Reply With QuoteGod allows it to accelerate.
Paul
After taking a quick look at this thread, this should get pretty interesting!! :idea:
Warp SpeedLove to get some of your input here, Warp. Maybe we can get Steven (gearhead) to chime back in.
God allows it to accelerate.
Paul
Pressure differential
Pressure.That's definately the beginning. Without 14.7psi, we're no where.
C'mon guys, this was a good thread and it just died. Something more than "what carb should I run"...
Pressure differentialFrom where to where?
I like these kinds of talks but, we are usually stuck with the parts that are given by manufactures. And the budgets given by customers. And the amount of time to get an engine running. Not trying to be a downer but what are we going to do when we all decide that there is a really good combo, but it needs special lenth/weight/size parts. We will comprimise! And try to get the closest thing made or off the shelf. Then you will be left walking the halls at night, puffin' a fattie and thinking what if. Not me. If its not huffing nitro and burning off 16 spark plugs in 5 seconds its a comprimise! But I really do like engine tech.
I like these kinds of talks but, we are usually stuck with the parts that are given by manufactures. And the budgets given by customers. And the amount of time to get an engine running. Not trying to be a downer but what are we going to do when we all decide that there is a really good combo, but it needs special lenth/weight/size parts. We will comprimise! And try to get the closest thing made or off the shelf. Then you will be left walking the halls at night, puffin' a fattie and thinking what if. Not me. If its not huffing nitro and burning off 16 spark plugs in 5 seconds its a comprimise! But I really do like engine tech.But what if...what if you cold design your own ports, your own chambers, your own piston domes and your own intake runners. What information goes into that kind of thinking? I've read so much of Larry Widmer's stuff, where he had the cpapbility to do those things, and I always wondered, where do you start? I know---picking a goal, but after that? What if you had a clean sheet of paper.
Old...yes, this is all about acceleration over time, since we're trying to get from point A to point B in the least amount of time as possible. Increasing velocity is increasing acceleration, etc, but that's symantics AFA my question.
What makes an engine accelerate? Your second paragraph touches on where I think this will eventually go.
Busby, in his not-so-eloquent terms says it's the short rod that helps. (I'll get back to you and your short jokes later, pal.) There's too many other things to consider to say that the rod ratio by itself is going to "make" an engine accelerate or not. But where's the motivation coming from? I'm thinking more in terms with what's going on in the combustion chamber. Good burn vs. better burn, vs. best burn. In this sense, Daryl Morgan may have a point.
Not if the drive mechanism is engaged at a higher RPM.
I haven't read past here yet, so I am sure I am missing alot. But decreasing rod ratio (longer rod) also is mechanically "easier" on the rotating assembly (less side loading), therefore alowwing higher, and quicker, rpm potential. Is it not?
Tommy
I have enjoyed reading this thread from start to here, but have little to add.
The most interesting thing I am left with is the comment about making the ex port flow as good as the intake port.
It is my nature to say why shouldn't it flow as good. Should that be so difficult to acheive? Doesn't seem like it. In fact it seems quite logical that if you had a room with two doors and your objective was to move people through the room, why would you make the out-door smaller than the in-door??
It seems to me that through the progression of engine building everyone was probably focused on getting more into the chamber and thinking "the exhaust port doesn't matter, it gets pushed out by the piston." That seems very wrong to me.
I also like the idea of waiting as long as possible for EVO so as to utilize the pressure as much as possible but around 90 ATDC wouldn't the piston be moving so fast that it would nearly make that small amount of pressure a mute point. It seems more important to make it easier for the piston to come back up at that point than try to "beat the dead horse" of the then used up combustion.
By the way I am pretty close to being at rock bottom (knowledge-wise, and have a large appetite to learn more. I have 3 or 4 big block books but would be open to any suggestions.
Hot, spent gasses have less volume or mass or whatever you want to call it. So the door does not need to be as large. Usually on a good head, average exhaust to intake flow ratios are about 70 to 80%. Also take into consideration that all modern engines have more intake area than exhaust area. Secondly, cam manufacturers all have very close to the same timing events,across the board, for a reason, it works!
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