Flathead chamber design

[jed]

Jack could confirm if these casting numbers are the high compression head.
1549218 and 1547738 the last number is the casting number of the head on the engine.
Also did studebaker use any form of dating their casting.

[jed]

image.jpeg

Flat head V8 ford combustion chamber.

[jed]

Open where the air wants and needs to go, closed where it doesn't to keep CR high, 10-1 on my engine, and angled to enhance rotation (swirl) into the cylinder. Side of chamber opposite exhaust side is cut deeper, closer to the stud, and beyond the gasket line, yellow in the picture.

Intake is shrouded at back and when open has little clearance over the top.

Exhaust flow may seem somewhat blocked off at the cylinder, but Flatdog flow tests on exhaust showed flow out of the chamber tends to go sideways from the intake side and it makes sense that the flow is influenced by the exhaust port flow direction past the valve.

Picture is a tweaked version of what's on my engine now. Good enough to get me a 13.822 timeslip, but needs the tweak to get targeted 13.5.

Flat32

This is the explanation of the chamber design.

[Pete1]

One of Newton's laws of motion says,"objects in motion tend to stay in motion". This applies to a gas flow column. When you deflect this column, it slows down. This is NOT what you want. Ridges, steps, angles in the combustion chamber deflect gas flow. You want an unrestricted path in BOTH directions with the maximum area consistent with the required compression ratio.

The chamber in the picture was developed over 40 years ago and while this is a street example with a dome piston, it is still capable of developing over one hp per cubic inch on gas. The race version has a flat top piston and no dome head.

Head chamber.png

[Nikolas Ojala]

If all intake and exhaust flow could be handled by a single poppet valve, at least as well as with two valves, would that enable an essentially improved shape of the L-head combustion chamber?

I noticed that quite many patents of principally the same idea exist, but I also found why none of them has become common.

There are usually three defects:

1. Too complex. Expensive to produce and probably won't last.
2. Inferior flow. Although side-valve engines are known of flow problems, many of those patented ideas would make that problem worse.
3. Insufficient scavenging of combustion chamber, or no scavenging at all.

If an invention could not avoid all those three defects, it may be patentable but not worth patenting. But would it be worth publishing ⸻ well, I would not do that either.

I have an idea, but instead of trying to patent it, I would rather produce a defensive publication. Thus my idea would become unpatentable and free for all, which is fine for me.

[jed]

Pete I realize you have a lot of experience with flat head engines. Thanks for the picture of the chamber design.
Your comment of that chamber design making 1 HP per CID is unusuall high especially if the engine were NA.
Could you share any other information about the engine like CID, roller cam or flat tappet, porting and relieving,
Compression ratio and any other information you might have.
I know that type of information is very proprietary.

[jed]

image.jpg

image.jpg

Interesting pictures of a Indian engine raced at bonneville. Piston sticking out quite a bit.
Both intake and ex valves are open at TDC.

[Pete1]

Pete I realize you have a lot of experience with flat head engines. Thanks for the picture of the chamber design.
Your comment of that chamber design making 1 HP per CID is unusuall high especially if the engine were NA.
Could you share any other information about the engine like CID, roller cam or flat tappet, porting and relieving,
Compression ratio and any other information you might have.
I know that type of information is very proprietary.

I will share any info I have if it will help someone go faster. That pic is of an older Edelbrock head. Not sure what year but maybe 20 years ago. Their production heads are quite cobby looking now days. I quit using them when they sold out to off shore.
All of my flathead engines are NA, injected. All in the last few years have been at least 321 ci. One was 352. It is easy to get compression with that many inches. I use drilled radius lifter cams of various lifts and timing depending on the intended use. In the last 20 years, all of my engines have gone into vintage circle track cars. The compression ratio is usually around 14 to 1 for alcohol. Flat top gas ported 2 ring pistons. Home made O ringed heads. 5 stage scavenge dry sump oiling. Small diameter, knife edge billet crank. Light weight H beam rods. H&C mag. All ports with .100 minimum wall all the way through. End ex. ports straightened. Both valves 1.7 dia. .190 deep relief. 2 inch "W" type headers with 3.5 inch collectors. Reverse cooling water flow.
The only item I don't discuss is output power. Type of fuel makes a BIG difference. Dynos are useful for tuning but the actual reading can sometimes vary all over the place due to lack of calibration and whether it is a steady or flash reading.. The best judge of power I have found over the years is how many car lengths down the straight can the car pull any others on the track.

[motormonkey]

Pete1. Can you share the max rpm your making power at. Also are you running the French blocks or ford blocks.

[Pete1]

Pete1. Can you share the max rpm your making power at. Also are you running the French blocks or ford blocks.

The cam will determine the hp peak but 6 to 6.5K rpm.
Ford 8ba blocks. No after market or foreign blocks allowed in most vintage racing.

[dwilliams]

If all intake and exhaust flow could be handled by a single poppet valve

Well, the Gnome Monosoupape was rather successful in its day. Packard spent a bunch of money working on a single-valve design that never made it far, though.

No scavenging, no intake tuning, and you can't have an exhaust system or anything past the naked port. That's a non-starter for almost any ground or sea based application nowadays, and a disadvantage on any aircraft that has an engine cowling. And, of course, no forced induction system will work, and throttling the engine when you don't want 100% output becomes complicated. The Gnome used an ignition cutout, like an old-fashioned push mower.

[midnightbluS10]

If all intake and exhaust flow could be handled by a single poppet valve

Well, the Gnome Monosoupape was rather successful in its day. Packard spent a bunch of money working on a single-valve design that never made it far, though.

No scavenging, no intake tuning, and you can't have an exhaust system or anything past the naked port. That's a non-starter for almost any ground or sea based application nowadays, and a disadvantage on any aircraft that has an engine cowling. And, of course, no forced induction system will work, and throttling the engine when you don't want 100% output becomes complicated. The Gnome used an ignition cutout, like an old-fashioned push mower.

I'm not sure if this is the exact engine you're referring to, but this patent for a single valve ICE is pretty interesting. Talks of 15-1 compression and needing the best fuel on the market or something to that extent.

https://patents.google.com/patent/US2791992A/en

[Nikolas Ojala]

If all intake and exhaust flow could be handled by a single poppet valve

Well, the Gnome Monosoupape was rather successful in its day.

Gnome Monosoupape is not the thing, because the intake valve was placed in the piston. So that was not truly a single valve design.

Gnome_Monosoupape.png

[midnightbluS10]

Yea this one, by HA Robinson, looks nothing like that. It is an actual single valve above the piston.

[Nikolas Ojala]

Yea this one, by HA Robinson, looks nothing like that. It is an actual single valve above the piston.

Yes that is one of them, and there are many more. Here is a short list:

• US1232108
• US1311200
• US2049186
• US2122806
• US2791992
• US2979046
• US3093959
• US7802552
• WO2015166264A1

Each of them got a different approach. A common feature is the single poppet valve that is used for both intake and exhaust, and then some method for separating them on the low pressure side. Some of them tried to offer also a solution for scavenging combustion chamber. That is one problem I have been trying to solve.