Max Tq vs Max Hp

[backintrouble]

May be an obvious question but i'm trying to design a small block to ski race at a pretty constant rpm for long durations...
If I cam the engine to make max hp at 7-7200 and Tq peak about 5500, will the engine be happiest at 7000 or 5500?
In practice of course i will course gear and prop it to run close to 5500 for longevity but it got me thinking about the
cam design and where the engine will be most efficient?
Thanks for any input!

 

[Justfishing]

You want to prop it so it can get to its max rpm at the typical load. Think of it as gears in a car. If youdrove a stick shift and ever started out in 2nd or 3rd gear you see howitlugs the engine. You mayhave engine got some engine knocking. Having the enginge able to get to maxrpms it like having yourcar in a correct gear

 

[obnoxious001]

May be an obvious question but i'm trying to design a small block to ski race at a pretty constant rpm for long durations...
If I cam the engine to make max hp at 7-7200 and Tq peak about 5500, will the engine be happiest at 7000 or 5500?
In practice of course i will course gear and prop it to run close to 5500 for longevity but it got me thinking about the
cam design and where the engine will be most efficient?
Thanks for any input!

So this is a ski race boat in Australia? Ford or Chevy? Factory block or stock. Makes a difference with the Ford since they like to crack. Tell me a bit more what types of speeds you plan to run, what sort of boat and drive. Bear in mind that horsepower and torque graphs cross over at 5252 rpm.

 

[rivermobster]

May be an obvious question but i'm trying to design a small block to ski race at a pretty constant rpm for long durations...
If I cam the engine to make max hp at 7-7200 and Tq peak about 5500, will the engine be happiest at 7000 or 5500?
In practice of course i will course gear and prop it to run close to 5500 for longevity but it got me thinking about the
cam design and where the engine will be most efficient?
Thanks for any input!

You might want to define what "most efficient" means to you...

Are you asking about fuel efficiency? Or?

 

[backintrouble]

You want to prop it so it can get to its max rpm at the typical load. Think of it as gears in a car. If youdrove a stick shift and ever started out in 2nd or 3rd gear you see howitlugs the engine. You mayhave engine got some engine knocking. Having the enginge able to get to maxrpms it like having yourcar in a correct gear

My v drive with 17% gears, 600hp LS1 will pull 2 guys out of water at half throttle, it will take more gear I believe.
Top speed is only 80mph at 7000 rpm- I need to be at 90 at less rpm. And fuel efficiency isn’t a huge concern

 

[Trash]

My v drive with 17% gears, 600hp LS1 will pull 2 guys out of water at half throttle, it will take more gear I believe.
Top speed is only 80mph at 7000 rpm- I need to be at 90 at less rpm. And fuel efficiency isn’t a huge concern

Add prop

 

[backintrouble]

Add prop

Advice I’ve been given is that going up in pitch will make it harder to drive… I’ve spoken to enough owners/experts on how to get where I need to be… my original question was more about engine theory