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Engine basics => Engine set up tips => Topic started by: Dave Rountree on June 18, 2008, 04:58:30 AM
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Randy as we move from 5% to 7.5% to 10% nitro as the season progresses do we need to add head gaskets to lower compression? also does increased nitro content increase pre-ignition possibilities? thanks for the help. Dave Rountree
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Hi Dave - Randy must be busy, I'll take a crack, and he can correct me...
The whole reason you would upping the nitro in the first place is to supercharge the mixture in the hot thin summer air. Adding head shims would mostly just undo the effect of the nitro you are trying to gain. Nitro and compression are almost (I said almost) synonymous. You could just as well pull a head shim in the summer as add nitro.
The whole idea of tuning with nitro is to have your engine shimmed in a mid-range so that you can use readily available fuels without ever having to take apart your motor. So, for instance, you can run 5% in the fall, 7.5% in the spring and 10% in the dog days of summer. Pre-ignition is just advanced timing, which adding nitro or compression can bring if overdone. Glow plug heat range is the other piece of the puzzle.
Bottom line, trial and error will tell you what you need to know. Bring a few cans of different nitro fuel to the field and mix in your syringe for effect, see what you get.
EricV
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Randy as we move from 5% to 7.5% to 10% nitro as the season progresses do we need to add head gaskets to lower compression? also does increased nitro content increase pre-ignition possibilities? thanks for the help. Dave Rountree
Hi Dave
I have been away all week and so I was not online much, Eric pretty much answered you question very well.
If you use the nitro in this manner it will require nothing most of the time, even though you may tweek the engine run with glo plugs
Example may people use an Enya # 3 in cooler months and the Enya#4 in hot weather,
This is a good reason to try several brands of plugs to see how they act in your setup
Regards
Randy
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Thanks guys for the information. I've got so much catching up to do. Eric see you sunday. Thanks again, Dave