Correct piston position

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red42hj
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Joined: Sun Oct 16, 2016 1:31 pm
Location: wiltshire

Correct piston position

Post by red42hj » Thu Jun 13, 2019 8:11 am

Hello again. A thread that I came across ( African Imp), cautioned him to make sure the" piston was the correct way up " on reassembly. Looking at his pics, it made me realise that , although I was careful to reassemble my 102 in the same position; I had not considered the implications had it been wrong. Does this mean that on all ,or some engines that it simply would not work? ie. Compression and scavenge unable to be acheived. Presumably a flat top piston would be ok?
Regards Red.

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Collector Inspector
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Re: Correct piston position

Post by Collector Inspector » Sun Jun 16, 2019 8:29 am

I have included a pic of what is similar to our beloved.

Nicely it shows how it works and with just a mind flip of it can be seen as "really not that efficient".....

Very hard to start if incorrect and so easy to stop. Upside wrong way piston install will have compression but........fails everywhere else of course.

Image321.jpg
That was easy aye.

Flat top pistons only have two issues with orientaion.

1. probably a transfer cut port in the skirt.

2. Offset of piston pin.

Skirt port wrong way......no run.

Offset of piston pin...........no revs and goodby big end. (It will be letting you know whist running)

Good question that and

Regards

BnC [/color][/b]
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JERSEYMAN
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Re: Correct piston position

Post by JERSEYMAN » Mon Jun 17, 2019 9:05 pm

Sorry, I was looking for diagram on piston position and found myself being a little hypnotised by this.... also I think it’s kinda sexy or is that the hypnosis talking...
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red42hj
Posts: 77
Joined: Sun Oct 16, 2016 1:31 pm
Location: wiltshire

Re: Correct piston position

Post by red42hj » Thu Jun 27, 2019 10:36 pm

Thanks guys, very interesting comments.Not as simple as I first thought. Worth studying.

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