Measuring the CC's of the cylinder head on omc 56 ci

[phillnjack]

Hi guys.
couple of questions that might seem obvious to most of you .

when measuring the cc's of the cylinder head to get an accurate volume on a omc 56 triple, do I

1. use normal spark plug threaded all the way in and take measurement inc the tiny bit down the plug ?
or
2. just tape over the plug hole or put in a dead flat bolt to fill the area level so just measuring the bowl volume on its own. ?


will it be ok to use just plain old tap water to measure the volume / or maybe petrol ?
I dont have any alcohol at hand to use other than the wife's vodka and that could get me kicked in the nuts if I uses that.

the way I am thinking to measure is to get the head upside down level, put a piece of clear Perspex over the complete chamber
with a small hole in centre to use as filling point, when all the Perspex has liquid touching it that is the total amount ?
is this correct or am I going about it completely wrong ?

I ask this as just got told some very strange ways to that this is done and it seems completely alien to do it that way.

[vnemous]

spark plug that is called for and just break the porcelain off so it will lay flat. A little grease on the plate to seal it and You got the rest figured out.

[phillnjack]

Thanks Vnemous

Grease to use as a seal sounds good, I have a 10 gallon drum of it given to me doing nothing ha ha .

I can take as much as 100 thou off before the head would start to be getting a bit thin, but I hope I only need to remove
about 65 to 70 thou to clean it up .and this could help me lose around 4cc off the chamber ( I think) ?

I only want to go to the compression that I can still run our 99 pump gas, its about equal to 95 octane in the usa.
so I am hoping for compression to be around 155 to 160 so I dont have to go looking for race fuel ( far too expensive over here).

.