Anyone Know Torque Limit of #6 Drives For Twin Turbo Diesels
08-17-2017, 07:44 AM
#11
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I do not think a 102mm turbo will work well in a boat, you will most likely have a lot of trouble getting on plane because it will want to spool up after planing rpm, maybe you could over come that with a 2 speed trans. You need to figure out a drivetrain that will live behind the compound turbos.
08-17-2017, 11:06 AM
#12
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The two speed Transmission may be the way to go. It's basically a Powergluide drag racing trans.
Spool it up quick to get it on plane and shift into overdrive.
My friend Bob had that on his 44 MTI "Speed Racer". He would shift it into first to get on plane and then bump the sticks into second gear and take off.
Spool it up quick to get it on plane and shift into overdrive.
My friend Bob had that on his 44 MTI "Speed Racer". He would shift it into first to get on plane and then bump the sticks into second gear and take off.
08-17-2017, 02:22 PM
#13
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My engines are specificly developed marine engines used in Class 1 offshore not Cummins with boltons or any other automotive derivative.
They are four valves per cylinder overhead cam, no push rods lifters or rockers to fail.
Come from the factory with forged bottom end ceramic coated pistons and come in single or twin turbo application, some class 1 teams have seen in excess of 1400hp for extended periods, they dominated class one for years.
Compare this to any Cummins rod and it clear to see.
They are four valves per cylinder overhead cam, no push rods lifters or rockers to fail.
Come from the factory with forged bottom end ceramic coated pistons and come in single or twin turbo application, some class 1 teams have seen in excess of 1400hp for extended periods, they dominated class one for years.
Compare this to any Cummins rod and it clear to see.
08-18-2017, 01:36 PM
#15
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Boats still being rigged, should be complete late October read for the water early December.
Seateks but not the standard MOD units, these are more substantial in many ways.
MPG not known as yet but cruise should be around 100mph and topped at at 110+ with at least 300 hours before injectors and valve clearances need to be checked.
Only routine maintenance until then.
Should be fun.
Seateks but not the standard MOD units, these are more substantial in many ways.
MPG not known as yet but cruise should be around 100mph and topped at at 110+ with at least 300 hours before injectors and valve clearances need to be checked.
Only routine maintenance until then.
Should be fun.
08-18-2017, 02:59 PM
#16
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Boats still being rigged, should be complete late October read for the water early December.
Seateks but not the standard MOD units, these are more substantial in many ways.
MPG not known as yet but cruise should be around 100mph and topped at at 110+ with at least 300 hours before injectors and valve clearances need to be checked.
Only routine maintenance until then.
Should be fun.
Seateks but not the standard MOD units, these are more substantial in many ways.
MPG not known as yet but cruise should be around 100mph and topped at at 110+ with at least 300 hours before injectors and valve clearances need to be checked.
Only routine maintenance until then.
Should be fun.
So you did you do the calculations and found this would be cheaper in the long term? less rebuilding the engines or what was your diesel motivation. I like it for that and also it will be a fun project that I can use for years or until I break the hull. I was thinking to build it the way the truck racers build it but with some changes of course but with the best of everything parts, by basically buying easily available parts.This way the repairs and the building process are more easy I can do the project also for a more reasonable price
08-18-2017, 03:11 PM
#17
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I am only i the USA 2-3 times a year and wanted to use my boat and not consistently be rebuilding blower motors, not bothered about doing 140mph as I normally have family members on board, the diesel is also much safer in the hot Florida conditions seen too many boat fires there lately.
Not to mention running to the Keys and back on a full tank of fuel.
Not to mention running to the Keys and back on a full tank of fuel.
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08-20-2017, 05:55 PM
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Hello,I am talking about this build on a cummins diesel forum learning about the best parts to use and about sleeving the engines and other tactics to use to build the strongest and most powerful motors available. I wanted to post this to you guys to see if you think this guy has a point or it is just talk
""I love your theories, but a reality check here. Here are a few things to take note of.
1. Unless you have custom built Arneson drives your lower units will be a direct fit into the crankshaft on your motors. you would need a custom crankshaft forged just for this.
2. You will blow up that Cummins Motor, even the QSB's are not rated that high, even the highest HP QSB 6.7 you can get on the market redlines at 3,300rpm. Cruise is usually 75% of full throttle.
3.Balancing that motor will not solve the issues of valve train float, and oil pressure issues. You still would need a dry sump system to handle the oil.
4. Dual speed transmissions were tried and are unreliable especially for your needs, you need to change the pitch of the propeller, if you intend to run diesels. I mean, unless you want to spend ~$10,000 for a tranmission,
5. Why not change the input reducer on the front? you will need to go the opposite, i suppose that in order to turn that motor at 2,500rpm's your propeller speed will be around 3,000 rpm, to match. But you have to watch that you don't go supersonic and you will caviatate to much.
6. Dual speed transmission for spool up is illogical with the current programming, you would have no issue spooling that turbo in the water, as it acts like a torque converter.
7. Cooling, you sill need risers, and a water cooled jacket for your turbo, and exhaust flow.
8. Radiator (you could steal from a QSB), But I've never seen a QSB that is raw water cooled.
9. Engine RPM vs Boost and torque. It would be very hard to try and dial back the torque on a diesel, especially since the ECM will retard timing and fueling as boost increases over RPM. They were never meant to run like a gasser.
Having spent my life growing up on the water building garvy racers, and cigarette boats, I can tell you, rebuilding your worn out 572's would be cheaper in the long run. If your goal is longevity there are a few things one can do to make your motors last longer between tbo's
I know this is hard to stomach, but big blocks are not meant to run 4,500 all day long, if you need that much speed, go up a propeller size. it's my non professional opinion that rebuilding would be cheaper, go with lower compression, longer stroke, and turn your boost up, and let that boat fly.
Now I'd be glad to help you figure this out, I'm not trying to be a butt here, just realistic because I grew up on the water and around boating all my life.""
""I love your theories, but a reality check here. Here are a few things to take note of.
1. Unless you have custom built Arneson drives your lower units will be a direct fit into the crankshaft on your motors. you would need a custom crankshaft forged just for this.
2. You will blow up that Cummins Motor, even the QSB's are not rated that high, even the highest HP QSB 6.7 you can get on the market redlines at 3,300rpm. Cruise is usually 75% of full throttle.
3.Balancing that motor will not solve the issues of valve train float, and oil pressure issues. You still would need a dry sump system to handle the oil.
4. Dual speed transmissions were tried and are unreliable especially for your needs, you need to change the pitch of the propeller, if you intend to run diesels. I mean, unless you want to spend ~$10,000 for a tranmission,
5. Why not change the input reducer on the front? you will need to go the opposite, i suppose that in order to turn that motor at 2,500rpm's your propeller speed will be around 3,000 rpm, to match. But you have to watch that you don't go supersonic and you will caviatate to much.
6. Dual speed transmission for spool up is illogical with the current programming, you would have no issue spooling that turbo in the water, as it acts like a torque converter.
7. Cooling, you sill need risers, and a water cooled jacket for your turbo, and exhaust flow.
8. Radiator (you could steal from a QSB), But I've never seen a QSB that is raw water cooled.
9. Engine RPM vs Boost and torque. It would be very hard to try and dial back the torque on a diesel, especially since the ECM will retard timing and fueling as boost increases over RPM. They were never meant to run like a gasser.
Having spent my life growing up on the water building garvy racers, and cigarette boats, I can tell you, rebuilding your worn out 572's would be cheaper in the long run. If your goal is longevity there are a few things one can do to make your motors last longer between tbo's
I know this is hard to stomach, but big blocks are not meant to run 4,500 all day long, if you need that much speed, go up a propeller size. it's my non professional opinion that rebuilding would be cheaper, go with lower compression, longer stroke, and turn your boost up, and let that boat fly.
Now I'd be glad to help you figure this out, I'm not trying to be a butt here, just realistic because I grew up on the water and around boating all my life.""
Last edited by turbos230; 08-20-2017 at 05:56 PM. Reason: spelling
