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If i am running an 11.2:1 compression ratio.....wat can i do to best counter detonation......i am also wondering if running 10.2:1 cr will be as powerful as as running 11.2:1 with a 383 and 500 horsepower....wat r the benefits of high compression ratios...this motor will probably see more track time than street
 

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Some Punk Kid
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You can also run methanol injection but your compression really isnt all that high to require something like that.
I would start mixin up fuels. There are a lot of recipes on the internet that should get you in the required octane range to light your fuel charge on time.
 

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Re: detonation

Increased compression adds more power and torque across the board, improves throttle response and promotes a more efficient burn as long as the onset of detonation is controlled. The engine masters challenges are a great source to research for pointers. They are running some insane c/r's on pump gas but you gotta keep in mind these engines are being built for a contest and not for long term use in a daily or even weekend driver. Still alot can be adapted. Polishing the combustion chambers has been an effective means of making an engine more tolerant to octane levels as well as slightly radiusing the chamber edges and valve reliefs on the piston. Any sharp edge will be more prone to auto ignition and should be smoothed out. AFR heads come with fully CNC'd chambers which eliminate the rough texture of the casting process but the chambers are also consistant in shape and size to each other which helps avoid overly-rich cylinders to satisfy one or two lean ones. A richer mixture WILL help prevent detonation but at the cost of optimun power and fuel consumption. Aluminum heads transfer heat into the cooling system much better than cast iron which also allows higher c/r's.(up to a full point) A closed chamber design with an effective squish or quench effect will promote high turbulence as the piston approaches TDC and helps cool the charge which aids in a smoother more complete burn to diminish detonation. A simple tip to isolate hot spots is to radius the electrode of the spark plug which also helps with pre ignition as do "colder" plugs. Copper head gaskets also eliminate some hot spots but are not intended for endurance and tend to be pricey. Alot can be benefited from cold air induction and a divorced runner intake like the air-gap series. Cooler/denser intake charge makes more power and resists detonation. The cooling system can be upgraded with a colder thermostat, aluminum radiator and reverse flow waterpump. Thermal barrier coatings on the piston crowns, combustion chambers exhaust valves etc. are suppose to have remarkable results but I have no personal experience with them. From your other posts, I see you're not too far on your build to consider some of the things listed here. Do some research and incorporate as much as you can now. It will help later when your nailing down your advance curve and experimenting with octane levels. If you dont know how to read spark plugs......learn how to. They will tell you what kind of fuel your mill likes.
 
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