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3208 marine engine 425b hp

3208 marine engine 425b hp

3208 marine engine 425b hp

(OP)
I replaced pistons 425hp in 3208 wher were 375 hp pistons, l changed intercooler and rest of components, when l started engine white smoke is comming out, l think is fuel pump phase , did you have anything like this, why is white smoke now comming out of engine on low rpm, repeat new pistons 425 hp are put in 3208 engine where 375 hp pistons were in, all other componenets are changed for 425 hp from 375 hp, engine block is same 3208 marine
 

RE: 3208 marine engine 425b hp

White smoke suggests you are not burning all the fuel that's injected.  How are the new pistons different from the old ones?  I.e. did you change the compression ratio?

Also, be sure that it's actually smoke.  Steam from a failed or misadjusted riser can be confused with white smoke.  Failed risers can take out pistons, too.  

Why did you rebuild the engine?


 

Mike Halloran
Pembroke Pines, FL, USA

RE: 3208 marine engine 425b hp

I agree with the lowered compression, what is the difference in the pistons?  Is the 425 turbo charged and the 375 not?
You said all components, are those components used?  
If such things as the fuel injection pump, and injectors were from a used unknown engine then they maybe faulty.
You need the injection pressures, time, and patterns checked. Depending on who did the engine work, you could be looking at things like broken rings, out of tolerance bores etc. and have massive compression losses there too.
 

RE: 3208 marine engine 425b hp

(OP)
yes pistons are new,rings also,  we had to put  two same engines 3208  425 hp, since owner found one used  block we got new 425 pistons, turbo charger, intercooler , wondering on fuel pump if it is correct, it was ok on old engine with 425 hp, repeat pistons are for 425 hp engine , they are different because on 375 hp is smaller compression hole on top of piston
it looks like white smoke

RE: 3208 marine engine 425b hp

When the 425hp rating was released white smoke at start was a known issue, and engine block heaters were standard equipment on that rating.

Does the smoke clear when the engine gets to about 165 degrees F and when under load?  If so then you have a problem that should be minimized by the block heaters, if not you have another problem.  

You may want to also check the fuel injection nozzles, been a while since I worked on a 3208, but I remember the 425 engine had a different nozzle with different spray angle than lower horsepower engines.

Hope that helps.

RE: 3208 marine engine 425b hp

(OP)
engine is having white smoke on high rpm, we have not tried  to make test run with boat, even engine is in the boat
it is smoke definatelly, and when we add gas it does not go , smoke stays
engine originally was 425hp but inside were 375 hp pistons, we did not knew this so when we opened engine we find out 375hp pistons, and
engine was running with fuel pump and it was ok ,
i am wondering if this fuel pump was working on 375 pistons , and now we put 425 pistons, what is possibility that fuel pump even if nozzles were 425 before and now are same
also wondering about timing gear if somebody did not replace this gears and timing for this reason is not ok
so if fuel pump is ok this might be also problem
also when is timeframe to change risers in this 3208 engines , is this on overhaul service or when is needed

RE: 3208 marine engine 425b hp

Possible your fuel injection pump timing is off.  White smoke is unburned atomized fuel, so an overfueling or timing issue is your likely culprit.

The injection pump doesn't care which pistons you have, the timing, rack setting and fuel nozzles are likely contributors.

When I was a mechanic we sent the risers out to the same shop that did our heat exchanger and aftercooler cores, boiled them out and pressure tested, popped the expansion plugs and did an inspection.  If they looked bad or leaked we replaced, if they cleaned up and tested ok they went back on.

White smoke and steam get confused sometimes, steam tends to drift upward and dissipate, white smoke tends to lay on the water and stays for a while.

What does your local CAT dealer say about this?  I mean besides you should have bought a REMAN engine.

RE: 3208 marine engine 425b hp

(OP)
we are maintaning yacht fleet and did not have problems so far , we have 75 3208 cat engines, so we are doing ok , but fortunatelly frokm time to time when we have problems we can adress to you guys, what l can say from my spot if you ever decide to pay ticket to Croatia you will have skipper, or vessel for yourself two weeks free of any charge, you will have free two weeks tuna fishing adventure , and any expences for accomodation, why l am saying this , because you guys are just great, thank you for all suport you are offering via e mail, you are just great, l am chief mechanic and l dont have lot of problems with Cat engines, sometimes 3208, and 3412 gas engines sometimes when we work on oilm rigs,
Cat mechanic here are not that expirienced so we have our own skilled mechanic which are great
anyway thanks, if l need l will ask you again
marko

RE: 3208 marine engine 425b hp

white smoke to me couold also mean it is gettin water/coolant into the cylinder

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