Re: [Amel Yacht Owners] Re: Perkins M 4.154 repairs

James Alton

On Dec 22, 2017, at 8:17 AM, 'Joel Potter' jfpottercys@... [amelyachtowners] <amelyachtowners@...> wrote:

More than likely your problem is the crankshaft bearings and the connecting rod bearings clearances are too large. As the engine warms the expansion of components causes the clearances to increase even more and hence the oil pressure to go down.

The prognosis for this situation is not good. Sorry to be the bearer of bad news…


Joel F. Potter/Cruising Yacht Specialist LLC


954 462 5869 office

954 812 2485 cell

From: [mailto:amelyachtowners@... <mailto:amelyachtowners@...>]
Sent: Friday, December 22, 2017 4:04 AM
To: James Alton lokiyawl2@... <mailto:lokiyawl2@...> [amelyachtowners] <amelyachtowners@... <mailto:amelyachtowners@...>>
Subject: Re: [Amel Yacht Owners] Re: Perkins M 4.154 repairs

Christian Alby,

First thanks for letting me know that your buzzer apparently comes on at 1 bar, that is something that I was wondering about and could not find the data online.

Ok, so your oil pressure at 1500 RPM is 3.2 bar. The Perkins specifications are saying the the oil pressure at full throttle RPM should be between 2.1 and 4.2 bar so since I assume that cruise RPM is 1500 or higher your engine would be operating well within the allowed design specifications currently. I personally would not be overly concerned with the oil pressure being a bit low at idle since the engine is not loaded at that time. If the oil pressure remains stable and does not drop much over time, I would think that it should be ok for a while. Normally however a new or a newly built engine should hit the highest pressure shown in the specifications (which in your case would be 4.2 bar) which would be the setting for the pressure relief valve in the oil pump. When this is happening, it tells you that the pump is supplying more oil than the engine can use at the max oil pressure so the balance of the oil is returned to the oil pan via the relief valve. The excess amount of oil being pumped is a really good thing because as the engine wears and the clearances open up, the proper oil pressure can be maintained for a much longer period. Since your engine is not reaching the higher pressure, it means that as any wear occurs the pressures will drop rather than remaining stable which will likely lead to shorter useable engine life. In your previous email, you stated that the bearings had been replaced but you did not say which ones. Were the Camshaft, connecting rod and main bearings all replaced? The rocker arm and bearings might have been ok but were these checked to be sure? Was the crankshaft and camshaft measured and verified to be within allowable tolerances? Hopefully all of the journals were smoothed up to remove any sharp edges. If all of this work was done and done correctly then you should have a tight engine and the scored oil pump might well be the culprit. If some of the bearings were not replaced or there was excess wear in any of the parts creating out of spec clearances, that might be the cause of the lower than expected oil pressure rather than the oil pump. If this were my engine and I knew that the engine had been properly rebuilt other than the scored oil pump I would certainly be inclined to change or at least see about rebuilding the original pump at a good machine shop if no replacement parts were found. Did you look on Ebay for replacement oil pump parts? I have seen recent listings for pumps that are supposed to be for the 4-154 but have not verified if those parts would fit our engines.

Just one more thing. If it were me, I would continue to be on the look out for any evidence of diesel getting back into the oil. While you feel sure that the lift pump was the cause of your problem, it is possible that the injection pump could be leaking some as well. Once your engine is broken in, you might be able to up the idle oil pressure a bit with the engine warm by switching to a synthetic oil which does not thin out as much when hot. Correcting the cause of the low oil pressure would certainly be the best solution but I also understand the need to use our boats.

Best of luck,

SV Sueño

Hi there James

Starting oïl pressure (cold engine) reads now 3 bars with 1300 rpm (goes up soon as engine starts - no time lag, good sign that pump is working)

goes down to 2.8 bars when warming up to 70°C

idling at 700 rpm when warm at 70°C drops down to 1 bar - sets on the warning beeper

changed setting on engine to run idling at 850 rpm - oïl pressure goes up to 1.2 bars (no more warning beeper - a rest for our ears)

when accelerating to 1500 rpm oïl pressure runs up to 3.2 - again immediate, no time lag)

oïl pressure gauge is reading; was on zero when first started & cooling hoses were inverted. Went up to reading when corrected.. No clue on correctness of reading as no calibration done.

However did the good old check on oïl pressure to unscrew the oïl filter & got a good shower, followed by unscreing the pressure gauge & watching the closest I know to a Blow-out on an oïl rig.

I did not find a replacement oïl pump for the engine & fitted the 'old scored' one back in; still looking & searching now with oïl pumps manufacturers as I have seen similar designs, but different sizes on the net. Intent is to find one to be available by early 2020 latest to allow for dismantling of engine (again) & refitting a new or reconditionend pump.

Guess I will try & stretch the life of my 4..154 to get some retunr on Investment for the repairs done here in Tenerife..

fair winds

christian alby - Désirade VIII - Maramu 116 - in SC de Tenerife (ETD 24/12 to Cabo Verde)

Christian Alby - France home fixe +33 (0)5 34 39 06 02 home Internet +33 (0)9 60 37 22 72 mobile +33 (0)6 42 69 07 80

Le ‎jeudi‎ ‎21‎ ‎décembre‎ ‎2017‎ ‎19‎:‎35‎:‎16‎ ‎GMT, James Alton lokiyawl2@... <mailto:lokiyawl2@...> [amelyachtowners] <amelyachtowners@... <mailto:amelyachtowners@...>> a écrit :

Christian Alby,

Thanks for the initial update on your rebuilt Perkins. The Perkins 4-154 manual that I just checked is showing the normal oil pressure to be between 30-60 PSI or about 2.1- 4.2 bar at “maximum engine speed”. They do not seem to list an idling oil pressure. What was the initial oil pressure when the engine was first started and cold? How is the oil pressure at your normal cruising RPM? Is there any chance that your oil pressure gauge is not reading correctly? I am really happy that the engine seems to be running so well for you. Were you unable to find a replacement oil pump for your engine?



SV Sueño

Maramu #220

On Dec 21, 2017, at 5:30 AM, christian alby calbyy@... <mailto:calbyy@...> [amelyachtowners] <amelyachtowners@... <mailto:amelyachtowners@...>> wrote:


will do an update when returning to home port in 2019

Just to complete results of trial run, oïl pressure went down to 1 bar at 700 rpm after 3 hrs running (cooling maintained at 70°C).

Engine purring nicely, no leaks.

I book it to the ol pump condition (scored innards).

Added Wynn's Supercharge to thicken oïl & oïl pressure went up to 1.2 bar at 700 Rpm; much better but temporary solution.

Thinking of adding one oïl pump piggy-back on engine (oïl cooling hoses) either driven by pulley or electric. Will pursue.

Fair winds

christian alby - Désirade VIII - Maramu 116 - SC de Tenerife

Christian Alby - France home fixe +33 (0)5 34 39 06 02 home Internet +33 (0)9 60 37 22 72 mobile +33 (0)6 42 69 07 80

Le ‎mercredi‎ ‎20‎ ‎décembre‎ ‎2017‎ ‎10‎:‎18‎:‎26‎ ‎GMT, James Alton lokiyawl2@... <mailto:lokiyawl2@...> [amelyachtowners] <amelyachtowners@... <mailto:amelyachtowners@...>> a écrit :

christian alby,

Thanks for taking the time to update us on your freshly rebuilt 4-154 along with verifying the cause of the failure. I hope that the engine provides you many years of good service. If not too much trouble, could you do another update in 1-2 years on how the engine has held up?



SV Sueno

Maramu #220

On Dec 20, 2017, at 4:54 AM, <mailto:calbyy@...> [amelyachtowners] <amelyachtowners@... <>> wrote:

Thanks to all Amel sailors who assisted me find parts for my 1982 Perkins M 4.154.

Engine is rebuilt now with new pistons, liners, bearings ... Including a brand new starter to replace the one burnt by the workshop electrician who tried to run faster by hooking my 'old faithfull' 12 volts starter on 2 batteries in series at 24 Volts !

Engine on board 19/12; hooked up & running same day at 17:00 (lost time on drive end bolts offset by 1/4 turn - lift engine & rotate whell -, then oïl cooler hoses inverted, no return = no oïl on pressure gauge).

the cause of the fault was definetly the diesel lift pump diaphragm; 63 US$ Worth of spare, Worth changing on engines which did not run for over a year or so. Check them often.

Otherwise I can only recommend UK & USA suppliers who responded & supplied replacement parts; And Tenerife workshop 'Precision T.' who did a perfect job on the mechanical part; Just keep electricians away from our installations, not their best show of experience.

We shall sail away on 24/12 to continue our round trip of South Atlantic.

fair winds to all

christian alby - Désirade VIII - Maramu 1982 now (not for long) in SC de Tenerife

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