9 Cylinder 4 Stroke Throttleable Radial

[Gent]

I thought I would put this here too as its getting burried quick in all the new scenes.

9 Cylinder Thro..​..ead Description

Gent

Rating:
Filesize: 159.76 kB
Comments: 16
Ratings: 10

[Someone Else]

Nice engine. Some small... large... problems, but with gravity off, it works fine, albeit laggy.

Also, note my comment on the scene.

[Gent]

Thanks for the comment and reply
This is realy strange gravity should only affect the low speed ballance
Could you tell me what the what the material menue box reads for the counterweight when you open the scene
I still think you are getting a corrupted download or your computer is sick god forbid.
If its messed up I want to fix it

[Someone Else]

I'm pretty sure the counterweight is not near as heavy as it should be.
I deleted all the menu boxes as soon as I downloaded the scene.
Thus, I do not know the contents of any of them.
I cannot download the scene to check now, for reasons that I do not care to explain at this moment.

However, I think it is mainly because I am using the 1.9.5 beta.

[Gent]

I bet thats the problem this was made in 1.8.5
Edit I checked it and it doesnt work at all in the new beta sorry
I'm reluctant to install the beta on my good comp so it may be a while till I can fix it
or more likely make a new one when the next version is released

[Dare]

I know the cam ring that controls the valve timing is in a certain ratio with the speed of the engine, but could you explain:
1) How you calculated the ratio?
2) What is the relevance of having the cam ring turn at that speed?

I'm still learning and your engines are just so fantastic to learn from. Thanks!

[Gent]

Hi Dare, that is a good question!
In most 4 stroke engines the camshaft turns at 1/2 crank speed and has 1 set of lobes, 1 intake and 1 exhaust
for each cylinder. Most Radial engines all the cylinders share the same cam ring in each bank
In this engine the cam ring turns at 1/8 crank speed and has 4 sets of lobes which is effectivly the same thing
but it has the advantage of allowing a lobe design that opens and closes the valve quickly while holding it fully open for a longer period, also the gear reduction requires less engine power to opperate the valves.
My 5 cylinder radial has a 4 to 1 ratio with 2 sets of lobes, same principal. Any even numbered multiple of 2
will work as the cam drive ratio in any radial 2,4,8,16,32.... with the # of sets of lobes = to 1/2 the gear ratio.
Now it gets a bit more complicated, a 6 or 12 to 1 ratio will work in a 5 or 7 cylinder but not a 9 because the number of lobes divides into the # of cylinders and you end up with 3 cylinders doing the same thing at the same time NOT a good thing
So the cam drive ratio MUST be a multiple of 2 and CAN NOT be divisible by the # of cylinders or any # that will
divide into the # of cylinders, hense a 10 or 20 to1 ratio would work fine on a 7 or 9 cylinder but not a 5
I hope this wasn't too confusing but you did ask
Here is a link that explanes a lot about cam timing better than I can:
http://www.compcams.com/catalog/COMP201 ... 2011_8.pdf
Link to the whole thing, previous link was page 6:
http://www.compcams.com/Company/CC/Cata ... fault.aspx
Hope this helps, I know all this stuff from more years of experience than I care to admit but its tough to explain without waving arms and diagrams

[Dare]

Okay that is helpful ... but how did you work out the timing?

[Gent]

The timing is not perfect and I just pulled it out of my head but the only realy crittical valve timing event in this is the exhaust, if that doesnt happen at all its BAD.
One thing that sets my engines apart from most is they dont "fire" till after top dead center, alot of the engines
on here fire as the piston is still coming up which is realistic but doesnt work well in this sim
PS what rad/s are you getting with this?
I know now it doesnt work at all in the new beta

[Dare]

Okay thanks. Good explanations.

I got about 23.5 rad/s on full throttle, on Algodoo V1.8.5.

[Gent]

Thanks for the reply, that is similar to the performance I am getting
This scene has had a lot of downloads but few comments so I wasnt sure if it worked right for anyone but me

[Gent]

I'm not sure what you mean?

[Dare]

Hehe Gent, he is a spam bot. Look at his sig.