Compression ratio - 3000S Essex V6

[CRM]

Is 11:1 compression too high to run on pump gas (98 Octane mainly with the occasional 95/96 Octane fill with Octane Booster)?

I have had the compression ratio professionally measured and am looking at purchasing this engine. It will be used primarily for road use the very occasional (1-2 year) track day. As I drive the unused windy roads I cannot always access 98 octane fuel.

Essentially I am concerned that the compression will be too high for pump gas. Can anyone please provide advise / experience about this.

Cheers

Leyton

Motor Specs

Balanced bottom end
Group A Heads - Capri touring car spec. Swaymar?
39mm exhaust ports, Polished and gas flowed
Standard inlet manifold
Harland Sharp Roller Rockers (1.5 Gold/Yellow)
Stainless Steel Valves
Double Valve Spring
Quafie Timing Gear
Holden V8 Rods - (shorter than standard)
Lightened and Balanced Flywheel
3.1 German RS Pistons (Not Forged) (numbers 093025 then in a circle 95,5,1215, 11,13)
Crank - Cross Drilled Journals
High Pressure / Volume Oil Pump
Head Temp Sensor
Road / Race Cam

Cam Profile - 333 lift, 238 degrees @ 050" (inlet and exhaust)
Rockers 1.45 ratio total lift .483

Engine still requires carburettor and rocker covers

Engine has not been run so unsure of power but it is estmated at 250BHP?

[heightswitch]

I would think you would need aviation fuel for that compression ratio?

N.

[Seabass]

My old 5Cyl 20v Audi had a stock compression ratio of 10.5 : 1 - this used to run fine on 98 unleaded... I guess you won't be able to run crazy advance though.

Cheers
James

[Electron]

Leyton,

I'll defer to Adrian and the experts on what the max ratio is you can run.

Have you considered running fully mapped fuel injection with the timing from a crank sensor ?

You'd then get closser timing and mixture across the rev range. You'd also be able to run multiple maps depending upon the available fuel.

Dave Walker at Emerald has built several V6 Essex configurations.

Chris