davva

Im gonna build a new engine this winter.
Horsepower gonna be around 750, with a 575 or 600 Dart Big m block and a blower. Gonna build for durability so its gonna be a oversized motor for the horsepower output.

Now im thinking of quad rotors like the merc.850sci.
What would the benefits be of that with say 2 x 2.3l whipples versus a bigger one?

any suggestion of intake plenum and intercooler for quad setup?

Young Performance

I would not even consider a quad rotor setup at that low power. Don't get me wrong, the quad rotors are awesome......if you want to really make some power. Personally, I won't use a 2.3 quad until I am looking to make north of 1100. When you spin them that slowly, fuel and air distribution is terrible when it's in vacuum. You would be spinning them ridiculously slow. For the power you are looking to make (750 hp), a 3.3 L single would be more than enough. Hell, the 525's make almost 800 hp with a 3.3 on a bone stock engine, and that's a 502 with crappy aluminum heads.

Just an FYI, using a bigger blower to make lower power does not equate to longevity. Sure, there are some exceptions when talking about a roots blower in some cases. For the other 99% of the time, a bigger blower will not make the engine live longer. Making the engine more efficient and making the power easier by using better heads, cam, intake, etc. will equate to a longer life. If everything else stays the same, it will take the same amount of boost to make your power goal whether you have a big blower or a small blower. Heat and blower efficiency will come into play if you are reaching the limit of the smaller blower. In your case, you would be no where near the limit of a 3.3 at 750 hp.

Save your money and use a 3.3 on a 540/547/555 ci setup. You will make all the power you want. If you build it right, with good parts that are assembled by someone that knows marine engines, you will have a bullet proof piece. Let me know if we can help.
Eddie

44MTI

Why would you even spend the money for a blower for that power level. You could easily make 750hp on a naturally aspirated pump gas, hydraulic roller motor that would live forever. Just a thought.

davva

Thanks for your reply guys.

Why im looking into quads is that i think it looks cool, and i cannot see any other benefits than that really, i understand that i will spin them real slow, but after looking at mercruiser who runs quads with as low as 850hp i thought it would work.. im always looked for stuff that anybody else dont usuly have, like all my street engines have had dry sump and electrical, waterpump,power steering etc. And i know you can make good power of a N/A engine my friend has a 578 with 780hp with a mild setup that idles like a dream at 700rpm but i want the blower for looks and i cant live without the sound. I have no problem spending a little more money to really get what i want.

What if i run even smaller blowers? like 2.1 whippels from like a Mbz AMG or something? still to big?. Im guessing im better off with just a single blower but the quads blow my mind hahaah. Reason i dont want to go bigger than 750hp is that i dont want to spend a fortune in outdrive and its a little short of space with a external gearbox.

Young performance: are you a engine builder? Can you send me a suggestion and qutoe with a reliable engine recepie for a blower engine?
I already have an Autronic that i was thinking of controlling the engine with so no need of electrics.
[email protected]

David

Black Baja

iTrader: (2)

David, just build your motor with the quad rotor, leave the blower belt off and run 87 octane. As far as the blower sound goes I'm sure you could find some recordings and play them through the stereo. There's your 750 hp with the quad blower look and blower sound. And if you get a bad tank of fuel you don't have to worry about being out another 20gs

Awash