Engine Care, Cleaning & Storage Chat

[David Hazell 1]

I've been doing a little search on here for cleaning up castor gummed up engines; I recently found the OS Max 35 FP that last ran over 32 years ago and it's "well protected" under a lot of burnt on castor residue and locked solid inside because of same I assume...

I have seen the assorted recommendations of using boiling antifreeze and the like, but I'd rather not create a situation akin to the scenes from a scifi movie where the protagonist is transformed into an antihero after inhaling some dodgy fumes.

I had a bit of a eureka moment and wondered if anyone else had an opinion on it: Alloy Wheel Cleaner. I have plenty of it and thought it might do the trick.

Whatdyareckon?

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:45:22

[Martin Arnold 1]

Having had great success with hot antifreeze and yes it is a messy smelly business, I think alloy wheel cleaner is a bit like oven cleaner (which I have tried), will probably change the colour of the alloy casting on the motor to a rather unpleasant dark grey. Most car type alloys have a very tough powder coating where as our engines are just bare alloy.

The thing with the antifreeze method, it is quite gentle on the finish of the engine and most things come out looking very clean and original.

Edited By Martin Arnold 1 on 26/05/2020 17:50:00

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:45:54

[David Hazell 1]

I'm going to give it a try in a small area and see if it looks like it messes with the finish. Will report back - apologies for thread hijack!

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:46:35

[Former Member]

[This posting has been removed]

[Denis Watkins]

I think it is fair to say that we don't actually wear fourstroke bearings out by flying.

Just these last 20 years alternating taking out to fly about 8 fourstroked models

I too have never replaced a bearing so is does seem that storage is the problem.

We all know, but should remember to do it

Run the motor dry when it is hot at the end of the day and get some form of after-run oil into it.

This is a drag, but monthly over the winter, just turn the motor over by hand to circulate the after- run

The thread becomes useful when we buy second-hand and can get the motor serviceable

Edited By Denis Watkins on 27/05/2020 07:27:37

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:52:22

[Jon H]

Its really hard to wear out a bearing.

Out of balance loads, impact, dirt ingress and corrosion are the things that usually kill off our bearings. If you think of the loads involved in something as simple as a nose over on takeoff our engines take one hell of a beating.

After run is a waste of time if its used in the conventional way. A few drips in the plug hole etc will do absolutely nothing to protect the engine. The only way after run really works is if you flush the crankcase with methanol to completely remove all of the contaminants, dry it out, and then back fill with clean oil and rotate to distribute it.

I never use any after run myself for this reason but if engines are run at their optimum tuning all the time, are run at a good temperature, and run on a decent fuel then there is little need.

Most of my models have not flown since last september time and i am slowly digging them all out. Of the 10 only 1 has slightly gritty bearings and its hardly a surprise to me as the engine is grossly overloaded and as a result has to run rich so its bearings dont last. Not that it matters, i have spares in stock and can have them replaced in half an hour.

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:52:55

[Nigel R]

"storage is the problem"

nail, head

if you are lucky enough to be able to store them indoors, most storage problems go away

cold and damp are the main enemies

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:53:25

[Jon H]

Posted by Nigel R on 27/05/2020 09:07:10:

"storage is the problem"

nail, head

if you are lucky enough to be able to store them indoors, most storage problems go away

cold and damp are the main enemies

very true. If it were not for the cost/complexity a zip up fuselage bag with a pouch inside for a big old bag of silica gel would probably be really good for storage. The problem is you would need a custom bag for every fuselage. It would also not prevent acid rusting of the engine although the problem would likely reduce as moisture is key to the chemistry of the whole thing.

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:53:59

[John Wagg]

I hang my planes up with engine pointing skywards which would mean any oil/residue falling to the back plate. (draining out of the bearings.)

I have seen models hung by the tail so obviously the opposite. Does it really matter which way up an engine is stored ?

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:54:24

[Jon H]

Posted by John Wagg on 27/05/2020 09:26:07:

I hang my planes up with engine pointing skywards which would mean any oil/residue falling to the back plate. (draining out of the bearings.)

I have seen models hung by the tail so obviously the opposite. Does it really matter which way up an engine is stored ?

6 of 1 and half dozen of the other. Generally i favour nose up, but then you can argue that evaporated residue will float up to the highest point, the bearings, and condense out.

Currently i have 4 models stored nose down, 5 nose up, and 2 sideways! One of the nose down models needs new bearings, but before i moved house it used to be stored nose up and still got through them for the reasons i detailed before. It also used to be stored outside, its now stored inside and yet the situation remains the same. 

One advantage of nose up is that its much more difficult for residual fuel in the tank to make its way into the engine and as its that raw methanol that really makes a mess of things you want to keep it out.

Brass tubes can also rot when oxidised in methanol so again nose up is better here than nose down...unless you use a dubro tank with that bulge on the front.

Another thing i always do with 4 strokes is lock them to TDC to prevent one valve spring being squished. On my 4 and 5 cylinder engines this is not possible so i rotate them as often as i can.

Edited By Jon - Laser Engines on 27/05/2020 09:47:12

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:54:55

[Paul Marsh]

I found that newer OS engines bearings don't last as long as the older models. For example, none of my early two and four stroke OS engines have had any bearing replaced. My OS 70FS never been after ran, stored in a shed once when lived with parents and still runs well, just oil soaked.
On the other hand a newer OS 95FSV, stored inside only a year old, the bearings were going. had many, even SC/ASPs, the old 90's ones still on original bearings.

Not a major problem, using better bearings now should last a lifetime...

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:47:03

[Nigel R]

Thought the V series were the 'budget' offering, would make sense if bearing price was slashed as part of that.

The alphas still look very much the same standard as the older surpass series, to me with my inexpert eye.

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:47:59

[Martin Arnold 1]

As Jon - Laser says, our bearings generally don't wear out they usually just rust and as such the bearings are going to rust whatever quality they are. On my latest run of bearing replacements (done 6 or 7 Saito and OS four strokes) I have fitted stainless bearings in the hope they might have better rust resistance.

On the subject of running an engine dry after use, I don't see much point on a naturally aspirated four stroke as it will have little or no effect on the combustion deposits already in the crankcase.

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:48:23

[Jon H]

Posted by Martin Arnold 1 on 27/05/2020 12:12:36:

As Jon - Laser says, our bearings generally don't wear out they usually just rust and as such the bearings are going to rust whatever quality they are. On my latest run of bearing replacements (done 6 or 7 Saito and OS four strokes) I have fitted stainless bearings in the hope they might have better rust resistance.

On the subject of running an engine dry after use, I don't see much point on a naturally aspirated four stroke as it will have little or no effect on the combustion deposits already in the crankcase.

Stainless bearings can be helpful but there are 2 potential problems. Often stainless is softer so it will wear quicker, and some stainless bearings still use normal steel in the races or cage so its a bit of a balance.

You are quite right about running 4 strokes dry. It wont hurt it, but its not as helpful as it would be in a 2 stroke.

 

As we are off down the rabbit hole on this i might ask one of the mods to start a new thread on the subject and move our posts given that its clearly a subject worth discussing. 

Edited By Jon - Laser Engines on 27/05/2020 12:17:19

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:48:43

[Former Member]

[This posting has been removed]

[Jon H]

Posted by Doc Marten on 27/05/2020 12:52:38:

Posted by Jon - Laser Engines on 27/05/2020 09:45:20:

Another thing i always do with 4 strokes is lock them to TDC to prevent one valve spring being squished. On my 4 and 5 cylinder engines this is not possible so i rotate them as often as i can.

Edited By Jon - Laser Engines on 27/05/2020 09:47:12

Why not BDC so all pressure is taken off the cam, the lobes and all the valve train components?

That only happens at TDC as both valves are closed, at BDC there will always be a valve open

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:49:35

[Former Member]

[This posting has been removed]

[Nigel R]

"compression stroke starts at BDC when both valves are closed"

Both valves not necessarily closed at BDC. Usually closing happens just after BDC. Gasses are still coming in through the port until the pressure from upgoing piston stops them. The valve timing is thus delayed a bit due to inertia of the intake charge.

Ready to be corrected but that was how I understood it.

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:50:20

[Former Member]

[This posting has been removed]

[Jon H]

Posted by Doc Marten on 27/05/2020 15:16:48:

Posted by Jon - Laser Engines on 27/05/2020 13:00:15:

Posted by Doc Marten on 27/05/2020 12:52:38:

Posted by Jon - Laser Engines on 27/05/2020 09:45:20:

Another thing i always do with 4 strokes is lock them to TDC to prevent one valve spring being squished. On my 4 and 5 cylinder engines this is not possible so i rotate them as often as i can.

Edited By Jon - Laser Engines on 27/05/2020 09:47:12

Why not BDC so all pressure is taken off the cam, the lobes and all the valve train components?

That only happens at TDC as both valves are closed, at BDC there will always be a valve open

I'm scratching my head here Jon, compression stroke starts at BDC when both valves are closed and the lobes are not bearing on the followers, where am I getting confused?

Edited By Doc Marten on 27/05/2020 15:18:37

Compression stroke starts after BDC. The amount will vary depending on the engine but i think a Laser is about 50 degrees after BDC off the top of my head.

In general terms, the only way to guarantee both valves are closed is at TDC of the compression stroke.

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:51:02

[Nigel R]

Posted by Doc Marten on 27/05/2020 15:32:59:

If the valves are not closed at BDC, the full (maximum) volume of air within the cylinder isn't compressed.

Edited By Doc Marten on 27/05/2020 15:39:15

You get more mass of air in and thus higher compression if you allow the gas inertia to do some of the work for the piston.

 

Edited By Steve Hargreaves - Moderator on 27/05/2020 16:47:39

[Steven Webb (Steve Webb Models)]

Many years ago and until now when it comes to storing engines between flights - after the last flight of the day I would run the OS & Enya Four Strokes up at full chat pinching the pipe to use all the fuel up. I would suck pump the remaining fuel out of the tank. Often not connecting the feed back onto the engine. I use plastic plugs to seal off the tubing.

I would then use a good quality oil in the engine while still hot and turn it over swish it around a little. I used various oils over the years there was a specific oil Technics made I used a lot. At home I would store the level or nose up. Storing models on the nose with fuel left in the tank is one of the biggest problems regard from bearings in two strokes and four stroke. I don't fly power at the moment but back when I did 20 years of flying with four strokes never had a bearing go and yet being privileged to see engines with problems in the Job I've seen a four stroke get a rusty front bearing or an Enya SS 40 rust up solid in a week/10 days when fuel is left in the tank in a damp atmosphere with the model on its nose and fuel running from the 1/2 full tank into the engine. Bad storage can wreck and engine in under two weeks.

If I could bring up a point that Paul Marsh has made regard some of OS engines newer engine designs. I would say that the life of the bearings is not as good as they used to be for OS. I am not sure why this should be, but I have a couple of pals that store engines similar to what I used to and yet in some modern OS they've had bearing problems , where as in the old series Surpass and before they never had problems.

Likes of the FSR and SF range had fantastic bearing life. Could it be increased power with less lubrication?

I buy a few vintage engines and often find them gummed up solid with castor. Its great when they are as usually the engine once cleaned is like new. Except in the case of some OS engines. I've bought a few old OS that lose the plating on the pistons. I can't pin point one reason why this is, it is something that I have seen more than a few times. Again it never used to with the FSR and SF series engines. A pal recently had the plating come of the 60FP piston. I had one similar a few years ago.

The Old OS Max. FP, FSR.SF, Pre Surpass and Surpass engines take some beating. Of course dealing with Enya, although haven't had engines like the SS40 available for years. There's still lots out there. I have yet to find some one that can wear an SS40 out. They take gallons to run in and they don't seem to run out. Most Enya designs have not changed that much for years and the only engine that ever had bad bearing issues was 46 4C Mk1 fourstroke. Bearings lasted a couple of runs. The Mark 2 'Beefy' front was the cure. It wasn't corrosion issues it was a small bearing, the size used on the first Enya Open Rocker engines in a new Powerful 46 4C. The bearings were not up to it. It was just before my time with Enya, but when we took over the agency we were still dealing with some fall out from the 46 Mk1

Steve

[paul d]

I agree Steve, my first ever engine was a SS40, had it for years in several models, I gave it away to a chap eventually and the last I heard it was still given the occasional outing.

Think I remember they had cast iron piston??

I know it's drifting somewhat but what's the situation with getting Enyas now?

[Former Member]

[This posting has been removed]