My engines were built in '96 and here's the Dyno sheet........soon after, boat and engines were stored away
for the next 20 years until I purchased the Mistress in March 2016.......one engine has 12 hrs other 5 hrs.
I'm not too well read about what all the numbers are and what they all mean...can somebody break it down.
I know they are Chevy NA engines w/Arizona EFI's...........one thing, they roar and pull great!...very happy!!

The engine description part that some is written in or the power part ?

Anything specific you want to know ?

I guess, Just a total impression of what the engine makes by the numbers...........is there any "Wow" factor that stands out?.......to look at this Dyno sheet could be a yawn to most
since alot here are running big power & maybe some not, but I had nothing to do with building these engines so there was no goal in mind as far as power. I do know that the engines
were built with allgood parts!

Stated 575 cubic inches, stated 4.5" stroke , not stated, but which means bore = 4.51"
Arizona Speed and Marine 1300cfm throttle body. Will need pics to confirm if they used a AS&M intake manifold or modified 502MPI intake
ECU: States 'GM Controller." In 1996 probably a MEFI 1. Will need pic and # to confirm.
Crane Hydraulic Roller Cam #139661 : Advertised Duration 318°/326° , at .050 256°,264° , lift with 1.7 rockers .632", .632" , Lobe Separation Angle 114°
World Products Merlin Cast Iron Cylinder Heads - does not state any other info (part #, size, valves, springs, etc)
Exhaust: Imco Powerflow Plus with Dry Tails
Oil Pan: Gil 14 Quart
Sea Water Pump: Jabsco #43210
Alternator: Prestolite Marine 65 Amp
Starter: High Torque . Does not provide manufacturer or part #
Mercruiser Engine Wire Harness and Pulleys

On to the dyno(s):
It appears line 1 thu 8 (marked 'Power'") is from an engine dyno
It appears line 13-20 (marked 'Prop') is from a propshaft dyno
This would make sense for 2 reasons, #1 difference between the two is about right , especially if this boat has TRS's (ie: transmissions) and #2 the fact both dyno's seem to be using Land and Sea dyno's - they are about the only one's I see report rpm's like that. Most others report in 100rpm increments. Also, Land and Sea makes both Engine and Propshaft dyno's.

Not counting CID and the engine's other parts, obviously these engines make good power to move a twin engine boat.
664 ft/lbs of torque and 637hp is obviously strong power.

Now, okay, these engines sport very large cubic inches and pretty big cams. The two together could easily make well over 700hp. So, why don't they ?
#1, intake manifold ! Again, undetermined for me right now (no pics or mention) but back in '96 there where two marine MPI intakes. Factory 502MPI (which ASM would have modified for this motor) or ASM's intake manifold. Good for the day, but not for the last bunch of years when say making over 500 + hp. #2 cylinder heads. Merlins are somewhat better than factory. We have a lot better to choose from now.

On the dyno sheet, they report what most dyno sheets printed don't show. Actual power measured and corrected power. Most sheets are just printed with corrected power.

Corrected power means taking power as measured and correcting for a standard set of weather conditions and altitude. Your power was corrected to the less typically used J1995 SAE standard which is 77F° , 0 % humidity, and 29.53"Hg air pressure. This will show less corrected horsepower than the more typically used J607 SAE standard correction which uses 60°F , 0% humidity, and a barometric pressure of 29.92 in-Hg Your corrected #'s are less than actual measured because the air conditions the day of testing was better (more powerful) than the J1995 standard conditions.

Why do most dyno's use J607 standards ? Simple, they show more corrected power than the other SAE standards.

Any other questions, feel free to ask.

BTW: I remember when the other OSO member had bought a boat from this place and posted that this boat was sitting there in storage too. What a boat ! and what a deal ! it seemed to me, and I'm sure others. Glad that someone (obviously you) took the ball, ran, and snagged this. What a time capsule !

BTW #2: Again, please show pics of engines so we can see what intake manifolds, and also let us know if TRS's or Bravo's.

[ATTACH=CONFIG]557919[/ATTACH][ATTACH=CONFIG]557920[/ATTACH][ATTACH=CONFIG]557921[/ATTACH][ATTACH=CONFIG]557922[/ATTACH]
SB........Thanks for taking the time to breakdown & elaborate my engine dyno sheet!............Here's some pics of the engines which definately are Arizon Speed & Marine EFI's
and the outdrives are Mercruiser SSM #3's............what would your opinnion be now?

Mine opinion is awesome score still. Lol. Still an awesome find.

Without a doubt a nice reliable package however like SB said there is definitely power left on the table however for now I'd keep the oil changed and have fun. The 139661 cam is going to make most hp near 6,400-6,600. What do you have it propped for at WOT? The dyno sheet contradicts this especially showing peak torque at 4,650. I've personally not seen a dyno sheet like this with the rpm's not being sequential. SB what happened in the scribbled out area? I can see where the split is but why would this not be making more hp at 5,700? Is cam installed 8 deg adv? Lol. To OP I am just trying to figure this out and have it make sense with me. Cam vs hp. I am jealous of your find. Haven't heard one of these in a while. Similar to 68 Shelby found in old lady's barn out in the country on a gravel road. Ha. Congrats. I am happy for you.

The intakes are the limiting factor on these engines. I've read many threads by smitty on these intakes and it seems they are limited to 575 hp. The issue is they just run out of air. I've thought about these intakes many times for my old 454's, and even thought about them for my 509's, but I would loose power with them. So, for now, I'm sticking with my carbs.

Opinion now is... Enjoy it and run the S#it out of it!!

getrdunn - #9-#13 was probably included on the sheet to show power drop off after peak power. It was probably scribbled so that it was not confusing to whomever ended up with it. It should have been up top, as it was a run on the engine dyno. The sheet shown was data from a min of 2 sheets, but probably 3 (1-2 engine dyno, and 1 from prop dyno)

So, even the whole sheet looks confusing, you have to clear your head from what we normally get for sheets, and look at it as the final report condensed on to one sheet. Remember, the top portion is the engine dyno #'s, and the bottom half is the prop shaft dyno's.

Maybe it's easier for me, since I'm in NH and thus there are a good amt of Land & Sea dyno's here and Maine because L&S is from NH.

I'll never forget my first L&S dyno sessions, which was on a chassis dyno, and seeing the rpms blew my head apart. Why not 100 rpm increments like all the others ? I don't know. A few dyno shops that I did some work for seemed to have dumb issues with their dyno's and we where left to fix them. Very disturbing as my attitude is / was on things I shouldn't have to learn to fix is, WTF ! You fix it dumbazzes.

Endeavor is correct - this is what Tuned Port intakes do. They are designed around certain paramaters to boost power at certain rpm range (this range will change due to cid's) on a certain motor . Think OE motors. Problem is (for us hotrodders) si that after that rpm the power will drop off like a cliff. If you change cid's, the 'boosted power' rpm range will be lower.

Boy did we learn this with GM's tuned port motors.

I was lucky enough to be working at a shop around 1988, 89 ? that had a customer with a 350 TPI Vette manual trans. He was wealthy and older (my age now, lol) and wanted to get back into drag racing in a big way. He was like me (now), drag raced all the time until getting married. LOL.

Anyway, we (like others later) couldn't get it past 4500 without nosing over. Better cam, better heads (Brodix. Brodix only had one street headThat was all that was available at the time. The Dart II (cast iron) would come out a yr or two later. The AFR, then wholly schit this is great ! LOL.

Accel came out with a intake that gained about 100hp over the factory. 100hp people asked and claimed bullchit.

Well, yes and no. The intake upped the rpm range to about 5800rpm. At 5500-5800rpm the Accell was 100hp better then the factory at the same rpm. Remember, the factory nosed over at 4500 and beyond.

Anyway, the car was a rocket ship now and it took people a while at the track to believe it was this intake that absolutely dominated. This was a stock Vette with stock 5.7 tuned port short block, TPIS cam, those old Brodix heads, and the Accell SuperRam. Like this, the Car ran 11.88's at 122 or so if I can remember right. We later did a 406 with AFR's and...well. whole nother story. Car was an animal. So wasn't the driver. LOL.

Anyway, We where heroes for a while because everyone was stuck at 4500rpm fora bit. LOL.

Tuned Port intakes usually reach for the 2nd and 3rd harmonic wave. A carburetor intake will be between 4th-5th wave because they can not physically use runner lengths that long.

Here's an example on data I ran for someone with a 540, AFR heads, 5600-5800 peak rpm: