Diesel engines in speed boat
10-08-2008, 06:59 PM
#291
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Thank you, I try!!!
My old posts about Seatek twin pararel turbos vs our axial divided houseings with blockers was all about overcoming this in a simpler way (we thought).
Volvo had an easier answer that was tried and proven for many years, I think we were just too full of ourselves to look at something so simple.
For my money, if I were to build a Cummins hot rod today with a single speed trans rather than a 2 speed - I would look to put something like one of those Vortex chargers on there with the belt drive and put a by-pass on it for once the turbo kicked in????? Very simple.
You need to get up on plane and if you can't accelerate you can't get to make boost to make the Hp.
Joe Gere
My old posts about Seatek twin pararel turbos vs our axial divided houseings with blockers was all about overcoming this in a simpler way (we thought).
Volvo had an easier answer that was tried and proven for many years, I think we were just too full of ourselves to look at something so simple.
For my money, if I were to build a Cummins hot rod today with a single speed trans rather than a 2 speed - I would look to put something like one of those Vortex chargers on there with the belt drive and put a by-pass on it for once the turbo kicked in????? Very simple.
You need to get up on plane and if you can't accelerate you can't get to make boost to make the Hp.
Joe Gere
10-08-2008, 08:28 PM
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Thank you, I try!!!
My old posts about Seatek twin pararel turbos vs our axial divided houseings with blockers was all about overcoming this in a simpler way (we thought).
Volvo had an easier answer that was tried and proven for many years, I think we were just too full of ourselves to look at something so simple.
For my money, if I were to build a Cummins hot rod today with a single speed trans rather than a 2 speed - I would look to put something like one of those Vortex chargers on there with the belt drive and put a by-pass on it for once the turbo kicked in????? Very simple.
You need to get up on plane and if you can't accelerate you can't get to make boost to make the Hp.
Joe Gere
My old posts about Seatek twin pararel turbos vs our axial divided houseings with blockers was all about overcoming this in a simpler way (we thought).
Volvo had an easier answer that was tried and proven for many years, I think we were just too full of ourselves to look at something so simple.
For my money, if I were to build a Cummins hot rod today with a single speed trans rather than a 2 speed - I would look to put something like one of those Vortex chargers on there with the belt drive and put a by-pass on it for once the turbo kicked in????? Very simple.
You need to get up on plane and if you can't accelerate you can't get to make boost to make the Hp.
Joe Gere
10-08-2008, 09:01 PM
#293
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The Banks twin turbo Duramax will for sure have a small turbo to make boost quickly for fast planing. That's how it works in trucks and boats too. I'd still want the multispeed tranny though. It worked for Zero Defect and it will work for diesel performance boats.
10-08-2008, 09:48 PM
#294
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I don't know that VGT's will do it? I don't have the money left especially after this week to play and test, I want to though!!!
I'm hoping things come around and then I'm going to play again. I want to build a diesel race boat again, I'd love to build a Buzzi bullet type boat. Single engine, 30 Phantom or similar (Maybe a Bat Boat?) with an outdrive and use a Lenco step-up box again inside.
I'd love to just go set records for the hell of it. That excites me not this round and round for 50 miles they call "Offshore".
I told stories here of our SH 34, maybe not the fastest at 75 mph but I would round Sandy Hook and run anyone down to AC and back!!! No one ever kept up even as far as Belmar.
Joe Gere
I'm hoping things come around and then I'm going to play again. I want to build a diesel race boat again, I'd love to build a Buzzi bullet type boat. Single engine, 30 Phantom or similar (Maybe a Bat Boat?) with an outdrive and use a Lenco step-up box again inside.
I'd love to just go set records for the hell of it. That excites me not this round and round for 50 miles they call "Offshore".
I told stories here of our SH 34, maybe not the fastest at 75 mph but I would round Sandy Hook and run anyone down to AC and back!!! No one ever kept up even as far as Belmar.
Joe Gere
10-08-2008, 10:03 PM
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I don't know that VGT's will do it? I don't have the money left especially after this week to play and test, I want to though!!!
I'm hoping things come around and then I'm going to play again. I want to build a diesel race boat again, I'd love to build a Buzzi bullet type boat. Single engine, 30 Phantom or similar (Maybe a Bat Boat?) with an outdrive and use a Lenco step-up box again inside.
I'd love to just go set records for the hell of it. That excites me not this round and round for 50 miles they call "Offshore".
I told stories here of our SH 34, maybe not the fastest at 75 mph but I would round Sandy Hook and run anyone down to AC and back!!! No one ever kept up even as far as Belmar.
Joe Gere
I'm hoping things come around and then I'm going to play again. I want to build a diesel race boat again, I'd love to build a Buzzi bullet type boat. Single engine, 30 Phantom or similar (Maybe a Bat Boat?) with an outdrive and use a Lenco step-up box again inside.
I'd love to just go set records for the hell of it. That excites me not this round and round for 50 miles they call "Offshore".
I told stories here of our SH 34, maybe not the fastest at 75 mph but I would round Sandy Hook and run anyone down to AC and back!!! No one ever kept up even as far as Belmar.
Joe Gere
10-09-2008, 08:08 AM
#296
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mthill,
My 2 cents on what 7075T6 is saying is not Hp but acceleration. I think your correct about shear Hp numbers be equal when normalized.
7075T6 is making refernce from "idle to 2,200 rpm's" hence I beleive acceleration or ability to pull from a dead idle to get up on plane and run.
I beleive him that the supercharger /turbo feels like it pulls stronger. In one of my old reponses I talked about a roots blower on top of a Nav 7.3 L and a turbo because of how it could accelerate better.
Take a 6-71TI (426 cui) (blower + turbo) and a Cummins 903 (903 cui) both 400-435 hp range and that 2 stroke DD will get a boat on plane much quicker than the Cummins could dream of ( I know old school engines but same principle).
7075T6 - if I mis-understood what you were saying I apologize, it's just how I interpret it.
My 2 cents on what 7075T6 is saying is not Hp but acceleration. I think your correct about shear Hp numbers be equal when normalized.
7075T6 is making refernce from "idle to 2,200 rpm's" hence I beleive acceleration or ability to pull from a dead idle to get up on plane and run.
I beleive him that the supercharger /turbo feels like it pulls stronger. In one of my old reponses I talked about a roots blower on top of a Nav 7.3 L and a turbo because of how it could accelerate better.
Take a 6-71TI (426 cui) (blower + turbo) and a Cummins 903 (903 cui) both 400-435 hp range and that 2 stroke DD will get a boat on plane much quicker than the Cummins could dream of ( I know old school engines but same principle).
7075T6 - if I mis-understood what you were saying I apologize, it's just how I interpret it.
I have tried quite a few dieselengines in different boats and the Volvos with SC are in a leauge of its own in response.
Volvo dynos every engine that leaves the factory and you can get the sheet from your dealer if you ask. My engines are slightly modified and the dynosheet looks like this except that they rev 3750 rpm.
10-09-2008, 10:05 AM
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The VGT might do it. You can close the vanes down to build boost virtually at idle. There's a limit because exhaust backpressure goes through the roof. It's not a trivial task to balance the two.
For example, the new Ford 6.4L with it's series turbos and VG makes about 1 psi boost at idle and 10-12 psi exhaust backpressure. On tip in, boost climbs rapidly, but it's against an ever increasing backpressure. The result is acceptable performance, but in my opinion, not great. No doubt Ford could do a lot better if they didn't have the emissions requirements that they do.
GM uses a single VGT on the dmax. In 2005 when they first started using it, there was a noticeable lag from when the accelertor pedal was depressed and when the engine responded with boost, maybe 2 seconds. In the latest iteration, they've substantially improved the VG calibration and there is almost no lag at all.
You could definitely make use of the VG in a marine application to aid low-end response. It would likely need a different control strategy than in a truck due to the load conditions being quite different, but it's doable.
For example, the new Ford 6.4L with it's series turbos and VG makes about 1 psi boost at idle and 10-12 psi exhaust backpressure. On tip in, boost climbs rapidly, but it's against an ever increasing backpressure. The result is acceptable performance, but in my opinion, not great. No doubt Ford could do a lot better if they didn't have the emissions requirements that they do.
GM uses a single VGT on the dmax. In 2005 when they first started using it, there was a noticeable lag from when the accelertor pedal was depressed and when the engine responded with boost, maybe 2 seconds. In the latest iteration, they've substantially improved the VG calibration and there is almost no lag at all.
You could definitely make use of the VG in a marine application to aid low-end response. It would likely need a different control strategy than in a truck due to the load conditions being quite different, but it's doable.
10-09-2008, 05:17 PM
#298
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mthill,
I don't doubt they could work, just never saw them in that appliation.
Again, if I were to build a boat today, and needed that extra boost to get up on plane I'd look to do a blower of some sort.
I think Volvo has the electric clutch on the blower?
If you wanted to be very crude why couldn't you take a blower on a clutch off the crank and blow it into the turbo instead of between the turbo and intake?
We're talking what 4" dia tubing on the intake, like firefox says a flapper valve and once you have enough suction from the turbo it will pull from the valve as the boost should keep the flapper closed while under pressure?
Crude, but maybe doable?
That would be an easier way to overcome the problem rather than through re-mapping the VGT controls and you could use existing engines.
That's a product to make to sell to these gys that want diesels in their boats - use stock engines, prop and gear them to run like hell and artifically boost them to get on plane?????
Joe Gere
I don't doubt they could work, just never saw them in that appliation.
Again, if I were to build a boat today, and needed that extra boost to get up on plane I'd look to do a blower of some sort.
I think Volvo has the electric clutch on the blower?
If you wanted to be very crude why couldn't you take a blower on a clutch off the crank and blow it into the turbo instead of between the turbo and intake?
We're talking what 4" dia tubing on the intake, like firefox says a flapper valve and once you have enough suction from the turbo it will pull from the valve as the boost should keep the flapper closed while under pressure?
Crude, but maybe doable?
That would be an easier way to overcome the problem rather than through re-mapping the VGT controls and you could use existing engines.
That's a product to make to sell to these gys that want diesels in their boats - use stock engines, prop and gear them to run like hell and artifically boost them to get on plane?????
Joe Gere
10-10-2008, 07:46 AM
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practical seatek
Love to see the surface drive/diesel talk. As I read this thread I figured I would chime in again regarding fixed surface drives and seatek combo as the experience may help someone as they decide on diesel power for a go fast.
On a fixed surface drive like the q-spd drives that i have, the entire exhaust exits above the prop all athe time. When you go to launch i dont experience an rpm bog down from load...the engines get right up to 3100 but nothing really happens...almost feels like too little bite.
if i put the throttles to 2800 or so and wait 5 secs or so you can feel props start to dig in. Granted i am moving 18,000 lbs minimum. At about 18kts is where magic starts to happen. The whole boat smooths out and starts to feel like it is not in the water and i bring the revs down to 2500 or so to cruise at 45 mph. If you like the drama of a hole shot these are not for you(surface drives).
i must say though how much happier i am with the diesel/fixed drive combo than I ever was with the 420 nmercs and trs drives. Bronze and stainless is all that remains in the salt water. I sleep at night compared to the constant worry about my aluminum drives dissolving in the salt water.
i still think a tweaked(marinized) cummins or powerstroke pair of engines with fixed surface drives would be a ball if the weight of the boat was low enough. Hmm maybe next year.
mark
factoryfive.com
On a fixed surface drive like the q-spd drives that i have, the entire exhaust exits above the prop all athe time. When you go to launch i dont experience an rpm bog down from load...the engines get right up to 3100 but nothing really happens...almost feels like too little bite.
if i put the throttles to 2800 or so and wait 5 secs or so you can feel props start to dig in. Granted i am moving 18,000 lbs minimum. At about 18kts is where magic starts to happen. The whole boat smooths out and starts to feel like it is not in the water and i bring the revs down to 2500 or so to cruise at 45 mph. If you like the drama of a hole shot these are not for you(surface drives).
i must say though how much happier i am with the diesel/fixed drive combo than I ever was with the 420 nmercs and trs drives. Bronze and stainless is all that remains in the salt water. I sleep at night compared to the constant worry about my aluminum drives dissolving in the salt water.
i still think a tweaked(marinized) cummins or powerstroke pair of engines with fixed surface drives would be a ball if the weight of the boat was low enough. Hmm maybe next year.
mark
factoryfive.com
10-10-2008, 09:13 AM
#300
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fact5,
What boat do you have?
The 38 was like that but the 46 had too much exhaust to put through 100%.
The 38 & 46 pleasure boats were like yours. It's a good set-up and works well but it's still to mask the fact that the engine has no Hp at low speeds.
Your just creating slip to allow the engine to accelerate to a point where the engine starts to make boost. Once the engine has some boost it can now overcome the drag/resistance the prop has on it from the increasing rpm's and the boat starts to move and once the wake leaves the transom the effect of the exhaust is now zero.
I'm going off on a tangent here but.............
It goes back to several statements I've made on here and what it takes to have a really successful performance diesel business. That is "Surface Drives are great but to be successful with diesels you have to be able to replace the existing gas engine without modifying the boat's structure, hook-up to the existing Merc drives and give similar performance." This came from Craig Barrie talking to a VP of Cummins and myself back in the 80's and it is as true today as it was then.
Until you can do all those things diesels will just be a novelty for those who like the fact they have diesels.
Joe Gere
What boat do you have?
The 38 was like that but the 46 had too much exhaust to put through 100%.
The 38 & 46 pleasure boats were like yours. It's a good set-up and works well but it's still to mask the fact that the engine has no Hp at low speeds.
Your just creating slip to allow the engine to accelerate to a point where the engine starts to make boost. Once the engine has some boost it can now overcome the drag/resistance the prop has on it from the increasing rpm's and the boat starts to move and once the wake leaves the transom the effect of the exhaust is now zero.
I'm going off on a tangent here but.............
It goes back to several statements I've made on here and what it takes to have a really successful performance diesel business. That is "Surface Drives are great but to be successful with diesels you have to be able to replace the existing gas engine without modifying the boat's structure, hook-up to the existing Merc drives and give similar performance." This came from Craig Barrie talking to a VP of Cummins and myself back in the 80's and it is as true today as it was then.
Until you can do all those things diesels will just be a novelty for those who like the fact they have diesels.
Joe Gere
