How I was told to run a cast iron/steel diesel engine in.
05-23-2014, 10:30 PM
#1
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How I was told to run a cast iron/steel diesel engine in.
Back in the 70's at the Cronulla club's at Taren Point in Sydney Australia there used to be a nice bloke called Lee Nilson who owned 2 hobby stores and brought his Bongo van down that was simply loaded with control line goodies to the field every Saturday .
I purchased from him my first PAW 19 and a Taipan Mk 13 diesel and part of the service including running in with instructive lessons along the way.
Now what Lee did was to clamp the engine in a Davis Charlton type engine test mount, that was bolted to an iron stand and proceed to install what looked like an old and very battered cut down 12" prop.
From memory the diameter of this 'prop' ended up about 10" but it had virtually no leading or trailing edge to speak of and was very oil soaked and heavy.
Further the props bore was inserted with a heavy steel sleeve nut that had what looked like wing nut lugs where typically the hex head would be.
His remarks were, have a go starting it and to my delight the 'club' that was used up front as a crank for starting was very easy to use due to the facts that it was impossible to cut your self on it (as it had no edges anywhere), was so heavy that the flywheel effect was simply enormous and the 5" leverage meant that the whole nervous hand could be used behind it instead of a single fragile finger.
Lee said that if he could use a marine flywheel and pull cord he would but this way made more sense for aircraft anyway.
And the amount of thrust made by the 'prop' was very little and it more or less stirred the wind around its arms - but this was kinda the point too.
We would only run the engine as long as we could tolerate holding the cooling jacket and then shut it down, cool thoroughly and repeat about 5 more times before even venturing to mount a true prop on it. The lack of windage from the wooden clubs arms meant that it heat cycled quite rapidly so it was entirely possible to run the engine in about 1.5 hours.
This story has lead me to believe that perhaps using a true running prop as a hand start crank may not be the best choice of lever up front and has convinced that flywheel more than anything is the best effect to get any engine started.
And thrust from a true prop is not necessary at all, except for providing some form of cooling, so why use one?
Thoughts?
I purchased from him my first PAW 19 and a Taipan Mk 13 diesel and part of the service including running in with instructive lessons along the way.
Now what Lee did was to clamp the engine in a Davis Charlton type engine test mount, that was bolted to an iron stand and proceed to install what looked like an old and very battered cut down 12" prop.
From memory the diameter of this 'prop' ended up about 10" but it had virtually no leading or trailing edge to speak of and was very oil soaked and heavy.
Further the props bore was inserted with a heavy steel sleeve nut that had what looked like wing nut lugs where typically the hex head would be.
His remarks were, have a go starting it and to my delight the 'club' that was used up front as a crank for starting was very easy to use due to the facts that it was impossible to cut your self on it (as it had no edges anywhere), was so heavy that the flywheel effect was simply enormous and the 5" leverage meant that the whole nervous hand could be used behind it instead of a single fragile finger.
Lee said that if he could use a marine flywheel and pull cord he would but this way made more sense for aircraft anyway.
And the amount of thrust made by the 'prop' was very little and it more or less stirred the wind around its arms - but this was kinda the point too.
We would only run the engine as long as we could tolerate holding the cooling jacket and then shut it down, cool thoroughly and repeat about 5 more times before even venturing to mount a true prop on it. The lack of windage from the wooden clubs arms meant that it heat cycled quite rapidly so it was entirely possible to run the engine in about 1.5 hours.
This story has lead me to believe that perhaps using a true running prop as a hand start crank may not be the best choice of lever up front and has convinced that flywheel more than anything is the best effect to get any engine started.
And thrust from a true prop is not necessary at all, except for providing some form of cooling, so why use one?
Thoughts?
05-24-2014, 05:39 AM
#2
My Feedback: (1)
I got my first diesel, a Taipan 1.5cc red head towards the end of 1959 when I was about twelve y/o. I bought a wooden prop (probably a 7x6), and a bottle of diesel fuel and a Keil Kraft 10cc tank. I mounted it all on a board held down by a brick on the back steps of our house and started flicking.
Occasionally it would fire but I couldn't get it to run constantly. I took it to a kid who lived up the road and knew all about model engines. He leant me a big brass flywheel, and showed me how to start it by using a push bike turned upside down so that it balanced on the handlebars. While I worked the pedals he held the flywheel against the rotating rear wheel and moved the compression screw. It burst into life and ran steadily. We soon sorted out a setting, and I spent the next few weeks running it in this way.
Regrettably it still wouldn't start with a prop on it. Eventually I found out about a local club and took it down. They swapped props to a better one with some flywheel effect and it started almost straight away. Seems that the wooden prop was too light and badly balanced and I didn't have the knack of the "diesel flick" .
What's the point to the story? There isn't one really, but over 50 years later I've still never ever ever heard of anyone else using the upside down bike wheel and a flywheel to start a diesel..
:-)
Occasionally it would fire but I couldn't get it to run constantly. I took it to a kid who lived up the road and knew all about model engines. He leant me a big brass flywheel, and showed me how to start it by using a push bike turned upside down so that it balanced on the handlebars. While I worked the pedals he held the flywheel against the rotating rear wheel and moved the compression screw. It burst into life and ran steadily. We soon sorted out a setting, and I spent the next few weeks running it in this way.
Regrettably it still wouldn't start with a prop on it. Eventually I found out about a local club and took it down. They swapped props to a better one with some flywheel effect and it started almost straight away. Seems that the wooden prop was too light and badly balanced and I didn't have the knack of the "diesel flick" .
What's the point to the story? There isn't one really, but over 50 years later I've still never ever ever heard of anyone else using the upside down bike wheel and a flywheel to start a diesel..
:-)
Last edited by qazimoto; 05-24-2014 at 04:01 PM.
05-24-2014, 06:10 AM
#5
My Feedback: (1)
I started running in a new piston/liner in an Oliver Tiger Cub (09 size) this afternoon. It arrived from Tom Ridley a few days ago. The engine uses the classic Iron piston and hardened Steel liner common in radially ported diesels. The OT Cub mk2 first went into production about 1963 and have more or less been available since then. There are a few clones as well.
This cub is a real "bitzer". It was built up for my son and myself in the mid 90's from bits and pieces of cubs by Stan Pilgrim, the well known diesel guru and "motor boy". We used it in a Phantom team racer for ages..
The engine went back to John Oliver in the late 90's for a rebore, new shaft and races, and a new rod. It was used extensively in a c/l 1/2A team racer until quite recently. The constant use in the dust had taken it's toll. The rear ball bearing was rough and there was extensive scoring on the piston.
I've just fitted a new set of R250 ballraces. C3 grade R6 in the rear and R4 in the front. I assembled the engine this morning after checking the exhaust timing duration. It was almost exactly 145 degrees with the old .010" shim under the liner. Exactly what it should be after being set up by Stan almost 20 years ago. The new liner must be precisely the same as the 50 year old one.
The engine felt squishy and lacked compression. The liner is chromed and the piston looked unlapped. This seems to be fairly common these days when you buy a new diesel p/l from a manufacturer. This isn't really a problem, it just needs running in.
I found a nice big chunky Thunder Tiger 8" x 4.5" plastic prop in the tool box. It was already bored out for an Oliver sized prop sleeve nut. Had there been a chunky 9 x 4 I would have used that.
After a fair bit of priming and flicking nothing much was happening bar a feeble fire every now and then.
So a mate applied his electric finger until it burst into life. I realise that using a starter on an Oliver Cub might offend some purists, but I do have special dispensations from both the Pope and the Dalai Lama allowing me to do such things. Basically it's because my parents sent me to Catholic school for ten years. :-)
After the first run it would start by flicking and compression increased a little with each 30cc tankfull of fuel.
This cub is a real "bitzer". It was built up for my son and myself in the mid 90's from bits and pieces of cubs by Stan Pilgrim, the well known diesel guru and "motor boy". We used it in a Phantom team racer for ages..
The engine went back to John Oliver in the late 90's for a rebore, new shaft and races, and a new rod. It was used extensively in a c/l 1/2A team racer until quite recently. The constant use in the dust had taken it's toll. The rear ball bearing was rough and there was extensive scoring on the piston.
I've just fitted a new set of R250 ballraces. C3 grade R6 in the rear and R4 in the front. I assembled the engine this morning after checking the exhaust timing duration. It was almost exactly 145 degrees with the old .010" shim under the liner. Exactly what it should be after being set up by Stan almost 20 years ago. The new liner must be precisely the same as the 50 year old one.
The engine felt squishy and lacked compression. The liner is chromed and the piston looked unlapped. This seems to be fairly common these days when you buy a new diesel p/l from a manufacturer. This isn't really a problem, it just needs running in.
I found a nice big chunky Thunder Tiger 8" x 4.5" plastic prop in the tool box. It was already bored out for an Oliver sized prop sleeve nut. Had there been a chunky 9 x 4 I would have used that.
After a fair bit of priming and flicking nothing much was happening bar a feeble fire every now and then.
So a mate applied his electric finger until it burst into life. I realise that using a starter on an Oliver Cub might offend some purists, but I do have special dispensations from both the Pope and the Dalai Lama allowing me to do such things. Basically it's because my parents sent me to Catholic school for ten years. :-)
After the first run it would start by flicking and compression increased a little with each 30cc tankfull of fuel.
Last edited by qazimoto; 05-25-2014 at 01:58 AM.
05-24-2014, 06:26 AM
#6
My Feedback: (1)
After a few tankfulls with the TT 8" prop, I switched to a more suitable APC 7 x 4" prop. This is a fairly common standard run in prop for 09 diesels in the team racing community. So rpm on this common prop tells us how well an engine compares.
I gradually added more compression and started to lean to peak it a few times each tank. In between leaning I richened it up about two turns.
The next few tanks ran rich and slightly under compressed. The p/l seal continued to improve.
After about half a litre of fuel it would hold a 18K rpm burst for about half a tank. Eventually the tacho showed 18250 rpm which is very good for an Olly Cub on an APC 7x4" prop. Mr Ridley certainly knows something about making good p/l.
The rest of the running in will be in the air. The whole episode took about 2 1/2 hours allowing cooling between most runs. This is one way of running in an engine.
The new Ridley Oliver Cub that arrived with the spares has been test run at the factory, so I expect it to start up straight away. Many new engines these days don't need any runin at all and can go into use almost out of the box.
I gradually added more compression and started to lean to peak it a few times each tank. In between leaning I richened it up about two turns.
The next few tanks ran rich and slightly under compressed. The p/l seal continued to improve.
After about half a litre of fuel it would hold a 18K rpm burst for about half a tank. Eventually the tacho showed 18250 rpm which is very good for an Olly Cub on an APC 7x4" prop. Mr Ridley certainly knows something about making good p/l.
The rest of the running in will be in the air. The whole episode took about 2 1/2 hours allowing cooling between most runs. This is one way of running in an engine.
The new Ridley Oliver Cub that arrived with the spares has been test run at the factory, so I expect it to start up straight away. Many new engines these days don't need any runin at all and can go into use almost out of the box.
Last edited by qazimoto; 05-24-2014 at 03:48 PM.
