Compression Ratio

[gagvanman]

I run a 1776 type 1 engine running 7.5:1 comp. I want get a bit more umph out of the engine. I run E5 petrol, but when this gets more scarce and too expensive I was wondering what would be the best and maximum ratio to use with E10 petrol.

Thanks in advance...

 

[K@rlos]

What’s the full spec of the engine? Will need to know that in order determine what you CR you ideally want.

 

[gagvanman]

Here are the current specs:
New Aluminium Autolinea case
Stroke 69mm
Bore 90.5
Cylinder Head - CB performance 044 40 x 35.5mm 90.5
Solid Rocker Shafts
Standard 1:1 rockers
Camshaft Scat C35
Valve train geometry set with 60" rocker shims and shortened pushrods
Compression Ratio 7.5:1 set with 1mm barrel shims
SVDA Distributor
Twin Weber 34 ICT carbs.

 

[K@rlos]

8.5:1 and upgrade to twin 40’s. Make the most of those big valve heads and the cam 8)

Should be an easy 100hp motor.

 

[Fast Panel]

Just leave it as it is until something more urgent is required like a valve job