Cams choice, Low CR vs VE%

[AJ/FormS]

Since I already had that 318 top end and cam in/on a 340 with 3.23s and a 904, in a 65 Valiant wagon,
and I had a 318 with all the 340 stuff on top in a 73Dart more-door,
I think I know the answer.
However, I don't think that's a fair response to the topic.

 

[318willrun]

Then keep building a bigger pump. But for those who want to extract more HP/TQ per cubic inch read it and think.

no answer on the question I posted ? Can't pick an engine in for the win???

 

[318willrun]

Since I already had that 318 top end and cam in/on a 340 with 3.23s and a 904, in a 65 Valiant wagon,
and I had a 318 with all the 340 stuff on top in a 73Dart more-door,
I think I know the answer.
However, I don't think that's a fair response to the topic.

It is a fair question, because he took what I said out of context. I said if I HAD to make the choice between compression or flow in a race, I'd pick flow everytime. Obviously he would too, that's why he didn't pick the 360 with compression that was all choked up. Why? Because the 360 with flow and low compression would eat it alive in a 1/4 mile race, which would mean he'd have to agree with my original post which would negate his point that I apparently don't understand something or I was apparently wrong about something.

 

[Hysteric]

You mean that extreme example you made up hoping to make yourself look intelligent?

How about 2 pump gas engines the same but one has 9-1 and the other 11-1 and the guy tuning the 11-1 knows what hes doing.

Again, Keep building a bigger pump but for those who want to extract more HP/TQ per cubic inch read it and think.

 

[318willrun]

You mean that extreme example you made up hoping to make yourself look intelligent?

How about 2 pump gas engines the same but one has 9-1 and the other 11-1 and the guy tuning the 11-1 knows what hes doing.

Again, Keep building a bigger pump but for those who want to extract more HP/TQ per cubic inch read it and think.

Did I EVER say compression is bad?? Nope. Both engines built the same I'd gladly take 9 to 1 over 8 to 1. But that isn't what I said. I simply said if I had to make the choice between compression or flow, I'd take flow every time. And you apparently would too.

 

[Hysteric]

You can lead a ***** to culture but you can't make her think.

You need more flow because you can't build any power with what you already have.

 

[fishmens67]

You mean that extreme example you made up hoping to make yourself look intelligent?

How about 2 pump gas engines the same but one has 9-1 and the other 11-1 and the guy tuning the 11-1 knows what hes doing.

Again, Keep building a bigger pump but for those who want to extract more HP/TQ per cubic inch read it and think.

same engine, but one with 2 point higher compression, 5% more Horsepower with 11.1 compression or about 25 or so more HP on a 500 horse engine.

 

[318willrun]

same engine, but one with 2 point higher compression, 5% more Horsepower with 11.1 compression or about 25 or so more HP on a 500 horse engine.

but what if you add "flow" with a supercharger to the lesser compression engine.... 50% more hp

 

[318willrun]

You can add chicken to soup but you can't eat the feathers...
So now YOU TOO can go with the flow.....

 

[fishmens67]

Did I EVER say compression is bad?? Nope. Both engines built the same I'd gladly take 9 to 1 over 8 to 1. But that isn't what I said. I simply said if I had to make the choice between compression or flow, I'd take flow every time. And you apparently would too.

Like I said before., at my old age I will take flow over compression on a street/ strip car.
For an ultimate build I would need 14 or 15.1 compression. and a cylinder head. lol

 

[318willrun]

Like I said before., at my old age I will take flow over compression on a street/ strip car.
For an ultimate build I would need 14 or 15.1 compression. and a cylinder head. lol

Precisely. I said I love compression. But, if you MAKE me choose between the two, I will take flow over compression in a race. Somehow, somewhere, I needed a lesson but like high school, I just skipped the class

 

[fishmens67]

I don't need no stink'n supercharger, maybe some juice, maybe. lol

 

[AJ/FormS]

increasing the horsepower, can only be done by increasing the amount of fuel burned, which can only be done by ingesting more air, which points straight to a higher VE; they are inextricably related.
How you get the additional air, well that can be complicated. or not.
But it's like Dcr. We increase Dcr by increasing Scr inn response to a later Ica.
VE is like that; it is the product of doing these other things. Targeting VE, IMO, is putting the cart before the horse.
Once you have a known VE, you can shuffle it back and forth or up and down, a bit, with other changes to target what you need, but it's a lotta work for very little gain.... IMO.
Getting 560cc of air into a 560cc hole is tough enough without it also having to be a streeter. Getting 560cc of air into a 750cc hole is a whole lot easier.

 

[318willrun]

increasing the horsepower, can only be done by increasing the amount of fuel burned, which can only be done by ingesting more air, which points straight to a higher VE; they are inextricably related.

well said

 

[yellow rose]

increasing the horsepower, can only be done by increasing the amount of fuel burned, which can only be done by ingesting more air, which points straight to a higher VE; they are inextricably related.
How you get the additional air, well that can be complicated. or not.
But it's like Dcr. We increase Dcr by increasing Scr inn response to a later Ica.
VE is like that; it is the product of doing these other things. Targeting VE, IMO, is putting the cart before the horse.
Once you have a known VE, you can shuffle it back and forth or up and down, a bit, with other changes to target what you need, but it's a lotta work for very little gain.... IMO.
Getting 560cc of air into a 560cc hole is tough enough without it also having to be a streeter. Getting 560cc of air into a 750cc hole is a whole lot easier.

Not true. Hysteric just gave you an example of same air flow/more power.

Some guys never look at HP/CID and that’s much more important than what the HP is.

I’ll never understand why anyone they can’t have flow AND compression. And no. You don’t need a cam with 280 duration to do it.

 

[Hysteric]

increasing the horsepower, can only be done by increasing the amount of fuel burned, which can only be done by ingesting more air

Ever heard of Brake Specific Fuel Consumption?

 

[318willrun]

I don't need no stink'n supercharger, maybe some juice, maybe. lol

but..... if you run out of juice, your 3 wishes from the genie are used up and you suddenly become 2 seconds slower. With a supercharger, you never run out of air..... even at 10,000 ft

 

[318willrun]

double post... LOL

 

[318willrun]

Not true. Hysteric just gave you an example of same air flow/more power.

Some guys never look at HP/CID and that’s much more important than what the HP is.

I’ll never understand why anyone they can’t have flow AND compression. And no. You don’t need a cam with 280 duration to do it.

What he said is on track, and true. What you said is also true that yes, you can gain more power/CI. I didn't read on this thread were somebody said you can't have both compression and flow. I just simply said if I had to make a choice between the two, I would pick flow. So would everyone here in a 1/4 mile race if their life depended on it. But for the sake of arguing, they won't admit it. I find it funny if somebody says they prefer red cars over blue cars, the crowd assumes they "hate" blue cars. LOL Truth is, you can love both colors

 

[Hysteric]

increasing the horsepower, can only be done by increasing the amount of fuel burned, which can only be done by ingesting more air,

You are right in the first part.But you've made the assumption you're actually burning 100% of the fuel your engine ingests and in reality it doesn't especially in low comp engines. If you're only using 70% of the energy present in the fuel and that's all your capable of utilizing with all the factors involved then yes you need more air and fuel to do it.

Now if you can extract 95% of the energy present in the fuel then you're making more power with the same amount fuel and air aren't you?

Build a bigger pump if you can't do the second.

 

[AJ/FormS]

You are right in the first part.But you've made the assumption you're actually burning 100% of the fuel your engine ingests and in reality it doesn't especially in low comp engines. If you're only using 70% of the energy present in the fuel and that's all your capable of utilizing all the factors involved then yes you need more air and fuel to do it.

Now if you can extract 95% of the energy present in the fuel then you're making more power with the same amount fuel and air.

Build a bigger pump if you can't do the second.

that post was in response to this below, and agreeing.
If I'm wrong then, I certainly see your logic.

same engine, but one with 2 point higher compression, 5% more Horsepower with 11.1 compression or about 25 or so more HP on a 500 horse engine.

 

[318willrun]

Years ago, I spent a little time at Dave Wofsey's shop in Denver, Colo. talking with him about his invention "sonic plug". While his plugs were a semi-failure, the topic of power in unburnt fuels generated a fun conversation. Leaving fuel unburnt (lack of efficiency) is a waste of money and power. Trying to capture a 100% burn is a dream. Some have chased it with timing, some have chased it with hotter-longer spark, and some have chased it with atomization. Yes, getting a higher % burnt will result in more power of equal air/fuel.

 

[Hysteric]

You need to work at extracting more energy from what you're currently using. Did you read that link i posted?

Here's some of what Shrinker wrote:

It is important to understand that analyzing individual factors is one thing, but seeing how they form an overall result is another. I can’t assemble all the factors into one simple document but I will layout some basic thoughts for people to follow or expand upon.
1. Increasing the time of fuel engagement within the engine induction system increases vaporization. Injector placement, carburetor placement.
2. Decreasing fuel droplet size improves vaporization. Injector design, carburetor design, port flows, turbulence.
3. Increasing the volume of hot exhaust gas present during the intake stroke increases vaporization. Exhaust closing time, backpressure, and compression ratio.
4. Closing the intake valve earlier increases the time available for compression energy. Compression is broken up into adiabatic and isothermal times. Piston speed.
5. Increasing vacuum increases vaporization. Volumetric efficiency, throttling.
6. Increasing vaporization reduces the charge temperature.
7. Increasing vaporization (up to a point) reduces detonation.

Basically the way that you input energy to the fuel prior to ignition determines the combustion efficiency of a particular chamber.
Note I didn’t mention squish, as squish has no effect upon vaporization; it only affects combustion speed due to turbulence.

 

[Hysteric]

Now think about Number.7 and ask yourself why some people can run more comp.

Now think about N.2 and what roll carb and carburetor design plays in this.

 

[RustyRatRod]

The problem begins when people say an engine is just an air pump. Its not, they totally ignore the fueling component.

Don't tell me what I ignore, because you don't know. An engine IS indeed an air pump, but a self driven one. Every air pump has to have a power source. An internal combustion engine just happens to create its own power.

But directed at @273, your question "as presented" is unanswerable. Though the forum gurus make think they can, they effectively cannot and neither can anyone else in the question's present form. For an answer, you "must" provide a basis of comparison. In other words "Does engine A have more VE% than engine B?" "If so why?" This is a comparison question and as such needs a basis for a comparison.

It's like all these stupid commercials on TV saying "You'll lose 40% more weight". Oh yeah? 40% more weight "THAN WHAT", yet people flock to them never realizing they just got took by the oldest trick in the book.

 

[318willrun]

Don't tell me what I ignore, because you don't know. An engine IS indeed an air pump, but a self driven one. Every air pump has to have a power source. An internal combustion engine just happens to create its own power.

But directed at @273, your question "as presented" is unanswerable. Though the forum gurus make think they can, they effectively cannot and neither can anyone else in the question's present form. For an answer, you "must" provide a basis of comparison. In other words "Does engine A have more VE% than engine B?" "If so why?" This is a comparison question and as such needs a basis for a comparison.

It's like all these stupid commercials on TV saying "You'll lose 40% more weight". Oh yeah? 40% more weight "THAN WHAT", yet people flock to them never realizing they just got took by the oldest trick in the book.

LOL.... Dave Wofsey promised results on my '90 Caravan I had at the time. After a long period at his shop, we installed his invention to burn more fuel and in the Denver high altitude he was going to give me sea level performance. It was a great time, a learning experience, but he failed. He was a engineer that entered the "Deep" on knowledge. Some think they are deep, but really they are stuck.