Building a Performance Marine Engines

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goatskin

New member
I am building a diesel-powered boat for endurance and marathon racing in Europe. The boat will be built in the states, and dialed-in and raced a little before being shipped to Britain, where it will be campaigned in Europe in A-B and marathon races.

The boat will measure 45'± with a burden of ±#17-18,000 and the design conditions are: run 60+kts for 6+hours in 6'seas (12' crest to trough.)

This will be a Summer 2014 project, and I am still collecting info and thoughts. The Hull has not been commissioned yet, but the gross power design is pretty stable: two 'B' Cummins, low in the hull, nose-to-nose on the centerline. Power will be delivered through a Weismann 6- or 8-speed tranny with a modest OD, through straight shafts, and steered by a single rudder. Closed cooling, water-to-water exchange, engine & transmission oil will be dry-sump and both cooling and oil will have 'hurry-up' pumps and excess capacity.

The basic form will be Cummins B, but the only Cummins part will (likely) be the crank.

I have done a lot of reading and talking and looking at Cummins and FPT/IVECO ... essentially the same 6.7L engine, and it appears the 'natural' (not detuned for consumer use) horsepower for the 6.7L is 8-900-ish at 33-3400turns. I don't MIND more horsepower (if it is 'free') but 8-900 is sufficient.

That is enough for my needs, but I want an engine with known failure rates and predictable consumption. Target is 500hr turbo, 1000hr head, 2000top&bottom, and 2mi/gal, WOT. I am NOT a wrench artisté, and as far as I am concerned, 'maintenance' is clean, fresh fuel and changing fluids, filters and belts regularly.

Here is my 'projected' build, and there are some holes, yes, that I would like discussed, please.

- Cummins OE 6.7 crank.
- LSM Aluminum B block, with bed-plate and 124mm (6.7L) steel sleeves (or maybe a bit wider? LSM says that 8.3L diameter, 135mm will fit nicely.)
- LSM bushings and roller lifters pressed in as part of the build (why? dunno. LSM seems like they know what they are doing?)
- PolyDyn coatings, everywhere: retard oil, repel oil, retain heat, reject heat ...
- 'H' bearings
- Forged conn-rods (no idea on brands) with squirter holes.
- Pistons? my first thought is well-engineered steel. Aluminum? Whose?
- Head. Does anybody make HP CGI or aluminum 6.7L heads & headers? Assuming an OE head, plenum gone, etc., are there ('cost-free') advantages to larger valves, different seat material?
- APR fasteners, everywhere, of course.
- Does the valve-train guy design the cam? If not, who does?
- Whose injectors?

- Fuel system? At this point, I am thinking older Bosch, whose control codes are known to the ECM builder (who I have yet to select, btw), but I am not married to this idea.

- Turbo(s). One small f/t gated at 1 Bar, with a 2nd Turbo whose gain can be turned up to '11' if the water is flat and finish line is in sight.

Generally, I prefer to run a boat with isolated battery, hard-wired Pyrometer, Turbo-boost and Oil-pressure gauges, and everything else on a screen I can look at later. Yeah, I'll have a Bendix cable on the throttle-bodies, too, just-in-case ... why do you ask?

I don't mind spending money, but I only want to spend it once and I would appreciate any thoughts you have - including some I may not like, but I'll still appreciate.

Bob
 
goatskin said:
- LSM Aluminum B block, with bed-plate and 124mm (6.7L) steel sleeves (or maybe a bit wider? LSM says that 8.3L diameter, 135mm will fit nicely.)
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B series bore spacing is only 120mm..........

Sounds like stroke figures are mixed in there somehow.
 
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9724VF350 said:
B series bore spacing is only 120mm..........

Sounds like stroke figures are mixed in there somehow.
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yup, that is exactly what happened, and when I re-proofed it a day after posting, I had to enjoy a face-palm. (and then the edit button was nowhere to be found).

Bore would be 107mm (4.210") plus a teeny for good luck.

thanks,

Bob
 
Will a LSM block allow enough coolant circulation for the application? I know they offer a cooled block, but there's a big difference beween a cooling system meant for a 7-15 second full power run, and flogging on it for 6 hours straight. Lots and lots of hot spots to develop.


No need to stroke any more than a 6.7 crank, even that is unnecessary in my opinion.

CGI blocks exist, or did at one time. not sure if they were 5.9 or 6.7, but since you plan on spending 30k for blocks, I would seriously investigate that option.

4.210 is all the bigger LSM will go?
 
9724VF350 said:
Will a LSM block allow enough coolant circulation for the application? I know they offer a cooled block, but there's a big difference beween a cooling system meant for a 7-15 second full power run, and flogging on it for 6 hours straight. Lots and lots of hot spots to develop.
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good point(s). (and aluminum block is not final choice, but it an attractive option) I'll be running a water-to-water heat exchange, with a in-line flow pumps: full stream, ±psi. The VW TDi setups I've seen rigged like that keep water a few degrees over raw-water, maybe 160-165º v. 130-140º raw-water.

No need to stroke any more than a 6.7 crank, even that is unnecessary in my opinion.
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'splain, please. I think I get it, but ...

CGI blocks exist, or did at one time. not sure if they were 5.9 or 6.7, but since you plan on spending 30k for blocks, I would seriously investigate that option.
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You hear various stories, but bottom-line is the Govvies have the contract from Brazil, and have not released any CGI blocks.

The current runs are full-strength plugs, no new tooling to make reduced weight.

4.210 is all the bigger LSM will go?
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Ambiguous. I got some song and dance about valves not sealing or assymetry or something. mumble, mumble maybe 4.25 or 4.28m depending on sleeves.

I did ask him how well/long without movement/backing ARP fasteners held, and he said forever. I have a call into ARP to know their history with alloy blocks.

We got sidetracted (as well as with a couple of highly-recommended engine builders) on how blue-water marine application has some interesting demands that no other application can duplicate.

It's a process, and I still have to go to school for 3 years to get up to ignernt.
 
goatskin said:
'splain, please. I think I get it, but ...
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For your horsepower goal and longevity that you want, I would stick with a 5.9 crank, a custom length longer than stock rod, and a OEM aluminum piston. Sisu has a short 4.250 bore piston that would probably work well for what you are doing.

I don't think I would get too carried away with compression ratio if you plan on making 900 hp for 6 hours straight.

You hear various stories, but bottom-line is the Govvies have the contract from Brazil, and have not released any CGI blocks.
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Well that sucks. I was hoping you would find some, I want one. LOL

Roller cam is better, but until someone can prove that their design will work for the endurance that you want, I would lean toward flat tappet.
 
cumminsman315 said:
I wouldn't bother with throttle bodies
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That was only a little hyperbole. Earlier, I was working with Isotta Fraschini trying to convince them to re-build their pre-'modern' 1306 into a full-mechanical beast.

When I told them lack of electronic controls were no issue - that I would just chisel-off the rpm limiter and hook up Bendix cables to throttle bodies making an 800kW beast - they wore their hands down to their elbows yelling at me (and all 'Mercains) about our horsepower fetish ... and our lack of concern about the environment ... and ... and ...

The Italians are always fun people to talk with.
 
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9724VF350 said:
For your horsepower goal and longevity that you want, I would stick with a 5.9 crank, a custom length longer than stock rod, and a OEM aluminum piston. Sisu has a short 4.250 bore piston that would probably work well for what you are doing.
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If all these other bits and pieces make me uncomfortable with different/competing performance claims, talking abt pistons seems like I am trying to understand Urdu, spoken rapidly.

Sisu, Arias, Mahle's sculpted head and land-ring ... whew. All aluminum. Can somebody tell me why I don't want steel?

I don't think I would get too carried away with compression ratio if you plan on making 900 hp for 6 hours straight.
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Most runs will be only 3-4hrs or will be composed of multiple legs. Some will be longer: NYC-Bermuda is 750nmi non-stop, KW-Cancun-KW is +800, Venice-Montecarlo is 1100 (with one- or two-stops for more gas & a glass).

The 60/6/6 not only is easy to say and remember, it is the design condition for both hull and haul. 'Marine' is the very hardest job any engine can do, and that 60/6/6 accurately describes the steepest hill in the mountain range.

I think the top speed (depending on how much fuel and how it is wheeled) will be 90-95kts, but if I'm light enough and the seas are flat enough for ME to run 100, most of the the other boats will have blown past me 20min ago.

800± day-and-night hp a side is about the minimum for moving a full #17-18,000 ride crisply through seas. If the ('natural') build happens to be 1,100hp, I can live with it, but making hp for hp's sake is a false goal.

At some point, there is going to be some 'build' configuration that is efficient, reliable, conservative and has a 'natural' 32-3300rpm sweet spot somewhere between 800-1000 (with another 200hp ready when I bury the sticks the last hour).

In the alternative, there is also something to be said for the same power range, running at ±38-4000rpm, as that would simplify the power train a lot by using crash boxes instead of trannys.

At this point, after talking with a few builders, what makes the most sense to to me (at THIS point ... I'm fickle) is to get a 12v Hamilton Head, turn it over to C-Tech and tell them, "I want WIND." then build the bottom-end to run the head, and see where HP actually is.

??

Since I'll have numbers on the side of the boat, I can (legally) make a fully-mechanical 'smoke and noise' motor, and the nannies and tree-huggers can like it, or not.

Well that sucks. I was hoping you would find some, I want one. LOL
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Actually, there are five 2nd- or 3rd-run CGI castings in Innovation's warehouse the Gov't rejected b/c LSM overbored the 'cam bed'(?) and neither paid for, nor returned them to LSM.

I have begun the paper chase with DOD/Navy to purchase them. If I am successful, do you want one or two?

Additionally, the Navy has (hinted) indicated they MAY release up to 50 late this summer for civilian use. May. Maybe. Perhaps. Possibly.

LSM says that since their Alloy block is so good (and weighs 200# less) the demands, bribes, moans and pleadings for Vermiculite Iron Blocks have slacked off a lot.

Roller cam is better, but until someone can prove that their design will work for the endurance that you want, I would lean toward flat tappet.
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I think that is 100% correct. The potential 'cost' of roller does not offset any performance advantage (if any).

Bob
 
goatskin said:
Sisu, Arias, Mahle's sculpted head and land-ring ... whew. All aluminum. Can somebody tell me why I don't want steel?
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I would forget Arias, Ross, custom Mahle, or anything else that does not have a steel top ring land.

I would be all for a steel crown, but I'm not sure about the steel skirt for a endurance application I'm not aware of a OEM piston that uses a steel skirt, that makes me question longevity.


At this point, after talking with a few builders, what makes the most sense to to me (at THIS point ... I'm fickle) is to get a 12v Hamilton Head, turn it over to C-Tech and tell them, "I want WIND." then build the bottom-end to run the head, and see where HP actually is.
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For what you are doing, "WIND" is not necessarily the answer. You need good air.

Since I'll have numbers on the side of the boat, I can (legally) make a fully-mechanical 'smoke and noise' motor, and the nannies and tree-huggers can like it, or not.
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I do like the fact that you are leaning toward 12V mechanical.



Actually, there are five 2nd- or 3rd-run CGI castings in Innovation's warehouse the Gov't rejected b/c LSM overbored the 'cam bed'(?) and neither paid for, nor returned them to LSM.

I have begun the paper chase with DOD/Navy to purchase them. If I am successful, do you want one or two?
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Let me know what you find, I have a customer that wants to go with a LSM block, but I would rather see a CGI in his application.

Additionally, the Navy has (hinted) indicated they MAY release up to 50 late this summer for civilian use. May. Maybe. Perhaps. Possibly.
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:Cheer:

LSM says that since their Alloy block is so good (and weighs 200# less) the demands, bribes, moans and pleadings for Vermiculite Iron Blocks have slacked off a lot.
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There's quite a few places where a OEM block is required, and something better than stock would be nice.
 
9724VF350 said:
... For what you are doing, "WIND" is not necessarily the answer. You need good air.
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To the extent it will be fresh, heavy and humid, we're gold. Temps? it is what it is. UIM/RYA Marathon Regs do not allow any kind of mechanical cooling, nor forced-air induction (2" gap is the reg).

I'll have the scoops mounted atop the cockpit, then through water separators, of course, but 2400cf/min put into a 'box' atop the headers is a piece of cake.

I do like the fact that you are leaning toward 12V mechanical.
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Old Style has some points in it's favour, yus.

Let me know what you find, I have a customer that wants to go with a LSM block, but I would rather see a CGI in his application.

There's quite a few places where a OEM block is required, and something better than stock would be nice.
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I have a suspicion that since Tupy is a licensed, limited&permitted use contract in favour of DoD (and their designated friends, like the Hong Cong Navy), v. the castings being owned/controlled by Cummins, then there are some IP issues, real or potential.

¿ Assuming competent short-run foundry capacity could be found, and new tooling for the old IVECO 6.7 (cough, cough Cummins cough, cough) produced, could the market soak up a couple of hundred smaller, lighter, stronger CGI blocks a year?

(I'm an i-banker, and I'm working with an Aircraft Diesel start-up who wants their production V8, 12 & 16 models to be CGI v. alloy, so I am noddingly familiar with some of the issues of small-volume CGI casting, incl QA/QC which are not trivial.)

Bob
 
estrada5.9 said:
What does that mean?
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In UIM Rules, there are lots of 'competition-leveling' rules, and I THINK it is a holdover rule-around against non-mechanical 'superchargers.' The only time you see it is related to gas inboard engines, but the 2" separation between the glasswork and intake is there for everybody.

You can't air condition the engine room, neither, and in most of the forms of racing, you can't mechanically cool the fuel.

I'll be running under Marathon Rules http://www.rya.org.uk/SiteCollectionDocuments/powerboatracing/2012%20Docs/Marathon%20Rules%202012%20Section%20WC%2005.12.2011%20.pdf but in the 'run what you brung' classes.

Still lots of 'picky' but different.
 
45' and 18,000 Lbs? 2000hp is not even getting you close to that speed in 0-1' seas.. Not even getting into carrying enough fuel to satisfy two B series running at their edge for 6 hours.
 
FV SarahBrent said:
60kts. @6hrs in 6ft. seas ? good luck with that!
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Yeah, you HOPE one of the three is not there when the green flag drops.

Offshore Racing is not for the faint of heart, nor thin of wallet, no, but if you are going to piss blood anyhow , standing on the podium spraying champagne (rather than being in the audience applauding) cures that little issue quicker.

Seating helps. The boats can take much more than the crew. We will be using a variant of this: http://shockwaveseats.com/products/three-axis/item/ice-2-2-to-5-man-shock-mitigated-multi-axis-cockpit-swp-1051?category_id=8 (be sure to look at the video at the bottom) and figure that will 'give' us 20kts and 2hrs.

This is one of the hulls we are considering: [ame="http://www.youtube.com/watch?v=mgUUjidWkRs"]WORLD CHAMPIONSHIP OFFSHORE POWERBOAT TEAM WITH DRIVER ALEXI SAHAGIAN NIGEL HOOK - YouTube[/ame]
 
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