29Firefox

Big trucks evolved from V-8s to the L-6. Not because of the size of the package but because of the Hp to displacement ratio. The larger older style trucks like the Peterbilt 379, Kenworth W900, Freightliner Classic XL and the now defunct cab overs went through the evolution. Those older designed trucks have plenty of room for a V type engine but go with the L-6 because they are more power efficient. As for light trucks what about all them Dodge and Ford pickups with Cummins L-6s?

fastlane40

29Firefox when was the last time you saw a real time drag racer using a buzz box Nissan engine?I think they are suited to that pathetic "drifting".Cubic inches always wins when comparing apples with apples.Stirling hit the nail on the head.

stirling

Well... not here in Europe ,when the power goes up all the big trucks go to V8 engine,s

Mercedes benz V8 16 litre 551 hp and 2600 nm or 1925 lbs/ftmax

Scania V8 16,4 L 620 hp 2600nm or 1925 lbs/ft max

MAN 16 L 680 hp 2700 nm or 2000 lbs/ft max

out of the box power

those are three popular trucks overhere .the MAN is the most powerfull engine ,next year Scania comes with a 700 hp V8

I work on these truck every day,one guy has a Scania V8 he weight empty 65 ton ,fully loaded 175 ton ( with a 110 ton dragline on the back 110 ft long total) and he kick azz with that thing

I can,t post here ,if I could, I would post a pic of that monster truck combo

The line 6 ,s are for light duty (thats what the truckdrivers use to say here )

Njawb

Don't tell 29Firefox, stirling, but those MAN and Scania V8s have a better horsepower to displacement ratio than the I6, 14.9l Cummins ISX 565.

HabanaJoe

I agree with all about the Man's and Scania's having greater HP.

No more BS, I'm too tired, was striper fishing all moring in NE winds in the cold here in NJ!

Why do the V-8's in the truck market here in the US seem not to do as well as the I-6 in terms of durability?

Do you think it is purely the fact that the I-6 are less hp/cui? I've seen some of the Scania's here and they can touch the I-6's but why, on paper the V-8's should kick BUTT!

I will tell you Cummins (903's), DD (8-92), Mack and Cat (3408) all tried V-8 diesels in over the road (OTR) trucks with little success. Aside from the weight factor these engimes just did not hold up well to all the shifting and the non-stop miles. The complaint we heard even from the manufactuers was the cranks could not cope with it???

Trucking (OTR) here in the US I think can only be compared to maybe trucking in AUS & Can. The European market does not have the no-stop long haul that we have here.

In the late 70's when we started trucking our first trucks were the 8-92's and then we changed to 855's and 3406's. We never got the miles (BOH) out of the 8-92 we could with the I-6's.

Our business was different than most, we were the first carrier to run deferred air frieght from coast to coast - 50 hr service JFK-LAX then back again. Our trucks in the course of 50 hours running went from chilly NY, snowny PA, 100 deg desert and into LAX and this was twice per week.

My involvement with Cummins started from the fact that we were the highest milage per year fleet running in the US, our trucks ran from 220,000 - 260,000 per year and as a fleet that was unrivaled. So, we got many thing to test before they came out and also could help design many things with Eaton, Rockwell, Spicer based simply from the point that we torn it up faster than anyone else.

I'll throw another infamous or two V-8's into the mix which will only help the V-8 for boats arguement(can't believe I'm saying this)

Remember the GM Toroflow!!!! It came out as a truck engine for the car carrier companies and almost put several of them out of business. Big law suits against GM!!! That engine was marinized (low HP of course) and they are still running today!!!

Also the GM 8.3 V-8, not bad short haul engine, sucked as an OTR but still many of those in boats running today, over 20 years old!!!!

This all goes back to original arguments I have with some of you about diesels in boats. When steady state in a cruiser the engines last but when in an aggressive race type boats where your throttleing the entire time will the V-8 vs I-6 make any difference?

Thanks,
Joe Gere

Njawb

You've lost me, Joe. What difference are you looking to be made?

HabanaJoe

The question is, our experience here in the US with big V-8 diesels is they don't hold up to a lot of rapid load changing. From what I have seen here the European V-8 diesels don't do much better either (trucking). Do you think that is maybe why with offshore racing diesels the I-6 seem to have done better than the V?

Isotta's and Boudlin (maybe spelled wrong) used the V configuration but could not run as good or long as a Seatek.

Is the I-6 better suited for lots of rapid load changes better than a V-8?

Is the I-6 going to last longer between overhauls than a V-8 in running hours due in part to have more bearings per cylinder?

Njawb

Good questions. How about a few more back at ya?

Were either of the two "good V8s" you mentioned above used successfully in what you would consider to be rapid load changing applications? I'm just trying to figure out whether the problem is inherent to all V8s, or just to certain problematic V8s.

The Isotta and other V diesels that didn't work as well as I6s in race boats, did they all fail in the same way, or were there multiple failure modes?

I don't see any reasonable or inexpensive way of making comparison tests between specific V8 models and specific I6 models (especially not when some of the models aren't even yet available in marinized form), let alone of making a reasonable comparison between all V8s and all I6s. Do you see any reasonable way of generating hard comparison data, or are the only recourses going to be to anecdotes and to caveats in the nature of, "I don't know if that Duramax is gonna work out for you, but I'll be interested to hear what you think of it five years after installing it"?

stirling

Most trucks are not having one driver overhere but two,while one is sleeping the other can drive the truck, a lot are flower transporters that bring flowers from Netherland to Italy ,France ,U.K,Spain etc so can be up to 1800 miles &1800 back,most do 180.000-200.000 mls a year.

Funny that you mentioned Isotta Fraschini,I have one overhere , its a ID 38 6V SS Isotta Fraschini V6 9,7 Litre 450 hp at 3100 rpm, its a twin turbo ,twin intercooler,year 1986

I don,t have a boat for the engine yet ,I am trying to find a 26 ft hull , I saw a video from Apache /Aronow some time ago ,and there were 3 Isotta,s in the back ,exactly the same engine,s ,does anybody know anything about that ?

I spoke to a guy in the UK ,and he said those Isotta,s were doing around 850 hp in the late eighties ,with bigger turbo,s and pumpsettings ,and injectors .

This engine has a HUGE bosch line fuelpump mounted in the center between the cilinderheads.

Joe ,can this pump modified to support the fuel for that horsepower ?

shifter

Depending on the project the number of gears will change. Gas or diesel or turbine or elecectric. Ratios and props are still down to testing and data and experience. We have run 6-speeds in the boats and I know we can and will run more. We will look at the installation and application and determine what will fit and what will be the best all around set-up. In the end it is down to what the customer wants.

The different speeds allows the motor to react better in different conditions. The throttle response is greatly improved.

pat W