What happened
09-21-2015, 11:53 AM
#21
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Shortly after I got it I installed a restrictor because it had no engine temp when running.
The builder was aware of the water temp and oil temp beforehand started the first rebuild and was comfortable with them.
09-21-2015, 11:55 AM
#22
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Yep! When I had my engine run on the dyno I asked them to put a load on it and run it with a steady state test from 3500 RPM to 4500 RPM. I wanted to make sure we had good A/F numbers in that range, and also wanted to ensure that there would be no oil drainback issues with valley screens installed. While running this way, we saw it go pretty lean and the headers began to glow. If I had simply dropped it in the boat and run it after making several quick pulls on the dyno for WOT power data, I am 100% sure I would have likely melted it down at a fast 4200 RPM cruise.
Thanks
09-21-2015, 12:11 PM
#23
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yes, and in my case especially since I didn't dyno, I run widebands all the time to keep eye on that stuff...what it does on a dyno and in the boat are 2 different things...in the boat being more important
Yep! When I had my engine run on the dyno I asked them to put a load on it and run it with a steady state test from 3500 RPM to 4500 RPM. I wanted to make sure we had good A/F numbers in that range, and also wanted to ensure that there would be no oil drainback issues with valley screens installed. While running this way, we saw it go pretty lean and the headers began to glow. If I had simply dropped it in the boat and run it after making several quick pulls on the dyno for WOT power data, I am 100% sure I would have likely melted it down at a fast 4200 RPM cruise.
09-21-2015, 12:47 PM
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How much timing are you running in this engine ?
Inconel or not, if mixture is lean, or timing to far retarded, or very narrow seat widths,, the exhaust temps can get out of hand real quick, and the valve can fail.
My guess, and its just that, a guess, is that the mixture is too lean, and possibly not enough timing. Many guys think timing is a tool for reducing power, adding safety margin, etc, but it is not. Its simply a point at which the plug should be fired for optimal combustion. There are many factors involved to what that number may be.
Inconel or not, if mixture is lean, or timing to far retarded, or very narrow seat widths,, the exhaust temps can get out of hand real quick, and the valve can fail.
My guess, and its just that, a guess, is that the mixture is too lean, and possibly not enough timing. Many guys think timing is a tool for reducing power, adding safety margin, etc, but it is not. Its simply a point at which the plug should be fired for optimal combustion. There are many factors involved to what that number may be.
09-21-2015, 01:00 PM
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yes, many guys think less timing is safe, not always the case... we used to retard timing to make EGT higher to get out street cars past emissions....
How much timing are you running in this engine ?
Inconel or not, if mixture is lean, or timing to far retarded, or very narrow seat widths,, the exhaust temps can get out of hand real quick, and the valve can fail.
My guess, and its just that, a guess, is that the mixture is too lean, and possibly not enough timing. Many guys think timing is a tool for reducing power, adding safety margin, etc, but it is not. Its simply a point at which the plug should be fired for optimal combustion. There are many factors involved to what that number may be.
Inconel or not, if mixture is lean, or timing to far retarded, or very narrow seat widths,, the exhaust temps can get out of hand real quick, and the valve can fail.
My guess, and its just that, a guess, is that the mixture is too lean, and possibly not enough timing. Many guys think timing is a tool for reducing power, adding safety margin, etc, but it is not. Its simply a point at which the plug should be fired for optimal combustion. There are many factors involved to what that number may be.
09-21-2015, 02:34 PM
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How much timing are you running in this engine ?
Inconel or not, if mixture is lean, or timing to far retarded, or very narrow seat widths,, the exhaust temps can get out of hand real quick, and the valve can fail.
My guess, and its just that, a guess, is that the mixture is too lean, and possibly not enough timing. Many guys think timing is a tool for reducing power, adding safety margin, etc, but it is not. Its simply a point at which the plug should be fired for optimal combustion. There are many factors involved to what that number may be.
Inconel or not, if mixture is lean, or timing to far retarded, or very narrow seat widths,, the exhaust temps can get out of hand real quick, and the valve can fail.
My guess, and its just that, a guess, is that the mixture is too lean, and possibly not enough timing. Many guys think timing is a tool for reducing power, adding safety margin, etc, but it is not. Its simply a point at which the plug should be fired for optimal combustion. There are many factors involved to what that number may be.
Last edited by the mayor; 09-21-2015 at 02:37 PM.
