1996 400 sedanbridge twin cats

[ship for brains]

bought this boat for a song 1600 very low stress hours with 2 state room lay out. All san pipes replaced with trident, port motor is the original 3116 starboard is a 3126 both are 350 horse. Outstanding performance. I have been reading some posts about them not getting on plane with full fuel and water, the only thing I have to say is my boat gets on plane at 12 to 13 knots and a spark sits on my platform for an extra 368lbs. ALL THIS HAPPENS AND MY MOTORS ARE TURNING AT 1800 RPM. Tops out at 2800 and by then i am flying at 34 to 36 knots. I love this boat, had carvers and silvertons but this is by far my favorite

 

[Gofirstclass]

Welcome to CSR. I have a brother to your boat and mine also has Cats and I also love 'em. Mine are 3406C's and they get my boat on plane with full fuel, water and a boat load of people.

I can cruise on plane anywhere from 17kts to 25kts and my WOT is 31.3kts at 2150rpm's.

Not bad for about 65,000 pounds.

 

[RollerCoastr]

So Cat replaced a 3116 with a 3126? Is there more to that story?

 

[fwebster]

Probably nothing any more sinister than Caterpillar stopped producing 3116’s in about 2003 when the 350 hp 3126e was introduced. Cat could not get the 3100 series engines to pass the coming EPA standards and they put the development $$ into their fully electronic C-series engines which did pass EPA scrutiny.

On this and other situations when an engine had to be replaced, Cat offered the boat owner a detuned 3126e because there were no more new 3116’s.

 

[ship for brains]

they are smokeless, almost odourlesst and when the turbos spool up it feels like the boat wants to leap out of the water. I also found very interesting is the bow pitches with even with 100 rpm increments all the way up to wot. I should add that I am a 43 year auto tech witch is why I should also add that I have seen my part of catastrophic engine failures be it gas or diesel so even though cat has work horse motors that have a 24 hr duty cycle, I cringe all the way to my destination for some reason and never run wot. That being said I am a big baby la la so cruise at 2200 rpm and suffer with butterflies and ibs until I get to where I want to goinstead of wot all day and suffer a dropped valve or valve seat. You know what I mean?

 

[ship for brains]

So Cat replaced a 3116 with a 3126? Is there more to that story?

not really except that some early production 3116 made in france had casting issues with soft blocks resulting, so if your motor had better then 500 hrs you were probably one of the lucky ones but if not then they replace the motor on there arm. eventually they ran out of 3116 and started poroducing 3126s. same basic motor just a little more displacement. That's the story

 

[JimG]

Some reading for you:
http://www.clubsearay.com/index.php?threads/40-sedan-bridge-forum.53961/

Congratulations and welcome to CSR!

 

[ship for brains]

Welcome to CSR. I have a brother to your boat and mine also has Cats and I also love 'em. Mine are 3406C's and they get my boat on plane with full fuel, water and a boat load of people.

I can cruise on plane anywhere from 17kts to 25kts and my WOT is 31.3kts at 2150rpm's.

Not bad for about 65,000 pounds.

Oh ya. Big brother more like it. that is what I call a yacht, you guys are fortunate to live by the sea. I live in Montreal quebec . Besides being surrounded by Frenchmen we also are surrounded by water, the St Laurence river which is water but full of locks and big rocks and is hard 7 months of the year so boating is short and very sweet here. If I had a boat your size I would barley be able to turn around

 

[ship for brains]

Some reading for you:
http://www.clubsearay.com/index.php?threads/40-sedan-bridge-forum.53961/

Congratulations and welcome to CSR!

thanks. Nice machine!

 

[RollerCoastr]

not really except that some early production 3116 made in france had casting issues with soft blocks resulting, so if your motor had better then 500 hrs you were probably one of the lucky ones but if not then they replace the motor on there arm. eventually they ran out of 3116 and started poroducing 3126s. same basic motor just a little more displacement. That's the story

Yeah, I've actually been aware of failures for 20 years now. Many neighbors and friends have gone through this. The soft-block issue was more likely to occur with the 3126. 3116's were more likely to swallow a valve, but we've seen each engine suffer each malady. Production of 3116's and 3126's overlapped for years.

I was just curious about the 3126 replacement. For all of the 31XX engines I've seen getting replaced, the only model change I've witnessed is a C12 replacing a 3196 (which is the same displacement).

 

[Gofirstclass]

Oh ya. Big brother more like it. that is what I call a yacht, you guys are fortunate to live by the sea. I live in Montreal quebec . Besides being surrounded by Frenchmen we also are surrounded by water, the St Laurence river which is water but full of locks and big rocks and is hard 7 months of the year so boating is short and very sweet here. If I had a boat your size I would barley be able to turn around

Ship, I wish I lived by the sea. We're about 325 miles up the Columbia River from where it empties into the Pacific. And there are 4 locks between here and the ocean. That's not a lot, but they are pretty big. Average lift in the 4 locks is about 80'.

We do have a long boating season though. Most years our waters never freeze. Three years ago we did have an unusually cold winter and the small bay my marina sits in froze over completely. The ice was about 3" thick and was gone in a couple of weeks so it wasn't too bad.

 

[fwebster]

Caterpillar rates it engines by type of use and RPM's from A&B, to C to D to E.

A&B are constant rpm applications for extended periods like ferries, crew boats, displacement hull fishing boats, long liners, etc.

C are displacement hull boats, fishing boats, ferries, etc.

D&E are pleasure craft boats with planing hulls

All 3116's in Sea Ray boats are E-Pleasure Craft engines rated at 300hp or 350hp....there is another rating of 325 hp but Sea Ray never used them. The hp ratings are at a recommended WOT setting of 2800 rpm. Cat says you can run an E-rated engine 8% of the time at WOT or 2800 rpm. The max recommended cruise rpms for E-rated 3116's is 2400 rpm and the engines can be run indefinitely at this throttle setting.

Many of us who own and run 3100 series engines have found, as you have, that these engines have a "sweet-spot" at somewhere between 2000 - 2250 rm where they are more efficient, quieter and have less turbo whine that at the recommended cruise rpms of 2400.

I have found that the 3116 is a workhorse and is extremely dependable. In the early years, there were some soft valve stems due to an improper hardness of the stem in some vendor supplied valves. The keepers would wear away the notch in the valve stem and the keeper would fall out. This defect always showed up in 125-150 hours or less. If the engine was producing power, the valves would drop into the cylinder and the effect was a catestrophic failure. A few of these engines were rebuilt but most were replaced with new engines....all covered by Caterpillar under their engine warranty. The important point here is that engines not having soft valves, or those repaired or replaced do suffer from a dropped valve problem.

So, if you have a parts failure at rpm, the chances are that it is not going to be a dropped valve, but rather will be an injector seat that fails. If one does fail, compression gasses leak past the injector into the fuel gallery and you will lose all the cylinders after the failed injector seat because there is air in the fuel supply gallery. The fix is reaming the injector seat with a special reaming tool and costs a few hundred $$, not thousands.

So, relax, and enjoy your boat; run your engines under 2400 rpm an enjoy the great, clean burning and efficient engines Cat has given us.

 

[ship for brains]

ya it was TRW valves that were dropping if I remember correctly Well your right but its really hard when you know too much. Ignorance is bliss. great talking to you by theway