M-3 ProCharger on 7.4 2-bolt main
 

I'm running a carburated 7.4 w/2-bolt and Lightning headers. Would an M3 procharger be too much, even at low boost?

I ran a 7.4 with lighting headers and a Procharger for three years at 9 pounds of boost.

The M3 is way overkill for the air demands of that engine, but boost is boost, for all practical purposes the engine does not know if it is an M1 or an M3 as long as the boost pressure is the same. You sure would not have to spin it fast.

2 bolt main should be fine as long as you don't spin high rpms.
Other great stuff will break first:cool:

Game, if you want a little added strength, you could put studs in the mains vs bolts. Studs have twice the holding power over bolts. However, if you do go to studs the mains saddles will most likely have to be align honed because of the different torque specs with the studs installed...this is a GOOD machining operation though because everything will be perfect---or at least as close to perfect as you can get it when spinning the crank. A good balance job would be a great idea as well.

Here is my take on this. Buy the M3, you will have to spin it slower to get same boost as M1. Advantages after you get past extra cost up front is

1-spining slower = less heat = motor lives longer.
2- When you build a bigger motor all you will have to do is buy a new pulley instead of a new procharger.

This is the theory I used in buying the M4 instead of the M3. Only time will tell if this goes under wise idea or another lesson learned.

I also subscribe to Jacks theory.

I also have a stage 4, single carb and a 4.5" pulley. I can only go another inch. no jokes please:p

DAVE:D

those are my thought in deciding which to get

Sorry for jumpin in here but, for you guys running carbed Procharges, I was woundering who set up your carbs and what the particulars were? Size, (cfm) jets, powervalves etc...?

Thanks in advance,

Bob

Bob

I have the stage 4 with twin holley 450's. factory stock. Motor has not been started yet so I do not know what is right. I was told to put 76 primary, stock PV, 88 secondary. I just got a email from friend who talked to some one who has a 622bbc with same setup with no PV, 63 primary, 84 secondary. Not sure of what carbs exactly. There has been much discussion on this & looks like nothing is the same.

I'm using a single Nickerson carb.
Holley 800
4 corner idle
8-9# of boost on a 502

I've picked Dean Nickerson's brain about a twin carb set up and he says he hasn't run into a situation to warrant the twin set up yet. He's dyno'd well over 900 hp. I think I'm around 875-900hp. I don't KNOW because I haven't dyno'd but I know how much hp it takes to push a Formula 242ls close to 95mph. My boat's a pig, but it rides decent.
Last year I was using a 4.75" pulley and saw black stuff on my transom. Using the 4.5" pulley this year should give me another pound maybe 2 of boost because I'm getting into the compressor's sweet spot a WOT.

He hasn't even given me bigger throttle plates yet and I'm still at 79/98's. Which means I have plenty of jet sizes to go.

I guess I'll find out.

DAVE

Turbojack, that was 63 with power valves in primary side, and 84 in secondaries no power valves. The carbs are 450 Holley's, done by Nickerson. He stated, no black transom and runs great low rpm, midrange, and top end. he was turning a 36 pitch prop 5800 rpm's with a 1.5 gear in a #6 drive.

Thanks for the response guys.
Hey Dave sounds like that Formula runs damn good! I've been thinking about going with the Prochargers on my carburated 502s but I've heard a lot of "bad press" on the carbed version. Glad you have proved them wrong! Looks like Nickerson is the way to go for a set-up.

Bob,

Pro Chargers are fine, if you know, or have someone who knows what they're doing. If not, there is a learning curve, and it costs money. Trust me...I know about the learning curve, cause I'm still learnin'.

In my opinion, Nickerson is definatley the way to go for any high performance set up where you need carb work done.

The blower subject has been discussed many, many times on this board. In my opinion, if you choose Pro Charger, Whipple, or a roots, you'll get the hp you're looking for, it just depends on what parameters you need to operate in. Those parameters will tell you which blower you'll be buying.

DAVE