80 mph + 24' Superboat (continued from Pantera Forum)
10-01-2007 | 11:04 AM
#93
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Joined: Oct 2002
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From: Ivoryton, CT
That is good to hear...
Like I said before, Dave M. and T-island are running B1 props and reaching speeds in the high 70s with the same hull.
With the older straight V hull, 3 blades work OK for high speed, but on the newer stepped, pad hull, I suggest 4 blade props...
Like I said before, Dave M. and T-island are running B1 props and reaching speeds in the high 70s with the same hull.
With the older straight V hull, 3 blades work OK for high speed, but on the newer stepped, pad hull, I suggest 4 blade props...
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Patrick
Patrick
10-02-2007 | 09:44 AM
#94
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From: Tulsa, OK
We were up at LOTO for the OSS races this weekend. She ran great, but we still have some work to do.
The bad: Brad said when we picked it up on Friday that he'd forgotten to do anything about the stock oil cooler and that I'd need to keep high rpm runs to a minimum to keep the oil from getting too hot. It would get hot pretty quick just by looking at the pressure. We did do some runs, but kept it to a minimum.
We have an RPM problem also. I was unable to get above 4900 rpm. There could be one of a few reasons for this. First, my trim gauge was not working, so I may not have had it trimmed up enough. I did try to look back and see how much "tail" I was putting out, and it looked like it I was trimmed pretty good. If not the trim, Brad was thinking that the stock pickup in the fuel tank may be too restrictive and I may be running out of fuel at the big end. It is interesting to note that the old engine would not rise above this rpm either. The last reason may be that the tach is simply off.
The prop is definitely too small. I had to feather it out of the hole to keep it from blowing out. Punching it from 3K, you could feel the slip. The right prop is going to make a BIG difference.
The computer has to go back to Tyler. We are still real fat at idle. I have to open the throttle to get it running when it's cold as the plugs got pretty fouled. The idle is about 100 rpm low also. He said no problem to fixing those issue up. My transom is now black. You'd think I was running a holley!
We blew a header gasket and had to listen to TICK TICK TICK on Sunday!
The Good: The thing runs like a monster. Hitting the stick at 3K throws you back like being in a hot rod. Pure hard acceleration! I'm nervous to see what it does when the prop bites properly. We ran the GPS on Saturday, but didn't hammer it real hard. We saw about 65 on a quick short run. The GPS batteries died on Sunday morning once we were out, and I didn't get a chance to replace them. I did make a couple of more sustained runs, and from the feel of it know we were well above 70. Once this thing is dialed, it is going to be a heck of ride!
The boat is back at Brad's shop for the oil cooler and to check out the rpm problem and trim gauge problem. We probably looking at about 2 weeks for him to finish it up and get it back. There won't be much time for prop testing left this season. I'm on the list at BBlades for testing a 25P Rev 4, but I think it is going to be too small. I think I need to start with a 26P B1 and go up from there.
Right now, I think I got my money's worth for sure. Once we get the rest of the bugs worked out, it is going to be a bit on the crazy side for that little boat!
The bad: Brad said when we picked it up on Friday that he'd forgotten to do anything about the stock oil cooler and that I'd need to keep high rpm runs to a minimum to keep the oil from getting too hot. It would get hot pretty quick just by looking at the pressure. We did do some runs, but kept it to a minimum.
We have an RPM problem also. I was unable to get above 4900 rpm. There could be one of a few reasons for this. First, my trim gauge was not working, so I may not have had it trimmed up enough. I did try to look back and see how much "tail" I was putting out, and it looked like it I was trimmed pretty good. If not the trim, Brad was thinking that the stock pickup in the fuel tank may be too restrictive and I may be running out of fuel at the big end. It is interesting to note that the old engine would not rise above this rpm either. The last reason may be that the tach is simply off.
The prop is definitely too small. I had to feather it out of the hole to keep it from blowing out. Punching it from 3K, you could feel the slip. The right prop is going to make a BIG difference.
The computer has to go back to Tyler. We are still real fat at idle. I have to open the throttle to get it running when it's cold as the plugs got pretty fouled. The idle is about 100 rpm low also. He said no problem to fixing those issue up. My transom is now black. You'd think I was running a holley!
We blew a header gasket and had to listen to TICK TICK TICK on Sunday!
The Good: The thing runs like a monster. Hitting the stick at 3K throws you back like being in a hot rod. Pure hard acceleration! I'm nervous to see what it does when the prop bites properly. We ran the GPS on Saturday, but didn't hammer it real hard. We saw about 65 on a quick short run. The GPS batteries died on Sunday morning once we were out, and I didn't get a chance to replace them. I did make a couple of more sustained runs, and from the feel of it know we were well above 70. Once this thing is dialed, it is going to be a heck of ride!
The boat is back at Brad's shop for the oil cooler and to check out the rpm problem and trim gauge problem. We probably looking at about 2 weeks for him to finish it up and get it back. There won't be much time for prop testing left this season. I'm on the list at BBlades for testing a 25P Rev 4, but I think it is going to be too small. I think I need to start with a 26P B1 and go up from there.
Right now, I think I got my money's worth for sure. Once we get the rest of the bugs worked out, it is going to be a bit on the crazy side for that little boat!
10-02-2007 | 09:54 AM
#95
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Joined: Apr 2005
Posts: 286
Likes: 2
From: Lehigh Valley, PA/1000 Islands
Jay,
I struggled with an RPM problem a couple of years ago and tried everything. As you mentioned it turned out to be the TACH. What ticked me off was it was so simple to check and the last thing that came to mind.
That would be the first thing I would check.....
I struggled with an RPM problem a couple of years ago and tried everything. As you mentioned it turned out to be the TACH. What ticked me off was it was so simple to check and the last thing that came to mind.
That would be the first thing I would check.....
10-02-2007 | 10:11 AM
#96
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Joined: Oct 2002
Posts: 5,246
Likes: 3
From: Ivoryton, CT
Sounds like you're getting there...
A 25p Rev 4 and 26p B1 are about the same pitch; B1s are stamped on the high side. On my boat, both the 25p Rev 4 and 26p B1 touch the limiter (5150) at just shy of 75mph.
T-Mone ran 80 @ 55-5600 with the 25p Rev and 78 @ 53-5400 with my labbed 27/28p B1.
I think Dave M. said 78mph @ 5000 with a stock 28p B1 on his boat.
You should be above 80mph if you can spin a 28p B1 at 5200rpm.
Have fun and be safe...
A 25p Rev 4 and 26p B1 are about the same pitch; B1s are stamped on the high side. On my boat, both the 25p Rev 4 and 26p B1 touch the limiter (5150) at just shy of 75mph.
T-Mone ran 80 @ 55-5600 with the 25p Rev and 78 @ 53-5400 with my labbed 27/28p B1.
I think Dave M. said 78mph @ 5000 with a stock 28p B1 on his boat.
You should be above 80mph if you can spin a 28p B1 at 5200rpm.
Have fun and be safe...
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Patrick
Patrick
10-02-2007 | 09:41 PM
#99
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Joined: Dec 2000
Posts: 6,283
Likes: 1
From: EASTON MA.
I don't no if this helps I was getting 83.2gps at 5900 to 6000 with a b1 26 prop 2'' shortie drive, my buddys 79SB 24 with a 25p mirage at 5500 was 74gps thats a trs ,I was trying to talk him into a sm3, or bravo he has about 550hp so it looks like he losing 6mph. oh the imco shortie 2'' drive made my boat handle better, fly flat it should help you non step guys I would think. well good luck, I HOPE TO MOVE UP TO A y2k, or 28 joker next year.
