Compression and flow

[3W Hank]

About compression in a FH.
Old speedparts heads had high compression as the Canada heads and to Kogel both cast iron and aluminium.
So idea must have been that compression got a stronger engine.
But this engines had a terrible flow around the piston so one can questionise if not a lower compression get more flow to spark, so more power in reality.

I has a set of the ’10 to 1’ L&S heads and Ross domed pistons.
Heads is at 59 CC and measure 10.5 mm or 0.413” deep chambers.
They get 10 in compression with 1/8” bore and a 4” stroke and a 0.04” thick gasket in a 59BA.
My cam is a Potvin 425 ( 425” lift ) so I might get away with this.
But I might has to mill the chambers or go with a thicker gasket.

-So the question is, do this engine like compression or do they make more power less compression.
That would cure all piston to head and valve to spark plug issues aswell.

In my case I’m not after max power, just like the sound and feeling and old parts.
So question is more technical.

[Ol' Ron]

WOW!!!
Gramps

[Brian]

It's the age old question; flow versus compression. Everyone has their own theories. Some things work better than others. Real serious racers keep their combustion chamber designs secret. I very much doubt that anybody on this board will tell you how to achieve the holy grail, it's up to you to experiment and discover what works best for you, in your case..Enjoy the challenge.

[3W Hank]

Whats the big secret today, competition is out since 1955 and this engine might give 150 HP or maybe go for it at Bonneville ( +300 ) but its no money or glory.
My idea was technical if someone had it on a dyno and tested 10 or 6 in comp.
As far as I know the old Harley racing design is hard to beat.
I has documents but question was just overall.
Its open to text me private.

[Ronnieroadster]

Originally Posted by 3W Hank

Whats the big secret today, competition is out since 1955 and this engine might give 150 HP or maybe go for it at Bonneville ( +300 ) but its no money or glory.
My idea was technical if someone had it on a dyno and tested 10 or 6 in comp.
As far as I know the old Harley racing design is hard to beat.
I has documents but question was just overall.
Its open to text me private.

Hank your question is not that simple to answer. Since your only building a traditional hot rod for the cool factor just use the parts you have and you will have at least 125 HP and maybe even up to 150. Certainly enough HP to hurt the Ford flathead three speed and twist the early Ford axle tips as well.

You know what it takes to make power you told me some time back you were involved with Super Stock Hemi stuff. To be fast with that engine it takes a lot of skill/secrets.
If someone was to ask you how to modify a Hemi to compete against you in drag race competition I think you would be hesitant to give away any information.

I will say to get the power needed to make decent HP with a normally aspirated flathead on gas is difficult but can be done. Many hours have been spent by me and a few others to figure things out. But to just give pointers on what to do is not so easy considering the time and Benjamin's each of us have invested to figure some things out.
Ronnieroadster

[Brian]

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There is a wealth of information about this matter in both printed form and on the internet. Ronnie above makes a valid point which backs up my comments....[Hemis] . Obviously, if one could achieve both flow and compression, that would be the ultimate, wouldn't it? Where do you want the flow? Considering that with a naturally aspirated engine, you are relying on atmospheric pressure to fill the cylinder[s], but the exhaust is 'blown' outta the cylinders by the rising piston, I'd say you need to concentrate on filling the cylinder[s]. And all this gibberish is only MY thoughts on the matter....The majority of aftermarket cylinder head manufacturers make pretty finned heads with combustion chambers which closely resemble those on stock Ford heads. The combustion chamber sorta resembles the shape of the head gasket, and to raise the compression we simply 'lower the roof'. what does this do to potential breathing? I reckon it restricts the flow. So, we need to narrow the passage from the intake valve to cylinder, but raise the roof. This will still give us a small combustion chamber [compression] but permit a good flow. Now, where do we locate the spark plug? Ford Located the plug sorta over the ex valve, is that the best location? Tubman swears by the location in Edmonds heads....I agree with him. When you've discovered the ultimate , please, by all means, report your findings on here. We all want to know. Good luck.

[3W Hank]

Brian, please send me the information on internet.

Yes as all things it is related to experiance and R&D.
My knowledge on Hemis in NHRA stock is work on friction, get oil down from head, good ringseal and get out max on compression and max cam lift.
I dig out 200 HP more than on the 80’s but its no real secrets going on here as company sell cams, rings etc and its more or less totally open but why cars go faster now is new speedparts is allowed ( or new tech ) so the RPM is higher and transmissions, converters and tires are way better than before.
Its actually most about the money and less any secrets.

My idea on this hotrod is classic parts and as Ron said ex 100 HP on the rear wheels is enought ruin all the parts after the engine… ;- )
But I will never do a burnout in this car.

I guess back then the gas was not as good even from our pump gas so I think this kind of engines might like a better flow than high compression.

The chamber that has both flow and ’high’ comp is ideal but that mean one need make new heads and a flow path and still has the CC down plus roof has high as needed.
But this question as I said was more technical as its more a basic test people must has done to classic hotrod set up and the finned heads that was out before and now.
I’m not talking on going deep and set records.