Building a V12 engine

[hotrodder]

Very cool!
I raise with a minature Ferrari 312PB complete with 100cc 4 stroke flat 12, working gearbox and all the trimings... http://www.youtube.com/watch?v=SeUMDY01uUA

 

[tigler]

Thats very famous !! I actually saw that run at the Car Show one year, when it was at the NEC, utterly amazing !

 

[rtbcomp]

This V12 runs

http://www.youtube.com/watch?NR=1&feature=endscreen&v=lc6jCGHj6Nc

 

[troppo]

Very cool!
I raise with a minature Ferrari 312PB complete with 100cc 4 stroke flat 12, working gearbox and all the trimings... http://www.youtube.com/watch?v=SeUMDY01uUA

Yeah that is pure mechanical porn

 

[tigler]

There are quite a few of these model radial aero engines but the video on this one is quite good ,

http://www.youtube.com/watch?v=omSt8ZiE7vM&feature=related

 

[roofman]

i think you will find there is

i think thats only for reference...dont cams need to be driven 2-1? those cam gears have the same ratio and size as the driven crank

 

[the snooper]

i think thats only for reference...dont cams need to be driven 2-1? those cam gears have the same ratio and size as the driven crank

in a fully working engine yes but they must be opening valves for it to run

 

[rtbcomp]

The camshafts both run at half crank speed, the size of the intermediate gear is unimportant, it's the ratio between the crank & cam gears that matters, and you can't see the crank gear to compare.

 

[troppo]

Gorgeous!!!!!!!!!!!!!!!!

 

[roofman]

The camshafts both run at half crank speed, the size of the intermediate gear is unimportant, it's the ratio between the crank & cam gears that matters, and you can't see the crank gear to compare.

http://www.mig-welding.co.uk/forum/showpost.php?p=325300&postcount=14
looks the same size to me

 

[the snooper]

just looked again there is no intermediate gear that is the end of the crank

 

[rtbcomp]

YES Those are the CAM gears that are BOTH THE SAME SIZE.

The gear in the middle is the INTERMEDIATE gear, whose size DOESN'T matter.

The timing marks are clearly visible too.

I'm going to lie down for a while now

 

[roofman]

YES Those are the CAM gears that are BOTH THE SAME SIZE.

The gear in the middle is the INTERMEDIATE gear, whose size DOESN'T matter.

The timing marks are clearly visible too.

I'm going to lie down for a while now

me too

 

[rtbcomp]

just looked again there is no intermediate gear that is the end of the crank

Actually I think you're right - funny place to put the camshafts.

But the middle gear is smaller than the other two, can't count the teeth though.

 

[roofman]

Actually I think you're right - funny place to put the camshafts.

But the middle gear is smaller than the other two, can't count the teeth though.

what a great way to spend a sunday night....
the crank is turning the cams at the same speed

 

[rtbcomp]

Yup it is

Some other frames give a clearer picture, I'd say all three gears are the same.

 

[rtbcomp]

Thinking through a haze of Chateau d'Asda I think an engine designed to run on compressed air (or steam) would have the cams & cranks running at the same speed because the power and compression strokes would be omitted.

 

[the snooper]

yeah i would agree as it doesnt require the 4 strokes 1 to 1 ratio to open the valves at the same point of every stroke

the gears seem to have around 20 teeth

 

[zzr1200]

Not exactly the same, but how about built it and then ride it.


http://www.youtube.com/watch?v=9wQA49EZucg

http://www.youtube.com/watch?v=6ratfuML9QA&feature=related

 

[roofman]

this thread has me crawling all over youtube looking at these marvels..some fantastic work out there i must say