ESE's works engine tuner

[Frits Overmars]

... why does the header pipe positive pressure behave like this? ......

Pipe pressure varies not only with throttle and rpm, it can also vary locally because of wave superposition.
It might be instructive to experiment with several pressure take-off points along the pipe.

[Lef16]

Hi there,
is there a way for measuring crankcase volume without drilling the piston crown?

[TZ350]

Pipe pressure varies not only with throttle and rpm, it can also vary locally because of wave superposition.

It might be instructive to experiment with several pressure take-off points along the pipe.

Yes I can see how wave superposition can create a localized high pressure spot although I would expect the node to move with frequency as the RPM dropped. I will look for that next time.

Assuming that the one way valve is working properly, and you still have that bleed between the one way valve and sensor, the lowest pressure you should ever see at the sensor is atmospheric, no matter how low the pressure in the pipe is.

Yes, that is how I read it too.

... the drop in pressure when opening the throttle:
Closed throttle => ~0 airflow thru the header
Open throttle (even without firing) => >0 airflow the the header.

Now, depending on the geometry around your pressure pickup position its not at all unlikely that the pressure drops in that position simply due to flow. -Think venturi..

The closed throttle no flow pressure was higher than atmospheric and dropped to atmospheric when the throttle was opened again. Your venturie idea is interesting.

Pressure node and venturie effect could explain it.......

[husaberg]

Hi there,
is there a way for measuring crankcase volume without drilling the piston crown?

Put in a very hot heat range plug such as a NGK5 and go for a ride no drill will be required.

[peewee]

Could have been the original Big Bang bike then. Filling a large volume with air and fuel (LPG in my car) can have surprising effects, like air filter boxes blown to smithereens and a very sporty-looking bulge on the hood.

I was thinking about the airbox blown to smithereens and wonder if squirting ether as close as possible to the combustion chamber is the best way. I wasn't about to take the engine apart to make a injection port in the head but right or wrong I decided to put a nipple on the front side of the carb slide. hopefully it doesn't blow my reeds out . I may try petrol first and see if that works as a good starting aid. if not, then ether it is. I put the hose free end where its easily accessible and can be bent upward when the starting aid is squirted in. the hose end is then pluged with a rubber cork. best of all is no body panel removal needed. ill report back how it works. im hoping to try it out tomorrow since last weekend was a failure

something strange today that had me wondering. I had to use ether to start the lawnmower so I squirted it in the airfilter area. after a few pulls of the starting rope a small backfire explosion happened then it started

[peewee]

Hi there,
is there a way for measuring crankcase volume without drilling the piston crown?

what size of piston do you have ? I have a few old spares of various sizes that might be what you can use to drill a hole. you can have it free if its the right size

[Haufen]

Hi there,
is there a way for measuring crankcase volume without drilling the piston crown?

There should be, if you are willing to take the engine apart, then measure crankcase (incl. crank at TDC position) and cylinder (incl piston and crank/rod at TDC position) volume seperately and add both values up at the end.

[Flettner]

700 twin start up, first time with the power valve. No prop and rev limited to 7500.
Ignitech runs the R1 servo nicely, starts opening at 3500 finished at 5500.

https://youtu.be/8IA3Xth6jXc

[Frits Overmars]

700 twin start up, first time with the power valve. No prop and rev limited to 7500.
Ignitech runs the R1 servo nicely, starts opening at 3500 finished at 5500. https://youtu.be/8IA3Xth6jXc

Ah, the lovely sound of a 180°-firing twin. Takes me back to my RD350-years. I'd really love to see that engine in a bike frame Neil. Reed valves will do fine (KISS, remember?) It will keep the width within limits and we won't be needing the last bit of power for a roadgoing bike. The power your engine is capable of right now, will be quite sufficient.

[RomeuPT]

Just killed a whole week of free afterwork hours doing a new flange and exhaust for the NSR...

Results, not sure, need a dyno

Oval to round transition, thick flange with some cooling fins, not sure if the best way has I have seen the flanges from honda kits are much thinner and polished.



Bike is sounding different.

Cheers

[teriks]

I was thinking about the airbox blown to smithereens and wonder if squirting ether as close as possible to the combustion chamber is the best way. I wasn't about to take the engine apart to make a injection port in the head but right or wrong I decided to put a nipple on the front side of the carb slide. hopefully it doesn't blow my reeds out . I may try petrol first and see if that works as a good starting aid. if not, then ether it is. I put the hose free end where its easily accessible and can be bent upward when the starting aid is squirted in. the hose end is then pluged with a rubber cork. best of all is no body panel removal needed. ill report back how it works. im hoping to try it out tomorrow since last weekend was a failure

Should work just fine, but be sure to have the hose perfectly sealed before starting.. but you knew that of course.

[teriks]

The closed throttle no flow pressure was higher than atmospheric and dropped to atmospheric when the throttle was opened again. Your venturie idea is interesting.

Pressure node and venturie effect could explain it.......

I should read more carefully, I was under the impression that you measured below atmospheric pressures..

[marsheng]

It can also i believe shuts off the fuel supply, as the frothy mixture raises the float level.
]

Not sure where I was the other day but I was told never jump into heavily bubbling water, you will drown. After a few thoughts I realized it was true. The float will sink lower.

[teriks]

Just killed a whole week of free afterwork hours doing a new flange and exhaust for the NSR...

Results, not sure, need a dyno

Oval to round transition, thick flange with some cooling fins, not sure if the best way has I have seen the flanges from honda kits are much thinner and polished.


Bike is sounding different.

Cheers

You need much larger gaps between the fins, that's no more than about 1,5mm, right?
Not that I think it would make a huge difference...

[RomeuPT]

You need much larger gaps between the fins, that's no more than about 1,5mm, right?
Not that I think it would make a huge difference...

They were cut with a angle grinder 2mm disk, so the gaps are much bigger then 2mm. I think you are also right, but since it had room for doing them....