CNC

Well over Labor Day weekend I dropped a valve and busted things (block,head,
etc) up real bad. The positive side is get to build up a new 540. I have been told my B&M 250 is to small for the 540, is the correct? Do I need to go to a 420? The builder is steering me toward Procharger M1?? Which one would be better? How is the reliability on the Procharger?

Thanks
Randy

Fountain38SC

I've got 545's. When I did my motors, the 250's wouldn't boost over 3.5lbs. That was with a smaller pully and really spinning the blowers. I went to 10-71's with chillers, problem solved.

VP

i built a 540 after my 468 broke -- i re-used the little Weiand 177 blower that was on the 468 -- when all said and done, the 540 produced a huge 700+ ft-lbs of torque at 4000 rpm, and 624 hp at 5400. I think the boost was about 4-1/4 psi at 4800 rpm, then dropped off a little as it went up in rpm --

the little blower produced huge bottom end torque instead of top end hp -- a real TRS drive breaker -- the 468 ran better too i think because when i reduced the pulley size to get the boost back up, i think i created way more fuel/air heat -- i actually ended up adding a second oil cooler to get rid of my high oil temps - high piston dome temps i think created high oil temps -- i installed a knock sensor, and an exhaust pyro, so i never melted anything - but the 177 was too little for the big cubes -- it works, but is not nearly the best for marine applications -- great stump pulling motor though

your 250 is a lot better, but i believe bigger yet is way better --- if you go with a big blower, you probably don't even need an intercooler -- the big blowers make big boost without spinning fast, thereby not generating all that intake heat from the friction created when spinning little guys so fast --

so GO BIG!

that my $.02 anyhow

Aggressor 25

I had the same question last year when building my 540. I had already purchased a B&M 250 and I knew it would fit under the hatch. I was planning on only putting 4lbs of boost since the engine was 9.0 to 1 compression. I ended up going with a M-4 Procharger and intercooler and selling the B&M 250. It fit under the hatch as well and was not at the limits for the cubic inches it was required to fill. I now run 5 lbs of boost safely. All said and done I could not be happier with the set up.

jpclear

This is not a blower question - but; just what is a 545? My 540 is 0.030" overbore and the math says that I'm now a 548. If the 545 mentioned was just a typo, then I'm sorry to intrude, otherwise, what IS that engine? --- JP

articfriends

iTrader: (1)

Buying a m-1 would be a mistake on a 540,you'd have to spin the hell out of it to make any real boost. The m-3 would be better and m-4 much better. The only thing i feel a roots style blower has over a centrifugal blower is the eye candy effect. People ask me why i didn't put a 6-71 OR 8-71 on my boat instead of the procharger and i tell them TECHNOLOGY,everyones seen these little 302 mustangs running 8's and 9's with superchargers,but they are always vortex and procharger not roots types.Either way,get the biggest supercharger you can so that you can make as much boost as possible without spinning it hard and adding heat,Smitty

mcollinstn

Get a new mechanic.
M1 is for a leetle motor.

Zanie

B&M/Holley 250 is just too small for anything above a 502 (in a marine app), too much heat.
B&M/Holley 420 has been discontinued and rotors are getting tough to find.
6/71 would probably do the job, but the cost diff erence to 8/71 or 10/71 isn't that great and you won't create as much heat.
Go big or Go home, right?
DS

tomcat

Something else that centrifugal superchargers allow you to do is get a big intercooler in the loop. Due to their placement and the size of the hole in the blower intake, you can only get about 200 in3 of intercooler core under a Roots blower. With the physically smaller centrifugal supercharger and its placement off the front of the cylinder head you have room for a much bigger intercooler. Since detonation is the true limit to power and intake air temperature is the main initiator of detonation, this is VERY IMPORTANT. This is how those little Mustangs make so much power.

Aggressor 25 has a very nice install and a 504 in3 intercooler. We package a 468 in3 intercooler into the same enclosure as the carb, eliminating all the pipes and elbows. This has been proven to add 85-100 HP without spinning the blower any faster. It's kind of like what porting does for a cylinder head. Less resistance to air flow = more HP.

This picture shows our supercooler "box" with a Vortech V-7 compressor, but it also fits Vortech V-4, and Procharger M-1, M-3 and M-4.

VP

roots blowers = eye candy