2270 build, 2270 compression question Options

[Alapone]

Hey guys,

I am having a 2270 built, 78mmx96mm. We are using the 163/86b webcam and 2.0l heads. Dellorto 45s and msds headers.

I am trying to decide on the right compression. The build is aimed at aggresive street use. I want to have as much power as possible and not have to run an external oil cooler or have any problems with detonation on 93/4 octane gas.

I have heard anything from 8.5:1 to 9.5:1. Please let me know your thoughts.

Thanks,

Andrew

[McMark]

I'll throw my votes in...

8.5:1 - Very safe on regular gas.
8.7:1 - Still safe, but starting to push things. Regular gas is probably still okay.
9.0:1 - More power, but you gotta pay attention for heat and detonation are starting to become serious factors. Premium fuel would be best.
9.3:1 - This level can't use the word safe at all. You must shed the heat and you must be very conscious of detonation/pinging.
9.5:1 - You better know what you're doing, at all times. This is no longer a jump in a drive motor, this is a motor that you must constantly be listening to and feeling. Above premium fuel is necessary.

[troth]

I'll throw my votes in...

8.5:1 - Very safe on regular gas.
8.7:1 - Still safe, but starting to push things. Regular gas is probably still okay.
9.0:1 - More power, but you gotta pay attention for heat and detonation are starting to become serious factors. Premium fuel would be best.
9.3:1 - This level can't use the word safe at all. You must shed the heat and you must be very conscious of detonation/pinging.
9.5:1 - You better know what you're doing, at all times. This is no longer a jump in a drive motor, this is a motor that you must constantly be listening to and feeling. Above premium fuel is necessary.

Mark, for future reference and general knowledge... Could you please clarify what you mean by regular vs. premium gas?

87ish octane low grade pump gas for regular 91ish premium pump gas for premium? Above premium = 95+ race fuel you get at the track?

I've only ever put the Shell V-Power in my car. I'm certain it's overkill for a stock 1.8.

[ChrisFoley]

I'll throw my votes in...

8.5:1 - Very safe on regular gas.
8.7:1 - Still safe, but starting to push things. Regular gas is probably still okay.
9.0:1 - More power, but you gotta pay attention for heat and detonation are starting to become serious factors. Premium fuel would be best.
9.3:1 - This level can't use the word safe at all. You must shed the heat and you must be very conscious of detonation/pinging.
9.5:1 - You better know what you're doing, at all times. This is no longer a jump in a drive motor, this is a motor that you must constantly be listening to and feeling. Above premium fuel is necessary.

Mark, for future reference and general knowledge... Could you please clarify what you mean by regular vs. premium gas?

87ish octane low grade pump gas for regular 91ish premium pump gas for premium? Above premium = 95+ race fuel you get at the track?

I've only ever put the Shell V-Power in my car. I'm certain it's overkill for a stock 1.8.

I recommend mid-grade (89 octane) gasoline for all stock 914-4 engines.
87 octane may ping under load going up hills. Premium is a waste of money, and it contains less energy than mid.