V10 idea:

[hightower99]

OK great, seems you have some nice ideas (thinking outside the box), and its funny we both want the same thing. we are narrowing down what should really be done on the V10.

Just to clean up the intake question, the plenum is treated more like a branch. for example if all 10 intake tracts lead back to a common branch then:
when intake valve opens expansion wave is created, it travels back up intake tract and reaches branch, at the branch the wave splits in 2, a compression wave travels down other 9 intake tracts towards cylinders(useful),a expansion wave travels back down the same tract (not so useful). i guess technically this is a plenum but it is small and exists in all intake systems.I like your IIM system, sounds great, i see them on racing engines.


i don't want a spec-monster (nice term) but a further extension to an engine such as the RS4 V8, superb low end torque but also high end capability.

The biggest reason you see IIMs on racing engines and not on normal cars is solely a question of space. IIMs will make the most power and will get the most out of shockwaves and if they are steplessly variable then they will optimise the whole rev range much better. However they require alot more space than a plenum design (any plenum design) This is the main reason that normal cars have plenum designs (they take up much less space) Also plenum chambers help to ensure that each cylinder gets an equal share of air and earlier in automotive history it helped ensure all cylinders got fuel even though you only had one carburetor or injecter. I say stick with steplessly variable IIM.

Also making an engine that has good low down power (through massive torque) and is also capable of revving high while maintaining suitable VE isn't too difficult if you think of these two extremes as seperate. The tricky bit is getting the transition from low down grunt to high rev screaming... What you want is a quick torque peak (at least before 2500rpm the earlier the better) that doesn't drop below 80% until really high revs. The torque line should be as flat as possible.

Do you know/understand/guess how IIMs use shockwaves?

[e31Bimmerman]

Wow, this could not have come at a better time. Jediali, your work is amazing. I am a freshman mech e student in a solidworks class, the final project of which is to create a simple everyday object. I chose instead to do the new M5's engine, much simplified, but otherwise complete, all before chancing upon what you have done. If you don't mind, I'd like to know how you got springs on the valve tappets, how to get the correct firing order and valve timing, and also, how or if it is possible to make timing chains in the educational edition of solidworks 2k6.

thanks a lot, and your work is, again, utterly amazing.

[jediali]

i can send you some parts/assembles, or instructions if you want e31bimmerman, just ask and i will see what i can do. i will answer those questions tonight too.

my work does have flaws, as people have noted here, but i am glad it has inspired you.

[e31Bimmerman]

Mine is far less detailed and much more simplified, I'll upload pics tomorrow(today?), it's ~4am here. If you could send me the springs I'd be grateful. Are they any different from a helical sweep and the only difference is in the mate or...? Same for the cams; is it just a gear mate to have them rotate at the different speeds and times?

not an inspiration to begin but an inspiration to finish and lose sleep .

[hightower99]

Jediali:

When can we expect to see some new pics of some of the systems we have discussed?

Is there anything you want to discuss more?

[jediali]

Jediali:

When can we expect to see some new pics of some of the systems we have discussed?

Is there anything you want to discuss more?

hello again. I am encouraged by your keenness. i cannot find much on IIMs, or at least the tuning of, its not in regular textbooks i have. can you perhaps tell me more.

As for the engine i will have something before the new year, yes i know its a long time, but i am really busy ( i am offshore a lot, and then i have 10hour office days- i am trying to get my Ceng chartership report in also)

In case you are interested about what I am doing at work I am designing AI motor monitoring systems and testing and installing them on north sea oil platforms.

[hightower99]

about the IIMs it would be cool if they not only were variable to account for rpm but also for air temperature and density! Hard to do I know but it would be the ultimate intake!

[jediali]

about the IIMs it would be cool if they not only were variable to account for rpm but also for air temperature and density! Hard to do I know but it would be the ultimate intake!

well you know that the fuel injection system might analyse the air density/temperature, but i agree.

[hightower99]

well you know that the fuel injection system might analyse the air density/temperature, but i agree.

Yeah but the speed of sound (an important factor to know precisely if you want to get the most out of shockwaves) is effected by air temperature and air density and air pressure so that most effective intake would be variable to account for all these factors to ensure that the first (and most powerfull) shockwave returns to the back of the valve at the right time. The more accurately you know the speed of sound through your intake the more effectively you can utilise the power of the shockwaves.

[stian1979]

I would make a sugestion for the cam. Make the gearig betwen cam and crank 1:4 and make dubble side lobed cams. It would reduce the frictional losses in the camshaft bearings. Used in modern f1 engines.

[jediali]

thanks for suggestion

[stian1979]

hello again. I am encouraged by your keenness. i cannot find much on IIMs, or at least the tuning of, its not in regular textbooks i have. can you perhaps tell me more.

Why don't you post or search on the atlas forum?

http://forums.atlasf1.com/index.php

[hightower99]

I would make a sugestion for the cam. Make the gearig betwen cam and crank 1:4 and make dubble side lobed cams. It would reduce the frictional losses in the camshaft bearings. Used in modern f1 engines.

Unfortunately this wouldn't get a net decrease in friction as you will have an equal increase in friction from the springs. Also there will be an increase in the weight of the camshaft.

This system is not used in F1 cars at the moment I wonder where you heard about that?

[stian1979]

This system is not used in F1 cars at the moment I wonder where you heard about that?

Where did you hear they are not?

If you got cams on both sides off the shaft the mass will outbalence eatch other and the frictions from bearings is a significant amount when running at 19-20 000RPM.

[jediali]

Unfortunately this wouldn't get a net decrease in friction as you will have an equal increase in friction from the springs. Also there will be an increase in the weight of the camshaft.

This system is not used in F1 cars at the moment I wonder where you heard about that?

i am looking into desmodromic valves..very interesting. why are these less popular? that wouldreduce friction a lot.