in-line 6 Cylinder Engines, 'straight-six'

Steyr offers you the choice between monoblock or a bolted on head, with appox. 25 kg weight difference, both with 9 different power settings. If 340 kg. can be called lightweight is a matter of opinion.

Their engines have a very good reputation, but because of the low production volume they are expensive. I think it is a matter of time until they join the large manufacturers and start converting commercial vehicle engines. In fact they are already doing that now, just the scale is too small to be competitive.

 

Mono block means when you swallow a valve the head can not be removed and repaired,
you get to buy a block too!

Fine for the military with unlimited funds , but for a recreational boater?

FF

 

they are fully repairable fred except you have to remove the crank and pistons which would be a pain. there is set of special tools for replacing the guides and valve inserts.

 

they are fully repairable fred

The aircraft engines with this setup are "repaired" at the factory that created the unit.

Not a delight for a cruising boater.

 

Repairs in Third World

There have been a few times in the past that I wish I had just 'sent it back to the factory' or bought a replacement,...rather than had a 'local expert' try to get the correct parts and do the repair correctly...over and over again. I'm sure I could find many other cruisers who would agree.

Now let me give you an example:

These quotes came from this subject thread:
http://www.yachtforums.com/forums/technical-discussion/13335-how-much-%24-rebuild-these-engines.html


Can you imagine trying to get all of the correct mods and changed parts to a third world country, and employing a 'backyard mechanic' to get it right.

At least the Steyr engine is light enough to be air freighted.

BTW, this very informative reply by K1W1 was the sort of information I was seeking about various marine 6 cylinder engines whe I started this subject thread.

 

Caterpillar C7

Anyone familiar with this engine?


http://www.ehow.com/info_8586669_specifications-caterpillar-c7.html

 

Yes if your a gynocologist. Consider it a throw away engine ...

Removing crank and pistons is a bit different from removing a head .

It was second on my list because of its light weight. Its non removable head horrified me, a dropped valve is catastrophic even though unlikely.

The cooling system is in some kind of jacket bolted together around the engine. Naaa not for me I bought the Yanmar.

Yes I may be a stick in the mud but I like being so if this is the choice.

 

IIRC B50 in trucks is 400k miles.
B50 is the mileage at which 50% of them will have blown up...

Just go on motorhome/trucking forums and read all the griping-blown turbos,blown injector pumps,ECU problems etc etc and these are in motorhomes and not a marine environment.

No thanks.

 

its not a real good day when you drop a valve on a conventional engine either. i don't know a lot about steyrs apart from the 1 i mentioned getting good reports from its owner. i do like the mono block idea though. maybe its just ahead of its time. remember when people used to say only buy a pushrod engine, them overhead cam things are to un reliable, now everything is overhead cam.

 

Didnt RR have head and block cast together 80+ years ago?
A bit like Louis Chevrolet making DOHC 4 valve conversion kits for T fords about 100 years ago...its all been done/tried before, materials and machining of the era determined what was success or failure

 

That monoblock, non-removable head of the Styre brothered me as well.

But then I think back to a blown head gasket I had once on a simple comman Perkins 4 cyl one time. (overheating had warped the head slightly in I remember correctly)

Now I was in the heart of boat repair country (Annapolis & Balt, MD) . First repair guy didn't recoqnize slight warp problem, so repair was unsucessful. Second repair job got a slightly different new head that ended up to be incompatible. I ended up buying a new engine rather than go around with this crap for a 3rd time.

Now I imagine being off in a more remote area with 3rd world mechanics trying to get me the correct parts.

I think I would just as soon have a new light-weight short block shipped in. And I might even be able to assemble the extra parts onto the new short block myself

 

brian, if you were buying a brand new diesel and keeping the services up to date i would doubt if repairs to the engine would be an issue.

 

Have you ever had little unforseen incidents happen to you....like maybe losing a clamp on a water cooling line while negoiating a tricky channel with lots of current?? ...like Moorehead City , NC I believe it was. Cut the engine or try to go under reduced power and suffer some overheating. You are certainly not going to be able to anchor there.

Or another one when i was trying to claw off a lee shore in a bad blow off Bimini island and the engine develops a 'misting fuel leak'

Numerous other examples are available I'm sure....SHappens to new and old engines.

 

yes i have had things like blown exhaust hoses and impellors pack up but that is lack of attention to the engine by myself. electronic diesels are protected to a large extent by the ecu. try and cook a new mack or cummins engine, it won't let you.

 

The proof of reliability on modern computer controlled engines, is that almost no one carries a set of tools on their boat or car. In the "good old days" drivers were constantly tinkering and repairing their vehicles.