Talking Diesels

[mull dog]

I am looking into the idea of a diesel sterndrive on the next boat. I have looked at the spec sheets of a few different brands but having trouble trying to gauge pricing. I have browsed Yanmar, Steyr, Cummins, Volvo etc and am looking around the 190-230 hp bracket. Would anyone be able to give a rough idea on a supply and install price on any of these brands or any general info that could be of use in regards to what to look out for. It will be powering a 7.5m aluminium craft.

Cheers MD

[Midnight]

Budget on 50k and you should be right. Really look at access to regular maintenance items on each of the engines. Volvo have the pick of the sterndrives, followed by the Yanmar ZT350.

If I was powering a 7.5m boat, I would be looking at the 315hp(it is actually about 298hp with our crappy diesel) 6LP Yanmar and the ZT350 drive. Prop it so you can reach 3900-4000rpm fully loaded, fresh water flush it after use, keep the anodes and normal maintenance up to it and it will be a great thing for years to come.

The Volvo D6 and DPH drive is really nice, but there have been a few computer issues with them around the place, and Volvo will rape you for parts.

QSB Cummins is really the pick of the 6 cylinders, but it is hard to find a drive to match up to it here. None of the Mercruisers will handle the torque. Konrad and TRS drives were popular in the USA.

Have fun with the search, but my pick is the Yanmar.

Cheers,
Myles

[arvor]

my pick would be yanmar as well. i had a yanmar in a previous boat with many hours on it .but when it came to rebuild it did cost.
if i was to repower now in this boat id look very close at the new hyundi seasal.modern tech great power range.and lightweight.have a look at the reports you may be surprised?
good luck .

[Alchemy]

Have a read of this. Engine with bravo 2 stern drive is 32k. Install was about 4k.
http://www.ausfish.com.au/vforum/showthread.php?167666-Our-new-Origin-Evolution-7500-diesel-sterndrive-%96-the-build&highlight=origin

[mull dog]

Thanks for the replies guys. i was trying to get a price comparo between a diesel and 250hp 4stk yammy. one of the best riding boats ive been in was a platey with diesel stern drive and was going to see if it was financially viable. I did have you in mind Alchemy when i posted this thread although im not going with Origin. How have you found the fuel savings compared with the old fisher?
once again thanks heaps

[Midnight]

The savings with the diesel over the outboard come in if you do a lot of trolling, and a lot of hours annually. The servicing costs of 4 stroke outboards gets up there when you have to service them every 100hrs at 700 bucks a pop and you are doing 300hrs a year. But then the 250 Suzi will be damn near half the initial purchase price.

I too prefer the diesel stern drive set up from a boat ride point of view, keeping the weight in the bilge.

Lots of pros and cons for both set ups.

Cheers,
Myles

[Nic]

Thanks for the replies guys. i was trying to get a price comparo between a diesel and 250hp 4stk yammy. one of the best riding boats ive been in was a platey with diesel stern drive and was going to see if it was financially viable. I did have you in mind Alchemy when i posted this thread although im not going with Origin. How have you found the fuel savings compared with the old fisher?
once again thanks heaps

I haven't worked it out for over 9 months now, but back then was just under 0.7 litres/km. My 200 suzi was 0.8 litres/km. Keep in mind the new boat is a lot bigger/heavier and the result is great. I have just returned from the Gulf of Carpentaria where I towed a 3.9m tinnie around at 15 - 18kts plus a big load aboard Alchemy. I covered 338km and estimate I used between 300 - 340 litres of diesel. Again, an excellent outcome.

[Smithy]

So many choices and pretty hard to pick. Know of one boat running a 5cyl Iveco that just didn't work. Had no balls down low. Could be a problem with all these bombed up common rail motors producing big horsepower with high revs. They repowered it straight away with a Yanmar. Still a lot to be said for CCs. When it comes time to repower I think I will look at them all for sure but may just go with a Yanmar again. A different brand will open up a lot of gearbox options and the potential to fit a trolling valve though. Currently my Yanmar to a ZF gearbox runs on auto transmission fluid and has a pretty tall ratio. Most of the bigger gearboxes run on the same oil you have in the engine. One serious option for me to repower with is the V6 Hyundai producing 300hp which will be lighter and more compact than my current 230hp 4 cyl Yanmar as well as cheaper. I am talking shaft drive here. I hear of the least amount of problems with the Yanmars and Cummins. A Cummins/Mercruiser combo would have to be a saft bet.

[myusernam]

check this out
http://www.yanmar.com.au/media/34462/mojo.pdf
even if a bit of exaggeration (18lph at 27 knots) a mile per litre should be easy

wasn't there a guy on here with a nossa cat with twin 4cyl diesels and he got 1nm per L at 25knots (combined)

looked at a bertie that had a single volvo (the super and turbocharged one) and he said he got a mile per litre or better

[mal555]

A W.A. Volvo agent told me last year that it will take 3000 engine hours to the break even point of installing a diesel over a petrol.
You would need to do a lot of trolling to justify the initial expense and don't forget about the noise the diesel will produce in a small alloy boat.

[Alchemy]

I'm not sure why some of you keep going on about the initial purchase cost. My Lombardini / mercruiser package is very competitive to a big four stroke outboard. It may not have the same top end speed as an outboard but it gets out of the hole just as well as one!

[arvor]

sorry mal but its not all about liters per n/mile.there are other advantages.275 to 300 kgs at or below waterline.as oposed to 200 odd kgs 1.5 mtrs above waterline.
servicing .i do my own at around $120 and two hours.
but each to there own .for me id never go back.

[myusernam]

did anyone check out the mojo link above in my previous post? I am in love with the idea. if only I had the cash. Honestly if thos perfomance figures are anywhere near correct I cant understand why you would build or buy anything else in that size range. what a top rig. yeah purchase price what the? $30 k for a big fourstroke that's going to use 50lph plus, need servicing by a dealer, not be as reliable etc etc

[Smithy]

Mojo had the Iveco in it originally. Parkesy had just come from a 33' Obrien with twin SRM33 Iveco/Fiats. I still find it hard to believe fuel consumptions people quote. Unless they have floscan or similar or electronic gauges that do actual consumption they are just guessing. Where you make it up is idling or trolling. There are still laws of physics at play. There is only so much calarific value of fuel in a litres of diesel, that has to be turned into horsepower and that in turn has to push a certain weight through water.

In my case my 3.45 litre 4 cyl does a worked out 29 litres an hour at cruising revs of 2600-2800 pushing my 3tonne boat. My redline is 3100 and few people have said I should probably pull about 3300 if propped right as they should spin easy. With a clean bum and light load I might hit 3250 or so. I don't like the idea of big 4.2 litre 6 cylinders having 4200 redlines and 3400 cruising revs for longevitity. Time will tell how the new motors go. Nothing like the old slow reving Gardners etc. for a motor that will last for ever and ever.

As per Arvor above, my filters cost about $40, $44 for an impellor and I use 12 litres of oil with a 20 litre costing around $110 so $66 for oil every 250 hours. Every 500 there is the gearbox oil and filter. Therefore about $150 every 250 hours and $300 every 500 hours.

[Midnight]

I'm the same re the high revving, high boost, low cube motors. They are a highly stressed beast and need to be under propped to last. Also the cooling system must be kept in perfect condition, as things end very quickly with these motors in an overheat situation.

All that said, well set up and well maintained, with rec boating hours, they won't wear out. It is the marine age that will kill them first.

My 3208 Cats are 10.4L, weight just under 1000kg each with the box on the back, and are only putting out 260hp. I cruise at 2300rpm. They have got nearly 5000hrs on em now and I expect another 5000 easily. They are dinosaur technology and can't come close to the efficiency of the modern engines.

The new QSB Cummins is 5.9L putting out 480hp at 3400rpm. A lot of HP per litre!

[Smithy]

Then you compare them with truck motors and it becomes how bombed up they are. Brooksy's Ivecos are 5.9 litre with the smallest injectors of that size range for that block (270-300-330hp) and for 270hp with a 2800rpm redline and a 2100rpm cruise and if his was in a truck it would probably be 90-120hp. Same as my motor which is basically a 2H Landcruiser motor with two cylinders chopped off. What is a 6cyl Landcruiser, 90hp or so? The 4WD experts can chime in here. For my 3.45litres Mr Yanmar is wringing 230hp out of it with the turbo.

[Greg P]

Dont worry about the little V8 Cats Myles. They were screwing over 430 BHP @ 2800rpm in the ATAAC marine versions before all the commission crap killed them off as a product line ;D;D;D Some of the truck versions were even low 520s. They lowered the compression ratio a little though ::)

[PB]

The diesel stern drives are very competitive against twin outboards, We have just priced a new Custom 680 with a Cummins and it was a little cheaper than doing the same boat with twin outboards.

[Midnight]

I'm not worried about em Greg, at 260hp they aren't breaking a sweat. Especially considering you can get 225hp out of a natural. It is a lot of iron for the HP.

[Midnight]

Smithy I know what you mean. The 6LP 4.2L Yanmar is a 100 series Cruiser motor essentially. In the Cruiser it makes 201hp at 3400rpm, Yanmar have it pumped up to 315hp at 3800rpm (298hp on our diesel). I guess some efficiency may be gained with the sea water cooled intercooler vs the air to air intercooler on the Landcruiser, but it is still over 70hp/Litre .
The QSB5.9 at 480hp and 5.9L still wins the highly stressed stakes at over 81hp/L. And that is from the old 6BT base engine which was 210hp originally.

I doubt there are many dudes in the USA getting 480hp out of their 6BTA powered Dodge utes!

But back to the original thread. I personally would still prefer a diesel sterndrive over an outboard in a big trailer boat.

Cheers,
Myles

[myusernam]

if it was a close choice between the yanmar and another brand the yanmar would have to be a good option in that you anre not bound by marine parts and you can head to supercheap for filters/ parts etc. lots of dead 100 series cruisers around.

you guys running diesels have you considered running frantz filters or a centurfuge and synthetic oil and just getting the oil tested rather than changeing it? (changing when needed) That's what I'd like to do. Frantz filters are th bomb There is an aussie company that tests your oil for free if you use their products. interstate truckers gettin over a million kays without rebuild

Smithy hearin ya about gardiners. My old man had ford lees in both his boats which were pretty good and parts were cheap. Gardiners are and always will be the holy grail but...and cheaper in fuel than the more modern engines in displacement hulls

[Smithy]

Myusername I have never heard of them. I did find a cheaper monograde SAE30 though for myself than the figures I mentioned. If I wanted to use a 15-40 multigrade I could nearly get it for nothing through one source but for most of it's life it has been run on Caltex Silver Delo 30 grade and the oil analysis came back perfect so I don't want to mess with that now it has 6,600 hours on it. The one mechanic I am using says the motor I have is pretty bulletproof if it breaths easy and the filters and oil changers are kept up to it but the only blown up ones he knows about have come from motors run on 15W-40 and it is to do with the little oil sprayers. I know how important those little suckers are as I think they contributed to one of Brooksy's rebuilds with starboard motor in Ymer.

Yep I was nearly going to mention Ford Lees in the same breath as the Gardner.

Filters for my Yanmar are easily and cheaply sourced at a truck place. I use Suncoast Truck Spares at Kunda Park on the Sunshine Coast and find them great. Thanks to Roger B on the heads up for that one.

[Greg P]

I think you are spot on Rob in not changing the oil type after along period. There is a lot of different additive packages used by each brand and they can sometimes have a long term impact on oil coolers/heat exchangers lifecyle etc in a marine applications. The key to oil analysis is to watch the trend of the oil (metals, additives, contaminates etc) and look for combination of elements that could indicate issues (chromium, silicon, iron = dust ingress), high copper with coolant trace. One off samples are good when buying as they can give you some idea if the owner is truthful about oil age (you can pick it up via viscosity reading) but the trending is what you need to monitor. Valvoline was a great example when you read a sample and did not have that oil type you would be advising customers to look for coolant leaks due to the additives. A lot of engine manufactures are going extended oil change intervals but in most cases they need to monitor oil and increase sump capacity to cope.

The new common rail/electronic management system diesel also cope much better than the old diesels with extended oil intervals. Look at the drama Toyota used to have with their small diesels in Hiluxs - sumps were like treacle if you went over 5000k. D4Ds are back out to 10K and the new Ford Rangers are 15K - I think.

As far as the Franz filters go - they can be good but sometimes a little too good and filter out additives - maybe that has changed since I was pullin spanners at Hastings.

The old Ford Lees diesels were great. We put plenty in marine and stationary gensets/fire pumps when I was doing my apprenticeship at Metro Power - crap work though.