B&M vs Procharger for 540??
 

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

Re: B&M vs Procharger for 540??
 

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.

Re: B&M vs Procharger for 540??
 

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 :p

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! :eek:

that my $.02 anyhow :rolleyes:

Re: B&M vs Procharger for 540??
 

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.

Re: B&M vs Procharger for 540??
 

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

Re: B&M vs Procharger for 540??
 

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

Re: B&M vs Procharger for 540??
 

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

Re: B&M vs Procharger for 540??
 

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

Re: B&M vs Procharger for 540??
 

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.

Re: B&M vs Procharger for 540??
 

roots blowers = eye candy :p

Re: B&M vs Procharger for 540??
 

Tom,them carb enclosure's ARE BEAUTIFUL!Roots blowers are definately eye candy,i'd rather not advertise that my boat rips though,Smitty

Re: B&M vs Procharger for 540??
 

Not advertise?? Why, afraid of that pressure to back up the looks??? Tis better to have raced and lost, than to never have raced at all....

Re: B&M vs Procharger for 540??
 

Hang time,your right,i would rather race someone and lose than not race anyone. I also would rather race another boat that run's close to mine than punks in a 65 mph boat that claim it goes 85(that used to be fun though but it gets boring),Smitty

Re: B&M vs Procharger for 540??
 

How much power are you looking for? With 540 ci, 700 reliable hp is obtainable without boost.

Re: B&M vs Procharger for 540??
 

A-men brother........................

Re: B&M vs Procharger for 540??
 

"How much power are you looking for? With 540 ci, 700 reliable hp is obtainable without boost."

Sure, but doesn't that mean over 700" lift and new valvesprings every summer at the least??..... I can see where boosting gets you a longer life on your valve train components - motor thinks it's mild until you crack into that boost.

Re: B&M vs Procharger for 540??
 

Build 650 HP with a naturally aspirated 540 using JimV's heads; valvetrain life is not an issue @ 5500 RPM. Add blower later for 1000 HP! :D

Building a good base engine for supercharging later requires some thought about cam and compression. If you use a moderate hydraulic roller cam and keep compression below 9:1, you can add a centrifugal blower later with no changes to the base engine. If you wanted to add a Roots blower later that compression would be too high.

If you wanted to add a Whipple later, you might pick a cam with more duration to kill cylinder pressure a bit due to their potential for high boost at low RPM. Dustin once gave me the specs for a cam he recommended for use with the Whipplecharger on a 454. The duration was in the 250 range @ 0.050". At first that sounds like way too much, but apparently it works with the screw compressor and maybe with other positive displacement blowers since they make boost quickly. It lowers cylinder pressure and avoids detonation in the midrange, then helps the engine to breathe at higher RPM.

The approach with a centrifugal blower is completely opposite. You want the engine to make as much low RPM torque as possible on its own, but you don't need to worry about the cam running out of steam at high RPM because that's where the centrifugal blowers outperform everything else. Lower discharge air temperatures for the centrifugal and the use of intercoolers which are much larger than can fit under a Roots or Whipple keep you out of detonation longer, which ultimately means more power with a given compression ratio/cylinder pressure.

Re: B&M vs Procharger for 540??
 

No way, .647 lift hydraulic roller cam. 300 hours + no valve train issues.

My new combination nets .706 lift H/roller, still testing for durability. No problems to date. I'm going faster now than when I had my blower at 850 hp. (avatar). I will admit the blower was faster accellerating but I havent blowed up the drive......yet.

Re: B&M vs Procharger for 540??
 

When it comes to blowers, bigger isn't always better. Every blower has an efficiency map plotted with air mass against boost pressure. On those plots are what are called efficiency islands, showing blower efficiency for various operating points. Also on the map are blower RPM curves. If you look at the efficiency maps, you'll see that putting an over-sized blower running at slow speed can end up running the blower in an area of reduced efficiency, resulting in higher drive horsepower to get the same amount of boost, and higher blower outlet temperatures. With a roots blower this is caused by leakage being too high as a percentage of actual flow. With a centrifugal blower, the aerodynamics are a bit more complicated, and can result in compressor surge.

Some manufacturers are reluctant to publish compressor maps, probably because their blowers are not particularly efficient. I would consider it a necessity for proper sizing, and you can often coax the maps out of them with some persistence. I would pass on anyone who refuses (but that's me - I like to know what I'm buying).

Michael

Re: B&M vs Procharger for 540??
 

Does that hold true with a teflon striped rotor?

Re: B&M vs Procharger for 540??
 

Hey Jim....
As you can see I still am trying to decide on motor combos....
Since I am basically starting from scratch I want to do it right. If you remember
I spoke with you on the 4th of July in Pentwater Mi. You can never ask to many
questions.....

Thanks
Randy

Re: B&M vs Procharger for 540??
 

This is very interesting , I too am in the same "boat". New 540-572,, boost or no boost. I 've learned alot from this thread,,,carry on. I already own a pair of 250 b-m's but looks like they should be for sale. Thank for the info. gene

Re: B&M vs Procharger for 540??
 

Dont get me wrong, the blower was great but I couldn't keep a bravo drive on it. With a 540 with a blower I was making over 950 hp and over 100mph. It got to the point where I couldn't trust the drive on long crusies after I beat on it the weekend before. I used to go thru three drives a season with the blower.


Randy, I thought you'd be boating by now.

Re: B&M vs Procharger for 540??
 

Sounds like a good group to ask this question to. I'm currently runing an M-2 procharger on a 468 chevy, stock heads, solid cam, emi's, making 7 lbs boost.

The 468 is getting swapped out with a 540, 8.2:1 compression, dart 320 heads., crane 741 cam. Anybody got a guess as to how much boost the 540 will make using the same procharger components that were on the 468.

Re: B&M vs Procharger for 540??
 

Scarab28, I'll guess that you drop the percentage amount that you increased in displacement?? But then that would be a guess.......

jimV,

Just checked out your website. Looks like you do create a little magic with that headwork.... on the one example you're "worked" heads only need .400 lift to get the same flow the stock head is getting at .700 ......sweet. No wonder that .650 lift number works so well.......... Is that example with aluminum darts??

I'm in the process of dropping that "little" red blower (in pic by "chambers" above) off my 540 to loose the heat and save my TRS drive. When I do resolve my drive issue this winter, what do you think your heads would do for me if dropped them on my current 8.9:1 compression(merlin315's), crane 741 cam, and dart intake?? I'm saddled with gil exhaust though.................sell me.....

Re: B&M vs Procharger for 540??
 

Jim,

The teflon will allow tighter clearances without scoring, which helps efficiency, but the same treatment can be done with smaller blowers, which could result in even higher efficiency. I say "could", because you really don't know without the compressor maps.

Now let's say you don't have compressor maps, but you do have all the blowers and a dyno available for testing. You're in luck. With a bit of work, you can rough out your own compressor maps. Just measure the blower outlet charge temperature, before the intercooler if there is one. Install blower 2, set the pulley ratio for the same boost at the same engine RPM, as blower 1 (may take some experimentation). Measure the blower outlet charge temperature on blower 2. The one with the lower charge temperature is the more efficient at that engine air flow rate and boost. You'll want to repeat these tests at various engine speeds. Higher charge temperatures are indicative of engine work going to heating air, rather than compressing it.

Hope this helps.

Michael

Re: B&M vs Procharger for 540??
 

The pressure ratio (boost) for centrifugal blowers is based on rotational speed. Therefore, if you use the same pulley system on the new engine, you should have approximately the same boost (may have some additional losses through the plumbing).

There is one potential problem, though. If the blower is undersized, you will end up running it is an area of low efficiency. This will result in more engine power going to drive the blower, and higher blower outlet temperatures. In the extreme case, you could end up in a compressor choke condition, which with the loss of boost, very low efficiency, and high outlet temperatures, would make the blower unusable.

Michael

Re: B&M vs Procharger for 540??
 

scarab28:

We had a customer do something very similar. Went from a 454 with stock heads and mild hydraulic roller cam to 502 with Merlin heads and more cam. Using the same pulley and RPM as before, his M1 went from 6.5 psi boost to 4.5 psi.

What you have to remember is that boost is just a measure of how restrictive your heads and cam are. Less restriction, less boost, but at the same blower RPM, the lower overall restriction to air flow allows the blower to use more of its energy for moving air as opposed to fighting restriction. So when you improve heads and cam, air flow goes up, even though your boost gauge goes down.

Now what's really going to blow your mind is what happened when we changed out his procharger intercooler for one of our supercoolers. With no other changes, including blower pulley size, boost jumped from 4.5 to 7.5 psi and the boat picked up 8.5 mph.

We have measured the restriction in the procharger intercooler, carb box and plumbing to be about 4 psi. There's only 1 psi lost going through the supercooler, so the blower has much more energy left over to move air. This extra air, however, is trying to get through the same heads and cam restriction as before so intake manifold boost has to go up. So when you improve air flow through the intercooler ahead of the intake manifold, airflow and HP go up at the same time as manifold boost goes up.

Re: B&M vs Procharger for 540??
 

Scarab28,

If I am reading these numbers correctly (gained 3 psi with your Supercooler, and Supercooler has 1 psi, total Procharger loss 4 psi), then almost all the restriction is in the Procharger interercooler (4 psi). That's a HUGE amount of loss in the Procharger cooler - half your boost!!!

What kind of intercooler inlet and outlet air temperatures did you see with the Procharger and Supercooler intercoolers in your tests?

Michael

Re: B&M vs Procharger for 540??
 

I installed a Procharger M3 on my brothers 28 Warlock SXT( with a stock HP500). Installation instructions were terrible, and tech help was almost non-existant.Once I threw the book away, I finished the installation, while fabricating some hardware, without too much trouble. Once the boat was up and running (and properly jetted) it was a different story. The Prochager flat out runs. It idles just like a stocker, and runs like a bear. Just ran 103 MPH (GPS) I have Installed several other B&M roots types, but although they made good power, the Idle quality was always a pain. Its no fun docking with a motor that wants to die! Good luck with your project.

Re: B&M vs Procharger for 540??
 

Michael1:

It is a huge loss, and it is very typical for a remotely mounted intercooler. But the restriction of the core is only a small part of the loss; the problem is all the elbows and abrupt changes in cross-sectional area.

Pretend for a moment that there is no blower. Do you think a big V-8 is going to be happy sucking it's air through 3" diameter twisted hose? At WOT the air velocity in that hose is 100+ mph. Do you think that air wants to make a turn? And yet that is exactly the plumbing supposedly needed to hook up a centrifugal supercharger and intercooler and carb box. Overall, when you add the blower, HP goes way up, but it is a case of 2 steps backward, then 3 forward.

The supercooler has no elbows, all turns are made at high cross-sectional area to reduce air velocity. This is a very powerful technique because resistance or pressure loss, whatever you want to call it, is proportional to air velocity squared. You can't eliminate all losses, but if you just take 1 step backwards and 3 steps forward you're much better off. People don't think about this because all attention is focused on manifold boost, not compressor discharge pressure.

To answer your other question; we measured compressor discharge temperature and temperature before the carb in this test (Family & Performance Boating, March 2004). The Procharger dropped temperature from 214F to 115F. The Supercooler dropped it to 90F, at the same time as an additional 100 HP of air flow was being handled (8.5mph X 12 HP/mph). The only way the Procharger would be able to deliver this much additional air is by spinning the blower much faster, which means a lot more heat. You probably would not achieve the HP before detonation called the party off.

"Pressure" and "pressure loss" both have the same units (psi) but they are different things. These numbers from our first dyno testing (F&PB, May 2003) show that loss is a calculation, the difference between two measurement points.

Procharger: Discharge Pressure 12 psi - Boost 7 psi = 5 psi loss
Supercooler: Discharge Pressure 11 psi - Boost 9 psi = 2 psi loss

These pressure loss measurements include the carb, which accounts for an unavoidable loss of about 1 psi, so the procharger intercooler setup loses 4 psi, the supercooler only loses 1 psi, and it does this at a higher flowrate, so it's actually even better.

The increase in air flow and HP comes from the decrease in overall system resistance, from 12psi to 11 psi. Since blower speed has not changed you can plot these points on a compressor map and read off the x-axis how much more flow is delivered. Since the heads and cam were not changed, this extra flow causes a higher manifold pressure (boost). You can estimate the power increase by taking the square root of the pressure increase.

square root of (9/7) = 1.134, or +13%

Sure enough, when we did this dyno test, engine HP increased from 650 to 740, just a bit over 13%. And air temperatures dropped at the same time. Not enough to make much difference in HP, but a significant change for preventing detonation, the true limit to power.

Re: B&M vs Procharger for 540??
 

Candy... gooooood

Re: B&M vs Procharger for 540??
 

When I read this thread this morning I was going to respond but I figured Tom would do a way better job at it then I.

"Procharger: Discharge Pressure 12 psi - Boost 7 psi = 5 psi loss
Supercooler: Discharge Pressure 11 psi - Boost 9 psi = 2 psi loss "

Tom, is the reason the supercooler has 11 psi is because it has less restriction getting air thru it?

Tom, some bench racing
In my setup are we going to see the boost go up 3psi? from 11 to 14?? & my air temp come down? If so then when I put a bigger pulley on to bring the boost back down to 11 psi will my air temp go down still further?

FYI, we are talking about a 540bbc M4 procharger with EFI & 2000cfm throttle body with existing 504 procharger intercooler compared to the suppercooler.

Re: B&M vs Procharger for 540??
 

Jack: Discharge pressure, which is the same thing as the total resistance of the air pathway, drops to 11 psi because the supercooler is less restrictive. This allows the blower to move more air automatically. Discharge pressure would be more like 9 psi if we changed pulleys to keep manifold boost at 7 psi in both cases.

You are definitely going to add boost with the supercooler, but not 3 psi because your existing setup is not as bad as the Procharger setup tested (less elbows, bigger hose). I would recommend putting the larger pulley on first so that you don't go too far. Your temperature will drop due to the lower discharge pressure from both the supercooler and the pulley change. Better air distribution across the supercooler core will help too.

When I look at your temperature log I also wonder if you have adequate water flow. How do you pick up water for the intercooler now, and have you ever back flushed it? If there is a problem here we need to address it before any back to back testing, to keep things valid.

Re: B&M vs Procharger for 540??
 

Tom,

Thank you for posting this test data. Great to see some numbers!!! Very informative and interesting! It looks like you really did your homework developing the Supercooler. Nice to see some good engineering, too.

I haven't quite figured out your equation for the horsepower increase. It seems like if your starting boost pressure were nearing zero (unboosted), then the horsepower increase would go to infinitity.

Anyway, here's the formula I use:

% increase = (P2/P1) x (T1/T2)

P1, P2 absolute pressure = 14.7 + boost
T1, T2 absolute temperature = 460 + degrees Fahrenheit = degrees Rankine

With your numbers:

% increase = (14.7+9)/(14.7+7) x (460+110)/(460+90) = 13.2%

Estimated power = 650 starting hp x 1.132 = 736 hp, also fairly close to the 740 you measured.

Of course, these calculations do not take into account blower drive horsepower requirements, so it's just an estimate.

Cheers,

Michael

Re: B&M vs Procharger for 540??
 

For quick and dirty predictions of HP that might be achieved with higher boost levels, you can use the square root of the boost increase to estimate the new flow rate through the head. This ignores changes in density and is only good when the change in boost is relatively small. It's kind of a bad habit of mine to find the edges of a problem with simple formulas.

Calculating the density ratio based on before and after measurements is the better way of estimating the new HP. Since blower RPM hasn't changed, drive HP won't change much.

Real numbers and real world experience are what the tech section is all about! You can look forward to some good bench racing here as guys develop their winter projects.