Start to Finish: Building Our 50' Skater
11-27-2017, 10:49 PM
#1401
Registered
I don't think attempting to achieve never before seen levels of hp/L with reliability will be fruitful. You don't have the budget, time, resources or experience to do a real engine development program.
This is my day job at Cat. In my opinion you're being incredibly naive and optimistic as to what will be possible.
If I were you, I would make an aluminum block and head for a larger diesel. And not attempt extreme specific outputs. This would still be challenging but more up your alley.
If high specific output is still what you want this is how you should go about it. Remove heat from the exhaust valves, custom machine the heads for added cooling passages around the exhaust valve seat.
pistons, they are likely already oil cooled. You could improve volumetric flow rate of oil to the piston with modified squirters and/or higher pressure. You could also lower oil temps with additional cooling and or prioritize piston squirters so the oil is cooler.
turbine temp and turbo speed also need to be considered. Additionally if you're intending to run higher speeds, you could have valvetrain issues. You could also have common rail pump issues. You could also overheat the injector coils if you extending injection times.
ideally you would have instrumented exhaust valves, Pistons with a telemetry system, instrumented pushrods, instrumented injectors, turbo speed measurement, exhaust temps on all cyls and CPPs. Then put all this on a waterbrake Dyno and develop your tune. Otherwise you're just flying blind and speculating.
This is my day job at Cat. In my opinion you're being incredibly naive and optimistic as to what will be possible.
If I were you, I would make an aluminum block and head for a larger diesel. And not attempt extreme specific outputs. This would still be challenging but more up your alley.
If high specific output is still what you want this is how you should go about it. Remove heat from the exhaust valves, custom machine the heads for added cooling passages around the exhaust valve seat.
pistons, they are likely already oil cooled. You could improve volumetric flow rate of oil to the piston with modified squirters and/or higher pressure. You could also lower oil temps with additional cooling and or prioritize piston squirters so the oil is cooler.
turbine temp and turbo speed also need to be considered. Additionally if you're intending to run higher speeds, you could have valvetrain issues. You could also have common rail pump issues. You could also overheat the injector coils if you extending injection times.
ideally you would have instrumented exhaust valves, Pistons with a telemetry system, instrumented pushrods, instrumented injectors, turbo speed measurement, exhaust temps on all cyls and CPPs. Then put all this on a waterbrake Dyno and develop your tune. Otherwise you're just flying blind and speculating.
11-28-2017, 08:20 AM
#1402
Registered
Sorry to see your engineprojects fail, but you listen to the wrong people.
As I said earlier, your engineconcept has been tried before without success.
No one has put more R&D into raceboat diesels than Fabio Buzzi and everytime he ends up with
multiple engines in his raceboats.
To reach your goals you need to go back to your original idea with mildly tuned 4 x Cummins 6,7.
...and you melt a piston in a diesel with very high PFP(Peak Firing Pressure) or to much fuel...not to little..
As I said earlier, your engineconcept has been tried before without success.
No one has put more R&D into raceboat diesels than Fabio Buzzi and everytime he ends up with
multiple engines in his raceboats.
To reach your goals you need to go back to your original idea with mildly tuned 4 x Cummins 6,7.
...and you melt a piston in a diesel with very high PFP(Peak Firing Pressure) or to much fuel...not to little..
11-28-2017, 08:21 AM
#1403
Registered
I don't think attempting to achieve never before seen levels of hp/L with reliability will be fruitful. You don't have the budget, time, resources or experience to do a real engine development program.
This is my day job at Cat. In my opinion you're being incredibly naive and optimistic as to what will be possible.
If I were you, I would make an aluminum block and head for a larger diesel. And not attempt extreme specific outputs. This would still be challenging but more up your alley.
If high specific output is still what you want this is how you should go about it. Remove heat from the exhaust valves, custom machine the heads for added cooling passages around the exhaust valve seat.
pistons, they are likely already oil cooled. You could improve volumetric flow rate of oil to the piston with modified squirters and/or higher pressure. You could also lower oil temps with additional cooling and or prioritize piston squirters so the oil is cooler.
turbine temp and turbo speed also need to be considered. Additionally if you're intending to run higher speeds, you could have valvetrain issues. You could also have common rail pump issues. You could also overheat the injector coils if you extending injection times.
ideally you would have instrumented exhaust valves, Pistons with a telemetry system, instrumented pushrods, instrumented injectors, turbo speed measurement, exhaust temps on all cyls and CPPs. Then put all this on a waterbrake Dyno and develop your tune. Otherwise you're just flying blind and speculating.
This is my day job at Cat. In my opinion you're being incredibly naive and optimistic as to what will be possible.
If I were you, I would make an aluminum block and head for a larger diesel. And not attempt extreme specific outputs. This would still be challenging but more up your alley.
If high specific output is still what you want this is how you should go about it. Remove heat from the exhaust valves, custom machine the heads for added cooling passages around the exhaust valve seat.
pistons, they are likely already oil cooled. You could improve volumetric flow rate of oil to the piston with modified squirters and/or higher pressure. You could also lower oil temps with additional cooling and or prioritize piston squirters so the oil is cooler.
turbine temp and turbo speed also need to be considered. Additionally if you're intending to run higher speeds, you could have valvetrain issues. You could also have common rail pump issues. You could also overheat the injector coils if you extending injection times.
ideally you would have instrumented exhaust valves, Pistons with a telemetry system, instrumented pushrods, instrumented injectors, turbo speed measurement, exhaust temps on all cyls and CPPs. Then put all this on a waterbrake Dyno and develop your tune. Otherwise you're just flying blind and speculating.
11-28-2017, 10:56 AM
#1404
Registered
The majority of an engine development programs budget is focused on emissions. But even despite that, a fraction of our budget would financially break someone not on the Forbes list.
11-28-2017, 11:30 AM
#1405
Registered
When we do Engine development here at work we monitor and set high limits for all the values
Engine Coolant Temps
Engine Oil Temps
Oil Pressure(high and low)
Cylinder Pressure in each cylinders. We drill our heads to except CP sensors(each sensors is 10k plus)
Knock
MAF
MAP
Spark timing(actually timing not computer timing)
Injector Open time(actually time not computer time)
EGT(each cylinder)
AFR(each cylinder)
This is all for cal work.
When we do true ground up development we do all the above plus.
Thermocouples 16 per cylinder.
Stress gauge on crankshaft and camshaft
Crank sensor that is good for .01 degrees (can tell if cylinder is not pulling its own weight)
Plus there are 100 of stand alone component testing.
I look at your "engine build" and chuckle on how II throws parts together runs them on the dyno and your making 1k so your good to go. They don't have 100 of engineering's on staff running 30 dynos doing development on 1 engine. It no shock to me that it burned down, and will in till you at the very least get some high dollar data logging that will allow you to set limits.
Then you tell us how you called all these big guys and they said your fine. I highly doubt you got anyone on the phone at cummins that said yup our blocks are good for 3x more then what we rate them for, let alone piston crank, rods etc.
Not everyone on this site is tire kickers that don't know anything. Some of us actually work in the engine development industry and have cut our teeth for say on this stuff. If cummins or anyone else could make a 6.7l diesel live at 1khp they would have done it by now.
Good luck and I hope you keep posting your results, I have a few engineers here at work following this as they are interested in the outcome.
Engine Coolant Temps
Engine Oil Temps
Oil Pressure(high and low)
Cylinder Pressure in each cylinders. We drill our heads to except CP sensors(each sensors is 10k plus)
Knock
MAF
MAP
Spark timing(actually timing not computer timing)
Injector Open time(actually time not computer time)
EGT(each cylinder)
AFR(each cylinder)
This is all for cal work.
When we do true ground up development we do all the above plus.
Thermocouples 16 per cylinder.
Stress gauge on crankshaft and camshaft
Crank sensor that is good for .01 degrees (can tell if cylinder is not pulling its own weight)
Plus there are 100 of stand alone component testing.
I look at your "engine build" and chuckle on how II throws parts together runs them on the dyno and your making 1k so your good to go. They don't have 100 of engineering's on staff running 30 dynos doing development on 1 engine. It no shock to me that it burned down, and will in till you at the very least get some high dollar data logging that will allow you to set limits.
Then you tell us how you called all these big guys and they said your fine. I highly doubt you got anyone on the phone at cummins that said yup our blocks are good for 3x more then what we rate them for, let alone piston crank, rods etc.
Not everyone on this site is tire kickers that don't know anything. Some of us actually work in the engine development industry and have cut our teeth for say on this stuff. If cummins or anyone else could make a 6.7l diesel live at 1khp they would have done it by now.
Good luck and I hope you keep posting your results, I have a few engineers here at work following this as they are interested in the outcome.
11-28-2017, 12:27 PM
#1406
11-28-2017, 12:39 PM
#1407
Registered
I sure hope this all gets worked out somehow, some way. Having planned for a 1000 mile boat trip 2 summers ago I can't even begin to imagine how much effort and planning would be involved in a trip like this. Best of luck.
11-28-2017, 01:34 PM
#1408
Registered
I am building fast cruiser in Finland and think lot of engine choise. Diesel are either heavy or small. There are not so many over 10liter diesel engines that weight under 700kg ever build. I'm going another way and bought 39 liter all aluminium russian V12 tank engine. Going single engine setup with 4 speed transmission and 1 to 2 shaft crossbox connected to two surface drives. 50hp/liter is almoust 2000hp. I appreciate if you can make continous power over 80hp/liter. Piston cooling must be redone. My opinion, just oil spay is not enough. Straight water or water meth injection may help cooling piston enough, but long periods at full power may need something else. Monotherm pistons have much less expand than alu pistons, much better. I have repaired lot of scania engines 9-13liters, every time aluminium piston engine have serious overheated, piston crown to 2. Comp ring area and liner are damaged. Monotherms, newer damaged to this day. Bigger engines are smartest way to go. Lighten up is easier than control extreme pressures and heat.
11-28-2017, 02:05 PM
#1409
Registered
I have really enjoyed the build and all the effort which has gone into it this far. While I'm just a guy which knows "maybe" just enough to fix things when something stops working, I'm in no way in the same league as you guys.Have been reading from the beginning and don't remember some of these comments coming up before.Sure hope some have just now found the thread and have not just been watching all along waiting for things to go wrong.
I'm pulling for ya Tyson
I'm pulling for ya Tyson
11-28-2017, 03:00 PM
#1410
Registered
You may want to look at making a BMW V12 into a diesel. Their highest rated 3.0L diesel had 376hp and a 5400rpm redline.
Assuming most of the parts are interchangeable you could make a nice 6.0L V12. However, I would still have reservations about temps due to the duty cycle in a boat vs a light car.
Assuming most of the parts are interchangeable you could make a nice 6.0L V12. However, I would still have reservations about temps due to the duty cycle in a boat vs a light car.
