Inboard Diesels for Leisure RIBs - choices?

willk · 06 January 2012, 18:34

A year has passed since Yamaha announced their departure from the inboard/outdrive market. Yanmar and Volvo seem well positioned to fill the gap. I've had a bit of time on the 6 cylinder Yanmar 315, managed to horse a Yanmar ZT-350 outdrive and failed to do the same with the ZT-370, so some experience there, however:

Any new thoughts on good power to weight ratio combos from these or other manufacturers?

Anyone had experience with the new Yanmar 320/370hp 8LV? It looks good on paper, but then, they all do - Nice test video below.

I see a couple of small Hyundai Seasall (sounds like a penetrating lubricant) in Redbay Boat's shed. I think they plan to try them on smallish RIBs with a Yanmar leg perhaps? I've never heard of them around here before - any takers for comment?

http://www.youtube.com/watch?v=XLD6mgycXYU

Turbodiesel · 06 January 2012, 20:34

The 8LV does look good and the outdrive, just been on a course for it in Holland at Yanmar.

willk · 06 January 2012, 21:04

Quote:

Originally Posted by Turbodiesel

The 8LV does look good and the outdrive, just been on a course for it in Holland at Yanmar.

Right! Was the course on the motor and leg, or just the leg. The ZT-350 was a piece of crap, I've seen the Yanmar agent's service upgrade sheet! What was your take on the improvements than should allow the 370 to handle all that torque?

Turbodiesel · 06 January 2012, 21:52

Just the motor really, didnt go into the leg to much other than they have improved the 350, which has been replaced by the 370. I have heard on the grape vine that the leg has been very good, but i have heard of a few problems with a couple engines not producing power.

Erin · 07 January 2012, 13:55

Steyr and VW (now CMD) are both pretty good in my view for power to weight and also fairly refined and advanced being based on modern car versions. Another deciding factor for me with the VW was ease of service as it was marinised by the manufacturer rather than a later company.

Cookee · 08 January 2012, 11:00

Don't forget the Yanmar 260's as well - they come with either a gearbox, Bravo I, III or the 370 leg.

willk · 08 January 2012, 11:24

Quote:

Originally Posted by willk

The ZT-350 was a piece of crap, I've seen the Yanmar agent's service upgrade sheet!

Linky

Gotchidad · 08 January 2012, 13:03

*Cough Redbay 16m flybridge with twin Mercury Racing 1350hp sterndrives *cough *cough

(think of the fuel bill!)

(gotchiguy)

jwalker · 09 January 2012, 20:19

Quote:

Originally Posted by willk

Linky

So, what's in Quicksilver HPGL that's not in GL5 80w90 I wonder. I'd guess it's still GL5 but synthetic and possibly 140 upper grade.

Siochair · 12 January 2012, 21:35

Hi Willk,

Have you had a look at Motorboats Monthly? It seems that one of their articles is a group test of various diesel in-boards. I've not managed to read it yet myself but I was told that the Yanmar 8LV was included.

Cheers

willk · 12 January 2012, 22:45

Oh that's interesting! What Month is it? As chance would have it, I'll be in Civilisation next week with some time to kill. That would do nicely...

Edit: orrite - February then. k.

willk · 12 January 2012, 22:48

Quote:

Originally Posted by jwalker

So, what's in Quicksilver HPGL that's not in GL5 80w90 I wonder. I'd guess it's still GL5 but synthetic and possibly 140 upper grade.

Prolly got less metally clutch bits in it

jwalker · 13 January 2012, 01:02

Quote:

Originally Posted by willk

Prolly got less metally clutch bits in it

Oh I see, you buy it pre fortified...

jwalker · 13 January 2012, 01:35

Mr Willk I'm sure you know but take care not to be driven by max power rather than drivability and reliability. Reliability is obviously essential to peace of mind wherever you are on the ocean and especially on your own boat rather than a borrowed one, you really don't want to be fekkin about with something you don't have confidence in. Aside from the hassle of repairing, down time and cost. It must never fail you as sea. Never is probably not certain but you need freedom from that worry. 10 miles offshore in twisty turny difficult water, the very time the drive line is stressed, you want the certainty that you can clip in and out of gear, steer freely and throttle without concern. You'll need that at Cushendall too...be embarrassing to get yourself grounded on those rocks while turning.

Which leads on to drivability, plenty of low down power and freedom from turbo lag is much more important than a few knots higher top speed. Having both is good, obviously, but if there's a choice it has to be a sacrifice of top end.
Imho as usual, of course. Just bringing you back down to reality from that talk of maximum horse power and drives that may or may not fail.

willk · 13 January 2012, 10:20

Quote:

Originally Posted by jwalker

Mr Willk I'm sure you know but take care not to be driven by max power rather than drivability and reliability. .........Just bringing you back down to reality from that talk of maximum horse power and drives that may or may not fail.

Your post reflects my thoughts exactly.

My reference re. Power to Weight was more to restrain the enthusiasm of the Caterpillar/Cummins/Iveco boys, as that kit is not the area hat I'm interested in.

Zippy · 13 January 2012, 14:14

We had a Steyr 256 in the rib (250 HP) with Bravo 1 leg and was very impressed. light engine, turbo would kick in early, little lag and easy to helm in big seas. very responsive.

I know they do a 300hp version of the same engine which would also be nice!

Cheap they are not both for purchase and service but very good power to weight and i though ideal in a rib. i was hugely impressed when comparing the steyr to a Yanmar 315.

Neville · 15 January 2012, 23:02

I would suggest that the power weight ratio of the larger 4 cylinder iveco and the smaller 5.9 N60 400 hp iveco block is not that far away from the toy 4.2 litre yanmars & yamahas. Longevity will be 6 - 10 times longer in my experience aswell. Cummins also make an almost identical 6 cylinder block but not the 4.

Whilst these are slightly heavier than the 4.2 counterpart, cost of the iveco at present may be the same if not cheaper from some dealers compared to the yanmar.

I am just in the process of repowering with a pair of Ivecos 370 hp and although slightly bulkier I like the idea of an engine that will last over 12000 hours before one needs to spend major money again on rebuilds or replacement.

You wont get that from a Yamaha or Yanmar.

willk · 16 January 2012, 00:52

Quote:

Originally Posted by Neville

I would suggest that the power weight ratio of the larger 4 cylinder iveco and the smaller 5.9 N60 400 hp iveco block is not that far away from the toy 4.2 litre yanmars & yamahas.

N60 Iveco (370hp) has 0.67Hp/Kg
Yanmar 8-LV (370Hp) has 0.85Hp/Kg
Yanmar 6-LP (315Hp) has 0.77Hp/Kg

I haven't had a chance to compare the dimensions yet but I wonder how bulkier the block is? The performance figures are fairly meaningless to me, I'm afraid - maybe someone would "compare & contrast" for me?

Are Ivecos REALLY that bulletproof - even the higher output leisure rated units?

Cookee · 17 January 2012, 08:58

I think everyone is missing a crucial point here - Diesels are notoriously hard on drives and the bigger the CC the more torque a motor has and the more torque the more stress it puts on the drive, now if it's used sensibly with the hull never leaving the water everything should be fine but you start doing full power launches and getting enthusiastic with big block diesels and you'er asking for trouble!

The smaller CC common rail motors are economical and less stressful on the drives - IMHO!

Zippy the 315 is old school now and is being replaced by the 370hp 8LV which is also a Landcruiser motor but a V8, the comparative Yanmar to the Steyr is the 260hp 6BY which we have in the race boat - the 280 Steyr is for jet drives only and there is no 300hp version of that motor, in fact Nick Gilley of "Swipewipes" tuned their Steyrs up to 290hp for Coniston and they are working closely with the factory.

Zippy · 17 January 2012, 10:20

Thanks Cookee,

Sorry, i was comparing the Steyr to a previous experience of the 315 in a Revenger so prehaps not a fair comparison for a new build, obviously everything moves forward thankfully!

I thought Nick changed the original 256's he had in Swipewipes to MO306's and turned them up from there? anyway, looking forward to later this year to see you and them run together.