mega blowers
 

does anybody have any experience with these blowers?pros/cons.i dont know anybody who has used them.they all use littlefield or BDS blowers.i am asking because i may have found some pretty reasonable with carbs and intercoolers. thanks

i they are 2 lobe like the 174 is, they aren't as efficient as the 3 lobe ones liek eth BDS or littlefield

Puder, in theory yes but we made the same power with them as a 6-71 BDS in back to back testing (at the same boost). Also found the fuel distribution to be better.

MEGA BLOWER
 

I AGREE PUDER THE TWO LOBE ROTOR IS EXCLENT IN A BOAT OR CAR AS IT DOES NOT TEND TO CHOP UP THE INTAKE CHARGE AS MUCH AN DOES SEEM TO MAKE ITS POWER AT A LOWER R P M ON THE DYNO WE FEEL LIKE ITS DUE TO MOVEING SO MUCH AIR AND FUEL IN TWO STROKES (ROUGH TERM) COMPARED TO THREE ALL IN ALL THERE GREAT :D :D

What about a larger motor install. Say a 540 or 572 and compared to a 871 or 1071 as to a 420 mega blower? Low boost say 6 to 8 lbs.

I pulled 1000 hp @ 6000 RPM out of my 557's, big roller cam, good heads, intercoooled, etc. I also built some 588's that made about 870 on 89 octane, hydrauilc flat tappet. No question that we were running out of blower on the 588's, but we reached the target HP. Used 1471's on some 653's. We did some back to back tests on them starting with 871's, but I cannot remember the numbers. It has been a number of years since I did any engines.

[QUOTE]Originally posted by Mbam
[B]I pulled 1000 hp @ 6000 RPM out of my 557's, big roller cam, good heads, intercoooled, etc. I also built some 588's that made about 870 on 89 octane, hydrauilc flat tappet.

Marc with todays gas I have thought about how much HP reliably could be built with a 540 or 572 with 89 or 87 octane. I am sure there is more to it than just lower boost. Care to share any secrets? :D

What do you consider a reasonable lifespan? The 557's would run on 89 octane, and were running fine at 40 hours when I pulled them apart - but I changed lifters every 50 hours and checked and set as needed the valve lash every 5 hours or so. The 653's made almost 1200HP on 89 octane, but broke a spring and dropped a valve at 50 hours. The one that would go the distance was the 588, that was a 0 maintainance package.

There is more to cooling than just dumping cold water in the front of the block, and more to the oil system than just a big pan. Once those are figured out the limitation is the valve train. I have not seen any magic bullets there yet. I still seem to be stuck at a 50 hour lifespan for the big HP (1000 +) roller tappet stuff. It might change as I have a few ideas kicking around, but it will be a while at the pace I am moving.

I,VE USED THE 420 ON 540'S A TON WITH GREAT SUCESS AT 8LBS
THE 572 STARTED TO GET UNHAPPY AT 6 LBS DUE TO HEAT SO I LIKE 540'S AND 557'S WITH THE MEGA BLOWER

USE SOME GOOD ALUM.HEADS WITH MIDDLE OF THE ROAD COMPRESSION AND GOOD CAM 114 LOBE CENTER AND THIS REALLY HELPS WITH PUMP GAS
PM ME WITH WHAT YOU WANT TO WORK WITH INCHS,ECT AND I'LL GIVE YOU ALL THE HELP I CAN ,,AFTER 30 YEARS I'VE MADE ALOT OF MISTAKES AND LEARNED ALITTLE

:D :D :D :D

Mbam, The 588 with reliability is what I am looking for. Looking for 800hp range. I here you on the cooling and oiling!

Bobby I will PM you.

Hey Marc,

Would you mind extrapolating a little on the cooling and oiling, if it isn't a trade secret??

Bobby, I was wondering if you could help me out here a little. I do NOT have blowers, rather my engines are naturally aspirated 540's (short decks) with Dart aluminum 310cc PRO-1 fully ported heads, Dart single plane intakes, stock Holley mech secondary 950HP carbs w/4-corner idling, Stellings tubular headers, MSD crank trigger system, Crane marine grade iginition boxes, Crower hydraulic roller cams 236*/244* on 114* lobes degreed in at 108*, 9.7 comp ratio, 32* of timing/full advance.

The engines were dyno'd.

I usually cruise at @3500rpm. The fuel burn rate per hour is 148lbs and BSFC is only 0.41 with EGT's @1350*

At 5500rpm the fuel burn rate per hour is 146lbs and BSFC is 0.39 and yet EGT's are roughly about 1350*

The BSFC numbers seem quite low and yet the EGT's say that I'm okay---I don't get it! The carbs came stock with #78 size jets on all four corners and that's what we used during the dyno tests and we didn't change them. And yet, when I put the engines in the boat and ran it on Lake Michigan in 45* air temps, 160* theromostats. And yet I still get BLACK TRANSOM which indicates a RICH condition. My question is: WHAT THE HECK IS GOING ON HERE? Do I still need to drop the jet sizes? Am I missing something? I just don't get it!

Thanks in advance
Mark/KAAMA

BTW Bobby, that's using 93 octane fuel from Amaco.

Kaama,

We have the same engine, other than the heads. Same cam but 112 ls on mine. I run 4" EMI Thunder w/ ss risers. I believe these are severely hurting performance for this size cu. in. Did you dyno yours and what were the results?
What results do you get in the boat and RPMs

My set up
540 cu in (w/ 6.135 Forged rod)
9.5:1 CR
236/244 cam 112 ls 108center
GM iron rect heads (ported polished bowl blend gasket matched 2.25 intakes 1.88 exhuasts, intakes unshrouded)
Dart single plane (polished, ported, gasket matched)
950HP Holley
EMI 4" exhaust

Not running how I believe it should

Razor1115,

My 540's make about 682hp @5500rpm. Heads have 2.30" intakes valves and 1.88" exhausts.

Depending on what boat you have, the results are going to vary. My boat is 32' Active Thunder. I am turning the engines up to 5700rpm with 30" Bravo One props. I do have a set of labbed 32's to bring the rpms down.

You didn't say whether your cams are hydraulic rollers or not. Rough guessing, I would say you should be right around the 590-620hp level. A friend of mine is running about the same set up as you with the cast iron World Products heads with some pocket porting, Crane hydraulic roller 236*/244* on 112* lobes, 9.0 comp ratio and his was dyno'd at 595hp each. He runs his in a 35' Cig with Stainless Marine exhaust manifolds with dry 4" pipes going all the way out/through the transom and it runs something like 70-71 on the GPS. Hope that has helped a little.

That helps a lot. I'm in a 24 Outlaw running 75mph. Cam is roller hydraulic. You're right on the number: Makes 585-600 hp on dyno at 5500. Problem is, can't get over 5200 in the boat. Thinking I may actually try a SMALLER prop??? Running same prop as 460 hp motor that came out, though.....Also used Dyno headers, my EMI's are probably pretty restrictive

Thanks,
Zack

HI KAAMA! HOPE THIS HELPS. FIRST, HAVE YOU DONE A PLUG CHECK? WE DO ONE WITH NEW CHAMPION PLUGS BECAUSE THEY ARE EASIER FOR ME TO READ. RECOMMEND ONE CHECK AFTER A FEW MINUITS CRUISE WITH A NEW PLUG. TRY ANOTHER AFTER A FULL RUN-NO IDLING!
YOU CAN HAVE MANY PROBLEMS WITH THE CARBS, POSSIBLY AIR BLEEDS NOT SIZED CORRECTLY, INTERNAL LEAKS, ETC. THAT COULD CAUSE THESE PROBLEMS.
THE TEMPS YOU QUOTED ARE HIGHER THAN WE LIKE TO SEE IN A BOAT THEREFORE I WOULD NOT TRY ANYTHING LEANER-YOU COULD HAVE A DISASTER!!!
IF YOU ARE LEAN, AS I SUSPECT, TRY 3 SIZES BIGGER JET. THE WORST IT WILL DO IS SLOW DOWN FOR ONE PASS, IF YOU LEAN IT ANY MORE AND IT IS ALREADY LEAN, YOUV'E GOT A SERIOUS PROBLEM.
ALSO CHECK THE IGNITION SYSTEM. (((CRANES ARE KNOWN FOR WEAK SPARK AT TIMES))) TIMING NOT REALLY CORRECT, MISSFIRE FOR ANY REASON FROM PLUGS, WIRES, CAP, ROTOR, BOX, COIL OR ANY OTHER PART CAN CAUSE BLACKENED TRANSOMS AND WEIRD THINGS TO HAPPEN. A WEAK COIL WILL CAUSE ALL THESE. ALSO, HOW DID YOU GET BSFC IN THE BOAT????:D :D
ALSO AND E-TYPE COIL WORKS GREAT WITH YOUR SET UP WHICH BY THE WAY LOOKS `LIKE ONE MEAN BULLET

Bobby, if I said that I got a BSFC in the boat then that is not correct. We got it off the dyno. The coils are Crane PS92 coils and the carbs are new----everything is pretty much new although I know that doesn't always mean much. We'll be doing a plug check in the spring. I just got the boat running about a month ago and it's cold here now. There is still raw fuel on the transom. I guess the plug check is our next step. Thanks Bobby

Mark, what kind of fuel pressure are you running? I have found anything over 5 lbs will dump fuel when you come off a wave. Brad, I am too poor a typist to go into it here. I have no plans to be in the engine bussiness, so I will think about putting some of it up on my site.

Fuel pressure...
 

Marc, I'm using Edlebrock mechanical fuel pumps with Holley fuel pressure regulators. The Edlebrock pumps have 6 valves internally and I went with them because the Holley mech fuel pumps weren't keeping up with the fuel demand real well---the Holley's have only 4 valves internally. I have mechanical fuel pressure gauges at the helm so we're running at about 7psi at idle and about 6.5psi or so at WOT. Since I have gotten my boat running again, I have only been testing it in CALM water so I'm doubting it is dumping fuel, but it's still something to watch for. Sounds like pehaps I should adjust them down a little eh?---or at least be more aware of. Thanks for the tip Marc! :)

MARC ,BRING IT DOWN SOUTH AND STAY HERE A WEEK-END AND WE CAN DIAL IT IN ,ITS MOST LIKLY THE AIR BLEEDS ,WE'VE HAD 3 CARBS LATLY NEW THAT THE AIR BLEED CIRCUITS HAD METAL ,BLOCKING THEM ,,
THE COIL IS A GOOD ONE JUST BE SURE ITS WORKING RIGHT CHECK THE COLOR OF THE SPARK AT THE DIST.
LET ME KNOW IF YOU TRY ANYTHING ,ITS AND AWSOME MOTOR
YOU DID IT RIGHT
:D :D

Re: Fuel pressure...
 

KAAMA/ Mark
Where are your EGT probes - in the header about 3 inches from the head flange or drilled into the head like mine are. If they are drilled into the head like mine than they may be seeing some flame because they are TOO close to the port. I run my engines at 1350 to 1375* constantly and have seen 1425* on short runs. My plugs still show as proper mixture.

Re: Fuel pressure...
 

[QUOTE]Originally posted by KAAMA
Marc, I'm using Edlebrock mechanical fuel pumps with Holley fuel pressure regulators. The Edlebrock pumps have 6 valves internally and I went with them because the Holley mech fuel pumps weren't keeping up with the fuel demand real well---the Holley's have only 4 valves internally. I have mechanical fuel pressure gauges at the helm so we're running at about 7psi at idle and about 6.5psi or so at WOT. Since I have gotten my boat running again, I have only been testing it in CALM water so I'm doubting it is dumping fuel, but it's still something to watch for. Sounds like pehaps I should adjust them down a little eh?---or at least be more aware of. Thanks for the tip Marc! :) [/QUOTE

WATCH THE HOLLEY PRESSURE REG. MOST ONLY HAVE A 135 THO
HOLE FOR FUEL FLOW THATS VERY SMALL THE MALLORY OR BARRY GRANT ARE 1/4 INCH OR LARGER AND SOME PROVIDE A PORT FOR RETURN TO THE TANK SO THE PUMP DOES NOT SIT THERE AND DEAD HEAD AND HEAT THE FUEL IT JUST CIRCULATES AND STAYS COOL ] :D :D :D :D

Kaama, I have a very similar setup to you but a milder cam and 9.4:1 compression. I have Cutler MPI system on it. When I dyno'd it, I used that 950HP carb to base line it before switching to the EFI. Using the 78 jets that it came with, it was so lean it wouldn't even rev past 4800 RPM. We ended up with 82's in it before it was close and even then it was too lean to run in a boat. Be careful, you may be extremely lean!

Bob

bobl,

Mine run up to 5700rpm on the dyno, with #78 jets on all four corners with no detonation or any other problems that we could see.

Again, I don't know how I could have a lean condition if I have signs of raw fuel on my transom (black transom). This is a tough one until we get some plug readings. Thanks bobl

OOPS you guys! I actually posted the wrong fuel burn rate per hour on Post #12 of this thread---dang! No wonder everyone thinks I'm running too lean.

Okay here's the correct numbers:

3500rpm (cruise) fuel burn rate is 148 lbs per hour

5500rpm fuel burn rate is 248 lbs per hour (I originally said 146 lbs per hour)

SORRY! :o

mbam / b daniels
 

Any info on valve bounce or reverse flow on aspirated motors, any info would be appreciated. repeat any info

Bobby, thanks for the tip on the fuel pressure regulators, etc.

Mark

NO PROBLEM MARK BRING YOU BOAT AND HEAD SOUTH WITH SOME FRIENDS AND WE'LL DIAL IT IN ,LET ME KNOW ON THE HEADS ALSO BLOCKS ECT

KAAMA, have you gotten your cranking pressures yet? I only ask because the 1350 exhaust temps with a possible rich condition could be a result of a very high dynamic compression. Another thing you should do is put a vacuum gage on one of the motors and see where it is when you are running. Short cams in large motors with efficient heads can cause a stiuation where the vacuum starts to rise substantially especially at high RPM. Your carb could be set rich in the mid range RPM due to the power valves dumping fuel and at high RPM the power valves may be pulling shut causing a lean condition, hence the higher EGT,s. I may be way off but I am just trying to give you some things to try. My Nickerson 1050 has 92's in all four corners and 4.5 power valves on the pri and sec. Seems like it should be way rich for a 496, but my transom is as clean as it was when I launched the boat after a day of hard runnin. Also I have heard of motors with a lot fo vacuum not seeing much of a difference when the jets are changed. Basically a carb is made to run properly at a certain vacuum level and if you are above where it is calibrated to run a lot more fuel will be pulled through the main jets. In this case the air bleeds need to be adjusted. Then the motor will lean out, but you may be in danger of detonation because cyl pressures will further rise. Talk to ya later. Just keep an eye on the plugs and you will be OK.
;) Keep up the bench racing. Winter is just starting.:(

Wette Vette...
 

Craig, thanks for your help again. I will give it a go in the spring. You have been an asset to this forum.

Bobby, I wouldn't mind bringing my boat down to your shop to help me solve this problem, but I am first going to try and solve it close to home. If I can't, then I may tow the boat down to your shop. BTW, with my parts combination what brand of spark plugs do you usually like to run? Thanks

KAAMA,
What exhaust are you running? I have had a sooty transom, yet was still running lean. I was informed on big inch engines, if you run exhaust that is too small, the engine doesn't like the restriction. Too much back pressure to exhaust gases, causes black transom and loading up like an overly rich condition, when in fact it is actually too lean. Just some more input...

Zack:)

Razor, That is a good question. The tailpipes on my boat stick out about 6-7 inches from the transom. I am running with Stellings full length tubular dry stack "green" headers with 4.5"dia. tailpipes. I don't even have any mufflers. If anything, I probably don't have ENOUGH back pressure---if you can actually believe that! About a year or so ago, I personally spoke with Keith Eickert about his full length primary runner headers that are in "manifold" form that he currently sells. In our conversation he told me that the manifolds come with a 4"...NOT a 4.5"......but again a 4" tailpipe. I asked him; why not a 4.5" tailpipe? His response was; his exhaust system with a 4" tailpipe is adequate enough up to 900HP! Hmmmph,------who was I to argue with him? Therefore, I highly highly doubt that back pressure is my problem. Pretty interesting though eh? :)

Bobby Daniels,

What is the name of your business? Can you please post your business (or whatever) phone number that we might be able to get ahold of you please?

Thanks,
Mark/KAAMA