1986 Perkins 4-236 Fuel Consumption

[michaelratinter]

My 1972 4.236 moves my 29,000lb ketch at 7 kts at 1800 rpm. Fuel consumptio is 1.5 usg/hr

Prop is 24x18

Gear reduction is 2.31

[michaelratinter]

My longest run was 66 hours continuous at 1800 rpm from Asuncion Baja Sur to Ensenada. Engine ran perfectly.

[Kenatsea]

Thank you Rick, great information added to the collection.

[Bundyon]

Over the years, I have ran with various Perkins engines in commercial boats and have had a very good run with them.
My 25ton 42' Lwl Ketch runs a 4-248 Perkins, very similar in all aspects to the 4-236. I run mine at 1500rpm (indicated) for a return of 6 knots (sog) with a clean bottom & smooth seas and 3.5 -3.8 litres per hour (1 U.S.gallon). Ultra reliable, starts instantly & settles down to an idle (700-750rpm). These old school diesels just keep on keeping on. Clean fuel, oil & air is the key to any diesels surviveability. Enjoy!

[Kenatsea]

Thanks Bundyon!

[SteveSadler]

My jeanneau 49 has a 75hp Yanmar and burns a gallon an hr at 6.5 kts, but when I drop to 5 kts it uses 2/3rds of a gph. Your most efficient speed will be when you don't see a stern wave.

[Kenatsea]

Good point Steve, thank you!

[jak3b]

Originally Posted by Kenatsea

Thanks for your info. Can you tell me your speed at 1800 rpm?

7 knots, My boat is a 26,000 lbs, 39 ' wood cutter

[HankOnthewater]

Originally Posted by Kenatsea

Hank,

Would you mind sharing how you feel about the engine? To hear that you have 10,000 hours is great. Mine is sitting at 4,370 with a recent injector service and head work. Any recommendations for someone new to this engine to ensure additional years of service?

-Ken

Hi Ken, previous posters already gave the info I would give. My boat is 53 ft, 22t-23 tons loaded. Clean fuel, change oil and filters often (I do mine yearly). I changed my impeller only once in 5 years, but always carry a spare. I have the full history of the engine/boat, I am the fourth owner since 1985, each owner had it about 10 years, so I have another 5 to go. I have not found any info of breakdowns. My tanks are clean and i can polish the fuel.
Like others have said, would not replace engine, just recondition if needed. And parts for it are very cheap compared with Yanmar and Volvo, and the work is simple enough for DIY with a workshop manual ( I helped a friend recondition a Perkins 6.354 which basically same engine with 2 more cylinders). Spare parts are available worldwide, as this engine is used in tractors, harvesters, welders, gensets, even cars/trucks.

Newer engines are a lot lighter (?about 50%), more economical with common rail, and a lot smaller, but...... don't want to start here another discussion about new vs old engines.

Get a manual, can be downloaded online, I can't remember from which site I did; some download sites are a bit dodgy I think. But I have still original hardcopy.
I have 2 alternators running on the Perkins, but in the process changing over to one, and then with a serpentine belt. Hopefully that will make less of a mess. My dream is to paint my bilges white one day....... hmmm with a perkins not likely as oil leaks are not unusual.

[Kenatsea]

Hi Hank,

Thanks for the details. I've been out of commission for a couple of days, sorry for the late appreciation on your comment.

Needless to say, but doing it anyways. Thank you all, you have helped build my confidence in this motor. My only prior experience is with Yanmars which have been very positive.

Best,
-Ken