Test props turning out and shutting down throttles.
#12
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T2x - Prop shaft is as high as we can get it (I'm assuming you didn't mean to go lower?). No more room for the X and we already have the IMCO shorter lowers. Prop shaft is approx 1" below the hull. The problem is, it's only a 26' Daytona, not a lot of room to move around for the twins. I'll need to check the measurement from the tunnell wall tomorrow when I see the boat.
I have a whopping 16 hours of seat time in a cat now, so any advice on driving is much appreciated!!!!!
I have a whopping 16 hours of seat time in a cat now, so any advice on driving is much appreciated!!!!!
#14
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Your the man T2x ! THanks for the info again !
I am dying to try this swap ,but I have not had mine to top speed yet because of motor problems . I will run it this way first just to see . I know it does not handle the best as is . After a few good passes I'll swap um ! My thing is I have to swap everything side for side . Motors ,trans, arnesons . I have reverse rotation motors due to old style Arneson 1600's that only turn one way . I am looking forward to trying it . Hell , I'm looking forward to boating PERIOD !!
I hope my prop shafts are in the right neighborhood as to tunnel wall ! My boat has seen enogh of the circular saw and chain saw for a while !
I am dying to try this swap ,but I have not had mine to top speed yet because of motor problems . I will run it this way first just to see . I know it does not handle the best as is . After a few good passes I'll swap um ! My thing is I have to swap everything side for side . Motors ,trans, arnesons . I have reverse rotation motors due to old style Arneson 1600's that only turn one way . I am looking forward to trying it . Hell , I'm looking forward to boating PERIOD !!
I hope my prop shafts are in the right neighborhood as to tunnel wall ! My boat has seen enogh of the circular saw and chain saw for a while !
#15
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U T,
I see you are turning 4,400 with the 26" props, why would you try 27" ? this will lower your rpm to 4,200. ? The center of your prop shafts are 1" below the bottom? seems very low to me, I would think you would want to be 1 or 1 1/2" above
Philip
I see you are turning 4,400 with the 26" props, why would you try 27" ? this will lower your rpm to 4,200. ? The center of your prop shafts are 1" below the bottom? seems very low to me, I would think you would want to be 1 or 1 1/2" above
Philip
Last edited by Philip; 02-25-2002 at 07:43 AM.
#16
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I have a 28' Daytona and saw less than 1 mph difference between runinning the props in or out on the same afternoon with the same conditions. The boat does lean in on the turns and turns a lot better with the props spinning out. I do get a little hop around 75 with them running out, but it quits at 80 and if I bring it back down to 75 after being at 80 there is no hop.
I did have my port motor quit from a loose wire at 90 and there was very, very little pull to the side. I brought the boat down to 40 on the one motor and tried to restart the dead one, but no go, I ran the boat 5 miles to the marina on one motor at 40. I didn't want to stop and have to idle all the back if I could stay on plane without any handling problems.
Good luck with your test and be careful.
I did have my port motor quit from a loose wire at 90 and there was very, very little pull to the side. I brought the boat down to 40 on the one motor and tried to restart the dead one, but no go, I ran the boat 5 miles to the marina on one motor at 40. I didn't want to stop and have to idle all the back if I could stay on plane without any handling problems.
Good luck with your test and be careful.
#17
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Philip - I'm just back in the office after being at Havasu and still trying to get caught up. I was going to send you a private response and let my prop thread die a natural death, but then I thought, what the heck - back to the top (TTT).
I have talked to a handful of experts on the prop issue. They all think the three bladed 27" will be the closest and worth a try (actually, one suggested a four bladed 24"). Mark at BAM was kind enough to spend time with me on the phone and after doing his science, that's the prop he came up with. I'm certainly no expert, but what I have picked up so far is, the four bladed 26" just has a lot more metal hitting the water and I guess, a lot more drag. Therefore, the lower rpm. When I tried the three bladed 25", I was all over the rev limiter. Had to bring the throttles back two inches before the rpm would come off. But as I am learning the hard way, the only sure thing is testing on your own boat. Certainly would enjoy more input.
I agree with you on the prop shaft height. But that's as high as we could get it without doing the super mod to the engine hatch, i.e. that's the highest X we could get with this boat and the twins (remember, this is the first 26' Daytona with twin engines they have done). I went with the two inch shorter lower from IMCO, but now I hear they are coming out with a 3" shorter lower. Typical! Although, I don't understand how they can fit the typical prop diameter with an additional inch shorter lower. Oh well, if they work it out, I guess I'll have to try it. I'm already down a convertible and a diamond tennis bracelet, what's one more bobble for my wife?
I have talked to a handful of experts on the prop issue. They all think the three bladed 27" will be the closest and worth a try (actually, one suggested a four bladed 24"). Mark at BAM was kind enough to spend time with me on the phone and after doing his science, that's the prop he came up with. I'm certainly no expert, but what I have picked up so far is, the four bladed 26" just has a lot more metal hitting the water and I guess, a lot more drag. Therefore, the lower rpm. When I tried the three bladed 25", I was all over the rev limiter. Had to bring the throttles back two inches before the rpm would come off. But as I am learning the hard way, the only sure thing is testing on your own boat. Certainly would enjoy more input.
I agree with you on the prop shaft height. But that's as high as we could get it without doing the super mod to the engine hatch, i.e. that's the highest X we could get with this boat and the twins (remember, this is the first 26' Daytona with twin engines they have done). I went with the two inch shorter lower from IMCO, but now I hear they are coming out with a 3" shorter lower. Typical! Although, I don't understand how they can fit the typical prop diameter with an additional inch shorter lower. Oh well, if they work it out, I guess I'll have to try it. I'm already down a convertible and a diamond tennis bracelet, what's one more bobble for my wife?
Last edited by Uncle Toys; 02-28-2002 at 02:06 PM.
#18
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Hi UT,
I see, the 26” props you are running are 4 blades, and you are going to try 27” 3 blades? If that is the case I agree, the 3 blades will spin more RPM. Usually the 4 blades run smoother, are better balanced. But the 27” 3 blades might run more RPM and more speed. I have the same question as you about the 3” shorter drives. What is the largest Dia. These drives can run? And what Dia prop are you running now?
Philip
I see, the 26” props you are running are 4 blades, and you are going to try 27” 3 blades? If that is the case I agree, the 3 blades will spin more RPM. Usually the 4 blades run smoother, are better balanced. But the 27” 3 blades might run more RPM and more speed. I have the same question as you about the 3” shorter drives. What is the largest Dia. These drives can run? And what Dia prop are you running now?
Philip
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UT
Here is my workbench take on props. Only your testing will tell. I think since you said that the 3 blade 25 would not grabe taking off you are still going to have that problem with the 27 3 blade. My 2 cents is on the 4 blade 24 bravo. So I guess this means I go along with one of the experts, but am in th minority. I guess we could take a poll on this new board?
I though you were going to put whipples on? Once you do that you get to start all over again trying props.
On turning I am going from memory now since I have not been in boat in 4 months, mine sometimes leans in & sometimes out on turns. I think it leans in on lower speed turns & out on high speed turns. Of course when it leans in the higher speed turns I am thowing somein the back or front around.
Hope to get back in water next week. Picked motor up tonight, installing prochargers & other misc., taking to Owens for dyno first of week & in boat for next weekend.
Here is my workbench take on props. Only your testing will tell. I think since you said that the 3 blade 25 would not grabe taking off you are still going to have that problem with the 27 3 blade. My 2 cents is on the 4 blade 24 bravo. So I guess this means I go along with one of the experts, but am in th minority. I guess we could take a poll on this new board?
I though you were going to put whipples on? Once you do that you get to start all over again trying props.
On turning I am going from memory now since I have not been in boat in 4 months, mine sometimes leans in & sometimes out on turns. I think it leans in on lower speed turns & out on high speed turns. Of course when it leans in the higher speed turns I am thowing somein the back or front around.
Hope to get back in water next week. Picked motor up tonight, installing prochargers & other misc., taking to Owens for dyno first of week & in boat for next weekend.
#20
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Turbojack - Good to hear from you again, where you been? I hear you on the 24" Bravo and getting on plane. I was torn, but it made sense to me about the extra metal in the water. Already giving up some speed (maybe) by turning the props out. Guess the answer is to get on with installing the Whipples and just power through all this. But I am enjoying the process, and later, once the Whipples are on, I get to go through it all again. I've got some 26' Daytona driving questions for you, but I am getting hungry, so I'll post that story tomorrow.