Compression ratio .

[ianh1968]

I ALWAYS use water...

A mop out with some paper and a blast with the air-line
soon sorts out the wet. For the paranoid amongst us,
a quick squirt of WD40 would keep any rust at bay.

I also use a burette - I can't tell from the photos, but my
1/4" thick perspex sheet has TWO holes in it.

One to feed the water in, and the other to let the air out.
I normally chock the heads slightly to make the air rise
and escape from the vent hole, which I position right at
the edge of the chamber.

The benefit of water here is that the increased surface
tension prevents it from leaking out of the feed hole.
(And when you are doing this on your kitchen sink
draining-board, like I do, you don't make your house smell...)

The burette I use was bought in about 1979 and is
"Terry Clipped" to a backboard with a piece of 2"x1"
prepared timber up each side to protect it. It also
has a silicone hose, so it should last for ever.

DON'T FORGET TO FLICK THE AIR BUBBLES OUT OF THE
HOSE/TUBE BEFORE TAKING ANY MEASUREMENTS.

My 1480cc was originally put together with a 16cc head.
I needed the Omega "short deck height" pistons, which
I further shortened by another 60thou purely to reduce
the CR. Even with a largish capacity in the block, I ended
up with about 13:1.

With a 649, this would probably be acceptable, but with
an MD276 it was way too high. I now have about 11:1
and it runs so much better...

Conclusion:
The final deck height will be dependent on the CR that you
want and what the rest of the "unswept volume" adds up to.
A sensible CR will be determined by the cam that is used.

Ian

[olddad]

My doctor gave me an irrigation syringe for free. It was the right size for fluid voluum and ease of reading. I use red automatic trans fluid just because it is red and shows up nice against the plexiglass sheet. I just seal down the sheet with vasoline.

[mk1]

(And when you are doing this on your kitchen sink
draining-board, like I do, you don't make your house smell...)

Now that is what I call a good reason!

[ianh1968]

I had a head to check, so I took the opportunity to get some
photos of my equipment...

All the burettes I have seen for sale have a fixed tap at the
bottom of the tube which looks a bit cumbersome to me.

When my burette was bought, my Dad sent me to school with
a letter addressed to the chemistry teacher asking where he
could get some "lab equipment"...

He subsequently got a 50cc tube, some silicone hose and
a tap, into which was fabricated a spout. The tube was clipped
into its wooden case which has a picture hanging hook at the
top. It is far more portable and protected than most and is
very easy to use as a result.

Always take the reading at the correct meniscus...
https://en.wikipedia.org/wiki/Meniscus_(liquid)
Edited to update link. 03062017

Ian

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