Does anyone have a port open/close duration chart for the stock FL350 ??
Adnoh ? Methodical ? CurtisR401 ? Anyone ?
I don't want to tear apart one of my engines to find out.

Thx in advance for any replies.
CO

CA, I have all kinds of info at the home stead. When I get in tonight I'll grab info for you. Are you looking for EX: degree open/close, Transfers: degree open/close?

Yes I am.
That would be great.
CO

Edit: I actually want to do something radical but I'm having an issue finding the supplies I need here in Canada. It wouldn't be possible to get it from the states because it has to cross the border.
Not sure if I'll ever get to this project but just looking right now.
CO

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) 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

CO, just curious about the 2300psi injection pressure you mention. Nitrous should be kept below around 1050 psi (at a certain temp) or it may reach it's supercritical fluid phase, definitely not desirable.

No -- I was talking about FUEL (AVGAS) pressure.

At two milliseconds, which is all the time I'll have to spray, there isn't much time to pressure up the combustion chamber with NOS/fuel.
The NOS is standard pressure, around the 900 psi range.
But yes, I do know what you are saying about the NOS.

I don't know of any fuel pumps that would put out the kind of psi but it doesn't matter, I don't need one. I solved that issue.
CO

Edit: The biggest issue I see would be: How do I trigger this set up ??
When you NOS an Engine in the standard way, the valves or reed valves take care of that problem.
I want to direct inject straight into the combustion chamber as soon as the exhaust port is closed but BEFORE the plug fires. How can this be done ??
That's the problem I got and can NOT solve because I'm not an electron mechanic, I'm a certified millwright.
CO

I should have some stuff on a drive.
I will see what I can dig up.

I thought in one of my posts I had some info.
I'll look and provide link if there.

could you pull fuel from a float bowl like an "adjust-a-jet" not sure if that's the name but if you put the nozzle say in front of the reed cage? trigger off the flywheel, it would need an insulated section the trigger would need to be make ground using something like a brush for a motor (( Internal Combustion Engine ? )), may be pretty difficult in making it smooth?
just tossing some ideas, good luck.

That won't work.
If you put any pressure behind the reed cage you would stall any flow going through a carb.
If you put any pressure ahead of the reed cage it could hold the reeds open.

NOS'in a two stroke is an iffy job.
It's a very delicate balance between to much or to little pressures.
It has been done successfully by many people, especially the drag two stroke guys but they all use the conventional spray before the reeds thing and the spray behind the reeds is a no go due to the carb thing.
My idea is totally different. Blast it right into the cylinder after the ports are all closed.
There are several issues with this.
VERY little time to do it at 9000 rpm
VERY high fuel pressures are needed
Separate signal to fire the nozzles since you won't be using the ports or reeds as timing.

To the best of my knowledge no one has done this on a two stroke.
In fact one of my ideas was to make a drag only Engine with NO CARB or intake ports at all, just an exhaust port.
It would run on pure NOS and AVGAS only. NO INTAKE SYSTEM.
If anyone has heard or seen anyone do this before please post so I could look it up.
CO

I found two port maps that I did some math on. will try to post them from a home computer Monday or Tuesday when I get back in town.

Have been reading up on how to figure port time opening and durations at rpm.

You going to have fun in this one.

viewtopic.php?f=1&t=7687

Some info on what I have.

Thanks Adnoh.
I have seen that post before and downloaded the pdf stuff.
Many of those pictures no longer exist because of the hack years ago --- to bad.

Port time opening and duration's at rpm would be an interesting read if it is made simple for a simple minded person like me .
Also would like distance traveled at 8000 rpm to 9500 rpm on a chart.

Since I'm asking a lot I'll just ask more --- how would I trigger those NOS coils at the correct time ?
Since I wouldn't be using the reeds or ports to fill the cylinder at the correct time, I would have to trigger the coils on the NOS system at the correct timing point.

Also of note is that my brothers Engine has those "eye brow" ports in the cylinder as well as 2mm shaved off the base. It's a hellish fast Engine compared to stock. The next time I take it apart I'm going to map it. But at the moment it runs good and we don't go out very much anymore. We are getting old. It hasn't run in 2 yrs. Compression is falling though.

Thanks in advance for any suggestions or info.
CO

I have those pictures I can post.
Also I can share the easy math so you can get a number.

I do them in a spreadsheet. Once you enter the formula you just add rpm super easy.

Then use the target port time opening at a given rpm.
Then you can change the port timing and see where the power plots to rpm.

Once you have. Target you work with the rest of the engines parameters. Like port roof angles and direction etc. You will be work in more of a Dynamic direction.

I will see what I can do to post pics tommorow night.

Thanks adnoh.

What would be really helpful is explaining how I could trigger the NOS coils at the correct time.
That's one of my biggest problems.
CO

Well I think this project may be dead.
I did a lot of looking tonight and found this out:

"How fast does a relay react?
The solid state relay is ideal for applications requiring fast response times.
Electromagnetic relays due to their construction (moving parts), have response times between 7 and 20 ms, while solid state relays are much faster and additionally handle better at high switching frequencies." -------- (apparently as low as 1 milli second).

Wellllllll ------ the coils on a NOS system are electromagnetic.
I rough calculated the firing time needed at 9000 rpm is about 2 milli seconds.
That's .002 of a second.
So those coils are out of the question.

I know there is a difference between a coil and a relay but the coil for the solenoids still needs to pull open the plunger to let the NOS and the fuel flow. So I see it as a relay in my little mind.
I'm struggling here because I'm not an electron mechanic.

I'm not sure if I "rough" calculated correctly but if I did then this idea is ded.
I'll have to see what adnoh posts.
I'm not an electron mechanic like adnoh, but in my millwright mechanical mind I don't think any type of solid state coils are even available for this or strong enough to do what I want them to do.
CO

pic of port maps

sounds like your attempting a direct inject set up.
I may need to think about this a little.

few more stock 350 pics

YES that's exactly what I'm trying to do.
CO

WOW an old style square port.
Love it.
Nice pictures and thanks for posting.
CO

Looks like this direct injection idea of mine isn't an easy thing to do.

https://www.youtube.com/watch?v=ql2-wW0LuWY

CO

The more I research this subject the more complicated it becomes.
Recently downloaded a PDF of the Evinrude E-TEC direct injection two stroke.
Learned a lot.
I attached the PDF for anyone that wants to read it, but be warned, it will give you a headache.
Very interesting stuff and I started at pg 30.
The "magic" number seems to be around 2 millisec for everything (coil charge up time, spray time, etc) so to speak. Keep in mind that this is at only under 5000 rpm.
CO

Results I found online with regards to the exhaust port design on a 50cc AR50 Engine.

Square vs oval exhaust port design differences:

Square port:
Lower hp at low and mid range
Higher hp at top end and also has over rev
Stonger pipe pulse
Dyno showed .6 hp more for and AR50 cc Engine
Hard on rings

Oval port:
Higher hp at low and mid range
Slightly lower hp at top end and less over rev

CO

I REALLY want to do this direct injection NOS thing but I don't know how to trigger it.
I wish I was electrically inclined or lived next to Adnoh.
CO