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Rapido 225 Squish

Posted: Thu Jan 15, 2009 10:28 pm
by Dimitrios_231
First of all,
is the squish measured at the very end of the solder?

I measured the squish,using both methods as per Sticky's book.

Using the 0.5mm base gasket and the 1mm head gasket,the squish is larger than 2mm.

Without the head gasket I get something less than 1.5mm (1.48mm).

Should I go without gasket and use Wellseal?
Or should I machine the barrel?
Don't want to machine the head and change compression.

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Re: Rapido 225 Squish

Posted: Thu Jan 15, 2009 10:31 pm
by sean brady scooters
yes mate.............dont use head gasket............ :D

Re: Rapido 225 Squish

Posted: Thu Jan 15, 2009 10:36 pm
by Dimitrios_231
Wellseal baby ;)

Re: Rapido 225 Squish

Posted: Thu Jan 15, 2009 11:43 pm
by sean brady scooters
you could choose to loose base gasket...............and end up with a squish less than 1mm...............but dont forget you would be also in effect lowering your port timings by .5mm...........

Re: Rapido 225 Squish

Posted: Thu Jan 15, 2009 11:55 pm
by Rob.R
just a suggestion but I always start by dry building with no gaskets at all and work from there.
I've found in the past that some engines require no gaskets at all (but as we all know they all vary) ;)

Re: Rapido 225 Squish

Posted: Fri Jan 16, 2009 1:06 am
by Dimitrios_231
Guys I have a problem.

I use a 2mm thick solder.
When I measure the squish,only the edge of the solder is pressed.
Less than 1cm in length is pressed.

The other part of the solder remains 2mm thick.

What does this mean?
My head is the 225 from AF, for rapido.

Re: Rapido 225 Squish

Posted: Fri Jan 16, 2009 1:47 am
by Rob.R
you could get the head machined to match the piston crown but for now take the smallest measurment as the squish (take 1mm as about the smallest you want and don't drop below that). Make sure when you push the solder in that it goes right up to the edge of the bore.
I find using thinner solder twisted together a bit better as it squashes easier.

Re: Rapido 225 Squish

Posted: Fri Jan 16, 2009 2:01 am
by Dimitrios_231
Cheers Rob.

I lapped the head, as it seems that I won't use head gasket.
At four points around the head I measured the squish,
and got minimum measurement as 1.31mm.
The maximum measurement is 1.33mm but this so small difference to worry about.

Initially,I thought that I should see the smaller squish measurement, for a longer length of solder.