Oil hose options

[Marty_d]

Hi all,

I've never plumbed oil hose in before so wondering what the options are.  When I go looking for fittings there's a million different types out there from Aeroquip, AN, straight end with a bead, etc.

When it comes to hose there's people using black, blue,  stainless steel braid...

Is there a specified type of hose and fitting I should be doing for oil line? And size? What should I avoid because it needs special tools?

Any advice,  as always,  appreciated!

Thanks,  Marty

[cscotthendry]

Marty:

If you're plumbing up a Rotax engine, consider this: Oil hoses on Rotax engines carry NO pressure.

The hose that goes from the tank to the oil pump is a suction line. All it has to do is not collapse from the low suction and high temps.
The hose that returns oil to the tank from the sump, does so at atmospheric pressure because the tank isn't a pressure vessel. All that hose has to do is not melt from the oil temps which are usually 100-150 degC or less.

IMHO, that is one of the most clever aspects of the Rotax engines, there is no high pressure oil outside of the engine.

Bert Floods will sell you oil hose (and that is what I use) but at a PRICE.

 

If on the other hand, you're plumbing up a Jabiru engine, ignore all of the above!

 

[Blueadventures]

10 minutes ago, cscotthendry said:

Marty:

If you're plumbing up a Rotax engine, consider this: Oil hoses on Rotax engines carry NO pressure.

The hose that goes from the tank to the oil pump is a suction line. All it has to do is not collapse from the low suction and high temps.
The hose that returns oil to the tank from the sump, does so at atmospheric pressure because the tank isn't a pressure vessel. All that hose has to do is not melt from the oil temps which are usually 100-150 degC or less.

IMHO, that is one of the most clever aspects of the Rotax engines, there is no high pressure oil outside of the engine.

Bert Floods will sell you oil hose (and that is what I use) but at a PRICE.

 

If on the other hand, you're plumbing up a Jabiru engine, ignore all of the above!

 

Agree with Scott, I also only use the Rotax (Floods) oil hose, its made for purpose and I don't want to muck with oil hose leaks / failure.  Cost may be high but don't need much length.

[RFguy]

Scott is right on. In addition I'll add:

1) I'd plumb in a T on the suction link (oil cooler to crankcase) so you can verify that the maximum suction (tension) is not exceeded (per the book ! ) 
2) If you have more than a meter run to the oil tank, I would go one bigger on oil hose above the rotax specification. This gives you a little more margin on cold running/starting

3) I have seen a few long tank rotax installs in the std book size hose that my calcs say would cause the system to exceed the maximum suction .
In cool winter climates, I would plumb in a Denali etc oil thermostat.  Although the Rotax oil, a multigrade, doesnt get too thick in the cold. Suction tension dominated most likely by the oil cooler. 

[skippydiesel]

I think you will find that this topic has already been exhaustively  discussed in this Forum. Recommendations, with rational (hoses meet/exceed Rotax speciation's) made.

 

 

Edited May 18, 2023 by skippydiesel

[skippydiesel]

2 hours ago, RFguy said:

Scott is right on. In addition I'll add:

1) I'd plumb in a T on the suction link (oil cooler to crankcase) so you can verify that the maximum suction (tension) is not exceeded (per the book ! ) 
2) If you have more than a meter run to the oil tank, I would go one bigger on oil hose above the rotax specification. This gives you a little more margin on cold running/starting

3) I have seen a few long tank rotax installs in the std book size hose that my calcs say would cause the system to exceed the maximum suction .
In cool winter climates, I would plumb in a Denali etc oil thermostat.  Although the Rotax oil, a multigrade, doesnt get too thick in the cold. Suction tension dominated most likely by the oil cooler. 

No offence RF, I disagree.

 

1) A highly unlikely scenario UNLESS the pilot exceeds the Rotax recommended warm up rpm/oil temperature - pilot error

2) Concerned about hose collapse? - use an internal/external anti collapse spring. 

3) as above

"In cool winter climates, I would plumb in a Denali etc oil thermostat." Australian, winter temperatures do not warrant this expensive, additional weight and complexity (more joins raises the potential for failure) of an oil or coolant thermostat - All that is required is a longer (than summer) warm up period , usually just a few additional minutes. If your aircraft is unable to achieve/sustain the 50C Rotax recommended minimum for higher rpm operations, first try restricting air flow through your oil cooler (several option, cheap, lightweight & fail safe). I used a fixed cowl flap, to good effect, for winter months

"Suction tension dominated most likely by the oil cooler." - ?????? Please expand.

[RFguy]

"Suction tension dominated most likely by the oil cooler." 
SKippy -go and read the oil cooler pressure drops at the rotax flow, and then cross reference to the manual. you will find it is thin ice and something to be adhered to and measured/verified PER THE BOOK.

[440032]

Nobody bothered to ask "what engine?"

 

What engine?

[Blueadventures]

1 hour ago, skippydiesel said:

No offence RF, I disagree.

 

1) A highly unlikely scenario UNLESS the pilot exceeds the Rotax recommended warm up rpm/oil temperature - pilot error

2) Concerned about hose collapse? - use an internal/external anti collapse spring. 

3) as above

"In cool winter climates, I would plumb in a Denali etc oil thermostat." Australian, winter temperatures do not warrant this expensive, additional weight and complexity (more joins raises the potential for failure) of an oil or coolant thermostat - All that is required is a longer (than summer) warm up period , usually just a few additional minutes. If your aircraft is unable to achieve/sustain the 50C Rotax recommended minimum for higher rpm operations, first try restricting air flow through your oil cooler (several option, cheap, lightweight & fail safe). I used a fixed cowl flap, to good effect, for winter months

"Suction tension dominated most likely by the oil cooler." - ?????? Please expand.

I disagree with you, winter low temps take forever for temp to come up and oil thermostats are a worthwhile option.  How long since you have flown during winter and how many start ups? Where you are winter would be cold at times and warm up times will be much longer than summer.  I certainly notice the difference up here.

 

[skippydiesel]

1 hour ago, RFguy said:

"Suction tension dominated most likely by the oil cooler." 
SKippy -go and read the oil cooler pressure drops at the rotax flow, and then cross reference to the manual. you will find it is thin ice and something to be adhered to and measured/verified PER THE BOOK.

By "adhered to" do you mean keeping below Rotax recommended rpm until min 50C oil temp has been reached?

 

Its too much RF - my engine is installed as per/within Rotax recommendations (go outside this and yes you start having to have a more in-depth knowledge) - I am confident that, as long as I then adhere to the Rotax operating recommendations, my engine will enjoy a long service life, I can do no more.

[skippydiesel]

2 minutes ago, Blueadventures said:

I disagree with you, winter low temps take forever for temp to come up and oil thermostats are a worthwhile option.  How long since you have flown during winter and how many start ups? Where you are winter would be cold at times and warm up times will be much longer than summer.  I certainly notice the difference up here.

 

Okay by me - I stand by my own experience - Did you actually note, that I have fitted a fixed cowl flap/exit air restrictor, during winter months - worked very well,  kept warm up time within acceptable (to me) limits and in flight temperatures stayed much the same as summer. Virtually 0 cost (sheet of aluminium/some small nuts/bolts/washers and a little time ), much lighter than an oil thermostat and no additional complexity, removed when day temps consistently got to 25C,  - whats not to like?

 

There are climates, where even the fitting of air blanking systems, are not sufficient for optimal engine operating temperatures, in winter - then & only then thermostats are a good option

[RFguy]

Skippy,  - Rotax also run on ACTUAL engine running hours, where as my Lycoming is Tacho / airswitch. so run-up hours on a cold Rotax really chew into the Rotax TBO- hence fast warmup by oil  thermostat (and ideally, water radiator 90% bypass thermostat) .  Both of those thermostat methods dont completely kill the cooler circulation. 

[skippydiesel]

1 hour ago, RFguy said:

Skippy,  - Rotax also run on ACTUAL engine running hours, where as my Lycoming is Tacho / airswitch. so run-up hours on a cold Rotax really chew into the Rotax TBO- hence fast warmup by oil  thermostat (and ideally, water radiator 90% bypass thermostat) .  Both of those thermostat methods dont completely kill the cooler circulation. 

Go for it mate!

 

You want to add "bling" to your aircraft - I support your right to do so.

 

I see little evidence for the need to add such cost, weight & complexity (in Australia) as oil/coolant thermostats. Well documented & effective alternatives already exist - temporary (winter months) reduction in air flow, through your cooling systems,  by partial blocking in and or exit air flow - simples!

 

I don't recall being "frustrated" by the time taken for my Rotax to warm up. Its a great time to check all your systems, focus the mind on the coming flight, double check the location of other aircraft in the vicinity, etc, etc.

 

As for engine warm up significantly impacting on TBO etc - 🤣 

[Marty_d]

3 hours ago, 440032 said:

Nobody bothered to ask "what engine?"

 

What engine?

Standard Rotax 912uls. 

[facthunter]

Make sure every extra you add is fail safe. The more fuel tanks, engines systems electric , hydraulic etc the more there is to fail. Flying id for fun not being a flying test bed. Onne "extra" I do like is cowl gills as you can look after your motor better and that's a PLUS.  Nev

[RFguy]

I am trained that "The Germans are coming- less than 5 minutes to get airborne".... get checks / checklist done and go. No 20 minute  ground running .

 

 

Edited May 19, 2023 by RFguy

[facthunter]

On one icy cold morning at Corryong it took me 18 minutes to get the Lycoming in the Citabria where it had to be. Flying over a bit of TIGER Country I'm going to have everything RIGHT before I go even IF it's an extra 10 minutes.  Nev

[turboplanner]

3 hours ago, RFguy said:

I am trained that "The Germans are coming- less than 5 minutes to get airborne".... get checks / checklist done and go. No 20 minute  ground running .

 

 

The Merlins are often quoted on this site even though they have noting to do with RA and usually the statements are true, but I've never seen the person quote the operating life of those Merlins; that tells a different story.

[facthunter]

In wartime it was about 200 hours. The highest ever achieved in civilian use was 650 hours. They were only allowed on the Civil register in a small number of countries, Canada being one, as they had a skew gear driving BOTH magnetos. They also had no rollers in the cam followers which sometimes scuffed  when oil was slow to get there on startup. Nev

[Area-51]

Wow... somebody asked about "what oil hose" to use, and we got about 8 pages of unrelated verbal rugby!!!

 

1. This topic has been covered thoroughly in depth about 16 months ago.

 

2. Oil hoses are required to meet a specification based upon environmental employment; Pressure, Suction, Bend Radius, Temperature, Fluid Chemistry.

3. Rotax factory Continental oil hose is not available to purchase.

 

4. Both Parker and Eaton can supply over the counter equivalent to the Continental product at a fraction of Floods pricing.

 

Search the forum for Eaton or Parker; all the specs and info are here.

 

Reputable hydraulic house such as Enzed will make up any length hose you require with any type steel fitting required.

 

when asked whats it for just say "oil cooler"

 

Edited May 19, 2023 by Area-51

[skippydiesel]

This is the discussion author & date - how do I give a quick link?

Oil Hose/Rotax 912

Rate this topic

By skippydiesel
January 20, 2022 in Engines and Props

 

Area-15;

 

3. Yes it is, but only through a Rotax distributer

4 . My recommendation was  for Gates GTH - 8  available through Hydraulink (the hose is classified as hydraulic, rather than the  automotive range purchased from Repco)

[Area-51]

Thanks for the correction... personally i would, and do, go for Parker products for hoses purely because they are designed and rated for Commercial Aviation use... not sure about Gates other than their Barricade Greenline fuel hoses... but as one ither poster mentioned its not a pressure situation, however the oil pump supply on the Rotax is a suction pipe... check the specs is always required.

[skippydiesel]

1 hour ago, Area-51 said:

Thanks for the correction... personally i would, and do, go for Parker products for hoses purely because they are designed and rated for Commercial Aviation use... not sure about Gates other than their Barricade Greenline fuel hoses... but as one ither poster mentioned its not a pressure situation, however the oil pump supply on the Rotax is a suction pipe... check the specs is always required.

At the time I did all my research, other suitable products weer not available in Australia - probably due to CV19 shipping/production delays - its all there in my thread.

 

From memory - the most common disqualification, for the hoses I looked at,  was on sustained temperature rating.

 

I checked out one of the big hydraulic service suppliers - hose had limited specifications available - probably would do the job but without a complete list of specifications, with which to compare with the Rotax Continental hose, I disqualified it.

 

Gates product information for GTH-8,  page A61, of catalouge https://www.gatesaustralia.com.au/catalogues-and-resources/product-catalogues/hydraulic-and-industrial-hose-couplings-and-equipment-catalogues

You can also  get Gates G3H but its quit a bit heavier for no, Rotax parameter, gain.

Edited May 19, 2023 by skippydiesel