How does cid make power?

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Rat Bastid said:
This doesn’t explain why so many strokers are giant underachievers.
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Depends…. Are the he engine owners trying for max output? I haven’t seen but one build that had a Victor head up top a stroker. All I see here being posted and talked about by a huge margin is 308’s with ported Edelbrock heads. A very few W engines, but not being built or asked questions on. The W head owners are or seemed to be happy just doing there thing.

Look at the PONTIAC. Long stroke tractor engines. Ou can make 600 HP at 5500 but it wold get killed by 600 HP at 7000.
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Why?

Edit: 7000 is NOTHING with today’s valve train components.
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Only if you know what your doing…..

:thumbsup:
 
rumblefish360 said:
Depends…. Are the he engine owners trying for max output? I haven’t seen but one build that had a Victor head up top a stroker. All I see here being posted and talked about by a huge margin is 308’s with ported Edelbrock heads. A very few W engines, but not being built or asked questions on. The W head owners are or seemed to be happy just doing there thing.

Why?


Only if you know what your doing…..

:thumbsup:
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If you don’t want max power why spend the money on a stroker?

Because the engine with more RPM can use lower gears (that is better than using the crank to make torque)and it has more power cycles in whatever distance you are running. Doesn’t matter if it’s 1/8th or 1/4 mile or a circle track engine, the higher RPM engine makes more power cycles. That is what matters. How many times the cylinder has a power stroke.

7k is nothing today. Even using 273 rockers you can do 7k forever. I’d venture to say that 8k if the oiling system is good is nothing today.
 
Rat Bastid said:
If you don’t want max power why spend the money on a stroker?
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Simply for more torque. Street guy area.
Because the engine with more RPM can use lower gears (that is better than using the crank to make torque)and it has more power cycles in whatever distance you are running. Doesn’t matter if it’s 1/8th or 1/4 mile or a circle track engine, the higher RPM engine makes more power cycles. That is what matters. How many times the cylinder has a power stroke.

7k is nothing today. Even using 273 rockers you can do 7k forever. I’d venture to say that 8k if the oiling system is good is nothing today.
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I see what your saying but also say that even though the stroker takes longer to make that rotation, the added torque maybe of some advantage as well as getting to peak power earlier & shifting sooner.
 
rumblefish360 said:
Simply for more torque. Street guy area.

I see what your saying but also say that even though the stroker takes longer to make that rotation, the added torque maybe of some advantage as well as getting to peak power earlier & shifting sooner.
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Street guys leave more on the table with horrible cam selection than they gain with stroke. I get it. “Street” guys want to smoke their tires and think that’s actual power. It’s not. And “street” guys love to lug the engine around and stuff like that. That’s why they can’t run as much compression as they could. And that’s a power loss too.

Ok, let’s talk this through. Stroke length does not matter when talking RPM. That’s because it doesn’t matter how long the stroke is because RPM is RPM.

Lets say we have a 3 inch stroke and a 4 inch stroke engine. The 3 inch stroke engine has a shift RPM of let’s say 8k and the 4 inch stroke engine has a shift RPM of 6k.

In a 1/4 mile, they both travel the same distance. That means that the 8k engine (lets say they both run 11.00 times) had more power cycles across that distance. Not because the longer stroke takes longer to RPM, it’s because it has less RPM. And that means it has less power cycles across the same distance.

And the power cycles (power stroke) are what move the car down the track, or down the road or what ever.

Think of it in terms of Diesel engines. They have huge torque numbers and low horsepower numbers. That same Diesel engine will have far less power cycles than a gasoline engine. That’s why the horsepower is low.

Power cycles is what matters. The other three strokes don’t make the car move.
 
Rat Bastid said:
Street guys leave more on the table with horrible cam selection than they gain with stroke. I get it. “Street” guys want to smoke their tires and think that’s actual power. It’s not. And “street” guys love to lug the engine around and stuff like that. That’s why they can’t run as much compression as they could. And that’s a power loss too.

Ok, let’s talk this through. Stroke length does not matter when talking RPM. That’s because it doesn’t matter how long the stroke is because RPM is RPM.

Lets say we have a 3 inch stroke and a 4 inch stroke engine. The 3 inch stroke engine has a shift RPM of let’s say 8k and the 4 inch stroke engine has a shift RPM of 6k.

In a 1/4 mile, they both travel the same distance. That means that the 8k engine (lets say they both run 11.00 times) had more power cycles across that distance. Not because the longer stroke takes longer to RPM, it’s because it has less RPM. And that means it has less power cycles across the same distance.

And the power cycles (power stroke) are what move the car down the track, or down the road or what ever.

Think of it in terms of Diesel engines. They have huge torque numbers and low horsepower numbers. That same Diesel engine will have far less power cycles than a gasoline engine. That’s why the horsepower is low.

Power cycles is what matters. The other three strokes don’t make the car move.
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So If you have 100 powerful strokes or 1000 not so powerful strokes somewhere in there is a trade off point. Otherwise the motor that turns the highest rpm would win everytime.
 
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92b said:
Torque and horsepower?
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if both have same horsepower curves but different torque curves when gear right for the track both will a have about same torque going to the tires through out the curve.
 
33IMP said:
Will someone please post the "beating a dead horse" meme?
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When you say "beating a dead horse" meme are you refering to a few long powerful blows meme or many less powerful blows meme to beat this dead horse?
 
273 said:
if both have same horsepower curves but different torque curves when gear right for the track both will a have about same torque going to the tires through out the curve.
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I meant to ask identical curves both torqe and horsepower at the crankshaft.
 
92b said:
Torque and horsepower?
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Horsepower. Both engines make 600 hp. Honestly, who cares about torque? But let’s say (for the sake of discussion) the low RPM engine made 600 TQ and the high RPM engine made 450 TQ.

What is the difference in ET and MPH? I say none. It’s based on horsepower. And when two engines make the same power, the engine that does it at a higher RPM will be quicker and faster.
 
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Rat Bastid said:
You tell me? How can an engine that has peak power at 6k have the same curves as an engine that has the same peak power but at 8k?
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You post says shift point of 6k and 8k. I'm not a drag racer but don't you shift at some rpm past peak usually? That part doesn't matter. You're saying now that the motors make the same power only at peak for each motor 6k and 8k? Wouldn't the rest of the curve matter as to how the car performs?
 
92b said:
You post says shift point of 6k and 8k. I'm not a drag racer but don't you shift at some rpm past peak usually? That part doesn't matter. You're saying now that the motors make the same power only at peak for each motor 6k and 8k? Wouldn't the rest of the curve matter as to how the car performs?
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It depends. And most of it depends on the engine builder. I guess there should be a qualification on what transmission is used.

If they are powerglide cars, then I’d want the power to hang on past peak longer. You want to stay above peak torque when your RPM fall back on the shift.

If it’s a 3 speed you can narrow up the power curve a bit but you lose power past peak. Once you go to 4 or better yet 5 gears, then you can narrow up the power curve even tighter. And that means you won’t have as much power past peak.

The latter two scenarios make the car harder to drive. You can’t short shift or the engine drops below peak torque and it’s a pig off the gear change.

Shift late and the power falls off so fast the car actually slows down before the shift. You can see this on a G meter if you data log.
 
Post #215: 'Who cares about torque'.

Anybody who wants to get as much HP rom their engine should care about TQ, because TQ is one of two components reqd to make hp, the other is rpm.....

I have a very interesting article from an old SS & DI magazine, Dec 1979.
About rod length. When you build a stroker engine, stroke is typically increased. And that reduces the rod/stroke ratio:

"At low rpm the engine depends on the suction of the piston for cyl filling & the short rod gets things moving quickly. At high rpm, the inertia of the moving air helps out the induction & the engine breathes in some ways like a two cycle & the smoother slower accelerations of the long rod are more compatible."

"On a short rod engine the point at which the rod is at right angles to the stroke occurrs higher in the bore, which increases the compression of the burning A/F....This is one reason that a short rod engine seems to have more tq & pulling power".

"One of the most intriguing cases of the long rod/short rod situation working was found in the junior fuelers just a few years ago. "

301 engine , 3" stroke, 4"bore, R/S ratio 1.90. 307 engine 3.88"bore, 3.25" stroke 1.75 R/S ratio.
"......despite running nearly 15 mph slower they [ the short rod ] would regularly et one or two tenths quicker."
 
@Rat Bastid

I want to apologize as well as say thanks for that awesome response as my reply was just simply a poke and a joke but not without merit, I understood and long ago got it. I just wanted to have a little fun and throw in a twist of a reply.

LMAO, I thought I’d get a very different reply.
NOPE! Instead I received a text book explained, thought out response that was delivered as from a concerned teacher. An honest straight up answer.

That was an awesome reply that really explained a few things very well.

Thanks :thankyou:
 
Here ya go

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