F1technical.net

gruntguru wrote: ↑

23 May 2017, 01:04

Vortex37 wrote: ↑

22 May 2017, 21:41

The other issue is the problem of increased efficiency leading to lower exhaust temps and the effect on MGU-H/Turbo - change the pre-chamber/main chamber then affect downstream - reprogram and back to the beginning again.

That is a red herring. Efficiency gains in the piston section are paramount. If you trade any piston work for exhaust heat, the increase in turbine work will be a small fraction of the piston work lost.

This.

Pre-Chamber CC still needs tumble in the main chamber.Bad tumble or swirl and then you get bad A/F ratio that leads to destroyed pistons.

That is Honda's problem now.

Sasha wrote: ↑

23 May 2017, 01:21

Pre-Chamber CC still needs tumble in the main chamber.Bad tumble or swirl and then you get bad A/F ratio that leads to destroyed pistons.

That is Honda's problem now.

Do you know this for a fact or are you speculating?

fact

Vortex37 wrote: ↑

22 May 2017, 21:41

Whilst the web link is substantially about lower emissions and improved fuel consumption, there are some lessons to be had.
https://www.pureburnengines.co.uk

I think that is a potentially good concept - as a replacement for petrol and diesel road car engines. Adapting the technology to a racing engine with 110% VE and 15,000 rpm capability is another matter (a big stretch actually). OTOH TJI adapts easily.

gruntguru wrote: ↑

23 May 2017, 03:49

Vortex37 wrote: ↑

22 May 2017, 21:41

Whilst the web link is substantially about lower emissions and improved fuel consumption, there are some lessons to be had.
https://www.pureburnengines.co.uk

I think that is a potentially good concept - as a replacement for petrol and diesel road car engines. Adapting the technology to a racing engine with 110% VE and 15,000 rpm capability is another matter (a big stretch actually). OTOH TJI adapts easily.

Reading up on the Merritt engine some more - the downside from testing is a 50% reduction in power output because of the pumping losses.
This is no surprise. And very much limits any use of it in racing.

Its moot anyway, as that design link was previously posted/discussed recently - on the '2 stroke' thread..

& esp' since the essentially 'fictional' premise of the current tightly proscribed/old tech-ish F1 engine reg's..
..as supposedly being both 'relevant' to today's 'green' road cars, via an emissions/efficiency exemplar showcase,
& to provide a 'level playing field' - for cost effective competition - as fairly evenly matched race machines..
..has in fact - been shown up as a classic of 'unintended consequences' - to the great cost of 'McHonda', in $, & 'face' wise..

A wild idea - what if the Pre-Chamber was purged on the compression stroke by a passageway that went to the valve seat and was opened when the intake valve opened.
Or a passageway that was opened to the intake port by an element of a pre-chamber mounted fuel injector.

In either case compressed air from the intake port would force a purge and fill of the pre chamber.

That's how i would do it.

MrPotatoHead wrote: ↑

23 May 2017, 14:39

A wild idea - what if the Pre-Chamber was purged on the compression stroke by a passageway that went to the valve seat and was opened when the intake valve opened.
Or a passageway that was opened to the intake port by an element of a pre-chamber mounted fuel injector.

In either case compressed air from the intake port would force a purge and fill of the pre chamber.

That's how i would do it.

That's the least crazy/difficult of all the ideas I've seen raised so far.

Craigy wrote: ↑

23 May 2017, 15:17

MrPotatoHead wrote: ↑

23 May 2017, 14:39

A wild idea - what if the Pre-Chamber was purged on the compression stroke by a passageway that went to the valve seat and was opened when the intake valve opened.
Or a passageway that was opened to the intake port by an element of a pre-chamber mounted fuel injector.

In either case compressed air from the intake port would force a purge and fill of the pre chamber.

That's how i would do it.

That's the least crazy/difficult of all the ideas I've seen raised so far.

Often the simplest ideas are the least obvious.

MrPotatoHead wrote:

Craigy wrote: ↑

23 May 2017, 15:17

MrPotatoHead wrote: ↑

23 May 2017, 14:39

A wild idea - what if the Pre-Chamber was purged on the compression stroke by a passageway that went to the valve seat and was opened when the intake valve opened.
Or a passageway that was opened to the intake port by an element of a pre-chamber mounted fuel injector.

In either case compressed air from the intake port would force a purge and fill of the pre chamber.

That's how i would do it.

That's the least crazy/difficult of all the ideas I've seen raised so far.

Often the simplest ideas are the least obvious.

I asked that a few pages earlier. I guess I didn't ask it properly.

JonoNic wrote: ↑

23 May 2017, 17:10

MrPotatoHead wrote:

Craigy wrote: ↑

23 May 2017, 15:17

That's the least crazy/difficult of all the ideas I've seen raised so far.

Often the simplest ideas are the least obvious.

I asked that a few pages earlier. I guess I didn't ask it properly.

I must have missed that or I would have commented on it. My apologies.

JonoNic wrote:Wow! Some conversations are becoming way too technical for me. Are you guys suggesting that the three pre-chambers on one bank be interlinked by some air passage? This would allow the unsealed per-chamber (and currently linked to the other pre-chambers) to reach the correct AFR as there is some form of 'outlet for this stroke'. When the pre chamber is 'filled' then it can be sealed via valve long before it affects compression and combustion in the chamber. This could allow the injector to be outside the pre-chamber. Isn't it? If I'm talking nonsense then at least I tried

No problem. Reposted here

JonoNic wrote: ↑

23 May 2017, 17:33

JonoNic wrote:Wow! Some conversations are becoming way too technical for me. Are you guys suggesting that the three pre-chambers on one bank be interlinked by some air passage? This would allow the unsealed per-chamber (and currently linked to the other pre-chambers) to reach the correct AFR as there is some form of 'outlet for this stroke'. When the pre chamber is 'filled' then it can be sealed via valve long before it affects compression and combustion in the chamber. This could allow the injector to be outside the pre-chamber. Isn't it? If I'm talking nonsense then at least I tried

No problem. Reposted here

Ah yes. I must have missed the mention of the valve part.
You wouldn't want to interlink the chambers on the same bank as that would not work because of the overlap in the cylinders cycles. But the basic premise I the same.

I still feel very strongly about the injector being partially or wholey in the pre-chamber though or rather the pre-chamber in the injector.

Mr. Potato Head (Patrick Head maybe? ). What about heating fuel in the combustion chamber with microwaves? One of the guys mentioned heating fuel is essential to TJI. However, is it necessary to heat all the fuel entering the chamber or just part of it? Microwaves could provide this additional control during the heating process.