Nitro engine where to get it pinched

[roker99]

Hi all

As above does anyone know a good place to get my engine re pinched please

I have never had this done with a engine before its a picco boost

But because they are a good engine it def worth a go

So looking for someone reliable and at a good price please

Thanks roker

[mugen mark]

tron on maxbashing,do a search though the services i think,he did one for me a while back,they got the proper tools

[roker99]

Thanks m8

Will have a look now as I belong to maxbashing anyway

Thanks roker

[bunnie]

Big T off maxbashing done mine before. Highly recommended

[TMaxxDave]

What is 'pinched'?

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[gavin28]

I've used http://www.rcengineservices.co.uk before, I think he is on the Maxbashing forum too, or was was he did mine.

Really fast turn around and did a good job too.

 

 

What is 'pinched'?


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This should help you understand

[atom3624]

What is 'pinched'?

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I was curious, so this is what they say on rcengineservices: 

Liner Re-Sizing

What is liner re-sizing and why is it useful?

First of all lets look at a full sized engine like in your car. As the piston moves up the cylinder it builds compression which is key to igniting the fuel/air and forcing the piston back down the bore of the cylinder. To allow the piston to build compression the piston has a set of metal rings which provides the seal between the piston and the cylinder wall, stopping the mixture escaping between gaps allowing the fuel and air to be compressed.

Now lets looks at the typical RC engine. The pistons inside these are small and the rings to seal the cylinder would be tiny. These engines also rev to very high RPMs which combined with small rings would rip the rings to pieces causing irreparable damage. To combat this, the typical RC engine does not have piston rings, instead the bore of the piston cylinder liner is tapered so that their is a very slight mechanical interference fit from the piston and the cylinder liner wall to stop the fuel/air mixture escaping, allowing for the mixture to be compressed and ignited. This is also why they need to be "broken in" allowing the piston and cylinder liner wall to properly seat together and create a good seal. Eventually this seal will become worn and less effective at stopping the fuel/air mixture from escaping, allowing unburnt fuel to be pushed back in to the crank case or out of the ports.

A piston liner re-size or "pinch" is the process of reducing the inner diameter of the piston cylinder liner so that the piston and liner may be restored to near original size for a better seal allowing the proper compression to be achieved.