Cummins 555 Cracked head

[555 in OZ]

OK.... here goes.... I have jsut bought a 38" Riviera Cruiser with twin Cummins 555's. During sea trails we wound her up to about 3000rpm and the previous owner was not too happy. Seem he never took it passed about 2600rpm. our first trip after the purchase we smell coolant, stb engine alarm goesand we shut off starboard side motor. ???

upon further investigation, coolant level was now low. we top up with about 10 litres of coolant and head back in on portside motor only.. all this time the engine never went over 80 degress celcius (Normal temp) we started the stb engine only to assist in putting the boat in the pen. once stopped we first thought heat exchanger and replaced it with a new one. when firing up we had a hydraulic lock and couldnt turn the motor over. we have since pulled off the exhaust manifold and tested OK and now pullled off the head, tthinking it must be a head, head gasket or liner/sleeve. the back cylinder on the port side was full of water (causing hydraulic lock up) but everything looks in mint condition. i feel terrible becasue it looks like we are pulling down a brand new engine... total hours 1350 on both motors... no visible evidence of head crack, head gasket issues nor sleeve/liner corrosion..

has anyone heard of such a thing in the Cummins triple nickels...???? (ps sorry about the long post)

[hartley]

G'Day to 555 in OZ.....Bad luck with the Riv 38 ,but winding up the 555's to

3000 should'nt hurt them ,they used to rev to 3300 if i remember correctly,if

they would only reach 3000 WOT it would appear they were overloaded.

However what I would suggest,post ALL information you have re RPM speed

temp's,boost, prop size ,and anything else you can think of ....to boat diesel .

com....there are real experts on Cummins there ....cheers Hartley

[longliner45]

hartly has good advise,,sometimes a crack may be under the valve seat,,,very hard to find ,,give this one to the pros,longliner,,,(pay now or pay later)

[Poida]

G'day 555
I'm from Perth as well. We work in the metric system. 35" that converts to 965mm.

What the fck replace the engine with a lacky band should work just as well.

Ah well, people like to quote what type of engine they have, but they all work on the same principle.

You got that much coolant in the combustion chamber, I would think that running your fingernail around the valve seat, you would feel something.

I would guess at a problem with the cylinder sleeve.

As the piston goes up and down it causes the sleeve to vibrate in and out.

As the cylinder sleeve expands it compresses the coolant around it.

As the cylinder sleeve contracts it depressurises the coolant causing cavitation, tiny air bubbles.

As the cylinder sleeve expands with the next compression stroke the bubbles formed by the cavitation emplode against the wall of the cylinder sleeve, eating away at it.

It could be possible that the cylinder sleeve has become porous alowing the coolant to enter the combustion chamber.

Bad news, but since you have checked the head and the head gasket, the coolant has got to be coming from somewhere.

Good luck
Poida

[Frosty]

Theres something very wrong here and it would help if the storey was easier to understand. The writer refers to topping up with 10 liters? thats an empty engine or near as damit. The writer also refers to everything as singular --exhaust was checked-- head--gasket this is a v8 engine. Bit confusing.

Ok we will get over that. The writer also says that the port engine did not go over 80 degrees-- why should it? That engine is Ok. Isnt it?

Starboard engine unable to start due to Hydraulic lock-- so how did you start it?
A cracked valve seat or any where near would have caused a missfire and smoke --probably white before overheat.

Was the engine filled with 10 liters of cold water on a seriously overheated engine?

The biggest problem here is the 10 liters that is not a top up. Thats 2.5 gallons. So was the water checked before you took the boat out? how long did the engine run before overheat? was there any noises -smoke or misfire before overheat?

The second major problem is youve already took it apart so diagnosis is now slim.

[Willallison]

We have twin 555's in our Offshore 48. They are nominally 320hp, but in reality are capable of producing rather less than that. Cummins put out a number of different versions of this engine, ranging from a normally aspirated commercial donk, rated at something like 190hp continuous thru to the '320' turbocharged version that we have.
I don't have the document with me, but I'm fairly certain that this engine is not supposed to run at more than 2800 rpm for more than 10 minutes. So I'm not surprised that the owner wasn't too happy that you revved the crap out of it. Sadly, (I'll stand corrected on this as I don;t have the figures at my fingertips) but it sounds like you just over-revved an elderly motor that hadn't been run hard before.... and blew it up.

[lazeyjack]

Originally Posted by 555 in OZ

OK.... here goes.... I have jsut bought a 38" Riviera Cruiser with twin Cummins 555's. During sea trails we wound her up to about 3000rpm and the previous owner was not too happy. Seem he never took it passed about 2600rpm. our first trip after the purchase we smell coolant, stb engine alarm goesand we shut off starboard side motor. ???

upon further investigation, coolant level was now low. we top up with about 10 litres of coolant and head back in on portside motor only.. all this time the engine never went over 80 degress celcius (Normal temp) we started the stb engine only to assist in putting the boat in the pen. once stopped we first thought heat exchanger and replaced it with a new one. when firing up we had a hydraulic lock and couldnt turn the motor over. we have since pulled off the exhaust manifold and tested OK and now pullled off the head, tthinking it must be a head, head gasket or liner/sleeve. the back cylinder on the port side was full of water (causing hydraulic lock up) but everything looks in mint condition. i feel terrible becasue it looks like we are pulling down a brand new engine... total hours 1350 on both motors... no visible evidence of head crack, head gasket issues nor sleeve/liner corrosion..

has anyone heard of such a thing in the Cummins triple nickels...???? (ps sorry about the long post)

I used to Work for Cumminas in Au
i rebuilt more 55 engines than I can remember, you MAY have a leaking injecter sleeve, check it out call me 0061754561210 but after this afternoon will be in out of Aust

[lazeyjack]

oh and By th e way they ddi not crack heads much rare, gaskets yes, check for bubbles in the header tank, pressure the header tank and hold

[lazeyjack]

Originally Posted by Willallison

We have twin 555's in our Offshore 48. They are nominally 320hp, but in reality are capable of producing rather less than that. Cummins put out a number of different versions of this engine, ranging from a normally aspirated commercial donk, rated at something like 190hp continuous thru to the '320' turbocharged version that we have.
I don't have the document with me, but I'm fairly certain that this engine is not supposed to run at more than 2800 rpm for more than 10 minutes. So I'm not surprised that the owner wasn't too happy that you revved the crap out of it. Sadly, (I'll stand corrected on this as I don;t have the figures at my fingertips) but it sounds like you just over-revved an elderly motor that hadn't been run hard before.... and blew it up.

he did NOT BLOW IT UP
rpm, have nothing to do with load
so many amatuers here, please think before you open your mouth)
Lugging kills oversquare V engines, I can rememeber these motors in truck with not enuff gear ratios, they like to spin high and not to lug
Stuart
ex cummins
Australia

[Willallison]

Lazey - no need to be rude! I'm fully aware that rpm's have nothing to do with load. But revving an engine to 3300 rpm that's not designed to go beyond 2800 for any length of time sure as hell won't do it any good. Perhaps, since you have so much experience with them you could confirm (or otherwise) my recollections as to Cummins' recommended 'redline'

[lazeyjack]

not being rude, at all, high idle on that engine, was 3300 on Highway, i,m 60!! I cant remeberr exactly in Pleasure boat, but think was same, the engine was rated 180 and as someone said to 320
My point is that if the engine was not healthy it would not pull full rpm
Try the engine at high idle, ie out of gear, thats your rated rpm!)
If the, engine is revving that speed then thats ok, if it can not reach that speed(foul bottom, bent screws whatever, it may be luugging A short burst for test purposes should not hurt the engine at all
Cummins now run upon inship inspection, the engine at FUll load full rpm, to moniter engine performance and temp rsier over ambient in the E/R
Now the thing that made me jump(sorry) was the term blown,
In my book thsi means clouds of white smoke, busted pistons, and broken shafts Good day

[Frosty]

Te only thing you can do now is clean up the parts ,give then a good inspection and rebuild --properly.

Dont try this yourelf, Im sorry but if your imediate reaction was that this problem was a heat exchanger then you are not skilled enough.

You can hope that there is a water leak somewhere-- you will find that after re build. You can also hope that your problem was due to a head gasket failure due to overheat --Or a overheat due to a head gasket.

Did you unseat the injectors to cure the hydraulic lock to start it?

Theres a moral to this story.

[Willallison]

It's ok Lazey - I didn't take offense - people have called me far worse than an amateur!
Ok - I have the data sheet in front of me now. Gross BHP @ 3000 rpm is 320, lop 20hp off that for alternator, water pump, gears. This is the Pleasure Duty Rating for the engine. This means you should not operate at full throttle for more than 15 minutes in an hour and should otherwise be reduced to 10% less than the maximum - ie 2700rpm
As you and Jack suggest, however, this is all somewhat moot now... but will at least provide 555 with some guidance for the future...

[Frosty]

Any way the point is, it would seem that it is underproped. Being able to exeed max RPM. If that is the RPM.

Like I said earlier its a cloudy picture and probably why not many have picked this up. How old is the boat? engine hours? standard props? Was levels checked before departure? Any previous work on engines? Were the heads ever re-torqued from new?

Could just be a simple head gaket failure and crew not paying attention to engine temp guages.

But 10 liters of water Jeees. I have seen some people when hearing alarms just look at each other, then after some one takes the throttles back they still walk around looking over the side as if to see something.

To those who dont know --an alarm means its already hot as hell, it does not mean walk around and think about it.

[hartley]

I would like to reply to Mr Poida's comments on the cummins 555's .and in particular his views on ''vibrating sleeves''
I have a sneaking suspicion Mr Poida has been visiting some establishments
called''adult shops'',I am reliably informed that they indeed do sell some items
called ''vibrating sleeves'' .admittedly this information is second or third hand
I have no knowledge of these things myself,as being far advanced in years I have no need of them .
perhaps because of over indulgence in the use of ''vibrating sleeves'' Mr Poida
has mistaken one for the other ,in any event perhaps Mr Poida could enlighten us all ,after all perhaps even I am not to old to learn these new tricks..........cheers for now ,and good evening to you all.