Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   502 carb 550hp - Blower vs NA (https://www.offshoreonly.com/forums/general-q/328561-502-carb-550hp-blower-vs-na.html)

onesickpantera 07-16-2015 12:48 PM

502 carb 550hp - Blower vs NA
 
I know there have been plenty of "NA vs Blower" threads and I have searched them. But, I would like to hear opinions from the gearheads on here about this specifically.

If you had a 502 Mag (carb version) and you wanted 550hp, would you replace the cam, lifters, pushrods, rockers, springs, intake, carb and exhaust or look at putting a small blower (420 or similar) blower on top with upgraded head bolts/studs, head gaskets and valves?

Which is more cost effective and reliable at this moderate hp level?

Rookie 07-16-2015 09:00 PM

I don't think you could make 550HP with a 420 on a 502. Lol
Also, I believe 550HP NA vs Blown are 2 different power levels in a boat.

airjunky 07-16-2015 09:14 PM

502 at 550 with typicall bolt ons will likely be peaky and wet exhaust un friendly
502 at 550 with a roots will not , but it will cost you space front and top

buck35 07-16-2015 10:10 PM

This kind of mirrors my thinking, decent cam, above average heads, what can a guy expect?
edit in ; I have zero room to get taller than the current stock setup.

onesickpantera 07-17-2015 11:27 AM

550 hp is obtainable with either, but I agree the delivery will be different. I was looking at getting there NA, and the costs add up quick. Which got me thinking, would it be cheaper and easier to pick up a used blower and go that route.

No right or wrong, just looking for opinions.

airjunky 07-17-2015 11:32 AM

If you can make it fit heck yea .

mike tkach 07-17-2015 05:46 PM

i think what rookie is saying is if you go with a 420 blower you will be way over 550 hp.i am a blower guy but only you can decide what is best for you.the n/a build will not make the torque a blown deal will make but that will extend your drive,s life.what ever direction you choose to go you will need to upgrade to a good exhaust system,change cam&components,either replace the heads or at least have your heads worked,buy a carb or two,etc.if i wanted only 550 hp i would go n/a.

SB 07-17-2015 06:08 PM

The blower deal will probably make a little more EGT and thus be a little harder on your exhaust valve seats / valves, and etc.

Maybe better to change to a better (thicker head if cast iron) and new aftmkt head with attention to detail from a cyl head guy with thicker seat margins and etc.

Anyway, a cast iron RHS, Engine Quest, Dart head with with a mild cam will put you at that.

A stock head with '731 cam will put you just under that.

=================================================

550 HP doesn't sound like much in todays world. But that's in comparison.

But, reality says it is still 550HP...which is, well, a lot.

Rookie 07-17-2015 06:10 PM


Originally Posted by mike tkach (Post 4331180)
i think what rookie is saying is if you go with a 420 blower you will be way over 550 hp.

Yes, that is exactly what I was saying.

Baja Rooster 07-17-2015 07:27 PM

Aaaaaand the next expense...what drive are you running?


All times are GMT -5. The time now is 08:31 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.