Who's got the fastest rig here?

6.6's are readily available in Topkicks and other GM medium duty trucks. From there you can option the Cat or the 6HK1-TC Duramax, which is a 7.8L I-6. It shares nothing in common with the 6.6 at all, besides the name.

 

Thats what I thought I read one time. An inline 6 dmax was used.

 

Are there any marine-version Dmaxes with more HP?

I'd imagine not due to the aluminum heads, but it's a possiblity with a closed cooling system.

 

Tim the AL head gets a bad rap. It is proving itself to be a good strong design that can handle abunch of boost. I have heard of a guy pushing almost 80 pounds of boost by accident with a twin turbo setup.
The heads can take a lot more than they get credit for.

 

Not to mention Isuzu has been using the aluminum head design for a LOOOOOONG time, it was a proven design 30 years ago.

 

There is nothing wrong with the aluminum heads. You guys both need to read my post again.

Boats, as you probably know, commonly cool the engine with raw water. Raw water would corrode the crap out of a set of aluminum heads, thus why I said any boat that had a Dmax would have to have a closed cooling system.

So, I'll ask the question again. Is the 6.6L Duramax available in anything else, with more power? Boats?

 

Is diesel fuel used at all in marine applications?

Hmmm, I guess a tug boat or biggass boats have diesel engines, do they?

 

My pops hade a 1953 double ended fishing boat with outriggers that had a 4 cylinder Volvo Penta diesel engine. He would sit on the valve cover as we drove around the bay, since the engine was uncovered right in the middle of the wheelhouse. Does that count? rotfl

 

Ya Tim I read it agian and was wondering if that is what you meant.

Kinda funny as I am sitting at my desk going through catalogs ordering pipe identification labels that say raw water.

 

Yes, diesels are used a lot in marine applications, and are becoming more and more popular is smaller boats, as in under 30'.

Tim, no, the Duramax is not used in Marine apps because of the agreement between GM and Isuzu. Gm gets to use it in their trucks, and Isuzu gets to use it in their DMAX trucks sold in Asia, and nobody else gets it. It has nothing to do with the aluminum heads. There are many outboards with aluminum heads, and they are all fine. Within the next two-three years you will see an aluminum block'd outboard as well in a further effort to reduce the weight of 4-stroke outboards, which is the biggest killer to their sales. Thats why mercury is now building the small displacement supercharged, I-6 outboards, more power with less weight, but it takes a lot of RPM to develop the power and they are WAY to expensive still.

 

I dont' know about fastest, but mine put out right at 400 HP, and right around 900 FT Lbs tourqe. It's kinda ugly for a stock clutch.


Southbend upgrade is next on the list.

Rob

 

I would assume the Dmax is not offered in anything else with more power then if it's not available in boats.

I used to work on boats, and I've never seen an inboard engine with aluminum heads and an open cooling system. They always had heat exhangers if they had aluminum block or heads.

Mercury even has an aluminum block with a cast iron head from a Ford 460 for a motor. waytogo rotfl

 

Any boat over 35' or so, generally has a Diesel engine.