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The hose were made by me by parts from Summet and/or my local race shop. Most of the fittings are Earls AN fittings and the hose is, IIRC, Aeroquip. It is NOT stainless braided but high pressure
rated. There was no interfearance with the hose rubbing anything. I am not at the hangar and I only glanced at the damage before I had to leave yesterday but I think it is a very short hose that burst. I can't recall where it is routed from. I will check
all that out later if/when I get to the hangar today.
NOW, just to verify the basics. If am an looking at the oil lubrication diagram properly and follow the little arrows in the picture, the oil EXITS the engine from the front of the engine (where the pully's are)
and ENTERS back into the engine via the left rear nearer the PSRU/Prop. As David Staten mentioned, the remote oil mount has little arrows cast to the mount showing an in and an out....actually it is two "ins" and two "outs". I have one "out" sealed with
a fitting and the other "in" has an adaptor that has my oil temp sensor installed. The hose goes IN to the filter from the hose that comes OUT of the engine and comes OUT of the filter to be routed back IN to the engine.
This install has a longer oil routing since it goes to a second oil cooler mounted in the front of the plane for cabin heating (per Velocity plans). My earlier concern was that oil pressure would be too low due to
the 15 feet or so run to the front of the plane and then back. Also, Chrissi has expressed concern over the aviation oil cooler provided by Velocity may not be up to the task. I think part of this concern has been due to the failurs of air conidtioning units
being used as coolers and burtsing in use. It seems as if the front cooler was up to the task, but, alas the line was not.
Of course my focus now is to the WHY.
I hope it is just a bad hose. Donno yet. I really did not have time to look it over before I had to leave. I had time to put a towel down with a oil drain pan on the towel to catch the remants of the dripping
oil. This "opportunity" will allow me to check the rest of the system. I had already concluded it needed to be reviewed due to the attempts at the filter/filter mount were not the problem. Again, the indicated oil pressure is what I expected, so now to
try and determine why indicated pressure was ok, but it was obvioulsy much higher as shown by the leaking filter and now burst hose.....I am guessin', as Lynn mentioned, this hose was bad, thus, while holding too high of pressure for a while and not to rated
pressure, it failure point was finally reached.
When I installed the system, I was getting good flow. Also, the entire system does heat up, so oil is still flowing.
I will advise what I find.
Thanks guys.
All the best,
Chris Barber
Houston
From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Lynn Hanover [lehanover@gmail.com]
Sent: Saturday, October 03, 2009 10:05 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Too much oil pressure.
Lynn Hanover wrote:
>
>
> The fittings from different manufacturers should not be interchanged.
> The fittings from different styles from the same manufacturer should
> not be interchanged. Be aware that AN (Airforce-Navy Standard) (the
> airplane stuff) and JIC (Joint Industry Standard) look identical.
> The SAE hose looks exactly the same as well but will more likely have
> 45 drgree flair angles rather than 37 degree flair angles.
> ........
All the fittings on the engine are AN fittings, and purchased from
Summit Racing by me, unless Chris has changed something since my exit
from the project.
The oil conduit hoses weren't the 3000 lb test but it wasn't cheap hose
by any means. It was build-a-hose kinda stuff from Summit.
Unless he has changed things, the front oil pressure relief was stock
and the rear oil pressure valve was stock.
The cooler was before the filter. The cooler was a mazda cooler.
The aftermarket oil filter mount has arrows on it indicating in/out for
flow.
I just checked the Summit Catalogue, and the page says the fittings are "AN". That suggests, at the least, that the pieces would be legal on a real airplane if you had the paper trail to an approved manufacturer. I saw no mention of pressure rating, but
even the lowest rating would be well above anything a homebuilt plane would need. I have hundreds of buys from Summit and never a bad part.
If the hose was assembled at home and not tested by a hose shop, then my idea about the hose is still valid. There are some tricks to assembling hose ends that do not show up in the directions. The process is easy if you have done it a few hundred times.
The Teflon liner is very soft and can be damaged easily during assembly. A single piece of braid wire folded back can pierce the liner on assembly or months later.
You must inspect the whole piece of hose before assembly for a single broken braid wire. If you can see both ends of the failure, fine. If only one end, the other end is free on the inside of the braid next to the hose liner. Cut the hose through the broken
braid and use the remaining pieces if you can, for shorter runs.
If all of the other statments are accurate, it has to be the hose.
Lynn E. Hanover
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