methodical wrote:
CO, I found one example of a cylinder I measured, it was an 80mm bore. Unported, but 80mm, as the bore increases the port timing changes due to the shape of the ports and their entry. I have EX: 175.36 degrees duration: port top is 42.67mm from the top of the cyl. The piston at TDC (Top Dead Center) (Top Dead Center) is 2.59mm down from the cyl top. The transfers I have 121 degrees: they are 56.80mm down from the top of the cyl. Hope this helps.
I'm sure Adnoh will have some good input..
Thanks that will help me.
I totally didn't even think about the top of the piston position -- thx.
As for the port changes due to port shape based on the size of the bore, I didn't think about that either but I was just trying to get reasonable degree duration's.
To spill the beans here, I wanted this info so that I could calculate the timing of the ports at 9000 rpm and the amount of time I would have.
I have been thinking for a couple of years already about a
NOS spray set up.
However, my idea is not the conventional NOS spray system used by the two stroke folks.
I want mine direct injected.
I rough calculated that I would have two milliseconds to spray.
One of the problems is actually fuel pressure needed but I solved that.
I could spray at 2300 psi easy and the NOS is already pressurized at 900 psi.
Another issue is jetting. There is NO data for nozzle sizes at those pressures. Get jets is no problem and I could drill them out but at what size ? I could potentially melt a lot of engines before I figured that out.
Another issue is NOS. Only one place anywhere near me fills NOS bottles. I found two kits a couple of guys are selling near me that are used. One guy is on smoke as he wants the price of a new system. The other guy does not have a bottle with his kit. Both are wet kits. I'm just not sure how much or IF those guys at that race shop will fill my bottle if I had one.
Another issue is a custom head. But again that is not an issue as I have already made one before and it's still running on the death machine (the one with the welded piston). I would need this custom head because I have to drill a hole or two in it to screw in injector nozzles. Easy fix here, but it's the other stuff above that's the problem.
Like I said, I still have to do some thinking and make some phone calls.
I would REALLY love to put a crankshaft through the bottom of a casing as I think this would be spectacular.
Just playing around in my mind right now and the thoughts won't go away.
Thanks for getting back to me and for the info.
CO