Re: [Amel Yacht Owners] Re: Perkins M 4.154 repairs
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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
THE EXPERIENCED AMEL GUY
954 462 5869 office
954 812 2485 cell
From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Friday, December 22, 2017 4:04 AM
To: James Alton lokiyawl2@... [amelyachtowners]
Subject: Re: [Amel Yacht Owners] Re: Perkins M 4.154 repairs
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.
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
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?