Double Cross Flow Cylinder Head

[Tony D]

Why not figure a way to use direct air injection as well? Operate a compressor off of the relatively underutilized alternator electrical supply and inject air as well as fuel. Skip the inlet plumbing altogether. You'd want a high flow, low pressure compressor.

 

To introduce the air at sufficient volume to make a difference you need Horsepower. High Flow, Low Pressure still takes HP. I can show you 6000ICFM compressors with a 600hp driver, and in the same frame show you a 2200 cfm compressor with the same 600HP driver, and the same frame.

 

If you are looking for self supercharged engines where the compression of offline cylinders in a multiple cylinder engine provides the compressed air source to a tank to be used for boosting pressure for spurts of acceleration, talk to Andy Flagg, he put his stuff into the public domain a couple of years ago due to lack of financial backing. The car does run, though... It's a Honda, with the three-valve head. (Want to guess what valve 3 cam is used for???)

 

On the best compressors, they get about 5cfm per horsepower and that's about it. Define the pressure, and I can give you a ballpark what kind of horsepower you will need for what flow...it's what I do for work (well, not really, I fix the problems the guys who lie about what airflow you will get per horsepower.... I'm more in the "make it make what they said it would make when the sold it to us department". They didn't give us a sign, so we bought one that said 'Service Department' because it was half-off. Guy that sold it to us said it had a 'self adhesive backing' and we didn't need to buy anything else. When we got it, it wouldn't stick to the door, and without thinking, three of the engineers had put screws through it before I mentioned perhaps we should go back to the guy who sold it to us and get our money back. They replied we already had a sign at the office, and it would be such a waste to send it back, why just not make this sign work...I think they have been in the field too long...)

[WizardBlack]

I think they have been in the field too long...)

I thought that of fellow students who had not even collected a paycheck yet when I was an ME major.

 

So that's scratched, then.

[WizardBlack]

I think Adam's biggest point is more the staggered valve placement than dual cross-flow. What do you guys think of that situation? I bet 5 valve head design might offer a little bit of insight into what kind of nature a staggered 4 would have.

[S130Z]

If the main concern was on the stagard valve placement, than you could make a single intake that kind of wraps over the top of the valve cover. But then you have the horrible task of changing spark plugs! Since you mentioned the 5 valve heads....I work in the PowerSports business and a few of the personal watercrafts have this design. If you have any questions about them, let me know and I can shoot the techs a question or two.

[cygnusx1]

I think the discussion should focus on the ability to run TWO DIFFERENT cam profiles simultaneously. A mild cam on on pair of valves and a wild cam on the other pair of valves. That is where S130Z was going, I think.

 

I had an idea that might be similar to the CVCC idea by Honda. Instead of injecting fuel and trying to optimize atomization, somehow create a high concentration of fuel vapor in a pre-process, and then blend it into the incoming air at the proper ratio. After all, it's the vapor that burns best.

[S130Z]

I think the discussion should focus on the ability to run TWO DIFFERENT cam profiles simultaneously. A mild cam on on pair of valves and a wild cam on the other pair of valves. That is where S130Z was going, I think........

.

 

 

That was where I was going with it to start with, but no one really picked up on that.

[WizardBlack]

That was where I was going with it to start with, but no one really picked up on that.

Well, the whole intake manifold thing and valve placement thing threw us off. What you are referring to has been done by Colt cams. Take a look at 'em.

[macambra]

This would be an interesting experiment if you know a good machinist. Twin turbos anyone??? LOL

[e_racer1999]

Looks like it could be interesting. The biggest difference I see with this in relation to quasi-similar engine set ups (VTEC et al., TVIS) is the separate cam and the "swirl" of the gases.

 

The weight could be negated somewhat by replacing the metal intake manifolds with plastic or carbon composite.

[michaelp]

Long runners look badass, make a 2 piece intake manifold with 1 large collector, the ports on the other side tuned for torque have long runners going over the valve cover and bolting to the collector, essentially a 2 piece intake manifold. Get into it more and use the Variable Intake manifold setup (like newer Nissans) with butterfly valves on runners to essentially make the runners larger (or switch from short to long etc) at a certain RPM.

[Daeron]

I think the discussion should focus on the ability to run TWO DIFFERENT cam profiles simultaneously. A mild cam on on pair of valves and a wild cam on the other pair of valves. That is where S130Z was going, I think.

 

I had an idea that might be similar to the CVCC idea by Honda. Instead of injecting fuel and trying to optimize atomization, somehow create a high concentration of fuel vapor in a pre-process, and then blend it into the incoming air at the proper ratio. After all, it's the vapor that burns best.

 

Its alot more than that, even...

 

Instead of having "intake valve open" and "...close" and "exhaust valve open and close" as four distinct events within the engine's cycle, you can divorce the "big valve" from the "little valve" and crack a tiny, but high inertia port into a cylinder early to aid in flushing out exhaust gasses, and leave that valve open until the very very last microsecond before sealing shut. Then, on TOP of that, your BIG valve profile can be designed for adequate flowing of air, and could even be (itself) a variable lobe timing design.

 

 

In a way, the potential of the concept seems much closer to an "ideal" otto cycle engine design. I've thought about this a time or two, but never in as much depth as this thread has already discussed it.

[grumpyvette]

http://www.gofastnews.com/board/technical-articles/281-polyquad-new-four-valve-power-concept.html

[Daeron]

http://www.gofastnews.com/board/technical-articles/281-polyquad-new-four-valve-power-concept.html

 

Thanks!! I had thoughts along these lines and wondered if my conclusions (presumptions) were absolute crazy, brought on by an incomplete (theory only, no actual practice) engine-building education.. or whether they might actually be right. Obviously I hadn't thought of everything Mr. Vizard explained, but all of my thoughts tended towards these directions.

 

That was an awesome, awesome read!

[z-spec]

So I came up with this idea the other night for a DOHC double cross flow cylinder head(DCFCH:icon45:). My idea was to have a DOHC head where you have an intake and exhaust valve on each side of the cylinder. This could possibly yeild you two advantages. One being to cross the intake valves to create a swirling effect for a more dense charge. The other advantage would be having two intake manifolds. You can potentially have a different sized runner on each side, one for torque and one side for HP. And sice you would have an intake and exhaust valve per side, you can have two different cam profiles. One profle for torque and one profile for HP.

 

The throttling would need to be different per manifold also. The torque side manifold would need to open first and then have them both open in your upper RPM's.

 

(Here is my paint picture I drew as a reference)

This system is already used in the 60e by BMW in a F2 formule car and been build by Dr Ing Apfelbeck as a 4 cilider engine , and been called the Apfelbeck engine

[blackice280zxt]

This system is already used in the 60e by BMW in a F2 formule car and been build by Dr Ing Apfelbeck as a 4 cilider engine , and been called the Apfelbeck engine

 

ha ha beat me to it. http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/1/1d/1966_BMW_Formula_2_Apfelbeck_Engine.JPG&imgrefurl=http://commons.wikimedia.org/wiki/File:1966_BMW_Formula_2_Apfelbeck_Engine.JPG&usg=__7wQaztm9NACDnfeniZhfwPJXi2Q=&h=2304&w=3072&sz=1665&hl=en&start=1&tbnid=0uMne9rjC28lFM:&tbnh=113&tbnw=150&prev=/images%3Fq%3DApfelbeck%2Bengine%26gbv%3D2%26hl%3Den%26safe%3Doff%26sa%3DG

 

truly a engine ahead of its time

[letitsnow]

It was also in a lancia rally car engine.

 

http://www.gofastnews.com/board/technical-articles/281-polyquad-new-four-valve-power-concept-5.html#post7669