Climbing EGTs on PME 480CE

[Kevin]

480CE on CC35 – Climbing EGTs on Port Main<br /><br />Boat: 35´ Carolina Classic 2003<br /><br />Engines 480 CE 6CTA<br /><br />Stbd Serial No: 46211591<br /><br />Port Serial No: 46211572<br /><br />(can someone run these engine s to see history or if heads were ever updated?)<br /><br />First season with the boat the wastegate plate rusted through which i ended up replacing the stbd turbo (sb mar) at the same time i had installed EGT probs post turbo and noticed the new turbo engine was 200 deg lower EGTS at cruise. WOT EGTs were about 850. Caused me to want to change the other turbo over the winter months.<br /><br />Over the winter I replaced the other turbo with new and performed all the cooler servicing. The new turbo had the same cross reference number as the SB mar turbo(4955231) 2nd turbo is (4041737 / 4041650).<br /><br />On de-winterizing the engines I accidentally left the fuel valves closed which led to the port engine shutting down. Opened the valves and reprimed the system, both engines fired up and sounded normal.<br /><br />On first test ride of the season everything appeared to operate correctly, though I can´t recall if I got to full throttle.<br /><br />On the second ride, I was ensuring engines still got to rated RPMS and saw 2670/2630 WOT<br /><br />I noticed the EGTs on the port engine start rapidly climbing – pulled back to 2100 and temps stabilize at their normal temps of ~650. Once engines cooled off I noticed a wiggley hose clamp. I ended up replacing most of the hose clamps on the charge air side that I loosened during the cooler services. Went for a test ride and things seemed okay then I heard a pop and black smoke and asap pulled back, and found that last hose clamp broke off and the turbo charge air tube popped off. Replaced that clamp and continued on. However when i go to 2580 or higher EGTS on the port engine rise fast atleast 150-200 degrees compared to the stbd engine. EGTS are pretty much the same from idle up to the 2500 turns.

Engines running normally at cruise 2150-2250 turns however anywhere above about 2580 the port EGTs start climbing above 950 and rapidly – I don´t see where they settle at since they have not run that hot; not even with the old turbo. I checked hose clamps again and hoses and didn´t see any cracks. I am looking for ideas to look for or check to diagnoses as I don´t want to just ignore this symptom even thou I don´t run at WOT much. I don’t know if the heads were ever updated so i don’t want to overload or have excessive heat on them.<br /><br />I cleaned the aftercoolers identically and followed Tonys recommendations.<br /><br />I installed the turbo same way as the stbd and same recommendations as tony gives.<br /><br />Couple data points:<br /><br />RPM       Boost psi             Load            Fuel                   EGT<br /><br />2150           24/25             63/68          13.8/14.3          597/607<br />2220         26/27              68/71           15.9/16.7          616/619<br />2265         28/29             69/73            16.8/17.5          622/621<br />2390         31/31              78/81             19.2/19.6         654/641<br />2450        31/32              84/85            20.7/21.1          689/669<br />2540        31/32              88/90          22.2/22.8          767/730<br />2660       30 32/32        100/100        25.5/25.3         950+/850<br /><br />If the high EGTS are not boost leak related where else can I investigate.

Topic

[Steve Lewis]

Tony,

Unfortunately I am not able to give you that data.  We have only operated our cruising boats in the Fresh Waters of the Great Lakes.  I am curious about what change in vessel performance we would see with our setup going into salt water but at this point we are staying in the Great Lakes.  we are actually trying to sell our boat so that we can acquire a different boat.  After owning and cruising this one for 3 seasons, we have learned a few things.  I need a residential queen sized bed to get good sleep.  We need a better galley layout and a larger freezer and I want a different bow entry hull shape for dealing with the steep waves on the Great Lakes.  

We will most likely cruise down the east coast at some point but for now……  Fresh Waters of the Great Lakes.

[Tony Athens]

Power needed in Fresh water vs Saltwater

Steve, Can you tell me what kind of difference  you see in GPH at some RPM near cruise speeds when in fresh water vs salt water..  Tony

[Steve Lewis]

Other temps

I have set our idle rpm to 650.  We have split throttle and shifters so I fire the engines and set the idle rpm with the throttle sticks.  That gives us an EGT of 300F.  WE leave the slip and travel a no wake channel out the inlet to the main lake.  Lake Erie.  Once out on the lake we advance to 1140rpm which gets us hull speed.  Temps advance to 500F.  Once oil press is below 50 on the analog gauges we will run up on plane and advance to ~2250 and that gets us the temps of 750/725.   We tend to cruise at 2250 as that feels right for our boat and gets us a reasonable vessel speed.  We ran at 2330 for half an hour up on Lake Huron to get in front of some crossing weather.  Other than that those are the speeds and temps we see

I have not run up to WOT and probably should to see what we get.  I did have a turbo air tube clamp break on our port engine while on plane and the temp on that engine shot up to 1000+.  Dropped off plane and stayed at hull speed and the normal 500F on both engines.

I have smartcrap instrumentation so I do not have boost values.  I have looked and just don’t see them.  

Engines still have original turbos.  Engines were built in 2004 as per QSOL.

[Kevin]

As a baseline, what is your idle temps? at 600 rpm declutched? What’s your boost at 2250 turns?

If I recall on startup cold engine I’m like 150 ish then 250-280 ish once warm.

[Kevin]

Some of the sensor screenshots from running. I’m out on a ship so won’t be able to test or get to the boat for a couple weeks.

[Kevin]

So interestingly, when I switched out my stbd turbo in October ’23, is when I installed both EGT sensors. And that showed the port turbo to be running 200* hotter, similar to your numbers. so over the winter I replaced the port turbo. Now the EGTs are lower, except at WOT on the port. 

I also suspect I am over pitched by 1-2″ which I also plan to change next time she’s out of the water.

35′ boat weights at 25000-30,000 lbs.

these numbers and the screen shots are light load, 100 gallons of fuel and light gear.

[Steve Lewis]

Interesting Data Points

Kevin,

We are Fellow 480CE owners.  We run a Sea Ray 460 Dancer of the ’05 vintage.  Our specs are 2250RPM we are burning a combined GPH of 30.3 and EGT’s show 750/725.  Your numbers are 2265rpm burning a combined 34.3 and EGT’s in the 620 range.  I expected your EGT’s to be higher than mine……….

Question to Tony.  Should we expect EGT’s to be this far different? His engines are tuning 15rpm more burning 4GPH more yet his EGT’s are showing almost 100F lower.  I know that boats and engines are different but something does not quite make sense to me.  with the added fuel burn at the ~similar RPM I would expect Kevin’s EGT’s to be higher than mine.  Is that an incorrect analysis?

Could these differences be attributed to cable length between the probe and gauge?  His turbos are new so they harvest more energy out of the exhaust flow?  Am I missing something or do we look at this as boats are different so base line your own boat and compare numbers only to your own boat and make sure they are in range?

For reference we have run 1 season ~150hours on the upgraded heads.  We are about to start season 2 with the new heads.

[Kevin]

2nd pics for now

[Kevin]

First photos, 

[Tony Athens]

Post good pictures of the engines from all around so I can see all.–What you are working with.. 

An example attached of what I need

[Author]

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