First post. Engine setup

[V8Astro]

Got my head back from my machinist friend. He took .020? (sorry I?m showing my American now posting measurements in thousandths of an inch) and I achieved .048? squish. Which I translated into 1.25mm

[Zman]

Looks great! 0.48 is good but you need to also check your compression. What octane fuel are you running?

[V8Astro]

Originally Posted by Zman

Looks great! 0.48 is good but you need to also check your compression. What octane fuel are you running?

That?s my next step. I bought a burette on amazon. I?m running US gas 93 octane (r+m)/2

[Jacob 'Berg]

I thought this may be useful:

http://49ccscoot.proboards.com/threa...ression-ratios

[(F5)]

And there's this
Gets a bit off topic but comes right in the end.

Actually it's not a bad thread if I say so myself. Lots of points I'd forgotten on the first page.

http://www.gasgasrider.org/forum/sho...highlight=Head

[V8Astro]

Very helpful links. Thanks everyone!

[V8Astro]

I cc?d the chamber today. I did it about 6 times to make sure my results were repeatable. Once I got bad reading because of an air bubble in my burette.

I settled on 23.4cc. Running the calculations I got 13.5:1 Comp. Should I leave the chamber alone or should I take some material off? I?d like the Comp high as 93 octane will allow.

[(F5)]

MON or RON? I forget which is higher. Google it for your country.

[V8Astro]

Average of the two (R+M)/2. I think our 93 is like euro 98 RON

[(F5)]

I wouldn't go any higher that should just be ok if your petrol is consistently ok.
So that is 2 threads up the spark plug threads? If it's to the top you will have to adjust.

I had to take quite a bit out of the chamber to get compression ok.