692 DDEC 111 625 hp small pin cylinder kits verses big pin kits.

Brad 692

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Aug 17, 2021
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4
it’s no secret that Detroit has recalled all their cylinder kids worldwide because of failures. I had my engine rebuilt and the rebuilder, much to my surprise, has figured that would solve the problem finding big pin kids by putting a small pin kit in my engine. In addition, he put in standard keys vs offset keys. Regarding the keys, I’ve heated offset in the front and standard in the gear train vs all offset.
The engine is not developing full horsepower so I’m left with two options. Repower the engine with A used take out and rebuild this engine when keys are avail or use the boat, as is, and run the boat on low idle until the kits are available. I’ve been told by the guy that rebuilt the engine that the small pins will work
TWO Questions:
1. Has anyone put small pin kids in these big horsepower engines to any success?
2. What keys do go in this engine with Advanced cam an advanced gear train and where do they go?
Several people have several different ideas, I could use a help, what do you think?
 

chris.olson

Petty Officer 2nd Class
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Mar 15, 2009
Messages
105
I disagree that the small pin cylinder kits will work. The rods are shorter in the big pin DDEC engines and if you put the small pins on those rods there will be a gap on both sides of the pin and the pin will only touch the rod in one place, plus the compression will be low.

The 6V92 DDEC3 is a highly stressed engine in the first place, its output is will above the design limits for a 552 cubic inch engine. Typical life is only 500 hrs, they are a loose-pin grenade (even with the correct wrist pins in them). If it were me, and you don't want to spend thousands on maintenance bills on those engines, I'd repower with a pair of Cummins engines.

There's a number of things going against those engines (besides the grossly over-rated power rating)
- the Reliabilt cylinder kits are junk and rarely produce normal compression after an overhaul
- the engine was only built from '96-'98 and you can't get injectors for them anymore (except crappy aftermarket that cause all sorts of problems)
- Detroit knew that the average "boat guy" runs his boat 100 hours a year or less. They figured that if these engines blew up at 500 hours they'd probably get out of warranty and the owner is hung with it

You're not experiencing anything that anybody else that has those engines hasn't already experienced - lack of proper parts to rebuilt one (because they've been mostly discontinued even by Detroit), and confusion with the offset keys in the advanced cam timing (which was done for emissions). You need to have the factory service manual, and all the Kent-Moore special tools, to even work on one. I've got a couple of them laying in my shed that were takeouts after they blew up. They're not worth overhauling anymore when you can get a couple used Cummins QSC's for the same money as overhauling those DDEC Detroits.
 

Brad 692

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Aug 17, 2021
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4
Thank for ur response. Not a lot that I disagree with. I have one good engine (for now) and when the kits come out I’ll rebuild and dump it
 

chris.olson

Petty Officer 2nd Class
Joined
Mar 15, 2009
Messages
105
That is IF the proper cylinder kits come out. MTU's Detroit Diesel Reliabilt division quit making them. You can get the small pin kits for the 6V92TA and TTA but the DDEC III's were pretty much a one-off.

Again, if it were me I'd sell the good engine as a running takeout (somebody will buy it) and repower. The John Deere 9.0L Power Tech engines are also a popular repower option these days for older boats with Detroits in 'em. The John Deere engines are virtually silent underway and we've seen some of them run 20,000 hrs in the Nordhavn's and never had a cylinder head off.

With propulsion engines in yachts it's pay me now or pay me later. Either way you're gonna pay.
 

Brad 692

Recruit
Joined
Aug 17, 2021
Messages
4
That is IF the proper cylinder kits come out. MTU's Detroit Diesel Reliabilt division quit making them. You can get the small pin kits for the 6V92TA and TTA but the DDEC III's were pretty much a one-off.

Again, if it were me I'd sell the good engine as a running takeout (somebody will buy it) and repower. The John Deere 9.0L Power Tech engines are also a popular repower option these days for older boats with Detroits in 'em. The John Deere engines are virtually silent underway and we've seen some of them run 20,000 hrs in the Nordhavn's and never had a cylinder head off.

With propulsion engines in yachts it's pay me now or pay me later. Either way you're gonna pay.
I figure that the big pin kits will come out eventually. I only get 1400 out of the small pin engine so I figure I'll reun at low idel and get by untill bigs come out. What keys do you believe go in the 625hp? Advanced or standard? Everyone has a difference opinion
 

chris.olson

Petty Officer 2nd Class
Joined
Mar 15, 2009
Messages
105
What keys do you believe go in the 625hp? Advanced or standard? Everyone has a difference opinion

It's not what you believe. Check the overhaul manual. The DDECIII uses the advance timing keys. But this doesn't affect it as much as you think. The advanced cam timing was done for emissions, no other reason. They even had advance timing kits for 8V-71's in buses.
 
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