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Cox .049 p/cylinder ?

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Cox .049 p/cylinder ?

Post  oldguy on Tue Feb 23, 2016 2:40 pm

Can the piston be enlarged on a typical .049?To tighten up the fit in the cylinder.
Jim
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Re: Cox .049 p/cylinder ?

Post  balogh on Tue Feb 23, 2016 3:35 pm

I do not think so..I do not know about any reliable technology that would expand the very accurately manufactured, small piston such that it remains loose enough to run in the cylinder unobstructed and enhance compression as well.

Piston balljoint resetting sometimes leaves - erroneously - the piston crown "mushroomed" i.e. a bit expanded if the resetting is done too tough, but this typically results in such a tight fit that the piston/cylinder combo remains useless.

But I invite the more experienced COX engine lovers to offer some more promising reply to your question.
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Re: Cox .049 p/cylinder ?

Post  JPvelo on Tue Feb 23, 2016 5:02 pm

balogh wrote:I do not think so..I do not know about any reliable technology that would expand the very accurately manufactured, small piston such that it remains loose enough to run in the cylinder unobstructed and enhance compression as well.

Piston balljoint resetting sometimes leaves - erroneously - the piston crown "mushroomed" i.e. a bit expanded if the resetting is done too tough, but this typically results in such a tight fit that the piston/cylinder combo remains useless.

But I invite the more experienced COX engine lovers to offer some more promising reply to your question.

I accidentally mushroomed a piston once to where it was a super tight fit. I decided to go ahead and run it in and see what happened, it ended up being one of fastest runners.

In no way am I suggesting you try it, just sharing my experience.

Jim
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Re: Cox .049 p/cylinder ?

Post  oldguy on Tue Feb 23, 2016 7:00 pm

JPvelo wrote:
balogh wrote:I do not think so..I do not know about any reliable technology that would expand the very accurately manufactured, small piston such that it remains loose enough to run in the cylinder unobstructed and enhance compression as well.

Piston balljoint resetting sometimes leaves - erroneously - the piston crown "mushroomed" i.e. a bit expanded if the resetting is done too tough, but this typically results in such a tight fit that the piston/cylinder combo remains useless.

But I invite the more experienced COX engine lovers to offer some more promising reply to your question.

I accidentally mushroomed a piston once to where it was a super tight fit. I decided to go ahead and run it in and see what happened, it ended up being one of fastest runners.

In no way am I suggesting you try it, just sharing my experience.

Jim

Did you mushroom this piston resetting piston socket?

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Re: Cox .049 p/cylinder ?

Post  JPvelo on Tue Feb 23, 2016 7:15 pm

oldguy wrote:
JPvelo wrote:
balogh wrote:I do not think so..I do not know about any reliable technology that would expand the very accurately manufactured, small piston such that it remains loose enough to run in the cylinder unobstructed and enhance compression as well.

Piston balljoint resetting sometimes leaves - erroneously - the piston crown "mushroomed" i.e. a bit expanded if the resetting is done too tough, but this typically results in such a tight fit that the piston/cylinder combo remains useless.

But I invite the more experienced COX engine lovers to offer some more promising reply to your question.

I accidentally mushroomed a piston once to where it was a super tight fit. I decided to go ahead and run it in and see what happened, it ended up being one of fastest runners.

In no way am I suggesting you try it, just sharing my experience.

Jim

Did you mushroom this piston resetting piston socket?


Yes
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Re: Cox .049 p/cylinder ?

Post  RknRusty on Tue Feb 23, 2016 11:32 pm

You could use fuel made with pure cheap pharmacy castor and bench run it until it gets enough varnish to tighten it up. Then forever run it on nearly pure castor fuel like Cox Super power, which is 18/2 castor/synthetic to maintain the varnish.
I've never done it, but I'd try that first.

Happy Birthday Oldguy
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Re: Cox .049 p/cylinder ?

Post  balogh on Wed Feb 24, 2016 1:15 am

Jim[/quote]

Did you mushroom this piston resetting piston socket?

[/quote]

When you hit the piston socket too hard while resetting, the socket flattens the piston top and it expands, slightly increasing the piston skirt diameter at the top. If you are lucky enough (but chances are very slim) the expansion is centrally symetrical and the top of the piston remains round, and if you can still tuck it into the cylinder, it may end up a tightly fit p/c combo.


Happy birthday !!!!
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Re: Cox .049 p/cylinder ?

Post  stuntflyr on Wed Feb 24, 2016 1:25 am

JPvelo wrote:
balogh wrote:I do not think so..I do not know about any reliable technology that would expand the very accurately manufactured, small piston such that it remains loose enough to run in the cylinder unobstructed and enhance compression as well.

Piston balljoint resetting sometimes leaves - erroneously - the piston crown "mushroomed" i.e. a bit expanded if the resetting is done too tough, but this typically results in such a tight fit that the piston/cylinder combo remains useless.

But I invite the more experienced COX engine lovers to offer some more promising reply to your question.

I accidentally mushroomed a piston once to where it was a super tight fit. I decided to go ahead and run it in and see what happened, it ended up being one of fastest runners.

In no way am I suggesting you try it, just sharing my experience.

Jim

Lucky!
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