Engine not making as much power as it should [Westerbeke W50]

[thematt]

This forum is a godsend and you folks are amazing. Thank you.

Step 1. Will be to measure the oil filter temp next time I'm out (this weekend).

Step 2. Will be to check the theromostat / coolant flush. The W50 is a marinized BMC/Leyland 1.8, so depending on the sender, the temp sensor could have the wrong resistance for the panel as well.

Happy to keep getting feedback, ideas, but I think with everything listed thus far I have many good starting points. I'll report back. Thanks again all.

[drgtmartin]

I had a Tartan 42, #29, with the original Westerbeke 50 and I can tell you that the engine always overheated (just a bit) over 2800 RPM. I repowered with a Yanmar 4JH57 and was surprised that the Yanmar install specifications required a much larger raw water intake and a much larger exhaust tube diameter for yes, more Hp's, but not that much more. It always made me wonder if the Westerbeke 50 installation was not designed properly and should have always had larger intake and exhaust tubing diameters.

The other thing that made me wonder about your symptoms is the exhaust elbow and if that much be somewhat occluded.

[thematt]

Originally Posted by drgtmartin

I had a Tartan 42, #29, with the original Westerbeke 50 and I can tell you that the engine always overheated (just a bit) over 2800 RPM. I repowered with a Yanmar 4JH57 and was surprised that the Yanmar install specifications required a much larger raw water intake and a much larger exhaust tube diameter for yes, more Hp's, but not that much more.

Hey there, I think we chatted in another thread about a repower. I was trying really hard to got with a new Yanmar, but was told that beside the new exhaust and intake the install angle was 17 degrees so stringers would have to be remade and there was no transmission on the market that would make the v drive/ stern tube combo work. My quote for total hands off install went from 35K to 70-80k. Hence I dropped in a surplus of less than half a new engine cost, but look at me, back here again with more and different questions.

Originally Posted by drgtmartin

The other thing that made me wonder about your symptoms is the exhaust elbow and if that much be somewhat occluded.

Exhaust elbow is brand new as my old one was quite bad.

[wcaswell]

What year is the Westerbeke 50? Mine is a 1979 which is the British Leyland block. I've never run higher than 1900 RPM and never over 1600 for more than a few seconds. I'm on a Tartan 37 so not as heavy as the 42, but I do 6 knots in smooth conditions at 1500 RPM. If I was running as fast as you say, I would be expecting it to bellow black smoke and start throwing pieces of itself into the bilge!

[rwallace]

Sounds like exhaust elbow clogged. Remove where it attaches engine and look inside. If constricted with rust and exhaust soot - which will be rock hard - it would constrict engines ability to make power at higher revs.

[gulfislandfred]

A compression test should not be expensive and time consuming. A compression tester is under $50 on Amazon. If you're not comfortable to do it yourself, find a mechanically inclined buddy to help. Do the test with all injector removed, or at least fully loosened.

[stormalong]

Originally Posted by thematt

The short story is, instead of repowering my Tartan 42 with a new engine, due to circumstances and engine install angle + v drive etc, when the original W50 started to die, I dropped a 'good running' surplus in.

Who determined that it was a "good running" engine? Hopefully not the person that sold it to you.

[donradcliffe]

Meh. Be happy with what you have, and don't run it firewalled all the time.

[Cat38skip]

Originally Posted by rwallace

Sounds like exhaust elbow clogged. Remove where it attaches engine and look inside. If constricted with rust and exhaust soot - which will be rock hard - it would constrict engines ability to make power at higher revs.

I'm with you on checking the exhaust system for restrictions. We had a loss of power and rpms due to carbon buildup in our yanmar. The engine seldom ran for more than a few minutes as we usually set sail immediately after leaving the harbor. The engine seldom ran up to operating temperature and never had a chance to clear itself. Turns out it was a rather common problem in our marina.

[skipperpete]

Originally Posted by rwallace

Sounds like exhaust elbow clogged. Remove where it attaches engine and look inside. If constricted with rust and exhaust soot - which will be rock hard - it would constrict engines ability to make power at higher revs.

The elbow was replaced, read back a few posts. I’m enthiastically agreeing with donradcliffe. I’d be interested to know how many forum members boats would handle a long run at full load, or even a short burst.

[gulfislandfred]

As normal maintenance, I run every diesel engine I've ever had at full throttle for a half hour to an hour, a couple of times a year, to burn out the carbon.
If the engine overheats, I consider it to be a problem, and fix it.
That would be at least 20 engines, from 8 to 100 hp, FWC and RWC over a period of 50 plus years.

[Wotname]

Originally Posted by skipperpete

....... I’d be interested to know how many forum members boats would handle a long run at full load, or even a short burst.

One data point - personally - 3 boats, 5 engines - all could (and did) run at WOT for hours. I am expecting the next boat (still to be re-splashed) will do likewise however I take your point, not all installations and routine maintenance activities are created 'equal'.