Building a Performance Marine Engines

Diesel Freak said:
Don't know diddly about Offshore Racing...

Just subscribing to learn something...


oh, and the thought of 6' swells at 60 KTS makes my kidneys hurt...almost as bad as Trophy Truck Whoops at 40 MPH...
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A trophy truck at 40mph is a walk in the park next to a boat! I'm always impressed with what 30" of suspension travel can do!
 
ok, so for giggles I wanted to see how much power it would take to "displace" 18000 pounds of water at a relative velocity of 60 kts...


um..that is 3313 HP!!!!

so, when do you need to be "on plane" to reduce the power requirement???
 
ok, working backwards from what I see here...(remember, I dont know diddly about boat racing)

I am using the affinity law P=N^3

2 engines, 800hp each.

Boat displacement...18000 pounds

max speed with no planing at all would be 47kts.

so, would it be safe to assume that if you were fully out of the water by 30kts, you would be in good shape??
 
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Diesel Freak said:
ok, so for giggles I wanted to see how much power it would take to "displace" 18000 pounds of water at a relative velocity of 60 kts... um..that is 3313 HP!!!!

so, when do you need to be "on plane" to reduce the power requirement???

ok, working backwards from what I see here...(remember, I dont know diddly about boat racing)

I am using the affinity law P=N^3

2 engines, 800hp each.

Boat displacement...18000 pounds

max speed with no planing at all would be 47kts.

so, would it be safe to assume that if you were fully out of the water by 30kts, you would be in good shape??
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Hi ... actually the speed of a displacement hull is Vhull (kts) = 1.34 x √Lwl (ft.) but your point it valid.

There are a couple of 'depends' (again), but for my penciled-in setup, it would be abt 30kts to plane, 25-30 seconds (read: forEVER!); something over a mile, mile & ½.

But once on plane, the time to 60-80kts would be minimal, and the engine would be loafing (considering).

My guess (assuming all the gearing, prop size, slight chop, etc.) top speed would be 80kts, wet or half-wet - and that would be draining the wheels. Different props & more turns, 100? maybe a bit more - and draining the motor.

there are no standing-starts in offshore, any more.
 
StainlessRRA said:
This is going to depend on your freeze plug set-up. Stock heads have a nasty tendency to toss them out when turning higher rpms.(Obviously mechanical water pumps increase pressure with RPM, hence electric pumps used in many motors) I'd love to give you a PSI range, but I can say we've never had a gauge on one that we've thrown freeze plugs out of. And I don't feel confident enough to take a guess.
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Is there any reason you can think of why I would even need freeze plugs (v. a plate welded over the holes)?

I would like as little electric stuff as possible, but some things just are ... like pumps. Dual pathways and carry spares. It happens.
 
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StainlessRRA said:
A trophy truck at 40mph is a walk in the park next to a boat! I'm always impressed with what 30" of suspension travel can do!
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Preliminarily ... http://shockwaveseats.com/products/three-axis/item/ice-2-2-to-5-man-shock-mitigated-multi-axis-cockpit-swp-1051?category_id=8 (video at bottom)

I am assuming truck racing has a cottage industry in sprung seating? I am not there yet, but the boat can take more than people can, and multi-axis suspension has not made it into marine, yet.

Duh.
 
COMP461 said:
The aluminum block I was speaking of is tremendously stronger the copy in aluminum of a stock block that LSM did. The block is billet aluminum and have replaceable sleeves.
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I found this: Diesel Performance | AERA Engine Builders Association by googling 'diesel performance engine builders' and that was my pointer to LSM.

I enquired abt their CGI blocks first, and that was a non-starter, then I asked abt their machined 4140 and Steve, Jnr said they'd prefer not to do any more of them, but how about their cast aluminum?

If you know of a machined Al Cummins B block, yes, please. There were more than one or two things I did not like abt LSM, but saving 1000# over a pair of OE Cummins 6.7 blocks certainly increases their attractiveness.

There are aftermarket heads for the Duramax come on the market in the next few months from two major mainstream cylinder head manufactures. With these blocks and heads and a reasonable short stroke, 3.600 the piston speed would be lower and aid longevity. The electronic is the only way to go with 40 degrees of timing swing on the fly vs. fixed timing.
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I have no idea what you said abt timing & electronics, I'm sorry. I am comfortable building and maintaining cast-iron diesels, and I need other things than max HP.

DMAX is a non-starter for me, however, for reasons I listed, PLUS when I have an option, I refuse to spend a single pound, pence, peso, penny with GM, so that's a two-fer: DM is completely untried AND it's from GummintMotors.

It is likely I will build a smaller, softer version of this boat, and I would swallow my angst and consider an aluminum DM, but NOT without a substantial service history.

Frankly, I think the VM Motari 3.0 offers a LOT of development potential, pus, it is sooooo cute.

Now to the fuel, The Shell LM 24 is no longer available, or available if you have a quota. I would use a blend of GTL Syndiesel and canola oil.
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I am in England, and I'm not worried abt fuel. My worst-case standby is Jet-A, and chainsaw oil, plus additives. I have enough synthetic diesel stashed to carry out testing in the states.

Again, 1120º, 1-1½ Bar, 625± kW & 6-10litre/mile, I'm gold.

Virtually every engine-builder I spoke with assured me he could make 1500hp as easy as he could make 1000. For MY purposes, that is counterproductive: can't use it, don't need it, needs more wrenching and it dies sooner.
 
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goatskin said:
I found this: Diesel Performance | AERA Engine Builders Association by googling 'diesel performance engine builders' and that was my pointer to LSM.

I enquired abt their CGI blocks first, and that was a non-starter, then I asked abt their machined 4140 and Steve, Jnr said they'd prefer not to do any more of them, but how about their cast aluminum?

If you know of a machined Al Cummins B block, yes, please. There were more than one or two things I did not like abt LSM, but saving 1000# over a pair of OE Cummins 6.7 blocks certainly increases their attractiveness.



I have no idea what you said abt timing & electronics, I'm sorry. I am comfortable building and maintaining cast-iron diesels, and I need other things than max HP.

DMAX is a non-starter for me, however, for reasons I listed, PLUS when I have an option, I refuse to spend a single pound, pence, peso, penny with GM, so that's a two-fer: DM is completely untried AND it's from GummintMotors.

It is likely I will build a smaller, softer version of this boat, and I would swallow my angst and consider an aluminum DM, but NOT without a substantial service history.

Frankly, I think the VM Motari 3.0 offers a LOT of development potential, pus, it is sooooo cute.



I am in England, and I'm not worried abt fuel. My worst-case standby is Jet-A, and chainsaw oil, plus additives. I have enough synthetic diesel stashed to carry out testing in the states.

Again, 1120º, 1-1½ Bar, 625± kW & 6-10litre/mile, I'm gold.

Virtually every engine-builder I spoke with assured me he could make 1500hp as easy as he could make 1000. For MY purposes, that is counterproductive: can't use it, don't need it, needs more wrenching and it dies sooner.
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You would be time and money ahead talking to the one who accually Designed/Built AND Runs the Aluminum Duramax engines...
 
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goatskin said:
Is there any reason you can think of why I would even need freeze plugs (v. a plate welded over the holes)?

I would like as little electric stuff as possible, but some things just are ... like pumps. Dual pathways and carry spares. It happens.
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IMHO wouldn't you want freeze plugs just for the simple fact of not over pressuring the block, and havering a fuse just in case it happened instead of blowing a HG or a cylinder? Idk this for sure just a thought.
 
Nothing wrong with an aluminum duramax endurance engine in a marine atmosphere. We accually have designed a platform for a customer on the westcoast wanting to do the same thing, only less HP.
 
6.4 F-350 said:
IMHO wouldn't you want freeze plugs just for the simple fact of not over pressuring the block, and havering a fuse just in case it happened instead of blowing a HG or a cylinder? Idk this for sure just a thought.
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I have not a clue, neither. I know in the big, slow diesels, they have pop-off valves. I never thought about it, other than I have not had a freeze plug save any car engine I manage to freeze.

I thought they were decorative, like teats on a boar hog.
 
DIESEL_POWER said:
Nothing wrong with an aluminum duramax endurance engine in a marine atmosphere. We accually have designed a platform for a customer on the westcoast wanting to do the same thing, only less HP.
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There are no analogous endurance or marathon events on the West Coast.

Several individuals have maranised DM with indifferent results. You have designed ... where is the seasoned product in a high-demand application.

You said I was wasting my time & money NOT investigating DM. please explain?

I am familiar - somewhat anyhow - with Sveden Marinediesel's offerings, and I have read Bank's releases, ad nauseum. I do not doubt they could be a good inshore, light-duty BBC/repower diesel option.

How costly are they? How much do they weigh? How many turnkey HP & how much torque could I get?

These are different markets, I think, and I cannot see how I could profit by investigating an option which: a) is dream-ware, b) clearly, facially insufficient for my needs.

Did you even look at what I want to do?
 
goatskin said:
There are no analogous endurance or marathon events on the West Coast.

Several individuals have maranised DM with indifferent results. You have designed ... where is the seasoned product in a high-demand application.

You said I was wasting my time & money NOT investigating DM. please explain?

I am familiar - somewhat anyhow - with Sveden Marinediesel's offerings, and I have read Bank's releases, ad nauseum. I do not doubt they could be a good inshore, light-duty BBC/repower diesel option.

How costly are they? How much do they weigh? How many turnkey HP & how much torque could I get?

These are different markets, I think, and I cannot see how I could profit by investigating an option which: a) is dream-ware, b) clearly, facially insufficient for my needs.

Did you even look at what I want to do?
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We currently do not have a seasoned Marine aluminum version to look at. at the end of year maybe we will. Cast iron blocks work but are a bit heavy

However Our Seasoned drag engine is showing very well, and with a few changes would suit the boat enviroment well.

weight is about 650lbs undressed

Marine endurance HP would be 800-1000+ . With higher #'s in the near future.
 
I think a duramax could be made to work, but for the simple fact he is looking for a mechanical injection system rules it out. Looking forward to hearing the progress on this build. Keep the Info coming!
 
DIESEL_POWER said:
We currently do not have a seasoned Marine aluminum version to look at. at the end of year maybe we will. Cast iron blocks work but are a bit heavy

However Our Seasoned drag engine is showing very well, and with a few changes would suit the boat enviroment well.

weight is about 650lbs undressed

Marine endurance HP would be 800-1000+ . With higher #'s in the near future.
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May I know who is "we?'
How much?

However Our Seasoned drag engine is showing very well, and with a few changes would suit the boat enviroment well.​

That is not necessarily true. Period. In fact, that is like comparing chalk and cheese. Green chalk and orange cheese.

I'll ask again. This engine does not exist. Why should I even bother to learn to spell DM.

I can put you in touch with my syndicate if you would like to discuss a sponsorship, when/if you have a real engine and a real history.

I have lives in balance, and I do not think vapourware is an appropriate counter-convo, for your purposes, whatever they are.
 
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