Input from survey results

[bigduby]

Survey was done on a 1999 400DA with 3116 350HP engines, 450 hrs and a couple things came up I wouldn't mind some feedback on. Sorry for the long post..
1. Small Racor fuel filters commented on by the Cat technician. I have seen posts about this before. Low fuel pressure was found in both engines, and by low I think his measurements were like 10 and 16. He commented VERY low pressure and said this is the most likely culprit if they were blocked filters. Then neither engine was able to get to 2800 WOT, they were 2740 and 2765. The plan is to get the filters changed and retest fuel pressure and WOT rpm. Anything else I should be concerned with?
2. Cat tech commented that all of the hoses and belts were original ( 10 yrs ) and he suggested they be changed on both engines ( big $$$$ apparently ). No obvious signs of wear on any of the hoses. What is the realistic time period/hrs these things get changed?
3. Assuming the heat exchangers have never been cleaned, what should i expect with them? Temps were within spec ( approx 180 ) but tech commented he would like to have seen a better temp difference between intake and outgoing with the current water temp/air temp. Where do you go to get them cleaned, assuming I can get it off myself. I don't think they have ever been cleaned.
4. I wish I would have ridden on a diesel boat before this. Since it was my first time, i didn't know what was normal sounds vs. a potential problem. Anyone familiar with a whinning noise at the helm that seems to get worse at higher rpm?

 

[Boatingfool]

I'll let the cat guys comment on most of your questions, but if this is the bulk of what they came up with out of the survey I'd say this is pretty normal on a boat 10yrs old.

If you can get sufficient access & tools to remove the aftercoolers yourself and they are similar to Cummins aftercoolers the process is straight forward. I did this on my old boat which had 450C Cummins. Once removed from your boat I'd recommend taking them to a boat yard where someone can go through the process with you this first time...if they are similar to the Cummins aftercoolers expect to take two-three hours of someones time if you do a very thorough job.

On the diesels... if you are used to gasoline engines diesels can seem downright crude at first! Whereas gasoline engines tend to be very smooth, diesels can be downright harsh when started cold (and a little smokey). Once running they clack around at idle and you'll feel it in the deck. When running a little more rpm they usually smooth out. When you bump the throttle to get the boat up on plane you will most likely hear the turbochargers and their whisteling like sound get louder. On my current boat if you were to go into the engine room while the boat is running up on plane you'd nearly go deafth. So if the Cat mechanic didn't tell you he heard anything abnormal I wouldn't worry about the sound too much :grin:

Hope to see you at BIH this year!

 

[fwebster]

Hoses?........probably need replacement, but look for cracks in the outer covering on the bends. The labor isn't much but 2" double wall water hoses are expensive by the ft. The Cat specific hoses will run about $100/engine.

DO NOT MESS WITH THE AFTERCOOLERS!.........unless the Cat technician recommended their cleaning. Cat says the cleaning interval is at 1000 hours. Either way, this is not an owner service item on Cats.

Heat exchangers.......probably should be cleaned to get you to a known starting point. ON some hulls the tube bundle can be removed with the heat exchanger on the boat; others, you must pull the whole heat exchanger off. Cleaning is very much like cleaning a radiator with a rod and acid. The Cat heat exchanger has a series of o-rings in the end caps that you will pinch and cut if you haven't done this before. THis is about a 6 hour job on 3116's so I'd just hire it done.

RPMs...are about normal for a fouled bottom. BE sure the props and bottom are clean.

Whine.......Normal for Cat engines to have a turbo squeal as the turbos spool up. Your boat should have Walker Air-Seps which dampen the intake noise significantly. If you don't, its an addition well worth making.


Hope that helps.........

 

[tobnpr]

Only things to add:
What size Racors? Check the chart here and compare against the flow rate at WOT for your engine (note: not fuel burn, but fuel flow)
http://www.parker.com/literature/Racor/Marine_Turbine_Series.pdf

'Course, the larger the filter element the more crud it can absorb before causing excessive vacuum. Most engines that size would be plumbed with 1000's- do you have 900's?

You're not that far off on rpms, especially if the boat was fully loaded at the time. Filter element restriction could cause it (has happened to me), fouled bottom or gear, or combination of both. Was the boat short-hauled for the out-of-water inspection yet? At least it sounds like the engines haven't been excessively overloaded. As far as temps go- assume the strainers were checked and they were clean?

Good luck.

 

[osd9]

My 410DA with 350 HP 3126-TA motors has the itty bitty 500MA filters.....and I suspect that you may have the same....

The PO added the petcocks and I added the tell tale vacuum gauges. IMHO, Sea Ray 'cheaped' out on this. I've gone back and forth on replacing them with the more man-ley 900MA, but for these motors, the 500MA's specs are 'just' within the limits....total of 60 gph.....which includes the return fuel circuit.

I've run the boat now for two seasons, and I've never had an issue with the filters prematurely clogging up. I change them at the begining of the season and then keep an eye on the vacuum gauge.....a very cool mod I might ad.

Justifying the cost to upgrade to 900MA filters is very difficult and I doubt that the size of the filter/housing is causing you not to reach rated WOT.

As stated above, you need to first confirm the condition of the bottom and the props.

Also, make sure that the tanks are full, and that there is suffiecient 'other' weight on board to simulate full water, stuff, passengers, etc before you re-run. Based on the WOT number you provided, I assume the CAT tech used an opto tach to measure the speeds. DO NOT base your survey on the dash mounted analog tachs!!!!!!

From my CAT engine survey, these were my fuel pressure numbers....

Fuel Pressure ---PORT------- STBD---- Range
PSI------------- 48-----------56 ----min 34 max 76

 

[bigduby]

Thanks everyone for the input. Here are some additional details. The boat was out of water for initial survey and the bottom was clean. The picture shows what the gear looked like. The fuel filter is the small 500 and I am hoping that is the problem with the WOT rpms. Also, am i chasing a ghost for the last 50 or so rpms? Is it really a small problem or a sign of something else? I am sure the props need to be tuned. There was one other comment I just noticed from the tech "Blowby slightly elevated for engine hours, oil samples should be monitored" and i noticed the hours are actually 460 and 412. Seems odd for such a large difference. Any ideas? All rpms are from the tech not the gauges also..

On the diesels... if you are used to gasoline engines diesels can seem downright crude at first! Whereas gasoline engines tend to be very smooth, diesels can be downright harsh when started cold (and a little smokey). Once running they clack around at idle and you'll feel it in the deck. When running a little more rpm they usually smooth out. When you bump the throttle to get the boat up on plane you will most likely hear the turbochargers and their whisteling like sound get louder

This seems to describe my experience pretty well... the other thing I notices was a surging sound like the motors were out of sync, even though they were in sync according to the gauge. Any thoughts on that?

Oh, and I know, I know, damn diesel rookies .... :grin:

Thanks again.

 

[osd9]

......, even though they were in sync according to the gauge. Any thoughts on that?.....

You may need to have someone calibrate the sync guage while using the photo tach to read RPMs.

The 500MA filters, although small, are not the reason for you not reaching full rated WOT RPMs. I run upto 2835 on both sides with the same setup....and a thad more HP.

edit: However, you should definitely replace both the racor primary, and CAT on engine secondary filters to assure you are running with clean filters.

With regard to chasing 50 RPMs. You don't say if you ran the boat fully loaded or not. If not 'FULLY' loaded, then IMHO, you are best chasing for another 75-100 RPMs. The commonly accepted range for these motors is 2825-2850 under fully loaded ideal conditions. That will give you some margin as you add stuff and the bottom fouls throughout the season. Also, this time of year, air and water temps are cooler. You may also loose some RPMs as the season warms.

 

[fwebster]

The problem I see with the 500MA filters is that you have no reserve filtration capacity. I have dual 900MA's on 3116's and in Florida I have have had a plugged filter before. Since I have roughly 3X the capacity of a single 500MA, how quick would a bad load of fuel block a single filter? If you do some long distance running then consider an upgrade to dual 900MA's or learn how to change Racors in your sleep on a roller coaster because that's what changing a filter feels like when you are 100 miles off shore and a filter gets plugged.

 

[osd9]

I agree Frank...I go back and forth with the idea, but something else always comes up.....I've even thought of just adding a second 500MA filter in parrallel so I could run off of one, and then if the need arrisess, I could just 'valve' over to the clean side and run home to change the filter at my liesure.....Again, Sea Ray 'cheaped' out big time on the 380,400,410 and maybe others with the 3116/3126 lower hp motors.

This is another very good reason to add the tell tale vacuum guages I posted above...

 

[Asureyez]

A 50 hour difference between engine run times is a bit odd, however I do see some skippers run on one engine when having to idle long distances on the ICW. I do not do this as it gives too much wear on the Hydrolic tranny's as they free wheel.

 

[bigduby]

The only load on the boat was 4 adults. There was barely 1/8th in each fuel tank and it was just splashed from winterization so I doubt any water in the tanks or anything in the holding tank ( just an assumption ). Only thing left I guess is running gear or an actual problem.

The tech recommended adding the larger filter so that in a jam, you could switch to the smaller as a backup but primarily the larger would be used. I'm not sure what the cost of adding larger filters is.

 

[quality time]

As Dom said you are chasing more than 50 RPMs with that light of a load during the survey. I would suggest having the Racors swapped out for new ones. I saw a big difference after changing mine.

 

[fwebster]

Dominic,

The dual Racors were usually an option, so it was the dealer who spec'ed and ordered the boat who "cheaped out", not Sea Ray.

 

[osd9]

The dual racors were not an option on the 410DA. Not according to the brochures, and not according to Sea Ray customer service......I called and asked a few years ago.

IMHO, it shouldn't have been an 'OPTION' in the first place....duals should have been standard.

This was Sea Ray's 'cheap out'.....they own it.

I may someday add that second 500MA for another Dom Mod.

 

[wish2fish]

Frank or others. he stated that the boat was just splashed from winter storage with 1/8 tank of fuel. What impact does not having any fresh diesel fuel have on this performance issue?

 

[tobnpr]

I would be more concerned about additional water in the fuel from condensation from the tanks being stored empty.
The more air volume in the tank, the more moisture that is available to condense onto the sides of the tank and end up in the fuel.
Fuel itself, no problem- especially if you use fuel treatments like Diesel-Kleen.

 

[fwebster]

Diesel will get stale, but not to the point that it can't be burnt, especially if you mix what is in the tanks with fresh treated fuel. You might get a little extra smoke and starting my be slightly affected since the cetane is lower in stale fuel, but I bought a backhoe a few years ago that had not been run in 5 years.......I put a fresh battery in it and it rotated 2X and fired up.

But I'm with tobnpr on this one........your problem is the amount of water in the tank and the microbial growth it has grown over the winter.

 

[bigduby]

But I'm with tobnpr on this one........your problem is the amount of water in the tank and the microbial growth it has grown over the winter.

Is this something that gets treated with additives, or just filtered out? It looks like we'll be running it again after the Racor filters are replaces so hopefully that shows the improvement in RPM's. I know at least one of the props was slightly off so I would expect to see an RPM improvement after having both tuned.

... by the way, this is quite a process.... :grin:

 

[tobnpr]

Is this something that gets treated with additives, or just filtered out?

Yes, and yes.

I think most diesel owners have an additive of choice (Frank W once suggested Diesel Kleen and I've been happy with it), others have never had fuel problems, don't use additives, and continually put many trouble-free hours of use on their engines.

I found out from a CAT technician a couple of years ago that whent the new USLD fuel was first introduced into an older tank that it would act as a solvent and dislodge any crud that might be sticking to the inner walls of the tank, and to be sure to keep spare filters aboard.
You want to keep your tanks as full as possible if they're going to be sitting for any extended length of time.

 

[bigduby]

Additional information from the mechanical survey:

I noticed that one of the blowby readings is higher than the other but ultimately don't know what this means. Any input would be appreciated. Does the 1.5 X HP mean that 1.5 X 350 = 525 is the MAX acceptable number?