the initial #s are in
03-23-2007, 08:35 AM
#22
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I have a guys 496HO from a Heat down at Larry's now. It experienced an overheat condition that caused some damage.
However before that it was a pretty good runner. I don't like to touch what I don't have experience or time with so we sent it to Larry for the full monty. 3.3 Whipple, forged crank, rods and pistons, cam, ports heads and it made 750hp on Larry's dyno with 7 lbs of boost. It ran consistent 78 mph on the GPS speedo at Powell and hit 80 once. I think it would run a consistent 82-83 at Havasu with the 750hp. Boat idles very well and starts up just like a stock HP500EFI.
From my experience the Heat runs rock solid up to 100 mph in good water conditions . That being said, with any boat you must respect everything at that speed no matter what hull
My ass still eats the back of the bolster
Figure full hydraulic steering and a drive upgrade into the equation as well.
Hope that helps...
Dave
03-23-2007, 10:06 AM
#23
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Thread Starter
One other thing that I forgot to mention in my earlier post(s) about how the boat is running..... Handling can obviously become an issue in a vee hull boat at these speeds. Even though I haven't been in the boat (ie, no seat time) in months, it ran like it was on rails. It always has, but you never know what another 7-9mph can bring. I think all the earlier mods we've done (new tabs/Imco drive with spacer/P5-X/etc) are really paying off now.
I could have literally taken my hands off the wheel @ 90. The extra horsepower has allowed me to use less trim, keeping the propshaft angle almost parallel to the hull (2.5 on the Livorsi guage, 0-10 range), which usually results in efficient slip #s and good handling. Tabs retracted all the way.
I'll be testing some props over the weekend and I'll let you guys know how it goes.
Regards,
Steve
I could have literally taken my hands off the wheel @ 90. The extra horsepower has allowed me to use less trim, keeping the propshaft angle almost parallel to the hull (2.5 on the Livorsi guage, 0-10 range), which usually results in efficient slip #s and good handling. Tabs retracted all the way.
I'll be testing some props over the weekend and I'll let you guys know how it goes.
Regards,
Steve
03-23-2007, 10:22 AM
#24
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Steve, you bring up a good point on the props...
Although under propped, the 27 P5X with added cup was very squirlly at best. The tuned 30 P5X is rock solid.
That being said, setup is key.
Another note...The spacer did not work out on this particular setup at all
Although under propped, the 27 P5X with added cup was very squirlly at best. The tuned 30 P5X is rock solid.
That being said, setup is key.
Another note...The spacer did not work out on this particular setup at all
03-23-2007, 06:19 PM
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03-23-2007, 08:15 PM
#26
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I guess the numbers that count are on your speedo and not the dyno. I tried to dyno mine down here but the guys equipment was just not cooperating. At least running it on the stand gives you a chance to check for leaks and makes adjustments easier.
I would love to see a flyby vid of your heat in action. (I may not make it to the regatta)
Great job on a killer heat!
I would love to see a flyby vid of your heat in action. (I may not make it to the regatta)
Great job on a killer heat!
03-23-2007, 09:16 PM
#27
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That's interesting. When I was racing outboards, I always used higher transom heights (x dimensions in this world) when the boats I was setting up had a higher HP to weight ratio. I actually set a few of my boats up with the propshaft above the bottom of the hull. I've seen a few high X dimension offshore race tunnels with similar propshaft heights.
I think when you have the HP that the 97MPH boat has, it just has the power to carry the bow, even @ 19 1/4"s. And if you can get away with it, you'll have a very efficient setup because you're not dragging the gearcase as deeply.
I've wondering if I could ditch my spacer with the extra HP I have now. Maybe with a 5 blade.
I did run the Merc lab 32" B1 today. It ran 90MPH @ 5600. OK, but not earth shattering. It would be better with a little more cup to lock it up and carry the bow a little better. The boat didn't like the 30" stock P5-X at all. Handling was off a little, and it only ran 87MPH @ 5700.
Looks like my old faithful 28" P5-X may the ticket. This motor really likes to rev. I will also try my old 30" B1, and would really like to try a 29" P5-X blueprinted. Hey Bob
!Regards,
Steve
Last edited by Steve Zuckerman; 03-23-2007 at 09:25 PM.
03-23-2007, 09:22 PM
#28
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I guess the numbers that count are on your speedo and not the dyno. I tried to dyno mine down here but the guys equipment was just not cooperating. At least running it on the stand gives you a chance to check for leaks and makes adjustments easier.
I would love to see a flyby vid of your heat in action. (I may not make it to the regatta)
Great job on a killer heat!
I would love to see a flyby vid of your heat in action. (I may not make it to the regatta)
Great job on a killer heat!
........Regards,
Steve
03-24-2007, 09:10 AM
#29
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I'd be happy to send it to you. It's still boxed up from when Dave's friend tried it. I'll be happy to ship it to you to try, but I need it back within a couple of weeks, since I hope to have my boat finished.
Bob
Bob
03-24-2007, 11:01 AM
#30
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Hey Dave,
I have a guys 496HO from a Heat down at Larry's now. It experienced an overheat condition that caused some damage.
However before that it was a pretty good runner. I don't like to touch what I don't have experience or time with so we sent it to Larry for the full monty. 3.3 Whipple, forged crank, rods and pistons, cam, ports heads and it made 750hp on Larry's dyno with 7 lbs of boost. It ran consistent 78 mph on the GPS speedo at Powell and hit 80 once. I think it would run a consistent 82-83 at Havasu with the 750hp. Boat idles very well and starts up just like a stock HP500EFI.
From my experience the Heat runs rock solid up to 100 mph in good water conditions . That being said, with any boat you must respect everything at that speed no matter what hull
My ass still eats the back of the bolster
Figure full hydraulic steering and a drive upgrade into the equation as well.
Hope that helps...
I have a guys 496HO from a Heat down at Larry's now. It experienced an overheat condition that caused some damage.
However before that it was a pretty good runner. I don't like to touch what I don't have experience or time with so we sent it to Larry for the full monty. 3.3 Whipple, forged crank, rods and pistons, cam, ports heads and it made 750hp on Larry's dyno with 7 lbs of boost. It ran consistent 78 mph on the GPS speedo at Powell and hit 80 once. I think it would run a consistent 82-83 at Havasu with the 750hp. Boat idles very well and starts up just like a stock HP500EFI.
From my experience the Heat runs rock solid up to 100 mph in good water conditions . That being said, with any boat you must respect everything at that speed no matter what hull
My ass still eats the back of the bolster
Figure full hydraulic steering and a drive upgrade into the equation as well.
Hope that helps...
Or, perhaps, a bigger craft? 28' at LOTO is entry. 35 is more the ticket.
