ISBe with articulated pistons...

[HoleshotHolset]

Thanks to Deo Read (TheRabbitTree) - I have found a lot of stuff to read about this weekend.



This link... will bring you to the partial 'National Fisherman' magazine story that describes how Maine 'Lobstah' fisherman are BOMBing their diesels so that they can race 'em. Ever seen a displacement hull @ 50mph? Neither have I... .



Deo read the whole article and found out that the 350hp marine version of the ISBe has STEEL ARTICULATED PISTONS! We thought this was cool and figured other folks may as well...



Matt

 

[Gary - K7GLD]

WELL, the pointer doesn't provide any insight, and *I* certainly haven't ever heard of any "articulated" pistons, or ones that are designed to provide some sort of flexibility or motion/movement along their path of motion - what I have heard of, is articulated connecting rod arrangements in long stroke engines (especially large ship engines) that are designed to maintain a straight-line application of force to and from the piston, and between the piston and crankshaft so there is minimal sideforce between the piston and cylinder walls...



Curious...

 

[rbattelle]

Originally posted by Gary - KJ6Q

WELL, the pointer doesn't provide any insight, and *I* certainly haven't ever heard of any "articulated" pistons, or ones that are designed to provide some sort of flexibility or motion/movement along their path of motion - what I have heard of, is articulated connecting rod arrangements in long stroke engines (especially large ship engines) that are designed to maintain a straight-line application of force to and from the piston, and between the piston and crankshaft so there is minimal sideforce between the piston and cylinder walls...



Curious...

Gary took the words right out of my mouth...

 

[JHayward]

Articulated pistons are common in larger diesel engines, and have been used in Detroit diesel 2 stroke engines for years, among others. Basically, the piston has two components, the crown - usually steel, and the skirt, typically aluminum. The wrist pin connects the two parts, and the conrod can actually be bolted to the pin. The articulated piston allows the skirt to do its job without getting over stressed and distorted by the high cylinder pressures acting on the crown.



Nowadays, the trend is towards one piece pistons, but of advanced design. Mahle has a nice Monotherm piston that is really a work ao art to look at - cast steel, with the skirt all hollowed out - really cool.

 

[HoleshotHolset]

JHayward: Thanks for clarifying that... . I should have done that in my first post.



The article on the internet that I posted the link to is only 1/8th of the whole story. The FULL magazine article goes into detail about the pistons and the rest of the technology behind the ISBe, amongst other cool diesels.



Bruce Mallison (I can never remember how to spell his last name... sorry Bruce!) from Diesel Injection of Pittsburgh (... more like Cheswick!) had a few things to say in the article as well.



Matt

 

[Gary - K7GLD]

I guess it woulda made it easier to understand if they had simply said a "2-piece piston" rather than "articulated"...



Articulation is more commonly used as seen in city buses that swivel in the middle to negotiate sharp turns - and other similar "articulation" - sorta threw me to see that terminology used to describe a pistons construction - just a matter of semantics I guess...

 

[OHale]

As a matter of fact I [have seen a lobster boat go > 50 mph.



In further fact, a co-worker of my wife made a bet at work and she lost. She (the co-worker) honored her bet by water skiing last winter behind a lobster boat off of East Boothbay. Made the paper, which is surprising. Stranger things than that go on all the time.



The lobster boats make so much torque that some will "torque over" and roll on their backs right in the middle of the race. We have our fun here in Maine.



The lobster boat races even put out a nice calendar.



Cool article indeed HoleShot, but don't let any more of our secrets out!

 

[DJW]

Of Articulated, in Britain and probaly other countries, ask a Truck Driver what type of vehicle he drives, in general the answer is Artic. short for Articulated, meaning to us Semi, although to some in US, Tractor, also to the rest of World, Tractor means Farm Tractor. Not forgetting, Good can also mean Bad. Scrum Down

 

[willyslover]

that is an interesting read for sure

 

[HoleshotHolset]

I've had a lot of good times in Maine, but none of them ever involved a lobster boat...



All of the following fine moments in watersports happened at Lake Wamponoag in Gardner/Ashburnham, MA:



I went tubing behind a Sea-Doo Speedster before... . fell off at 45mph. That was NOT fun at all. Besides the 'full-body enema'... I had the wind knocked out of me... .



I also dove off a pontoon boat doing only 19mph - you know... just like the folks on Baywatch. I did it twice... the second time I was not as successful.



Matt

 

[JustinAdams]

ive been tryin to find some one to build a set of articulated pistons for my 96 12 valve b its about time cummins got smart theyve been running them in m-11s and n14s for a while now

m-11s new articulated piston doesnt even use pin bushings u have to use 75-140 gear oil to assemble instead of eng oil

 

[Blakers]

Originally posted by Gary - KJ6Q

what I have heard of, is articulated connecting rod arrangements in long stroke engines (especially large ship engines) that are designed to maintain a straight-line application of force to and from the piston, and between the piston and crankshaft so there is minimal sideforce between the piston and cylinder walls...

Gary, I think you're talking about a crosshead. In this case you'd have a piston connected to a piston rod (which goes up and down with the piston - no wrist pin in the piston). The piston rod is connected to the crosshead, which rides on some rails, in general motion with the piston. The crosshead has a wrist pin in it, which connects to the connecting rod, and thus to the crankshaft.



Crossheads are generally used in steam engines because they are double acting (steam pushes the piston both ways), some diesels and gas engines that are also double acting, and some 2-cycle diesel and gas engines that use a sealed space under the piston as a charge cylinder that forces air into the conbustion cylinder on the downstroke.