Originally Posted by fbc25el (Post 4356975)

Do you run a cross over? IMO 100* of water temp is not enough. I also think you should have water lines from the front to back on the intake manifold.

Originally Posted by Budman II (Post 4356987)

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.

Originally Posted by Budman II (Post 4356987)

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.

Originally Posted by MILD THUNDER (Post 4357118)

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.

Originally Posted by Full Force (Post 4357128)

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....

Originally Posted by MILD THUNDER (Post 4357118)

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.

Originally Posted by sutphen 30 (Post 4356845)

looks a little lean compared to the other cylinders.to much heat will stick that valve..could also come down to water flow thru the cylinder head.2 engines down,,something in the set up is amiss.