Superchargers...Whipple 4.0 or 5.0 vs Roots 14-71
01-05-2012, 10:44 PM
#51
Ok, wasn't sure I was reading you right. And as far as me knowing something you didn't---hey, I'm still in the classroom with a learning curve on much of this blower and head stuff.
01-06-2012, 08:59 AM
#53
Btw, I remember back around 2001 or so, the 41' Apache WARHAWK had roots superchargers on his carbed 572's that made something like 850hp with open exhaust and I would watch him idle by on the St. Joseph River as he headed for Lake Michigan....and that thing had a very smooth crisp idle---I could hardly believe how smooth it was!
So, I asked his mechanics at the Marina if they knew what cams he had and one said they were Crane "741" hyd rollers...which I thought may have been a little too small for a 572cid and is probably why it idled so smoothly.
So, I asked his mechanics at the Marina if they knew what cams he had and one said they were Crane "741" hyd rollers...which I thought may have been a little too small for a 572cid and is probably why it idled so smoothly.
01-06-2012, 09:28 AM
#54
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Btw, I remember back around 2001 or so, the 41' Apache WARHAWK had roots superchargers on his carbed 572's that made something like 850hp with open exhaust and I would watch him idle by on the St. Joseph River as he headed for Lake Michigan....and that thing had a very smooth crisp idle---I could hardly believe how smooth it was!
So, I asked his mechanics at the Marina if they knew what cams he had and one said they were Crane "741" hyd rollers...which I thought may have been a little too small for a 572cid and is probably why it idled so smoothly.
So, I asked his mechanics at the Marina if they knew what cams he had and one said they were Crane "741" hyd rollers...which I thought may have been a little too small for a 572cid and is probably why it idled so smoothly.
Im definitley no cam guru Mark, but I suppose its all in how much power you want to make. If say your trying to make 1000+ out of your motors, you may want the best in heads, somewhat long duration cams, and turn some RPM.
If building something like a 800-850HP setup suits your needs, I'd think you can do it, and be conservative on your cam selection, and not need super expensive fancy cnc modded heads.
Take for example, merc's two old school blower engines.
The 800SC was a 572CI, low compression, iron headed flat tappet setup with no intercooler, 420 mega blower, gm heads. I do believe they did dyno under 800HP stock, but idled like the family station wagon, and lived a long long time if maintained. Ive heard guys going 400-500 hours on them before tearing down.
The 900SC, was a 540CI, Alum headed 10-71 mooneyham, intercooled, solid lifter cammed, twin dominator carbs, they werent so tame. Valvetrain intervals were 50 hours i believe.
I think your the kind of guy who would prefer something like a 800SC over a 900SC. With that being said, I'd run the heads you have, stay on the conservative side with the cam and compression, and run it. I would like to think with your setup, chilled 14-71s, moderate boost, if you dont make 850HP you probably left a plug wire or two off. Enjoy a nice idle, long valvetrain life, and a fatter wallet.
Dave W. did a set of engines for Brian with the 1990 Top gun. He did 598CI, Dart blocks, Dart heads (stock I believe), mild hyd roller setup, and weiand 256 blowers. Yes, 256!! No intercoolers. The blowers were brians choice, as he didnt want to run scoops or big hatches. I believe they did over 800HP/800Ft lbs, at 5600RPM, 3psi of boost. Those engines idle ALL DAY. I think they have been in the boat for about 4 years now, without a screwdriver taken to the carb since Dave tuned them when installed.
01-06-2012, 12:14 PM
#55
Dave W. did a set of engines for Brian with the 1990 Top gun. He did 598CI, Dart blocks, Dart heads (stock I believe), mild hyd roller setup, and weiand 256 blowers. Yes, 256!! No intercoolers. The blowers were brians choice, as he didnt want to run scoops or big hatches. I believe they did over 800HP/800Ft lbs, at 5600RPM, 3psi of boost. Those engines idle ALL DAY. I think they have been in the boat for about 4 years now, without a screwdriver taken to the carb since Dave tuned them when installed.
I'm going to try and get everything else I can out the engines, and exhaust system (Stellings headers) and heads....cnc'd ported AFR's. Concerning the cam, it will be easier to get a smoother idle out of a blower engine than a NA engine so, that should help.
Last edited by KAAMA; 01-06-2012 at 01:23 PM.
01-06-2012, 06:02 PM
#57
Platinum Member
Platinum Member
What he's saying is that port velocity isn't a driving factor in a blown PORT INJECTED application. That's because the fuel is sprayed at the back of the intake valve, and doesn't have any opportunity to fall out of suspension into a puddle of wet fuel in the plenum.
Even that can go out the window with big ports and too much overlap, cause you can still get reversion or standing waves in the intake which can pull some of the fuel "back out of the port" into the plenum if you're overly wild with cam selection.
MC
01-06-2012, 10:18 PM
#58
Registered
Btw, I remember back around 2001 or so, the 41' Apache WARHAWK had roots superchargers on his carbed 572's that made something like 850hp with open exhaust and I would watch him idle by on the St. Joseph River as he headed for Lake Michigan....and that thing had a very smooth crisp idle---I could hardly believe how smooth it was!
So, I asked his mechanics at the Marina if they knew what cams he had and one said they were Crane "741" hyd rollers...which I thought may have been a little too small for a 572cid and is probably why it idled so smoothly.
So, I asked his mechanics at the Marina if they knew what cams he had and one said they were Crane "741" hyd rollers...which I thought may have been a little too small for a 572cid and is probably why it idled so smoothly.
Sissy!!!
01-07-2012, 07:55 AM
#59
Registered
we are using solids,357's went to about 5600rpm,want the 385's to tickle 6000.have a new camshaft in mind that should get the job done.
01-07-2012, 08:33 AM
#60
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Hey Mark, I dont think you will be dissapointed in the carbed roots setup.
My buddy built a set of blower engines last year, 509CI, 238/248 112LSA cams, 8-71 mooneyhams, superchiller intercoolers. Engines dynoed about 800HP and 800FT lbs give or take a few. Idles good, no plug fouling or stalling around the dock.
I ran almost the same cam as him ,in my smaller 460CI engines, 250 blowers with single dominator. Intially i had them setup with 12* base timing, and a 18* advance. They would puke when put into gear cold. Locked them at 30*, much better. Idle all day, no fouled plugs, no stalling.
From what ive seen, if properly tuned setup, the supercharged setup seems to idle/start better than the same setup N/A. Fire up with a slight blip of the key.
Granted you'll have larger blowers, and larger carbs, but also larger engines.
My buddy built a set of blower engines last year, 509CI, 238/248 112LSA cams, 8-71 mooneyhams, superchiller intercoolers. Engines dynoed about 800HP and 800FT lbs give or take a few. Idles good, no plug fouling or stalling around the dock.
I ran almost the same cam as him ,in my smaller 460CI engines, 250 blowers with single dominator. Intially i had them setup with 12* base timing, and a 18* advance. They would puke when put into gear cold. Locked them at 30*, much better. Idle all day, no fouled plugs, no stalling.
From what ive seen, if properly tuned setup, the supercharged setup seems to idle/start better than the same setup N/A. Fire up with a slight blip of the key.
Granted you'll have larger blowers, and larger carbs, but also larger engines.
Bingo.....i ve been running root blowers for 12 years and with the right set up their will be no problems plus you can work on the enigine without having to bring it into the shop and letting them charge you out the ass to work on it....good luck
