Offshoreonly.com - Supercharged v NA

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Quote:

Originally Posted by articfriends (Post 4410888)

Unless you can make same hp at same rpm the na motor will never compare to a sc motor. A local guy (todd kramer) had a 27 foot fountain, someone who supposedly worked for Sterling at somepoint built him a NA 540. Had a solid roller cam, dynosheet showed something like 745hp at 7300 or so from what I remember. He previuosly had a 502 and a 26 pitch prop, he bought a 30 pitch BEFORE ever running the motor, absolutely wouldnt pull it, wouldnt pull the 26 either. He ended up with a 23 pitch to break 78 mph but oil temp was sky high, cruise rpms sucked. My Baja at that time had a blown 502 that made about same hp but at much lower rpm, had much more useable midrange torque and beat the fountain every time we ran. Now sure, you could compare a blown 454 to a na 572 then the tq would be similar depending on boost, cyl heads etc, fwiw, Smitty

Do blower motors run cooler oil temps simply because you're not banging the crap out of them to get the same power?

Quote:

Originally Posted by Baja Rooster (Post 4411227)

Do blower motors run cooler oil temps simply because you're not banging the crap out of them to get the same power?

No. Blower motors have to make more power (burn more fuel/air) to make the same power at the crank. Power = BTU's. An engine burns fuel to push the pistons down and make power. It has to take in an appropriate amt of air to support the fuel so it can burn right.

Thinking further, if you greatly increase the NA's rpm to make same hp as the blower motor, than the engine fricition, especially the valvetrain (think springs) could add more heat. So...this may trump what I said above.

I believe a 700HP blower motor will outperform a built 700HP NA motor in all aspects everyday of the week maybe twice on Sunday. If they are relatively close in cu/in. I've seen the difference when someone went from 700+ blown vs 700+ NA I believe he lost 4mph, 102mph to 98mph.
But now the drives last 2-3 years vs 2-3/yr.

It seems to me with a blower you can run a much smaller cam, with less lift and lighter springs. How does the benefit of a smaller cam and manifold style exhaust compare to the maintenance of a blower?

Quote:

Originally Posted by articfriends (Post 4411070)

Did you ever meet Todd, he lives on 15 between richville and Vassar?

I don't think I know Todd, but I am terrible with names. It just seems like this builder knew nothing about marine motors, cuz high rpm and stern drives rarely end well.

I do like hearing the experiences of those like yourself who have owned both and which they prefer

Quote:

Originally Posted by Rookie (Post 4411267)

I believe a 700HP blower motor will outperform a built 700HP NA motor in all aspects everyday of the week maybe twice on Sunday. If the are relatively close in cu/in. I've seen the difference when someone went from 700+ blower vs 700+ NA I believe he lost 4mph, 102mph to 98mph.
But now the drives last 2-3 years vs 2-3/yr.

Tell 14 Apache his boat is 4mph too slow. It's only one of the fastest apaches around :D

their is no replacement for displacement,except BOOST.

Quote:

Originally Posted by mike tkach (Post 4411721)

their is no replacement for displacement,except BOOST.

Boost IS displacement. ;)

cubic inch displacement.the big cu in n/a guys like to say [no replacement for displacement]surly you have heard that through the years.