Honda Power Unit Hardware & Software

[Sasha]

If I remember correctly that Honda tried the Big Bang with their Indy V8 Turbo engine in 1993 and it didn't go good.

[shady]

What if the big end wasnt split longitudinally, but laterally.

[ncassi22]

Could Honda be doing a really compact head to place the the compressor and turbine at either ends of the the V, but lower; where the cam gears are now. It'll lower cg, as well as keep the turbo shaft short while freeing up a lot of space for the the intake runners and plenum. You can do this by driving the outside cam only and put the gears further inwards like in the Nissan Zeod engine... Honda actually has a patent for something like this as well. In the Nissan the gears are between the 1 and 2 cylinder front the right.

[wuzak]

Like I said before, I think there is no way that they use forked rods. However, since this rumor goes around again and again, I think I found a solution which (I think atleast) is comparable to the one from Honda.

Was about two hours of work in Inventor. Nothing perfect, just made up fast and simple models. Two little simulations give a safety factor of 1.4 at 350bar peak cylinder pressure. I'm sure that, if this model would get perfectionated, they could really have two banks without cylinder offset without using these forked rods no one wants

The view from top:
http://fs5.directupload.net/images/170216/3ccxz42y.jpg

The crankshaft with U-shaped crankpins:
http://fs5.directupload.net/images/170216/54sejwhb.jpg

Also, I'm right now working on a little model of the cylinder head which implements the idea I gave yesterday with the combustion priciple. Maybe I can also realize some little CFD-Simulations, which could give a further hint how things look like in reality.

Can I ask, why U-shaped crank pins?

In your analysis, did you include piston and rod accelerations, which must be significant at 10,000rpm+?

My first thought is that arrangement would induce a side load on the piston to compensate for the moment caused by having the support (the bearing) offset from the load (combustion forces and piston loads).

[wuzak]

What if the big end wasnt split longitudinally, but laterally.

As in parallel to the axis of the cylinder, rather than parallel to the crankshaft?

[glenntws]

Like I said before, I think there is no way that they use forked rods. However, since this rumor goes around again and again, I think I found a solution which (I think atleast) is comparable to the one from Honda.

Was about two hours of work in Inventor. Nothing perfect, just made up fast and simple models. Two little simulations give a safety factor of 1.4 at 350bar peak cylinder pressure. I'm sure that, if this model would get perfectionated, they could really have two banks without cylinder offset without using these forked rods no one wants

The view from top:
http://fs5.directupload.net/images/170216/3ccxz42y.jpg

The crankshaft with U-shaped crankpins:
http://fs5.directupload.net/images/170216/54sejwhb.jpg

Also, I'm right now working on a little model of the cylinder head which implements the idea I gave yesterday with the combustion priciple. Maybe I can also realize some little CFD-Simulations, which could give a further hint how things look like in reality.

Can I ask, why U-shaped crank pins?

In your analysis, did you include piston and rod accelerations, which must be significant at 10,000rpm+?

My first thought is that arrangement would induce a side load on the piston to compensate for the moment caused by having the support (the bearing) offset from the load (combustion forces and piston loads).

The U-shaped crank Pins increase the bearing area which in turn makes the cranktrain safer for higher loads. Also, the oil naturally gets pushed more outwards in higher rpms which Supports the lubrication in the complete bearing area.

Accelerations are not included, but I think they are not a big Problem. What I do think, is that the side load on the piston is fairly high at these rpms, so i think that a lower side support would be necessary (like you find it in many street vehicles).

Then again, it's pretty sure that Honda (like all other manufacutrers) uses steel as a material for the piston. From my experience, I would go for steel at everything higher than 20MPa Peak cylinder pressure. Using steel also dramatically increases the possible side load. I will make some screenshots of the simulations later.

[shady]

So what Im thinking is if If the rods shared a big end but the way its normally split (rod/big end cap) is rotated 90* so each end would be half of a big end.

the split would be perpendicular(orthog) to the coplanar axis of the cylinders.

[ncassi22]

The U-shaped crank Pins increase the bearing area which in turn makes the cranktrain safer for higher loads. Also, the oil naturally gets pushed more outwards in higher rpms which Supports the lubrication in the complete bearing area.

Would it not be better to make the 'U' the other way? In the rod and cap for example.

[glenntws]

The U-shaped crank Pins increase the bearing area which in turn makes the cranktrain safer for higher loads. Also, the oil naturally gets pushed more outwards in higher rpms which Supports the lubrication in the complete bearing area.

Would it not be better to make the 'U' the other way? In the rod and cap for example.

I don't understand you exactly to be true, but i made a little sketch to show you what i was thinking of:

In regards to the combustion idea of yesterday: The 8 hours from right after school to right now have been enough to make a little prototype with the right specifications accordingly to the fia regulations

The combustion chamber looks this way:

The Piston crown has this design (pretty sleek and simple, nothing special, just the closing in the center):

The intake and exhaust ports are angled very high. In this configuration, the intake ports are positioned vertically(45°):

And at last, another closeup render of the negative model of the chamber:


I hope to be able to make some cold flow simulations over the weekend, maybe even a little combustion simulation. Without exaggerating ,I think that this could really be a thing Honda or the other ones could use.

[hurril]

Nothing short of awesome work. Truly impressive!

I can see why you would want the injector situated where you've drawn it should its role be similar to that of a port injector (in that it would inject on intake.) But why not mount it where it'd sit next to the spark plug? Not enough room? Beacause it it were there, it would still inject (with a higher pressure) during the intake stroke, and finish off with a short (and fat) pilot injection right before triggering the spark plug.

What do you think?

[ncassi22]

In regards to the combustion idea of yesterday: The 8 hours from right after school to right now have been enough to make a little prototype with the right specifications accordingly to the fia regulations

I wonder which one would have more heat loss. The in-piston style chamber or yours. It would be interesting to know.

[wuzak]

I don't understand you exactly to be true, but i made a little sketch to show you what i was thinking of: http://fs5.directupload.net/images/170216/rvw96rw9.jpg

No bearings?

[wuzak]

What I do think, is that the side load on the piston is fairly high at these rpms, so i think that a lower side support would be necessary (like you find it in many street vehicles).

A deeper skirt?

The additional side loading adds friction, and the additional support adds some more. So that means less power.

[glenntws]

Nothing short of awesome work. Truly impressive!

I can see why you would want the injector situated where you've drawn it should its role be similar to that of a port injector (in that it would inject on intake.) But why not mount it where it'd sit next to the spark plug? Not enough room? Beacause it it were there, it would still inject (with a higher pressure) during the intake stroke, and finish off with a short (and fat) pilot injection right before triggering the spark plug.

What do you think?

I don't have the idea to inject during intake. The idea is to have a pre-injection almost before the intake stroke is completed to get a lean mix in the whole cylinder. After that, during mid-compression, another big injection is triggered. The injector could have 5 holes. 4 wide angle spray holes and one with a very narrow angle. This center-placed, narrow angled hole would then shoot onto the pin on top of the piston, which also has the role of closing the pre-chamber at TDC. This way, because of the impact and narrow angle, a fast generated, almost stationary, fat cloud will form almost directly over the pin.

This cloud is then partially moved into the pre-chamber, where it makes up a great fat mixture for fast ignition. The rest of the cloud will stay around the little holes of the pre-chamber and will create (thanks to the tumble in the main chamber) a nice transition from fat mixture to lean from the center of the chamber to the outside. This could improve the thermal efficiency a lot!

[glenntws]

I don't understand you exactly to be true, but i made a little sketch to show you what i was thinking of: http://fs5.directupload.net/images/170216/rvw96rw9.jpg

No bearings?

They are not in the sketch, just imagine them being on the rod. So you can see that the bearings have a convex shape and the crankpin has a concave one. Theoretically you could also apply that to the main bearings of the crankshaft.

A deeper skirt?

The additional side loading adds friction, and the additional support adds some more. So that means less power.

You're right with that. Overall, I try to figure out how the engineer's could realize the 0 offset thing, but i'm still sceptical about it. Honestly, in my opinion, I think it's useless to do that and I'm sure they are not doing it.

The 20-30mm less length are not that necessary I think. But then on the other side, if they use a MFT-Turbine on the turbocharger, it's hard to save more space by shaving of some millimeters of the housings...