[Jeff Lewis]

They are probably the original pumps (20 years) and will be a pain to replace. I should for your reasons, but there is no movement in the cam so I hesitate to replace. As a side, they are working great now (even after the “hot burn in” of the impellers. Great water flow, perfect cooling, and the pumps run cool to the touch.

[Jeff Lewis]

The pump primed immediately (within 10 seconds), although there was air in the hose between the strainer and pump. So I need to bleed that air out? It seems hard to believe that 10 seconds dry (with a very liberal coat of grease on the impeller) would cause damage.

Any ideas about the “tight fit” of the impeller? ie. the end of the impeller is extremely tight against the pump housing cover, causing excessive friction until it is worn down

[Jeff Lewis]

Yes, I used plenty of lubrication. The pump primed quickly.

[Jeff Lewis]

not sure when it was last rebuilt, if ever. The shaft is solid, with no noticeable play.

[Jeff Lewis]

What is burping the system?

[Jeff Lewis]

I’m out of town, but I’ll look next week. It looks the same in pictures (ie the tensioner pulley relation to the alternator and idler pulley seem the same). This wobble is either the cause of or the result of the belt “jumping” or “slapping” between the crank and water pump. As I said before, both of those pulleys run smooth. I tried adding additional tension to the tensioner while the engine was running with mixed results (smoothed out some, but still not rock solid like other engine). I have included pictures from both engines so you can see relation.
Jeff

[Jeff Lewis]

Identical. All solid. It looks almost like the belt is too long or the tensioner is not providing enough tension (but it’s new). I’ll look into the idler pulley upgrade, although I don’t think it is responsible for my current problem.
Jeff

[Jeff Lewis]

And the simple reason is…?

[Jeff Lewis]

Is it possible the ventilation hose diameter is too small? Have you ever put a vacuum gauge on it?
Jeff

[Jeff Lewis]

1. The Crank Case Vent went straight to the bilge (never saw smoke coming from tube though)
2. I saw it static, hot and cold rpms 600-1600. I didn’t check while underway or at high rpms
3. 1177
4. Yes, so they suggested the Valve Cover install option, versus the Timing Cover Install
5. I’m not on boat, but at least 5 inches
6. Order #11521

Jeff

[Jeff Lewis]

Before I drained the oil, the port engine oil level was 1/8″ below high mark on dipstick (but no venting issues on this engine). The starboard engine was venting oil badly (1 Qt / hr) when the oil was “between the marks”. It stopped venting oil when the level got to 1/2″ below low level dipstick mark. I drained both engines and found both had near 16 Qt. Previous owner must’ve been running engine 1 gallon overfilled the last 10 years? Anyway, I remarked at 12 Qt. All is fine – I still plan on CCV system (just received it) and rest on Tony’s recommendations.

[Jeff Lewis]

Thanks Bill,
I’m starting to get a handle on it. I still would like to know what a “reasonable” cruising rpm is . Cummins just throws out 2400 rpm continuous duty (no more than 300 hrs/yr). This is obviously high. This boat cruises nicely at 2100 – 2200 rpm at 14-16 kts. Is that reasonable for a 100 mile Florida to Bahama run? Best fuel economy is 6 – 8 kts.

Rob and Tony, I’ll get some pics after Christmas because I’m still concerned about the crank ventilation and fumes.

Merry Christmas,
Jeff

[Jeff Lewis]

Tony,
I’m not interested in running the boat on the “edge”. I’ve been a military and commercial pilot for thirty years and been primarily a sailor that time. I like to know operational limits, not because I push them, but so I can better understand my aircraft or boat. This is my first experience in big diesels. I’m just trying to figure out how best to use this great boat. So far I’ve primarily cruised between 6-8 kts. On occasion I have run it at 2100 – 2200 rpm and gotten 14-16 kts. I’m trying not to do major changes if I don’t have to. I did purchase a CCV system from Seaboard – haven’t received it yet. I’ll reprop this summer per your instructions.
Jeff

[Jeff Lewis]

Thanks Rob, the graph explains it all.
Jeff

[Jeff Lewis]

Makes sense. The graph Rob supplied explains all. If I reprop to 2700 should I still limit speeds above 2400 to 1 hr in 8 per Cummins? Just got boat. I will change oil next week and let you know how much is in pan. I’m planing on putting 13 qt in.
Jeff

[Jeff Lewis]

Great info Rob,
It thoroughly explains what I’m seeing. The boat was propped at 2650 WOT when I sea trialed it. When I took delivery I filled the tanks (200 gal diesel and 100 gal water – over 2000 lbs) and my WOT rpm obviously dropped 75-100 because of the increased drag. Please correct me if I’m wrong, but if I have the WOT rpm right at 2600 the Cummins Ops Limits (2600 rpm max 1 hour out of 8 hours for a 300 hr/yr pleasure craft and 2400 rpm max continuous) should still keep me “safe”? Re-pitching to 2700 rpm just gives me some cushion and will decrease the load and wear and tear on the engines for the same rpm (but a slower speed).
Jeff

[Jeff Lewis]

Thanks Rob,
Props are 22” dia, 25” pitch

[Jeff Lewis]

Thanks Rob,
Yes it is a 36 Express Trawler. No CCV, just a vinyl tube from vent port down to the bilge. I’ll definitely check the pan oil quantity. As for WOT, I thought the engine specifications are 2600 WOT (I originally got 2650, now 2550).
Am I not in the ballpark of correct WOT? Why would I prop for 2700? I have 22R/L25 props. I’ll get some pics and check side vents in a couple of days. I just ordered the V-drive CCV from Seaboard.
Jeff

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