You guys can't be serious! A 40 - 45 MPH boat is NOT fast, a 60 - 80 MPH boat is fast....
A boat built to go 60-80mph would not be scary. A 17,000# floating mobile home that goes 50mph is scary. Get it?
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You guys can't be serious! A 40 - 45 MPH boat is NOT fast, a 60 - 80 MPH boat is fast....
Horizon's are fresh water cooled and can be on a stern drive. I have them on mine. Mercury now calls them "Seacore"
A boat built to go 60-80mph would not be scary. A 17,000# floating mobile home that goes 50mph is scary. Get it?
Anyone know what makes a Magnum a Magnum?
Here are the differences:
Regular 350: 350 Magnum:
Cast iron pistons Steel pistons
Cast iron crank Steel crank
Regular intake manifold High rise intake manifold
260 HP 270 HP
Anyone know what makes a Magnum a Magnum?
Your question was answered a few times.So, nobody really knows. If a 496 Magnum is high output at 375 HP, then there is the 496 Magnum HO with 425 HP. Would that be a 496 Mag Mag? Then shouldn't there be a plane old 496 with 325 HP?
So, when someone askes me what a 496 Mag is when they see the cool black covers on my engines and hears that start-up baritone music, I'm going to say it is a high output version with 50 extra HP per engine.
i wonder what the differences are between the Horizon's and Seacore?No, you can have fresh water cooled stern drives that are not Sea Core engines/BIIIs. They do not call all fresh water cooled stern drives Sea Cores. Sea Core is an upgrade.
Seacore is a Merc upgraded corrosion protection package.i wonder what the differences are between the Horizon's and Seacore?
i wonder what the differences are between the Horizon's and Seacore?
Your question was answered a few times.
Now days, A New Mag engine really means nothing.
A base GM 8.1 marine engine is 375 HP. Thats about as detuned as they come. It would not have been cost effective for MFG's to change cams, etc to have HP in the 320HP range like the base 454ci. The 8.1 is a replacement engine for the 454ci and 502ci.
HO is the higher HP engine now days.
The 8.1 HO has a different cam and fueling calibration to get the extra HP over the basic Mag engine. The max TQ is the same on both engines. The HO models max HP/TQ is at a higher RPM then a Mag engine.
The 8.1 Mag has about the same Grunt/TQ as a 320HP 6 cyl inline diesel. Over 500 lbs tq at 3200rpm :grin:
The 5.7 engines have tq around 355 lbs. Adding HP does not help the 5.7 tq much. :smt089
The max torque is the same but at different rpms 3200rpm for the Mag vs 3600 rpm. Max Tq for the 8.1 HO is 3600 or 3700rpm. The HO actually has a little less Tq at lower rpms then the Mag.Thanks. That makes it more clear. I was thinking that the torque of the 496 Mags feel exactly like a diesel.
Am I right in thinking that the "detuned" 496 Mag having 375 HP will last longer than the HO 496 Mag? There is a formula using HP and displacement to determine a ratio. I forgot where I read about this. The lower the ratio the better in terms of longevity. 375/496 = 0.76. 425/496 = 0.85
If the 496 Mag and HO have the same HP, why bother with the HO?
That engine does show some nice numbers.http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/marine/marine_engines.jsp
Check that Super Charged LSA engine...I would really like to be in a position to drop a pair of those into a late model 34DA and see how it would perform. When you compare the TQ curve to an 8.1 and then look at the weight difference it's a real eye opener. You would pick up about 200 Ft. lbs in the water and shave about 1000 lbs of displacement off the boat....bound to be significant in a boat that size.:thumbsup:
That engine does show some nice numbers.
If I was freshwater into going fast a lot. That engine would be a very good choice. It may be a bit overstressed for long term dependability.
With my boat being a converted fishing boat. I kind of wish I had a simple carbed big block with 500 lbs Tq. Not enough power in a 454ci and I could not get a turn key 502ci.
500 lbs of Tq is was needed to move my boat at least 26 mph at 3000rpm or under. Hopefully having easier starting with a EFI engine is going to be worth it.
Would be fun to have the money to drop in and try out different engines at will. Maybe even let someone else do the work
I already have the 8.1 sitting in my garage. All I have to do now is turn the computer off long enough to install it :smt021I wouldn't hessitate for "Salt Life" with the LSA...look again...it comes "closed cooling only":thumbsup: God only know what they will ask for that bad boy...would be fun to open the hatches and watch some jaws drop.:grin: