Too much timing?
Which is part of the reason, that I set my DCr so high, and set the minimum coolant temp to 207*, and she often idles with header temps at the ports being in the range of 450 +/- 25 degrees. Now granted some of that heat could be due to the exhaust still burning in the header due to my retarded idle-timing of just 14*, and partly because of the relatively short time spent in extraction of just 105*. But I did what I could, running 87E10 at 180 to 185 psi.
The previous cam had 111* of extraction, and did way better in every area except power after 5000 rpm or so.
I will never again, willingly, run pressure lower than about 160psi, with a carburator, on 87E10. The fuel in the old tanks just will not remain fresh enough, long enough, and the engine ends up with not enough VOCs to start on, or idle decently. And at the other end 10 or 20% or more won't burn either, so is it any wonder the engine uses a a lot of gas?
No wonder at all.
Check out the cross-over at 50%; is that about 212*F? lol.
Check out the 100% burn at 425*F for 8%
I would run hotter than 207, but 207 allows me to run a 7psi cap, and so, my hoses last for decades, not to mention my rad is from 1973; which, if my math is right is coming 48 or more years old . I mean, until recently, a guy could buy a lotta gas for the price of a new rad.........
Nice chart @MattaxFor example, this 8% eth fuel began to vaporze just over 100 degrees F, same as the non-eth. But it required over 300 degrees to vaporize the last 20% of the fuel.
It needed over 400 degrees to completely vaporize all of the fuel.
Which is part of the reason, that I set my DCr so high, and set the minimum coolant temp to 207*, and she often idles with header temps at the ports being in the range of 450 +/- 25 degrees. Now granted some of that heat could be due to the exhaust still burning in the header due to my retarded idle-timing of just 14*, and partly because of the relatively short time spent in extraction of just 105*. But I did what I could, running 87E10 at 180 to 185 psi.
The previous cam had 111* of extraction, and did way better in every area except power after 5000 rpm or so.
I will never again, willingly, run pressure lower than about 160psi, with a carburator, on 87E10. The fuel in the old tanks just will not remain fresh enough, long enough, and the engine ends up with not enough VOCs to start on, or idle decently. And at the other end 10 or 20% or more won't burn either, so is it any wonder the engine uses a a lot of gas?
No wonder at all.
Check out the cross-over at 50%; is that about 212*F? lol.
Check out the 100% burn at 425*F for 8%
I would run hotter than 207, but 207 allows me to run a 7psi cap, and so, my hoses last for decades, not to mention my rad is from 1973; which, if my math is right is coming 48 or more years old . I mean, until recently, a guy could buy a lotta gas for the price of a new rad.........