Author Topic: Centaur gas engine  (Read 1796 times)

Offline Frank Boyle

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Centaur gas engine
« on: February 17, 2016, 07:58:10 AM »
I am starting the gudgeon pin and the drawing shows it bored through,is this to allow oil to be picked up from the cylinder walls as there is no cross hole shown to lubricate the little end.
Frank

Offline Jasonb

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Re: Centaur gas engine
« Reply #1 on: February 17, 2016, 08:04:35 AM »
Quite common practice to keep the weight down and also gives you a hole to poke the end caps into

Offline RayW

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Re: Centaur gas engine
« Reply #2 on: February 17, 2016, 11:38:50 AM »
The gudgeon pin on the Westbury Wyvern is exactly the same and I too have puzzled over the reason for it being hollow, especially as the brass end caps are also drilled 1/32" diameter. It is obviously not for lubrication for the little end because, as Frank says, there is no cross hole for the oil to reach the bearing. I assume, as Jason says, that it is for lightness but, if so, what is the purpose of drilling the end caps?
Ray

Offline Ian S C

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Re: Centaur gas engine
« Reply #3 on: February 17, 2016, 11:46:46 AM »
If the end caps are a tight fit in the pin, the hole will let the air out (maybe).
Ian S C

Offline Jo

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Re: Centaur gas engine
« Reply #4 on: February 17, 2016, 11:58:17 AM »
Yes if the pins are a good air tight fit without holes then the compressed air will push them back out. If not then, it is likely to do it once the engine is running and the trapped warm air increases the pressure.

Jo
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Offline michaelr

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Re: Centaur gas engine
« Reply #5 on: February 17, 2016, 12:53:33 PM »
There is modification for the Centaur for lubrication of the small end, there was a article in the Model Engineer of some extra mods for the Centaur, the following link may help


http://www.model-engineer.co.uk/sites/7/documents/me-3549-1.pdf

Mike.


Offline Frank Boyle

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Re: Centaur gas engine
« Reply #6 on: February 17, 2016, 04:43:38 PM »
Thanks for the information ,it makes a lot of sense and the link is great as I am machining the piston and was working to the original dimensions and this is just in time as I am reducing the skirt and I will now work to these revised dimensions.
Frank

 

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