Supercharged 7 port head, suitable compression ratio?
Turbo Mini Forums

I am looking for guidance for suitable compression ratio. Static CR figures are welcome but I find theoretical dynamic compression figures more reliable (perhaps as close to reality as it gets theoretically without a lot of assumptions).

My set up:
- A+ block, sleeved and bored to +020
- Omega diecast pistons, 10cc dish
- RS FI (int valve close 46 deg ABDC)
- Pierce 7 port Al head (36/29 valves)
- Supercharged (Eaton R410), ~10psi boost, no intercooler
- Plenum with 90mm full radii runners with an injector into each runner at head entrance
- Stand alone ECU controlling ignition (trigger wheel) and fuel injectors

Deck height have not been possible to measure but it is untouched since production so I assume >40 thou. At the moment, the combustion chamber volume is 20.2cc. I guess it is possible to open up tp some extent. As the head is made out of Al, I assume that I can stretch the CR a bit compared to a 5-port cast iron head.

The intension is that the engine is supposed to be an engine used in a road car and run on 95 RON petrol.

road car, poor fuel, no intercooler.....be real and err on the side of caution.

I'd say certainly do not go higher than 9.0:1 unless you're going to be using some other form of detonation suppressant

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

A little late to the conversation but i would suggest a Cometic head gasket a little on the thicker side to help reduce your CR and look at lowering your boost expectations.

Own the day