other than the cost to implement it, would there be any benefits to make an OHV&C engine?

say... OHV for intake, 2 valves and vvt.

OHC for exhaust, 1 valve and vvt.

: or vice versa

yes, i bet there would be packaging problems on the front of the engine and in the heads/valve covers... oh well

anyone else thought of this or any other "crazy" engine designs?

should this be in tech section?

edit:changed an accidental smilie

Edited May 19, 200619 yr by loki

no one likes this topic?

erm...I'm not sure...sorry

As a teenager, I had envisioned ovaloid pistons (to increase displacement) in free-rotating cylinder bores (to reduce wear).

I got an idea for a really out there engine design:

instead of valves there would be a rotating cylinder with a wedge shape cut into it that would rotate around the center of the bore to the outside. As the opening came to the intake side air would move in then the opening would turn and close against the sidewall of the cylinder then it would open as an exhaust opening as it rotated further with combustion occuring when the cylinder was closed off. There would be sealing problems with this design, just like a rotary, but because it wouldn't be limited because of valve springs it could have high rotational numbers without failure. Also I have thought of ways to get increased opening area and other stuff but nothing will come of it because I am not an engineer, nor would I have any idea how to do it. But the idea came to me in a flash and seems plausible in theory.

I invisioned a "flat" engine where instead of the pistons facing out, they would face inward. There would be two crankshafts attached to equal sized gears that would connect to the transmission.

The camshaft(s) would run up the center over the top of the cylinders.

It would be a side valve.

The piston heads would face each other so that during a compression stroke, you'd have *both* pistons compressing the gas vapor in the cylinder.

It would need to be something around a 4 cylinder/8 piston.

It would really change the way we talked about engines... since the number of pistons is double the number of cylinders.

I got an idea for a really out there engine design:

instead of valves there would be a rotating cylinder with a wedge shape cut into it that would rotate around the center of the bore to the outside.  As the opening came to the intake side air would move in then the opening would turn and close against the sidewall of the cylinder then it would open as an exhaust opening as it rotated further with combustion occuring when the cylinder was closed off.  There would be sealing problems with this design, just like a rotary, but because it wouldn't be limited because of valve springs it could have high rotational numbers without failure.  Also I have thought of ways to get increased opening area and other stuff but nothing will come of it because I am not an engineer, nor would I have any idea how to do it.  But the idea came to me in a flash and seems plausible in theory.

Honda has already done that in some of their race engines. They use a ceramic tube so to withstand the heat better. It's excellent in super high RPM situations.... the downside is that it makes VVT even harder to do then in "cam in block" designs.

Honda has already done that in some of their race engines.  They use a ceramic tube so to withstand the heat better. It's excellent in super high RPM situations.... the downside is that it makes VVT even harder to do then in "cam in block" designs.

My tubes ran with the cylinders and rotated around the bore centers not longitudinally, which I had seen done. My idea for variable opening area revolved around a 2 piece design for the cylinder that would rotate on each other making the opening bigger or smaller (narrower or wider) based upon need. I was thinking hydraulic control would be used as opposed to gears to quiet it down.

I invisioned a "flat" engine where instead of the pistons facing out, they would face inward.  There would be two crankshafts attached to equal sized gears that would connect to the transmission.

The camshaft(s) would run up the center over the top of the cylinders.

It would be a side valve.

The piston heads would face each other so that during a compression stroke, you'd have *both* pistons compressing the gas vapor in the cylinder.

It would need to be something around a 4 cylinder/8 piston.

It would really change the way we talked about engines... since the number of pistons is double the number of cylinders.

i had kinda thought of that once, but more like just two engines ( I4's) side by side, could be connected to the trans like yours, but could have a "kick out feature", turn off one engine and disconnect from the trans to save gas when one engine was enough...

I'm not sure that a combination ohv and ohc engine would be a necessarily good idea, think of how many timing chain/belts you'd have to run, plus how many tensioners, guides, ect. However some of the other ideas do seem really interesting and plausible.

Rear mounted Wankel mated to a rear mounted transmission...

longitudinaly & low for great center of gravity. Give the body a

sleek 3rd gen. RX-7 look & call it an RMX-7 or something like

that. Make twin-turbo optional. Now THAT is a true 911 fighter.

Rear mounted Wankel mated to a rear mounted transmission...

longitudinaly & low for great center of gravity. Give the body a

sleek 3rd gen. RX-7 look & call it an RMX-7 or something like

that. Make twin-turbo optional. Now THAT is a true 911 fighter.

That sounds really Awesome 68!