Gummed up Irvine 61

[Robert Cracknell]

I have been gifted an Irvine 61 which, externally, looks in VGC. It even came with the plastic cap over the intake.

 

The problem is the engine appears to have been stored for many years having been put away full of castor based fuel. Result – carb and engine totally solid. The carb freed up after a couple of days immersed in cellulose thinners and has cleaned up well and functions smoothly.

 

The engine, now that is a different ball game. The piston is at BDC and will not move. At the moment it is having sessions in a DK Sonic cleaner immersed in Paraffin (Don’t panic – it is outside so no fume build up) After about 30 minutes treatment there is no discernible movement. What castor was in the crank case now resembles treacle toffee both visually and in consistency.

 

My question to the collective IQ of the forum is what measures would you take to free up this engine (for the sake of expediency I will ignore anyone who says go electric or bin it) On that line a modelling pal told me to give it a Senokot tablet – he said that will shift anything!

 

As usual any and all help gratefully received.

[Paul De Tourtoulon]

Try hot soapy water in your sonic cleaner.

[Brian Cooper]

Castor certainly was - and still is - an engine killer.

 

The only thing I would suggest is, leave it soaking for longer. 

Hopefully the goo will soften and dissolve.... eventually. 

[Paul De Tourtoulon]

3 hours ago, Brian Cooper said:

Castor certainly was - and still is - an engine Preserver

Corrected for you, Brian.🤣

[Robert Cracknell]

It has certainly preserved my engine! Like a biological specimen encased in resin.

Useless stuff.......!

[Engine Doctor]

Hi Robert clean and dry your engine off and then heat it up either with a hot air gun or in the oven . You will need some decent gloves 🥵.

This wil soften the castor enough to dissasemble the engine. Dont forget if its the old silver 61 it will have imperial allen bolts . Later red ones used metric screws. Parraffin wont touch it . The only other liquid i know that quickly softens it is model diesel fuel ,much too expensive for cleaning . Once its in pieces then an old tooth brush and some cellulose thinner or acetone should remove any castor residue. 

Another thing is if its the early silver 61 then its fitted with a dykes piston ring. Be very careful with this as they are delicate but srill available should it break.

Bearings will need changing as even if they feel free the likelyhood is that the balls could in the races are stuck and can skid quickly breaking and causing damage .

Good luck . Let us know jow you get on and any pics ?

Edited August 8, 2024 by Engine Doctor

[Andy Stephenson]

No one has mentioned the use of heat, a gentle blast with a filming gun is to be recommended in cases like this just don't be tempted to use a flame.

PS see above.

Edited August 8, 2024 by Andy Stephenson

[Robert Cracknell]

Thanks guys, will be trying these suggestions later today. Will report back if successful. 

[Paul De Tourtoulon]

22 minutes ago, Andy Stephenson said:

No one has mentioned the use of heat,

Read my post,,,,

[J D 8 - Moderator]

   Glow fuel [ without castor]  or straight methanol works well as a softener and if engine has plastic/nylon parts it won't affect them.   

[Don Fry]

1 hour ago, Engine Doctor said:

Hi Robert clean and dry your engine off and then heat it up either with a hot air gun or in the oven . You will need some decent gloves 🥵.

This wil soften the castor enough to dissasemble the engine. Dont forget if its the old silver 61 it will have imperial allen bolts . Later red ones used metric screws. Parraffin wont touch it . The only other liquid i know that quickly softens it is model diesel fuel ,much too expensive for cleaning . Once its in pieces then an old tooth brush and some cellulose thinner or acetone should remove any castor residue. 

Another thing is if its the early silver 61 then its fitted with a dykes piston ring. Be very careful with this as they are delicate but srill available should it break.

Bearings will need changing as even if they feel free the likelyhood is that the balls could in the races are stuck and can skid quickly breaking and causing damage .

Good luck . Let us know jow you get on and any pics ?

ED, not a comment but a query. If cellulose thinners and/or acetone shifts residue, why can’t the soften the gunk to free it up.

Edited August 8, 2024 by Don Fry
Spell checker causing bad language. Naughty spell checker.

[Robert Cracknell]

Guys

Re: cellulose thinners

Appreciate that it is a good cleaning agent but a lot would be needed to immerse a whole engine and it evaporates at rate that would be difficult (and costly) to maintain. I did the carb in a sealed jam jar so no problem. When I get the beast apart I can do the small components this way.

[Engine Doctor]

Hi Don the problem is it wont penetrate into tight fitting areas like the bearings etc. It will attack an area of dried castor though with a scrub/ meichanical assistance.

Rob . As I do quite a few engines I have a couple of large jars with lids that  I use to soak parts. When it gets dirty , usually after every use i pass it through a filter fo reuse. 

Its also useful for freeling corroded parts if its mixed 50 / 50 with auto tranmission fluid.

I only use standard  or gun wash thinners .Its not expensive if bought in 5ltr cans from around £15  or from a local body shop. This lasts me over a year even using as a thinner for painting odds and ends.

Do wear gloves and dont get it on your skin if you can help it as i does contain some nasty stuff and only use in a well ventilated area away from heat and sparks/ sources of ignition. 

 

[extra slim]

I remove carb and any O ring, plastic parts, and sometimes remove the head if it will come off.  Stick it in an oven for 6-10mins, whip it out, stick an old prop on and tighten, and then gently try and rock it until it frees. Might take a couple of goes.. decent oven gloves a must, and try and do it when the Mrs is out!!. Works for me. Once it is moving, then the other methods here and oil help to really free it off.

[Engine Doctor]

As Extraslim says use the oven when SWMBO is out 😉. Similarly use any smelly liquids when shes not about. Do it indoors when the mrs is at home at your peril . Its the H&S that industry dont tell you about .🙂

[David Davis]

I've had a similar problem with an old OS 40SR. "Stand to attention that man!"

 

My club acquired lots of very old stuff built by an aeromodeller who has gone to that great flying field in the sky. I was given the model pictured below because I like to build and revive old models. It's beautifully built, fully sheeted and covered in tissue. The servos date from before Pontius was a pilot! The one operating the throttle is fore and aft rather than rotary. However, I really don't have the time for it so I gave it to the adult son of one of my protegés who plans to convert it to fly on electric power.

 

That meant the engine was mine! This morning I removed it from the airframe and like your Irvine Robert, I found that the engine was locked solid with old castor oil. I removed the engine from the airframe, the glow plug from the cylinder head and the silencer from the engine, and being a Founder Member of the Unmarried Modeller's Club, I set the oven to 150C and left it in the oven for several minutes. Fan setting! I returned with welder's gloves and a can of two-stroke oil. Removing the engine from the oven, I found that it would turn so I squirted oil into the engine via glow plug hole, the exhaust port and the carburetter. This afternoon if I get the time I plan to fire it up on the test bench. Even the old glow plug still works, idle bar and all! I regret that ther will be no photographs as my camera is hors service.

 

To return briefly to the model, no-one knows what it is called so I called it "Le Truc" or "The Thingy!" It could be an old British or American design as most of the measurements suggest Imperial sizes. The fuselage from the propeller to the elevator is 4'6" long the wingspan it 7" and the chord outside of the centre section is 12."  The wings have a reflex aerofoil section and are attached to the centre section with long threaded bolts.

[Paul De Tourtoulon]

57 minutes ago, David Davis said:

a Founder Member of the Unmarried Modeller's Club,

Your garage says it all.🤢

[David Davis 2]

Ah! But you do not know the Unmarried Modellers' Club's motto.

 

"We Haven't The Time For That!"

[David Davis]

Just a brief note to say that I successfully started the OS 40 SR this morning on the test stand.

 

Having freed the engine I found that the caburetter was stuck. I let it soak overnight in some straight glow fuel and I was able to take some components off the carburetter body but the barrel refused to move. I fixed the caburetter in a vice between two pieces of scrap plywood and applied heat from an electric paint stripper scorching the plywood in the process. That melted the castor and I was able to remove the barrell and to deal with rust and castor residue by using cellulose and wet and dry paper.

 

I mounted the engine in the test stand and it was immediately obvious that the main needle needed screwing in. I had to use a pait of pliers to get the needle to turn but having adjusted it I was rewarded by the engine starting up after heaven knows how many years. I even used the old glow plug with an idle bar! 😄 When did you last see one of them! I regret that there is no picture because my camera is broken, so is the stylus on the hi-fi and I need to order some central heating fuel.

 

The low speed needle needs adjusting and it probably could do with a set of bearings but I have no plans to use it as I have several unemployed two-strokes of about the same size ranging from and Irvine 39 to an Irvine 52 but it has been a nice excercise.

 

How do you guys remove cator staining from the crankcase and silencer?

[Paul De Tourtoulon]

33 minutes ago, David Davis said:

How do you guys remove cator staining from the crankcase and silencer?

Now that's a question that you will be getting some answers from 'unbelievers".😄

 

Say no more,,,,

[Engine Doctor]

Castor doesnt really stain but damp storage conditions combined will old castor can etch the surface to a dark colour. Some people I know would oil up their engines with 3 in 1 oil !! Its awful stuff and really eats into the surface and sets like paint/ varnish.

The only way I know to restore the finish once etched is to thoroughly clean/de-grease an then bead blast the cases using fine beads. Douse not grit or crushed glass as this is too course and will leave a coarse finish that grabs dirts etc even more.  

Some parts can be mounted on the lathe or a pillar drill an spun up using various papers or steel wool but be careful. 

Also be careful of cleaners like Mr Muscle as they ar srtong alkaly and will make castings turn a near black colour.

Ultra sonic cleaners are very good but if using one with a flamable solvent put the part to be cleaned into glass jar wuth a screw on lid. Cover with your chosen solvent then stand jar in the US cleaner and fill the basin with water to the indicated level. NEVER use flams in a US cleaner in any other way.

[Jonathan M]

Slightly off topic, but would it be suitable to use 3-in-1 to pre-oil bearings, rockers, tappets, etc before starting engines that haven't been run for a long time?  If not recommended, then what oil would be preferable?

 

Also, what exactly is after-run oil (except very expensive stuff retailed in ever smaller bottles)?

[Martin Harris - Moderator]

I would avoid 3 in 1 oil like the plague.
 

Air tool oil is my lubricant of choice (even available in Halfords) but some use automatic transmission fluid (ATF).

 

I’ve also seen a mixture of the two recommended as after run oil.  

[David Davis]

5 hours ago, Jonathan M said:

Slightly off topic, but would it be suitable to use 3-in-1 to pre-oil bearings, rockers, tappets, etc before starting engines that haven't been run for a long time?  If not recommended, then what oil would be preferable?

 

Also, what exactly is after-run oil (except very expensive stuff retailed in ever smaller bottles)?

 

I use two-stroke oil to pre-lube an engine which has been dismantled.

[Christopher Wolfe]

19 hours ago, David Davis said:

 

 

How do you guys remove cator staining from the crankcase and silencer?

Here in the land of the kangaroo this is readily available CLR Oil and grease remover.

 

For a muffler with brown castor stains just brush it on neat, wait five minutes and flush it off with water aided by maybe a toothbrush (use hers not yours 🙃)

 

CLR also works well in an ultrasonic cleaner when diluted 50:50 with water and the parts are placed in a plastic baggie that is immersed in warm water.

 

Staining of aluminium alloy crankcases by alkaline solutions is possibly related to the copper content of the aluminium alloy (so I read online) 🙄