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Naturally aspirated, HPs per Cu. In.???

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Naturally aspirated, HPs per Cu. In.???

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Old 04-15-2019, 07:51 AM
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Default Naturally aspirated, HPs per Cu. In.???

As a life long, ate up, internal combustion gear head, I have always followed that math.

Want to impress me?
Show me that math.

I grew up thinking that anything at or above 1:1 is good.
As in, 500 Cu in = 500 HP is good.

IMO, remains true today.

Just watched a Top Gear rerun where they tested a Ferrari that had a naturally aspirated 6.5 liter/403 Cu in V-12 making 800 HPs!

Thats 1.985 HP per Cu In!

Bern a while since I paid a lot of attention to this but I still know that number is up there!

Who can think of what, non race, 4 stroke (a 2 stroke w/an expansion chamber easily surpasses 2:1) that beats this?

Nothing against forced induction but start w/this then screw in a pair of turbos 😎
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Old 04-15-2019, 11:35 AM
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How about Aston Martin's new Valkyrie V12? Makes 1000 HP from 6.5L @ 11,000 RPM - 2.52 HP per cu in.

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Old 04-15-2019, 12:06 PM
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Our Super cat engines are 509 cuin and in theory make 800 HP (unless your NZ-1, AMH, WHM, performance, ect. there's probably make 2000 hp) So around 1.6 hp per cuin but that is on 93 octane fuel and ours lived a whole season of testing and running.

I do have a 2 stroke that makes close to 6 hp cuin n/a and a rotary that makes close to 7 hp cuin. And a diesel that makes 4 hp cuin but on lots of boost.

Last edited by BigSilverCat; 04-15-2019 at 12:08 PM.
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Old 04-15-2019, 12:43 PM
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I agree, while growing up 1hp/cuin was doing well, Sixteen Power is claiming 1400hp from its LS based V16
854 cuin 1400 hp is 1.64ish
In the 90's GM's LT small block was hot stuff at less than 1 hp/cuin
And Fords' 5 point nothing (5.0) was about the same in a lighter package
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Old 04-15-2019, 01:49 PM
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Motorcycle engines are pumping out 200hp at 1 liter, or 61cu, so they are 3.27hp per cube, reliable for 50k miles and idles like a *****cat. Once you go overhead cams its a whole new ballgame.
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Old 04-15-2019, 07:24 PM
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Good stuff.

Is the Aston normally asperated?

The Super Cat post is funny and wayyy impressive.
Great numbers and a full season on those motors is damned
impressive.

Forgot about the bikes.
The lighter the load, the wilder they can be.
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Old 04-15-2019, 08:54 PM
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I thought the first time a car company did 1HP /cu was the injected 283 vette engine in 1957???
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Old 04-15-2019, 09:34 PM
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Wildman, that sounds right.

I have an addition.
Pro Stock drag cars.

500 Cu ins @ 1500 HP = 3 per.
I remember thinking they were about top of the food chain.
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Old 04-16-2019, 06:13 AM
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Manufacturers made more power in the 50's and 60' before emission control. Their solution to meet standards was to retard camshaft timing and decrease to static compression so low most engines in the 70's and early 80' were anchors
for example to Ford 460 was mid 300's in 1970 (D0VE) and dropped to 200 a couple years later
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Old 04-16-2019, 06:22 AM
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Originally Posted by resurrected View Post
Manufacturers made more power in the 50's and 60' before emission control. Their solution to meet standards was to retard camshaft timing and decrease to static compression so low most engines in the 70's and early 80' were anchors
for example to Ford 460 was mid 300's in 1970 (D0VE) and dropped to 200 a couple years later
Yes ,,, lived it hel late 70's vettes have less HP then most motorcycles do now. But now they are doing way better. The HP and drive ability are something now a days. WHo even thinks about changing plugs, worried that they car will start in the cold, etc.
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