This is the "logic" I use in assigning "ownership" of a part...

Regardless of what facility casts/forges/or fabs a particular piece, if the part is built to a customer design and to an exclusive SPEC than that part "belongs" to the entity who "ordered it". At least in the case of outdrive castings, if they are MERC spec and are not made available to any other, then they are MERC castings. Just done outside. Still Merc castings.

On the other hand, stuff like Dart intakes with bronze liners and a Merc emblem are NOT merc parts. Gil manifolds with Merc cast into the sides are NOT merc parts. A Weiand blower housing with a Merc emblem on the side of it is NOT a merc part. Even those H-beam rods with Merc on the beams aren't Merc parts (they are somebody else's rods with a "private label" sort of character mark on them).

Dam...

I got fooled.

I thought MC was back.

My preference is for roots type as they are "displacement" compressors. You get a fixed volume of air/fuel for every revolution, regardless if its 500 or 5000 RPM. Very predictable and the efficiency increases only slightly as you get up in RPM's (80% adiabatic max). You feel the torque throughout the entire range.
I haven't owned centrifugal units, but they are basically belt driven turbo's.
I was under the impression that cent. blowers were more efficient at higher RPM's but suffered from boost lag, and the boost pressure went up exponentially as RPM's increased. Not a good thing if you are constantly leaving the water and going from 5 to 10#. I know waste gates control the psi, but still a scary proposition for my taste.
Besides, twin blowers through dominators at 5500 RPM sounds like a 747 is chasin’ ya.

So while we are talking about blower efficiency, i heard from a very good source that on a top alcohol funny car, a 1471 takes about 1000hp to spin and a PSI only takes 300hp or so. Just a random fact to throw out.

screw superchargers like the psi work so well the nhra limited the amout pat austin could overdrive his screw supercharger and the roots guys could over drive thiers as much as they wanted. they did it to level the playing feild cuz austin was kickin everybody azz in alcohol funny car

Nobody..........

AND don't say Whipple because they can't and will not have anything for LONG LONG time....so its LIKE they are out of business

the only reason an engine builder would remove a whipple to use a roots, is to save a drive from too much power. care to name the many top engine builders??? i love the way roots look & how simple they are, but if you want to make big power it's whipple or procharger.

ttt

I hate to chime in an old thread, but seriously folks... it's either turbo or whipple...adiabatic wise, they are very similar, other than the lag factor. The controlling factor is cylinder pressure and octane. Keep in mind that octane requirements increase based on time and heat.

how do psi's stack up???