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Evolving the Side valve flat head design idea

Engine tech, for those engines, products, and technologies of yesteryear.

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prechamberflatty
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Evolving the Side valve flat head design idea

Post by prechamberflatty » Thu Oct 17, 2019 11:55 pm

G`day fellas new old bloke here from Oz

For decades flat heads have sucked me in, their simplicity fascinates me to no end.
Sure they have their shortcomings for certain applications but in some ways they
work similar to Diesel, good torque down low and reliable but way less efficiency.

As my Avatar name suggests, my point of focus has been combining a pre-chamber
and combustion chamber together as one not just using a separate pre-chamber.

Im old so sorry for the pixelated pics done on paint with the help of arthritis!

My idea is to use a funnel like design with lots of bias on one side of the
valves and shroud the other. This is to direct the flow on the outer side of
the "elephants trunk" to tumble the charge before the exit.

Image

The exit although not visible in my pics is shaped like a small banana
or quarter of a circle line exit passage. This is my thinking to arrive
at a tumbling charge that goes deep down to the bottom of the downstroke
on a very under-square design that creates a strong clean pull effect.

Image

(valves like most of it is not drawn up to scale - they would be larger but
didnt want to interfere with the general shape funnel shape)

This design would allow the use of short inlet manifold runners and the
usual exhaust design.

Spark plugs would a small industrial units with the pre chamber already on
the end which are common for industrial and Formula 1 but not the street.

These would have 2 - 3 holes biased towards the inlet to allow a directional flame front
that burns and exits along the tunnel shaped elephants horn etc.

I termed it FEP for now for Flat or Fast Elephant Port

Another version of this design is to swap the inlet and exhaust ports
to keep the chamber cooler by inlet charge flowing over exhaust valve
but not sure this would interfere with inlet flow speed which is one
of the aims of my design to have less interference for the inlet as possible.

Can anyone put me on to a fluids dynamic dude that is able to help me
further my dream of making a flat-head more efficient?
Also your constructive views are welcome.

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Re: Evolving the Side valve flat head design idea

Post by PackardV8 » Fri Oct 18, 2019 12:41 pm

Your photos/illustrations don't show for me so can't comment on the design thinking.

As someone who has always wanted what you want, more power with the simplicity and packaging of a flathead, I feel your pain. However, I've also learned from sixty years of research and hands-on, there isn't much which can be done to a flathead that has been overlooked. Better minds than yours and mine have tried most of what is possible. Every time I come up with a new-to-me idea, someone will point out Henry Ford/Ricardo/Navarro/et al, tried that way back when and it didn't work.

Wish I had more time to spend over on the little tractor pulling and Jr Dragster sites. Some of the most interesting flathead work is being done over there on the Kohler/Briggs platforms.

Only slightly off topic, when I used to have lunch with Ed Iskenderian, I'd always stop by the little shed where Tim ground the flathead single cylinder cams. The machine is a shop-built kluge and used a bicycle wheel as a speed reducing pulley. Ed said that was the most profitable thing in the company.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering

prechamberflatty
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Re: Evolving the Side valve flat head design idea

Post by prechamberflatty » Fri Oct 18, 2019 10:47 pm

Thank you Packardv8 sorry I couldnt get them to display, will try again
and can you or anyone recommend any forums for tractor pulling engine talk?




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Re: Evolving the Side valve flat head design idea

Post by prechamberflatty » Sat Oct 19, 2019 1:42 am



Here is the correct one, somehow loaded an older file.

To my 50 years of looking never seen my design applied to a flat head

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Re: Evolving the Side valve flat head design idea

Post by learner1 » Sat Oct 19, 2019 8:55 am

I've spent ALOT of time in the past thinking about ways to improve the flat head design. I see what you're trying to do here but where do you plan on placing the spark plug?

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Re: Evolving the Side valve flat head design idea

Post by PackardV8 » Sat Oct 19, 2019 12:40 pm

Have you calculated the volume of your prechamber? That's always the barrier to flathead breathing versus compression.
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Re: Evolving the Side valve flat head design idea

Post by exhaustgases » Sat Oct 19, 2019 4:20 pm

Flat heads? Most sleeve valve designs are flat heads.

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Re: Evolving the Side valve flat head design idea

Post by prechamberflatty » Sun Oct 20, 2019 8:57 am

Spark plug will be at the start of the smallest section of the chamber on the image below (exhaust valve)
It is not the most detailed drawing, its just to show my idea. The detailed drawing is done traditionally.



Compression can easily be modified but so far its starts at 8.8 to 1 by my calculations
the most important part of this design is to run a long rod to make the flow consistent
like a person breathing deeply and consistently albeit at 4500rpm max :D
The slower the burn the better this design can work as would any traditional flat head port.

Heat resistant coatings would be ideal as well to avoid pre-ignition at all costs when
increasing the compression ratio or using boost as this chamber is still in its infancy
to say the least. There are many of us that have toyed with flattys but this design
came to me with my fascination with the Proboscis of Elephants since I was a child
which is at least 50 summers ago.

The turbulence path has similar turns as would a human where the cylinder are
the lungs and the turn the Pharynx the chamber the nasal cavity with the short inlets
required as the nostrils. This design would not suit long inlet runners and even better
as it wont cause packaging issues or need for complicated manifolds/plenums etc.

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Re: Evolving the Side valve flat head design idea

Post by MichaelThompson » Sun Oct 20, 2019 1:25 pm

Kenny Kloth tried something like what you have pictured on a Flathead Ford V8. I don’t think it worked out for him though.

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Re: Evolving the Side valve flat head design idea

Post by MichaelThompson » Sun Oct 20, 2019 1:32 pm

http://hcgarage.net/T-Head.htm

Here is his latest thinking in side valve combustion chamber design.

Image

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Re: Evolving the Side valve flat head design idea

Post by PackardV8 » Sun Oct 20, 2019 2:25 pm

Interesting discussion, but don't expect complete agreement.
prechamberflatty wrote:
Sun Oct 20, 2019 8:57 am
Compression can easily be modified but so far its starts at 8.8 to 1 by my calculations.
It would be well to recheck your calculations. It's not "easily modified compression" in flatheads to retain enough breathing to make a lot of horsepower. Harley-Davidson engineers and privateers spent thirty years working on the K-model and found the tradeoff of power stopped at less than 7':1. Any more compression cost more in power because of the restricted flow.
prechamberflatty wrote:
Sun Oct 20, 2019 8:57 am
the most important part of this design is to run a long rod to make the flow consistent like a person breathing deeply and consistently albeit at 4500rpm max
The rod length will make less difference than you seem to think it will.
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Re: Evolving the Side valve flat head design idea

Post by mk e » Sun Oct 20, 2019 3:45 pm

MichaelThompson wrote:
Sun Oct 20, 2019 1:32 pm
http://hcgarage.net/T-Head.htm

Here is his latest thinking in side valve combustion chamber design.

Image
It looks cool but there is nothing I saw on the linked page that even suggests it adds hp???? That confused me not seeing an A-B dyno sheet.

This is related to a comment I was going to make about the OP....keeping the combination chamber is pretty important to making hp and tolerating compression.
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Re: Evolving the Side valve flat head design idea

Post by prechamberflatty » Mon Oct 21, 2019 1:14 am

Totally agree with compression limits on traditional open chamber designs
that just bolt up to the head with the chamber windows quite largely
exposed to the cylinder but this is a 3 stage event engine design.

The example from that Mister is still quite traditional in concept.
My design has 2 expansion events before entering the cylinder.

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Re: Evolving the Side valve flat head design idea

Post by prechamberflatty » Mon Oct 21, 2019 2:21 am

Again sorry got cut off from editing my last post!... :oops:

Totally agree with compression limits on traditional open chamber designs
with large right angled flow towards the cylinder area.
Mine is not trying to make more rpm but use a 3 stage event to maximize
torque and efficient in that range. No use trying to mimic a Honda!
Thats for the OHV die-hards and they are happily well numbered :wink:

Michael thank you for the example from that effort in billet however
that is still quite traditional in flat head architecture of the past
rather than an isolated combustion chamber as mine is.

My design has 2 expansion events before entering the cylinder.
My combustion chamber is almost completely isolated from the
cylinder except for the small wedge opening which on a 3.5 inch bore
would only be the size of an average almond nut.

The small opening to the cylinder will see supersonic velocities
1.3-1.4L sport bike engines experience but at 3 times less rpm.
Its ironically a low rpm engine that utilizes supersonic jets from
the spark plug to the cylinder with the combustion chamber acting
as an intermediate between the first and last expansion stage.

As experienced in our daily cars, bikes and pumps "the sweet spot"
where they spend most of their time is from 1500-3000rpm during normal
cruising conditions. Not need for start stop complicated mechanisms/ecus
will make do with a large flywheel. Idle could be as low as 300rpm and start
making torque from 800-1000rpm which was the plan.
The design has its limits ONLY if aiming beyond its grunter application.

Thermal coatings and gapless pistons rings of good thickness can
be used as in the 60s and 70s eras without worrying about cylinder
wall friction due to the low rpm operation requirements.

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Re: Evolving the Side valve flat head design idea

Post by Nikolas Ojala » Mon Oct 21, 2019 6:09 pm

Two possible ways to produce better flathead engines:
  1. Shape of the combustion chamber. If there was only one valve, the combustion chamber could be designed better. Scavenging of burnt gas from the chamber would be tricky but not impossible.
  2. Ignition. The combustion chamber under the flat head is low and wide, and that is one reason why combustion is slow. Combustion speed could be improved by using laser ignition, microwave ignition or plasma ignition, or with completely different combustion process, such as RCCI, if the combustion chamber shape was compatible.

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