OS MAX-D

Cool !!! Free Bee too , Nice looking engine Ken , got plans for it ?

Seeing that I built the Warlord combat plane for the Enya, I was thinking of doing something similar with the OS. I would just like to fly a friendly combat match with some old British combat wings.

I too would like to fly some friendly combat matches with old british combat wings. but unfortunately everyone where I do and can fly is into stunt, speed, or modern fast crash demo derby combat The old british combat wings and some Australian ones are my favourite models I remember watching older lads fly combat with warlords, dominators, and liquidators down the local oval/park before I got my first plane. loved watching the planes manauvering and chasing each other and listening to the engines and the smell of the fuel.

Ken Cook wrote:                 I was gifted this very low time diesel from a fellow flyer. It was quite unexpected but he decided that I should own it. I took the engine home and freed it up. Put a prop on it and within two flips it was already trying to start. I was quite shocked at this as I really oiled it up when heating and freeing it. A few bursts and all the oil cleaned out and it was running.  The OS .15's are not very common and owning this one and my Enya .15 is pretty fascinating. Both engines  are terrific quality. The exhaust note is a bit louder than what I anticipated.
         

The best thing to do with it is to sell it to a collector. They are very collectable, being judged as one of OS's major failures. Not a really bad engine but pretty disappointing when released in the late 195o's amid much fanfare. The local Australian dealer actually bought the engines back when they flopped in competition.

If you do a Google search you'll see what I mean.

I sold one on ebay for almost AUD500 IIRC. You could sell it and buy a new PAW .15 and take your wife away for the weekend.

Interesting, a hall of shamer, it was a good sport engine but wasn't as competitive with other offerings of the day. It appears to be an adaptation of the glow version. With dual ball bearings nonetheless ...

Perhaps needed more stroke and less bore as was typical of diesels?

When I get a chance out of curiosity, will look up its engine review on Sceptre Flight or Adrian's.

GallopingGhostler wrote:Interesting, a hall of shamer, it was a good sport engine but wasn't as competitive with other offerings of the day. It appears to be an adaptation of the glow version. With dual ball bearings nonetheless ...

Perhaps needed more stroke and less bore as was typical of diesels?

When I get a chance out of curiosity, will look up its engine review on Sceptre Flight or Adrian's.

Adrian has a really good article about them. Much discusion on Barton as well. The diesel came first and the glow later. The ENYA MK2 Diesel is a much better engine. Back in the mid 1990's my son and I flew against a Club Racer fitted with one (OS 15D) and it did win. So they were used. I think we were using a Taipan Blackhead diesel.

The OS have a baffled piston and a corresponding contra piston with a anti-baffle. Interesting feature. Perhaps the only example ever :-)

Good luck!

However-this engine did form the basis of the limited production 15 glow...of which apparently only about 50 were made-and proved outstanding in FAI FF Power: the one featured in this double engine test: https://sceptreflight.com/Model%20Engine%20Tests/OS%20Max-D%20Racing%2015%20Glow.html

I note-for the first time (and i've read the report quite a few times over the years..!) that it uses a 10.5mm crankshaft.....which means that OS must've had a special run of 10.5mm ball bearings made for them....I wonder if this was where Rossi got the idea from-the Mk2 Rossi 15 also had a 10.5mm dia crankshaft-increased from the 10mm diameter of the Mk1....and the bearings were only available from Rossi themselves at a premium price. Cunning Italians...

ChrisM
'ffkiwi'

I'm not a collector and certainly not a diesel aficionado. My son collects them and is quite knowledgeable in using them. I've noted the OS produces more rpm's over my two Enya MK II's I own. It also starts easier. Having owned the Enya for over 5 years, I've tried every known combination and it comes down to one thing, don't flood the engine. If I don't get the Enya to run after a prime, it's start the entire procedure all over and it's a pain in the rear. It requires minimal prime not too mention, I can't forget to slightly back off the contra piston on it's last run or it gets stuck making the next outing that much more difficult. The Oliver reigned supreme back then and probably still does. I have one new in the box Oliver and one we run. I enjoy all of them and have no intent of getting rid of them. They're all different and they're all mechanical wonders that I enjoy owning.

I have the entire collection of the Enya 15 Diesel engines.
Starting from the 15D-I (never run / in collector's inventory -- crankshaft usually broke on them -- afraid to run it because of that?).
Purchased the Enya 15D-I from a collector this year for $300.00 USD

Then to the 15D-II (of which I have three --(two never run yet).
One of those engines (15D-II) my 1st Enya 15D-II my dad gave it to me for a Christmas present.
It was to replace the Enya 19-III that my dad took out of my Falcon 56 to replace dad's Webra that seized in his Falcon 56.
Dad didn't know it was a "diesel", and we never could get it to run? Didn't have any experience starting/running a diesel engine.
So, it is still like new, and I have not tried to run it since dad, and I tried back in 1970.
I think we (dad) was trying to use glow fuel?

Purchased an Anniversary 15D-II back in 2016 and a friend gave me this year for building a plane for him his 60th Anniversary Enya 15D-II (which purchased in 2016 for $300.00 USD)
Then I have a couple of the Enya SS-15D diesels (last of the 15 diesels made by Enya) purchased in 2018 from R/C Japan.
Those cost about $200.00 USD (each -- muffler included)

Currently don't have a photo of the 15D-I. I need to do that and as a group of the entire Enya 15D diesel family together.

Below are photos I do have of my Enya 15D Diesels:

1st is my one Enya 15-II I have photos of (My 1st diesel engine given to me by my dad as a Christmas present):



Next, is my Enya 15D-II 60th Anniversary engines (#38 is the one I purchased and #23 was payment for a plane build)






Last is of my Enya SS-15D (last diesel engines built by Enya):



The easiest Diesels that I have found to start/run are the PAW diesels.
The trickiest ones were the Modela/MVVS (09/12/15) which were square engines (bore x stroke the same) but once running, they were screamers!

My MVVS engine I have photos of (no photos of my MVVS .15(2.0cc):

My MVVS 1.0cc


My MVVS 1.5




Like the O.S. 15, the MVVS engines were designed close to their glow engines.

The most interesting engine I ran was the Irvine 20 and 40. As they had both a glow head and diesel head in the box when you purchased the "diesel" version.
And the instructions suggest that you 1st break the engine in using the glow head?

I have two of each Irvine 20 and 40 but never have taken them out of the box.
I've just read the instructions and stashed them away in my filing cabinet drawer with other of my engines.

My MVVS .09 was incredibly tight. I ran it and ran it and it would always seize when trying to lean it up. I finally took it apart and lapped the piston. It took to tries but it finally turns up now and runs quite well.

The early MVVS .09 engines had some issues with asymmetric transfer channels etc. but the later ones are real gems:

In the pictures of the MVVS diesels the white throttle arm is broken, Mine is broken as well and I've tried to find others to fit which don't. My version is the white plastic as well but my arm isn't broken all the way across. It's hanging on by a little piece. I'm certain if I run it again it will break off.

Ken Cook wrote:           My MVVS .09 was incredibly tight. I ran it and ran it and it would always seize when trying to lean it up. I finally took it apart and lapped the piston. It took to tries but it finally turns up now and runs quite well.

I did it the old fashion way and took forever to break-in running rich/lean.
Great runners and will last forever!

Surfer_kris wrote:The early MVVS .09 engines had some issues with asymmetric transfer channels etc. but the later ones are real gems:

The early MVVS engines were originally made by Modela until MVVS scooped them up.
I have two of the Modela engines.

Ken Cook wrote:               In the pictures of the MVVS diesels the white throttle arm is broken, Mine is broken as well and I've tried to find others to fit which don't. My version is the white plastic as well but my arm isn't broken all the way across. It's hanging on by a little piece. I'm certain if I run it again it will break off.

I replaced the original broken white throttle are with an Enya .09 throttle arm which never got brittle like the white MVVS arm did.

Ken Cook wrote:           My MVVS .09 was incredibly tight. I ran it and ran it and it would always seize when trying to lean it up. I finally took it apart and lapped the piston. It took to tries but it finally turns up now and runs quite well.

I found the same and had to resort to the electric finger for the first couple of bench runs. Since then it has improved-but i'd never rate it a good starter...a pity really as they are quite powerful and light. I've observed a similar reluctance to hand start in several other examples here over the years.  The 2cc models seem to be somewhat better handling.....

ChrisM

I have used left-over servo arms as replacements for the throttle lever. Works well if you find a suitable size.

The 2cc Modela/MVVS diesel (the "Junior") is a really sweet engine too, powerful for its size and throttles well.
The glow version is actually even better/nicer, to me, it idles down below 2000rpm and sort of runs like a "diesel engine" in practise (i.e. a soft and pleasant exhaust note and reliable running at lower rpms than modern glow engines):

I have two of the diesel and three of the glow versions and haven't yet got round to running them....I also have a fairly rare glow example of the 1.5cc diesel model....

ChrisM