Start to Finish: Building Our 50' Skater
08-14-2017, 09:45 PM
#1151
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Join Date: Aug 2006
Location: Bedford, NH
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I spent a lot more then $100k on the first experiment and lost a year and a half of my life getting lied to by the first guy that was building me diesels for the boat. But at this point I have to keep trying to reach my goal with what I want the boat to do.
Any gas engine would not be effective for what we are doing. The diesels even being heavily modified will get twice the gas mileage as gas engines or turbines, and with some of the long runs we are going to do you would never be able to carry enough fuel to make it.
Gale Banks has done a lot of things, he has spent most of his life doing custom engine stuff, but he would be too conservative to be associated with this engine project for the high profile but risk that it might not work. And he is really busy on a few military contracts. We contacted him several times about this project right when we started it.
We got it to over 90 mph with the drives not being straight so it might have been able to hit 100. It did accelerate good from the torque. The one with the seateks from all the notes we could find at skater and a few of the companies that worked on it and test it was a top speed of 101 mph, we want a lot more speed then that out of it.
After we get these running and make sure they work we are going to move into building aluminum blocks and heads for it. To use a bigger displacement would lower our rpm so we are wanting to stick to this size.
We talked with seatek's people, the biggest they have had 1200 hp but weighs twice as much as what we are putting in and cannot turn the high rpm we need. They are also so long we would have to move the cockpit forward just to fit them in.
The seateks were originally a low hp engine that are already turned up as high as they can get them and they actually advised us not to use them for the endurance,/mileage/weight/ect that we needed
When we first started this project the engines we wanted were the Audi diesels they used in the lemans race car. They were 750 hp and only weight 500 lbs. we planned on using 4 of them and would have a little better hp and mileage then in the race car by not having to meet racing rules. They would have had the high rpm and would have been set up to run on 2 if we needed so there would be less chance of getting stranded. There is a warehouse overseas that has 20 of them sitting in it and they will not sell them. I tried for a long time to get one and never got to the right person. If anyone has a high enough contact at Audi racing I would still like to get two for my cigarette gladiator and use it to do v-bottom records.
Any gas engine would not be effective for what we are doing. The diesels even being heavily modified will get twice the gas mileage as gas engines or turbines, and with some of the long runs we are going to do you would never be able to carry enough fuel to make it.
Gale Banks has done a lot of things, he has spent most of his life doing custom engine stuff, but he would be too conservative to be associated with this engine project for the high profile but risk that it might not work. And he is really busy on a few military contracts. We contacted him several times about this project right when we started it.
We got it to over 90 mph with the drives not being straight so it might have been able to hit 100. It did accelerate good from the torque. The one with the seateks from all the notes we could find at skater and a few of the companies that worked on it and test it was a top speed of 101 mph, we want a lot more speed then that out of it.
After we get these running and make sure they work we are going to move into building aluminum blocks and heads for it. To use a bigger displacement would lower our rpm so we are wanting to stick to this size.
We talked with seatek's people, the biggest they have had 1200 hp but weighs twice as much as what we are putting in and cannot turn the high rpm we need. They are also so long we would have to move the cockpit forward just to fit them in.
The seateks were originally a low hp engine that are already turned up as high as they can get them and they actually advised us not to use them for the endurance,/mileage/weight/ect that we needed
When we first started this project the engines we wanted were the Audi diesels they used in the lemans race car. They were 750 hp and only weight 500 lbs. we planned on using 4 of them and would have a little better hp and mileage then in the race car by not having to meet racing rules. They would have had the high rpm and would have been set up to run on 2 if we needed so there would be less chance of getting stranded. There is a warehouse overseas that has 20 of them sitting in it and they will not sell them. I tried for a long time to get one and never got to the right person. If anyone has a high enough contact at Audi racing I would still like to get two for my cigarette gladiator and use it to do v-bottom records.
08-15-2017, 09:07 AM
#1152
Registered
i would go with your gut on this one after reading prior posts lol. very Jim darr-ish
08-15-2017, 09:14 AM
#1153
Registered
Bell housing screw up:
When it's 2 am you should not be loading tools for the machine and I guess I did not get the end mill tightened good enough and it started pulling out of the holder and went through the part where we were making a lightening pocket. You can see in the upper pocket it started pulling out and going deeper as it went around making a pyramid then on the next pocket it went through.
If this was a customers part we would have to start over and it would be a costly mistake. But since its mine where the hole is at it does not matter . I was going to machine a couple of holes into it after I test fit it in the boat so I can see inside to inspect the spring dampener and for water drainage and its on the backside under the engine so I will just call it an inspection port. Had the end mill pulled out a little sooner when it was doing the flat part it would have ruined the part.
When it's 2 am you should not be loading tools for the machine and I guess I did not get the end mill tightened good enough and it started pulling out of the holder and went through the part where we were making a lightening pocket. You can see in the upper pocket it started pulling out and going deeper as it went around making a pyramid then on the next pocket it went through.
If this was a customers part we would have to start over and it would be a costly mistake. But since its mine where the hole is at it does not matter . I was going to machine a couple of holes into it after I test fit it in the boat so I can see inside to inspect the spring dampener and for water drainage and its on the backside under the engine so I will just call it an inspection port. Had the end mill pulled out a little sooner when it was doing the flat part it would have ruined the part.
08-15-2017, 11:43 AM
#1154
Registered
that just makes the prototype part more special than any that follow it,
the other engines not even gonna have pyramid in the hole next to an all the way thru hole
did you ever find the inner transom plate ?
the other engines not even gonna have pyramid in the hole next to an all the way thru hole
did you ever find the inner transom plate ?
08-15-2017, 01:56 PM
#1156
Registered
I always like to work with the maximum engine rpm range available for each power source to give a good comparison.
I agree with you about the power it doesn’t matter whether its gas, diesel or turbine power it’s all about the prop speed and the torque available at the prop no matter what the power source.
Just for comparison a 1350 has a max rpm of around 6600 rpm and most run a 1.3-1 ratio giving a maximum prop speed of 5076rpm and 1456 lbs torque at the prop.
I guess your safe maximum engine speed is around 3800rpm and an OD ratio of 0.91 giving you a prop speed of around 4200rpm and 1250 lbs torque at the prop.
So you’re right it’s probably only around 800 rpm lower but the torque is also lower at the prop reducing the amount of pitch your able to run.
I have been deliberating all of this with my diesel Nortech it makes 800-1000hp+ at 3300 rpm with a ratio of 0.881 that gives me a prop speed of 3750rpm and 1400lbs.
It looks like we will never match to top speed of the higher HP gas motors but our cruise speed should be around the same given the ability of the diesels to run for extended periods closer to their maximum rpm.
Our long term reliability should certainly be better, rebuild costs lower and fuel burn considerably less, not to mention I would rather have 300 gallon of diesel on board than 95 octane.
I agree with you about the power it doesn’t matter whether its gas, diesel or turbine power it’s all about the prop speed and the torque available at the prop no matter what the power source.
Just for comparison a 1350 has a max rpm of around 6600 rpm and most run a 1.3-1 ratio giving a maximum prop speed of 5076rpm and 1456 lbs torque at the prop.
I guess your safe maximum engine speed is around 3800rpm and an OD ratio of 0.91 giving you a prop speed of around 4200rpm and 1250 lbs torque at the prop.
So you’re right it’s probably only around 800 rpm lower but the torque is also lower at the prop reducing the amount of pitch your able to run.
I have been deliberating all of this with my diesel Nortech it makes 800-1000hp+ at 3300 rpm with a ratio of 0.881 that gives me a prop speed of 3750rpm and 1400lbs.
It looks like we will never match to top speed of the higher HP gas motors but our cruise speed should be around the same given the ability of the diesels to run for extended periods closer to their maximum rpm.
Our long term reliability should certainly be better, rebuild costs lower and fuel burn considerably less, not to mention I would rather have 300 gallon of diesel on board than 95 octane.
08-15-2017, 04:55 PM
#1157
Registered
I always like to work with the maximum engine rpm range available for each power source to give a good comparison.
I agree with you about the power it doesn’t matter whether its gas, diesel or turbine power it’s all about the prop speed and the torque available at the prop no matter what the power source.
Just for comparison a 1350 has a max rpm of around 6600 rpm and most run a 1.3-1 ratio giving a maximum prop speed of 5076rpm and 1456 lbs torque at the prop.
I guess your safe maximum engine speed is around 3800rpm and an OD ratio of 0.91 giving you a prop speed of around 4200rpm and 1250 lbs torque at the prop.
So you’re right it’s probably only around 800 rpm lower but the torque is also lower at the prop reducing the amount of pitch your able to run.
I have been deliberating all of this with my diesel Nortech it makes 800-1000hp+ at 3300 rpm with a ratio of 0.881 that gives me a prop speed of 3750rpm and 1400lbs.
It looks like we will never match to top speed of the higher HP gas motors but our cruise speed should be around the same given the ability of the diesels to run for extended periods closer to their maximum rpm.
Our long term reliability should certainly be better, rebuild costs lower and fuel burn considerably less, not to mention I would rather have 300 gallon of diesel on board than 95 octane.
I agree with you about the power it doesn’t matter whether its gas, diesel or turbine power it’s all about the prop speed and the torque available at the prop no matter what the power source.
Just for comparison a 1350 has a max rpm of around 6600 rpm and most run a 1.3-1 ratio giving a maximum prop speed of 5076rpm and 1456 lbs torque at the prop.
I guess your safe maximum engine speed is around 3800rpm and an OD ratio of 0.91 giving you a prop speed of around 4200rpm and 1250 lbs torque at the prop.
So you’re right it’s probably only around 800 rpm lower but the torque is also lower at the prop reducing the amount of pitch your able to run.
I have been deliberating all of this with my diesel Nortech it makes 800-1000hp+ at 3300 rpm with a ratio of 0.881 that gives me a prop speed of 3750rpm and 1400lbs.
It looks like we will never match to top speed of the higher HP gas motors but our cruise speed should be around the same given the ability of the diesels to run for extended periods closer to their maximum rpm.
Our long term reliability should certainly be better, rebuild costs lower and fuel burn considerably less, not to mention I would rather have 300 gallon of diesel on board than 95 octane.
For a cruise speed of 3200 RPM on my diesel it would have a torque of 1750 ftlb's and a prop speed of 3516 rpm with the .91 overdrive the water seeing 1592 ftlbs of torque.
The merc. 1350 with the same prop speed of 3512 will have an engine speed of 4922 through the 1.4 M8 drive and a max torque at that rpm of 1100 ftlbs at the engine which will be 1540 ftlbs at the water.
So I should have basically the same torque at the same prop speed as a 1350.
for max rpm's we will turn the diesel 4200 rpm continuous at 1500 ftlbs which will give a prop speed of 4615 rpm at 1365 ftlbs to the water.
at max rpm the 1350 will turn 6350 RPM at 1110 ftlbs at the engine which will give a prop speed of 4535 rpm at 1554 ftlbs to the water.
The 1350 will have a little more power at the top rpm but I will have more prop rpm and could pitch down to make up some torque difference.
In the end they should be pretty close. But we have no idea whats going to happen till they are in the boat and start doing testing.
.
08-16-2017, 01:06 PM
#1159
Registered
I thought I would pop this question at you.
With you engineering and machining experience why didn't you go for a quick change transfer box after the engine gearbox or a drop box with quick change gears similar to the SCS unit when running the Arnesons?
This would have given you the ability to swap ratios and props to suit different conditions.
I know the Class 1 guys used to run this technology with great results.
With you engineering and machining experience why didn't you go for a quick change transfer box after the engine gearbox or a drop box with quick change gears similar to the SCS unit when running the Arnesons?
This would have given you the ability to swap ratios and props to suit different conditions.
I know the Class 1 guys used to run this technology with great results.
08-16-2017, 01:40 PM
#1160
Registered
Like these in the WMD's?
Bet I know the answer. Them Cummins be LONG.. LOL.. "Quick" change isn't the best definition for this design either.
Bet I know the answer. Them Cummins be LONG.. LOL.. "Quick" change isn't the best definition for this design either.
