WELCOME TO RIVER DAVES PLACE

Horse power calculator?

pkrrvr619

pkrrvr619

Well-Known Member
Joined
Sep 2, 2014
Messages
1,918
Reaction score
2,357
Does anyone have an online horsepower calculator?

I am getting so many conflicting estimates on how much hp my boat has and didnt know if there is a calculator or any hard fast rules.

Engine specs in case anyone wants to guess and maybe we can put together a consensus.

516 motor (efi)
8.75/1 compression
hp 500 cam efi model
cmi headers
world product 345 iron heads
6 pounds of boost on 91 octane.
Crower valve train
Crower link bar
Crower push rods
Roller rockers


Any guesses? Ive heard anything from 630 to 775.
 
DaveH

DaveH

Well-Known Member
Joined
Sep 9, 2008
Messages
2,863
Reaction score
4,214
at that displacment and relativively low CR, I am guessing 1-1.1hp per cube NA. that means 516-567hp plus about 25% for the boost level you wish to run.

I'm guessing between 675-685hp if you keep the RPM under 6000.
 
Blubyu

Blubyu

Well-Known Member
Joined
Feb 9, 2011
Messages
4,217
Reaction score
1,719
That compression ratio, cam, and heads. Around 600-670.


Sent from my iPhone using Tapatalk
 
obnoxious001

obnoxious001

Engine building character
Joined
Dec 28, 2007
Messages
6,636
Reaction score
4,144
pkrrvr619 said:
its a small 2.3l
Click to expand...
With the smaller blower, it needs to spin faster to make boost. Along with the faster speed comes more heat. You don't mention an intercooler, so my thinking would be towards the lower end of the scale of what's been suggested. Heated air will not make as much power as cooler, denser air.

Friend of mine has a 516 cu in deal that I built for him about 10 years ago with a 3.3 Whipple in a Stoker, making about 7 lbs boost. The boat will peg a 120 mph GPS.
 
pkrrvr619

pkrrvr619

Well-Known Member
Joined
Sep 2, 2014
Messages
1,918
Reaction score
2,357
obnoxious001 said:
With the smaller blower, it needs to spin faster to make boost. Along with the faster speed comes more heat. You don't mention an intercooler, so my thinking would be towards the lower end of the scale of what's been suggested. Heated air will not make as much power as cooler, denser air.

Friend of mine has a 516 cu in deal that I built for him about 10 years ago with a 3.3 Whipple in a Stoker, making about 7 lbs boost. The boat will peg a 120 mph GPS.
Click to expand...

Ah left that part out, yes it has an intercooler.
 
rivermobster

rivermobster

Club Banned
Joined
Dec 28, 2009
Messages
60,318
Reaction score
61,762
pkrrvr619 said:
Does anyone have an online horsepower calculator?

I am getting so many conflicting estimates on how much hp my boat has and didnt know if there is a calculator or any hard fast rules.

Engine specs in case anyone wants to guess and maybe we can put together a consensus.

516 motor (efi)
8.75/1 compression
hp 500 cam efi model
cmi headers
world product 345 iron heads
6 pounds of boost on 91 octane.
Crower valve train
Crower link bar
Crower push rods
Roller rockers


Any guesses? Ive heard anything from 630 to 775.
Click to expand...

To answer your question...

No. There are no hard and fast rules. There are literally hundreds of different things that can change the HP on your engine, including the Dyno you measure it on!

HP is not a measurement, it's a calculation. The only actual measurements being performed (on a Dyno) is torque.

The only real way to know what HP/Torque you're getting is by putting the boat/engine on a Dyno. Anyone's guess is just that, a guess.
 
Nanu/Nanu

Nanu/Nanu

Don't wait til' life's easy to be happy
Joined
Jul 30, 2020
Messages
2,726
Reaction score
4,950
I could meet you and do a tug of war match against your boat. If you win that's easily a 1000hp motor. But there's a good chance I'll break your boat.
 
You must log in or register to reply here.
Top