4-stroke conversion ideas
#1
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4-stroke conversion ideas
Hi guys!
This forum has been busy with all the lil' diesels I've been having my share here too, bench running my PAW 09 RC almost everyday for 2 tanks of fuel. I'm a proud smelly dude!
I'll be receiving a used OS FS-26 shortly and began to think on how to dieselise it without having all the problems with valve clearance that arise on this little engine. On my past experiments with my other FS-26 (sold in the meantime to a fellow airboater from down under), the maximum compression ratio achieved was around 11~12:1. More than this and I had no valve clearance from the piston.
So, today I burned a few neurons and came up with the following idea (see attachment):
Instead of lowering the chamber, why not fill it up like we "do" on 2-stroke engines? This way valve clearance would be the same as from factory, and thus no valve binding on the piston problems!
Holes would be provided for the valves and the glow plug hole would still function as support for the Lanova cell (or another simple compression adjustment device).
The filling block could be cast and then machined to proper dimensions, with a couple of screws holding it to the inside of the cylinder head.
What do you engine gurus think of this approach?
This forum has been busy with all the lil' diesels I've been having my share here too, bench running my PAW 09 RC almost everyday for 2 tanks of fuel. I'm a proud smelly dude!
I'll be receiving a used OS FS-26 shortly and began to think on how to dieselise it without having all the problems with valve clearance that arise on this little engine. On my past experiments with my other FS-26 (sold in the meantime to a fellow airboater from down under), the maximum compression ratio achieved was around 11~12:1. More than this and I had no valve clearance from the piston.
So, today I burned a few neurons and came up with the following idea (see attachment):
Instead of lowering the chamber, why not fill it up like we "do" on 2-stroke engines? This way valve clearance would be the same as from factory, and thus no valve binding on the piston problems!
Holes would be provided for the valves and the glow plug hole would still function as support for the Lanova cell (or another simple compression adjustment device).
The filling block could be cast and then machined to proper dimensions, with a couple of screws holding it to the inside of the cylinder head.
What do you engine gurus think of this approach?
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RE: 4-stroke conversion ideas
I'm thinking of dieselizing an os four stroke making a longer rod to boost the compression. I think filling the head would take a lot of work. just a thought there's a thread in here some where about doing that. good luck Erik
#3
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RE: 4-stroke conversion ideas
How about filling the squish band instead of filling the dome area around the valve seats and plug hole? You could make several ring inserts and experiment with blending the radius to the dome.
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RE: 4-stroke conversion ideas
Erik, making a longer rod will present the same valve binding problems as lowering the head [:@]
lildiesel, could you explain better? I don't get the idea[&:]
lildiesel, could you explain better? I don't get the idea[&:]
#5
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RE: 4-stroke conversion ideas
ORIGINAL: Patxipt
Erik, making a longer rod will present the same valve binding problems as lowering the head [:@]
lildiesel, could you explain better? I don't get the idea[&:]
Erik, making a longer rod will present the same valve binding problems as lowering the head [:@]
lildiesel, could you explain better? I don't get the idea[&:]
The squish band is essentially the area you don't cover in yellow in your illustration. Fill the squish band and not the combusition dome. Check out this illustration from a machinist's site about karting engines. [link=http://www.muller.net/mullermachine/docs/squish1.html]squish band explained[/link] The illustration is for a domed piston but the concept also applies to a flat topped piston.
#7
RE: 4-stroke conversion ideas
This is allready old news.. follow all history how to convert the 4 stroke engine to run as a diesel engine as here: http://www.rcuniverse.com/forum/fb.asp?m=900816
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RE: 4-stroke conversion ideas
Oh, I remember that thread! It just wasn't showing up on the search facility for me[&:]
Any more Qs will be posted there.
But, Jens, what do you think of my approach above? (just for the sake of it )
Any more Qs will be posted there.
But, Jens, what do you think of my approach above? (just for the sake of it )
#9
RE: 4-stroke conversion ideas
ORIGINAL: Patxipt
Oh, I remember that thread! It just wasn't showing up on the search facility for me[&:]
Any more Qs will be posted there.
But, Jens, what do you think of my approach above? (just for the sake of it )
Oh, I remember that thread! It just wasn't showing up on the search facility for me[&:]
Any more Qs will be posted there.
But, Jens, what do you think of my approach above? (just for the sake of it )
1. With adjustable compression ratio (as i showed the link in early post.)
2. Fixed compression ratio and will be adjusted with cylinder head gasket depent on fuelmix.
See the engine with fixed compression ratio in the Enya 41-4CD as here how to remove the material from cylinder head and check the compression with fluid and the 1 ml syringe with needle. Follow the history of the engine with too low compression ratio (fault production by Enya Mfg..) here: http://www.rcuniverse.com/forum/fb.asp?m=5493013
#11
RE: 4-stroke conversion ideas
ORIGINAL: erik58
machine notches in the piston for valve clearence or home made piston. Erik
machine notches in the piston for valve clearence or home made piston. Erik
The piston in the Enya 4 stroke dieselengine are without pistonring. Lapped castiron piston and steel sleeve.