4 PSI under 9.9V with Jersey filler pump, still wouldn't attribute the fault to the CAT.

The only theory that I could come up with is debris clogging port during filling, and I offered a different plumbing method to avoid this, which could apply to any UAT. And this scenario may or may not apply to the failure either. If anyone comes up with other possibilities let me know.

We are only reporting what we find, and making recommendations, it's all.

Good Luck!

Barry
I still fail to understand why/how you attribute said flameouts to the CAT product as originally contested?! Would you blame Honda if your car stalled out after filling your fuel tank with water??
There are tools built into the ECU which are valuable in monitoring and diagnosing a pending problem with your fuel system health! Just need understand how they work and use them...
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Old 01-26-2016, 02:36 PM
  #56  
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Originally Posted by lov2flyrc View Post
I still fail to understand why/how you attribute said flameouts to the CAT product as originally contested?! Would you blame Honda if your car stalled out after filling your fuel tank with water??
There are tools built into the ECU which are valuable in monitoring and diagnosing a pending problem with your fuel system health! Just need understand how they work and use them...
Todd the issue was one that Dirk found helping people over the phone trouble shooting flame outs on other planes. We don't know what they had going on but several said they changed out the CAT and problems solved. They might have been using to small of a CAT or had other plumbing issues that happens to get fixed while changing out the CAT. This is not only about Barry's F16.

Also a guy from the UK contacted me saying he has been seeing the same thing. Its all here say and I don't have any first hand experience with CAT problems.
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Old 01-26-2016, 05:16 PM
  #57  
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Kris,
Fair enough, but based on the findings when opened, it should have been clear that FOD was the obvious culprit in that case. Back flushing fill method has nothing to do with the cause of the issue but can cause random starvation issues if the offending FOD gets flushed back into the tank. When assembling tanks, especially pre-joined, I take a magnet And toss it in the tank, then drag it around the tank surface and seams using a magnet on the outside. This helps knock off errant fibers and glue that could get knocked off by the clunk and enter your fuel system. ALWAYS flush your tanks throughly before installing the stopper. Debris lodged anywhere in the fuel system can create serious restriction.

If a customer calls me with a fuel flow problem the first question I have is what size fuel line and fittings! Undersized lines and fittings is the #1 issue I have seen with the larger class engines. Kingtech is a little higher on fuel consumption than others in its class, perhaps it would help kingtech customers by specifying which tubing / fitting dimensions are suggested based on engine class?
The CAT has been a very popular product, that alone may simply account for your higher ratio of common fuel system problems/errors/mysteries encountered. Nothing presented points to a problem with the CAT itself....
Todd
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Old 01-26-2016, 06:16 PM
  #58  
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Originally Posted by lov2flyrc View Post
I still fail to understand why/how you attribute said flameouts to the CAT product as originally contested?! Would you blame Honda if your car stalled out after filling your fuel tank with water??
There are tools built into the ECU which are valuable in monitoring and diagnosing a pending problem with your fuel system health! Just need understand how they work and use them...
No doubt as to the intent of said software, sometimes hardware or its display may have discrepancy as a result, even Gaspar thought it is possible with certain synchronization issue may have caused such discrepancy.

Todd, if you must understand, the slightest attribution if any, would probably be that of the debris which seemed may have been fuel soaked fiber and resin, and based on the size and shape not likely from elsewhere. Let it go Todd!
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Old 01-26-2016, 06:21 PM
  #59  
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Originally Posted by lov2flyrc View Post
Kris,
Fair enough, but based on the findings when opened, it should have been clear that FOD was the obvious culprit in that case. Back flushing fill method has nothing to do with the cause of the issue but can cause random starvation issues if the offending FOD gets flushed back into the tank. When assembling tanks, especially pre-joined, I take a magnet And toss it in the tank, then drag it around the tank surface and seams using a magnet on the outside. This helps knock off errant fibers and glue that could get knocked off by the clunk and enter your fuel system. ALWAYS flush your tanks throughly before installing the stopper. Debris lodged anywhere in the fuel system can create serious restriction.

If a customer calls me with a fuel flow problem the first question I have is what size fuel line and fittings! Undersized lines and fittings is the #1 issue I have seen with the larger class engines. Kingtech is a little higher on fuel consumption than others in its class, perhaps it would help kingtech customers by specifying which tubing / fitting dimensions are suggested based on engine class?
The CAT has been a very popular product, that alone may simply account for your higher ratio of common fuel system problems/errors/mysteries encountered. Nothing presented points to a problem with the CAT itself....
Todd
My suggested plumbing will do exactly to prevent flushing debris back into the tanks Todd.

The difference in consumption has nothing to do with this, nor did the size of tubing on the installs we were troubleshooting. Again, nothing against CAT, so good luck!

Barry
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Old 01-26-2016, 07:39 PM
  #60  
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Barry,
I spend a fair amount of my day sourcing the best products available on the market. Many of these jet specific products come from cottage industry suppliers; avid highly talented modelers for the most part, that produce these superb specialty items for us in addition to their full time job. We are extremely lucky to have them and I personally value their contributions to the industry.
my weight in this has nothing to do with marketing or a nickel earned on the sale of a CAT ( hell, I own Hanson, I make more selling you one!). It's about assuring their isn't a true problem with a product line we represent that could induce a safety issue or cost a customer a model. It's about making accusations regarding a product based on assumptions and hearsay and nothing valid to substantiate the claims. It's about wrongs being addressed by some of the most talented, knowledgable people in the industry and not even offering so much as an apology to Marc. Now I'm happy to let it go....
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Old 01-26-2016, 08:19 PM
  #61  
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Originally Posted by marquisvns View Post
Between myself and Dirk, we've had troubleshot over a dozen complaints of flame outs, with pump limit reached and speed low message display on these ECU, after exhausted all possibilities, all came down to the same solution - change out the CAT [for] UAT. A customer based in Florida Dirk was supporting went as far as cutting it open and found much debris in the canister.



We have been holding back on this matter with caution to damage the reputation of CAT, but ultimately, I suppose revealing facts that has direct impact to safety is always important.

Barry, if not the CAT, then what high capacity air trap does KT recommend? I ask because the UAT and related devices, including the product you carry, simply does not cut it over 500ML/mn flow. Even with great caution taken to make sure all fuel line, clunk, and clunk line IDs remain at least 4mm in a 120N system, the sides of the plastic UAT bottle suck in and pump voltage is over target. This means reduced working area on the UT membrane (cavitation) and higher vacuum pull on the UAT side of the pump, which means higher bubble risk. I have seen this consistently.

I know BVM has rolled out a new UAT with larger fittings, but the weakness of the soft bottle sidewalls and limited element area remains. Turbine fuel flow has come a long way since the days of the RAM 500s and the original UAT. So if not the CAT, then which one for high flow systems: JMP, Intairco? Have you tested these? All I know is that "just go back to the UAT" for larger turbines is just not a realistic recommendation. With all sue respect and IMO, of course.

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Old 01-27-2016, 02:21 AM
  #62  
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Hell, just how hard can you guys make this problem ?

I am using the standard CAT size on my two JetCat 180Rxs installed in my AW Hawks, NO engine problems except for static issues, now resolved, (as do many many others here in the UK and around the world, ) and they work PERFECTLY, never heard of anyone in the UK complaining about them, in fact I changed my BVM UATS TO the CAT because it was getting such good reports from my very competent flying friends. I saw quite a few installed in models at the last JWM.

Now, if you are using a 160 or larger engine you could use the CAT 260 HIGH FLOW which I bought for the Olympus in my SkyGate Hawk. It is specifically designed for high power engines with large fuel flows.

These CATS are beautifully made and perfect for the jpb.

The Intairco UAT is also an outstanding product, beautifully made too, and has the additional features of a drain tube and TWIN fuel inlets.It ticks ALL the boxes .

So for the gozillianth time THOROUGHLY FILTER your fuel, at every stage, start with a MR Funnel and then install reducing mesh filters as the fuel moves to the tanks.

and a further point:

If your engine DOES flameout and you are pushed for height and trying to stretch the glide to reach the runway BVM (see his web site) suggests lowering flap to improve the L/D ratio. Lowering flap WORSENS L/D ratio and the best glide range is obtained with flaps UP. (at a speed which is about 1.3 Vimd) but how you work that out on a model is a problem, but it does mean keeping the speed up, particularly when flying into wind !

The rest of the article makes very good sense but on that point I disagree.

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Old 01-27-2016, 08:28 AM
  #63  
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Originally Posted by TTRotary View Post
Barry, if not the CAT, then what high capacity air trap does KT recommend? I ask because the UAT and related devices, including the product you carry, simply does not cut it over 500ML/mn flow. Even with great caution taken to make sure all fuel line, clunk, and clunk line IDs remain at least 4mm in a 120N system, the sides of the plastic UAT bottle suck in and pump voltage is over target. This means reduced working area on the UT membrane (cavitation) and higher vacuum pull on the UAT side of the pump, which means higher bubble risk. I have seen this consistently.

I know BVM has rolled out a new UAT with larger fittings, but the weakness of the soft bottle sidewalls and limited element area remains. Turbine fuel flow has come a long way since the days of the RAM 500s and the original UAT. So if not the CAT, then which one for high flow systems: JMP, Intairco? Have you tested these? All I know is that "just go back to the UAT" for larger turbines is just not a realistic recommendation. With all sue respect and IMO, of course.

Me personally I like High Flow BVM UAT. I am using 2 of the kingtech UATs in planes and they are doing fine. A friend of mine is using the Intairco high flow with great success also. The CAT might work out fine also and the problems we have seen might be contributed to other problems in the fuel system on these customers aircraft and its just showing itself in the CAT.

If you like the CAT then by all means install it. Kingtech has not come out and said (do not use CATs and our engines) . In our own personal aircraft we are not going to use them. Nothing against the product its our personal choice to go with something else.

Kingtech has not come up with a guideline for tubing sizes ect. In my personal installs now if the engine is bigger then a 180 it gets high flow everything and no T fittings anywhere in the system. All 8MM tubing the clear stuff not tygon. I have seen K210s run fine on 6mm tubing and regular clunks with no issues but I choose to go high flow to be on the safe side.

A great way to test your fuel system is to fill your tanks and simply put your fuel pump in test mode and it will run full power. This will put the maximum suction on the fuel system and you can rotate your plane and simulate flight conditions for a whole tank of fuel and check your system. If you have a fuel problem it should show during this test. Any restrictions will show up as fuel starts to vaporize in the fuel lines causing air bubbles.
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Old 01-27-2016, 10:35 AM
  #64  
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Just for information the fittings on all the CAT's in all four sizes, are optimised, for the biggest bore size to suit your turbine size. When they were designed over 5 years ago the bore required for the feed and draw barbs was not available off the shelf so this resulted in me making a custom range of barbs to specifically fit the CAT range and deliver the fuel flow needed. I also made the fill barb smaller in bore to help restrict the filling pressure on the fuel system as I had come across many instances where fuel tanks had been split as a result of fuelling pressures being too high.

For reference the internal diameter on the CAT-M and the CAT-L are 3.9-4mm, the CAT-L will run up to 300N turbines without any issues and the CAT-M will run up to 200N.

I also make a 'special' CAT-U 450ml (Ultra), which is available on request, this has been tested and used on turbines up to 500N, the bore diameter of the fittings used on this CAT are 4.9-5mm



Twin ported CAT-L's and CAT-U's are available on request for those who want a twin feed set up, it's not a stocked item and is made to order, I have made many of them for customers over the years so to clarify the CAT is available to those who want a dual feed too.

For whatever reason, if you want to fully drain a CAT just rotate it so the fill barb is at the bottom, this allows drain down to be easily done.

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Old 01-27-2016, 11:07 AM
  #65  
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Marc,

Did you stop making the smoke model? I don't see them offered by Chief or DreamWorks any more. I used one on my first hawk on the smoke side. I am going to use a 130 for the smoke system in my new one.

Is there anything different about either one?
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Old 01-27-2016, 11:11 AM
  #66  
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Jeff,

The CAT-M is great for smoke, originally i used a sintered pickup in the smoke model but people had used the normal CAT for smoke so seemed pointless making a special just for smoke.

Enjoy and happy flying.

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Old 01-27-2016, 02:17 PM
  #67  
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Originally Posted by David Gladwin View Post
Hell, just how hard can you guys make this problem ?

I am using the standard CAT size on my two JetCat 180Rxs installed in my AW Hawks, NO engine problems except for static issues, now resolved, (as do many many others here in the UK and around the world, ) and they work PERFECTLY, never heard of anyone in the UK complaining about them, in fact I changed my BVM UATS TO the CAT because it was getting such good reports from my very competent flying friends. I saw quite a few installed in models at the last JWM.

Now, if you are using a 160 or larger engine you could use the CAT 260 HIGH FLOW which I bought for the Olympus in my SkyGate Hawk. It is specifically designed for high power engines with large fuel flows.

These CATS are beautifully made and perfect for the jpb.

The Intairco UAT is also an outstanding product, beautifully made too, and has the additional features of a drain tube and TWIN fuel inlets.It ticks ALL the boxes .

So for the gozillianth time THOROUGHLY FILTER your fuel, at every stage, start with a MR Funnel and then install reducing mesh filters as the fuel moves to the tanks.

and a further point:

If your engine DOES flameout and you are pushed for height and trying to stretch the glide to reach the runway BVM (see his web site) suggests lowering flap to improve the L/D ratio. Lowering flap WORSENS L/D ratio and the best glide range is obtained with flaps UP. (at a speed which is about 1.3 Vimd) but how you work that out on a model is a problem, but it does mean keeping the speed up, particularly when flying into wind !

The rest of the article makes very good sense but on that point I disagree.
Spot on David.

People don't seem to understand why we filter multiple times.

My system goes like this.

To protect the engine there is a filter after the pump (often the manufacturer puts one under the front cover). However it is vital that this filter is not clogged so I install another one (usually in the air-trap or header tank) as a protection. It is still expensive and awkward to replace or clean this one so we filter the fuel whilst refuelling the engine. I use a pleated paper motorcycle fuel filter for this. Nothing will get through this but it can become clogged. Now since this filter costs a few pounds to replace I filter the fuel on it's way into the fuelstation using a funnel and a coffee filter paper - this costs a few pence and can be replaced every time.
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Old 01-27-2016, 04:08 PM
  #68  
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Originally Posted by David Gladwin View Post

If your engine DOES flameout and you are pushed for height and trying to stretch the glide to reach the runway BVM (see his web site) suggests lowering flap to improve the L/D ratio. Lowering flap WORSENS L/D ratio and the best glide range is obtained with flaps UP. (at a speed which is about 1.3 Vimd) but how you work that out on a model is a problem, but it does mean keeping the speed up, particularly when flying into wind !

The rest of the article makes very good sense but on that point I disagree.
David,

BV may be right at least for some planes. If you look at the full scale F-104 flight manual the emergency procedure for a flame out says that for optimal glide distance is reached with take off flap. For sure the 104 is a very unusual plane and it was the only full scale plane I found this procedure.

On a pratical side with my bandit I flew about 150 ft above me on runaway direction and put the plane on idle simulating a flame out and landed applying flaps and gear close to the runaway. On another pass at the same height, direction and speed I did as BV said appling take off flap after losing some speed but not gaining altittude and the plane glided better and crossed runaway start at a higher altitude. Not a very scientific valid experiment but a good one.

Gabriel
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Old 01-28-2016, 11:28 AM
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Originally Posted by gapellegrini View Post
David,

BV may be right at least for some planes. If you look at the full scale F-104 flight manual the emergency procedure for a flame out says that for optimal glide distance is reached with take off flap. For sure the 104 is a very unusual plane and it was the only full scale plane I found this procedure.

On a pratical side with my bandit I flew about 150 ft above me on runaway direction and put the plane on idle simulating a flame out and landed applying flaps and gear close to the runaway. On another pass at the same height, direction and speed I did as BV said appling take off flap after losing some speed but not gaining altittude and the plane glided better and crossed runaway start at a higher altitude. Not a very scientific valid experiment but a good one.

Gabriel
I fly the F-104 and you definitely do not want to drop flaps on this plane without having power. The plane gets very dirty on approach and will slow down surprisingly fast. I need at least 50% power all the way to the ground. I would not consider my chances to be very good in the F-104 in a dead stick, but they would be better with flaps up.

You have to keep in mind that no -104 model flies like the real plane because the wing profile must be totally different in order for the model to fly at all. Most of the RC 104s that fly well have 8-9% symmetrical airfoils, so they will get very draggy once you go into AOA, and drop the flaps and gear.
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Old 01-28-2016, 12:10 PM
  #70  
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Originally Posted by TTRotary View Post
I fly the F-104 and you definitely do not want to drop flaps on this plane without having power. The plane gets very dirty on approach and will slow down surprisingly fast. I need at least 50% power all the way to the ground. I would not consider my chances to be very good in the F-104 in a dead stick, but they would be better with flaps up.

You have to keep in mind that no -104 model flies like the real plane because the wing profile must be totally different in order for the model to fly at all. Most of the RC 104s that fly well have 8-9% symmetrical airfoils, so they will get very draggy once you go into AOA, and drop the flaps and gear.
TT I have one Skymaster F-104 and agree with you about the landing. Not sure if on the model the best approach

About the full scale 104 it lands with a lot of power as well just like the SM 104 or maybe more. It lands with at least 82% RPM until touchdown. I have also attached the glide parts on the manual.
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Old 01-29-2016, 03:01 PM
  #71  
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Interesting, thanks. And (LOL) just want to clarify that when I say "I fly the 104" I mean the model, not the full size! I'd love to fly the real plane, but probably wouldn't be here to talk about it if I tried.
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Old 01-30-2016, 01:40 AM
  #72  
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Guys while the F104 is a great plane can you post the discussion around landing techniques on another thread as its not really relevant now to this one

Hopefully a CAT or UAT will reduce your requirement to make a flame out landing, but maybe a new post around peoples experiences of how to land rc jets in the event of a FO. That would be a good knowledge bank.

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Old 01-30-2016, 04:15 AM
  #73  
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Marc,

Well said. Completely off topic. For the record I have one CAT UAT in my f-104 that is working very well.
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Old 01-30-2016, 08:23 AM
  #74  
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Hello Mark,
the CAT 260 is not available on your website. Any idea when it is available ? Many thanks in advance.
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Old 02-13-2016, 07:26 PM
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philjac94
 
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Sometimes we overcomplicate fuel systems in our models, thinking we are doing good but ultimately doing bad. Common practice for pumps in any application is to use a strainer on the suction and filter on the discharge.
The strainer is only there to trap larger particulates which will hinder or damage the pump, the filter is there to catch all particulates to whatever level of cleanliness is required downstream.
When filters are installed on the suction so long as they are clean and flow well problems are not seen. But when a suction filter becomes dirty and blocked it will induce cavitation and liberate air within the fuel. It is far better to install the filter downstream of the pump, even if this filter blocks it will require a higher pump power to provide the same flow but will stay away from cavitation unless the blockage is so bad the flow is considered to be "dead heading" but in this condition the engine would require a pump power so high that its limit is reached.
Assuming no air is coming through from your tanks/clunks:
If you see no air in your fuel lines but a high Pump Pwr then your downstream filter is blocked.
If you see air in your fuel lines close to the suction port of the pump and in the discharge lines from the pump and a high Pump Pwr then your suction or suction filter is the culprit.

Whatever your setup is, it is primarily it is important to take Dave Gladwins advice and clean clean clean your fuel before it reaches your jet.
If your finding sludge on your filters and your sure your fuel is clean then the only thing it can be is one or more of the ingredients in your added oil is reacting or you have biological growth forming.
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