3116 cats

[Mike Moran]

Had a 3116 350 h.p. in a bruno stillman lobster boat ran the hell out of it. no problem , 7000 hours on the engine sold it when we had lobster die off. went to Calf. last I know still going. lobster fishing is tough on a engine idle full speed idle ect. Mike Moran CT. I think Bruce had some mention on some of his post on 3116. good luck

[Ryan]

I have a set of 300 hp in my 35 Bertram and haven't had a single problem with them. They have a bad rap from people that have no clue as to what they are talking about (mostly poeople on boat diesel). They do love to be tuned every couple hundred hours and it makes a huge difference afterward. Somewhere on yachtworld is a 31 Express Cruiser with a set in it, so it's possible in a 31. It is a very tall engine though.

[Bruce]

Not all 3116's had problems but as Ryan said, large forums with no one monitoring the truth content lead to everyone running off the side of the cliff.

There were casting problems that did lend themselves to severe problems. A little research on serial numbers will let you know what you are looking at.

I believe John and Ray Jr. installed the 316's in John's classic 31, but that had larger engine boxes which in the long run is not a problem with the kits available.

I don't believe they fit under stock 31 boxes.

John I think got somewhere around the 40 knot range with those engines.

Pat will correct me if I'm wrong.

[CaptPatrick]

John,

John Avala & Rey Cabrera installed 3116 350s in John's B31. This included installation of prop pockets & the Cabrera cockpit kit, (bulkhead, engine boxes, companion way, & deck), which is configured specifically for the 3116 Cats.

The engine boxes are considerably longer, somewhat wider & somewhat taller. If you are considering using your stock engine boxes & wings, you'll have to modify them quite a bit. Length will be the main thing, & you'll probably be better off adding extensions from the cabin bulkhead. That extension would allow you to effectively lengthen the engine compartment without lengthening the boxes.

If the engines you're considering are above 320 hp, you'd have to add prop pockets. Major expense & must be done by a qualified professional...

Recommend that you call John Avala at 954.675.3383 and talk to him before you commit to the 3116s.

Br,

Patrick

[Capt. Mike Holmes]

When Vic gets back from NY, he can comment on "Call me Doctor" in New Orleans, who brought the 31 with 3116's to Port Eads for the second UVII. I looked beneath the engine boxes - tight fit, but he was happy with them. I think another 31 that year that Timmy rode on had them, also. Belonged to a shipyard owner on the LA coast.

[Charlie]

Ryan is right about the existing 3116's. All the ones that had problems have long since passed into history. Yes they do need tuning at least once a year. The engine is really needs to be propped right. Many boat manufactures prop the boat for delivery at light weights (Luhrs). Once you add your gear the engines are not making WOT RPMs. In this condition the 3116 takes a quick dump!! A buddy of mine keeps a number 3116's running in buses. They are tougher to tune then most and require some special tools. Danny says they run just fine; but are buggers to get past emission standards in NJ.

[IRGuy]

While searching for a boat before I bought mine, I looked at a couple with 3116s and one with 3216s. I then made a bunch of calls, ending up with a call to Cat corporate and a couple of present and ex cat techs. The concensus of opinion is what Bruce said above.. there were some "soft block" otherwise called "French block" issues, which resulted in much shortened engine life. Cat's response at the time these engines were failing was pretty dismal, supposedly being.. "we can't tell if your engines are likely to have these blocks or not, so run them and if they fail we will discuss this with you". Not a heartwarming response to a boat owner with these engines.

The opinions two years ago from the people I spoke with was all pretty much the same.. if you have 3116s and they are running now, they don't have the problem blocks, and they should fine for a long time to come. I can't comment on tuning them, or how they perform except to say the owners I have spoken with said they run fine. Occasionally an owner on the Boatdiesel forum states that today.

My personal concern is that, with so much negative information, rumor and misinformation out there in the market, even if these engines ran fine for you for several years the resale issue would be problematic. You never know what a potential buyer has heard or believes. Personally, I would not buy or install them for this reason.. you always have to think about the day you will want to sell your boat. I have avoided looking at boats with these engines, regardless of price.. and I am sure other potential buyers pass on them as well.

[scot]

Capt Pat,

If the engines you're considering are above 320 hp, you'd have to add prop pockets

Pat I assume that pockets are required to fully utilize that much power based on prop dia requirements....but couldn't the boat be set up with the largest prop dia feasible and the 320 +hp have a real easy life? say only utilizing 300 esh hp?

Could "under-propping" the engines create a bad scenario? Can the engines be governed to stop at a predetermined max rpm?

[CaptPatrick]

Scot,

Probably some questions for Bruce to answer... But, with a deep v hull a pocket will have to be developed anyway, so make it large enough to handle the correct size wheel... Still not a good idea in my book.

Br,

Patrick

[JohnCranston]

I had a 25" Blackfin with a single 240 Perkins 17 or 18 yrs ago. She was a 1980 model called "Marlin Darlin" very deep v...24 degree deadrise from what I remember. Mike H. knows the boat. Had a 55 gal fuel tank on either side. Had a
borg Warner 1to 1 gear and a 18" wheel...I forget the pitch. Fantastic in a head sea...and any other sea for that matter. Center console with a fisherman's cuddy up front. Very economical to run...but, fuel was .50 a gal back then. I wish that I still had her...along with the 31 of course. Seems like back then, I could afford to go fishing...I don't know about now...I might be able to afford going to the jetties and back, If I'm lucky.

[JohnCranston]

Sorry...I kind of got off of the topic. UV probably remembers my old boat from Benice. She was named something else back then and was owned by a doctor...probably 20 years ago.
Sorry...must be the rum.

[ed c.]

Who needs problems? Why not use the KISS method of life? Use Cummins or Yanmars and eliminate prop. pockets, extending engine boxes, etc. Today is Tuesday, Election Day and as they say in NJ, vote early and often.

[JPRS51]

Does any have any experience or knowledge of using the newer cat engine?

I think the 3126 is the one.

http://www.cat.com/cda/layout?m=53580&x=7

[JohnD]

The 3126 had some improvements/changes over the 3116, but are basically the same motor. You can still get them new in mechanical, 385hp I think. That would be way too much for the B31.

Most B31 owner's are going with the slightly smaller cummins, yanmar, volvo, stryer and so on. After all a B31 only needs 250-300hp any more and the shaft angle and hull design make it impractical.

Surf around here and read the other discussions. The knowledge and advice you'll find is priceless (not just because it's free). If you've never done a repower before, what ever you think it takes double it...

br,
JohnD

[In Memory of Vicroy]

The 3126 has a steel plate at the bottom of the block to stiffen it, sort of a spacer between the block and the oil pan. I'm told this makes it work vs. the high hp 3116s that broke stuff internally.

At the risk of offending some of my Faithful friends, it is hard for me to think that anything other than the Cummins 6BTAs are right for our beloved B31s. Strong, simple, durable, cheap to maintain, fit real good without any mods to the boxes, smooth, and just right for our boats, up to about 330 hp....the 250s like I have work just fine too. One real plus to the 6BTAs in the 250-270 hp range is that the aftercooler is fresh warter cooled, eleminating a major maintaince item with the raw water cooled aftercoolers on the higher hp Cummins. The trade off for getting that extra 50+ hp by using 70-80 degree raw water to cool the turbo air vs. using 180 degree fresh water is a lot of maintaince vs. none.

UV

[John C]

So much crap has been posted by the internet shade tree mechanics that I was leary to look at boats with 3116. So I spoke with seveal cat master techs and caterpillar HQ . There were never any soft block 3116 engines !!! But I read it on the internet !!! The The soft blocks were the 3126 engines. The 420 hp 3126 gave cat the most trouble. They think there were several 100 blocks that were bad. Thousands were cast at that foundry. They replaced the ones that were soft. Just because your block has FAPS on the side does not mean its bad. If fact I know of one guy with a set in an albemarle with 3500 trouble free hrs. So when people talk about boats or engines on the net make sure they have a clue. I read a**holes taking about how a boat rides then when pushed about how much time they have at the helm and you get well.. none but my friend had one back in the eighties. I read these posts for shits and giggles when I want to learn something I listen to Bruce or Pat. The bigggest problem wtih the 3116/3126 is that builders were putting them in boats over 40 ft. ( read Searay Carver etc) Remember this has less displacement than a gm big block. In smaller boat these engines are lasting a long time.