Lister Engine Forum

Lister Engines => Petteroids => Topic started by: Blue on February 25, 2016, 03:17:44 PM

Title: Petter M
Post by: Blue on February 25, 2016, 03:17:44 PM
Hello, a friend has given me a Petter M to play with and overhaul. It has been sitting unused for a while so things like rust in the fuel base, stuck fuel foot valve, broken spring on the fuel return plunger but nothing major found yet. It has a lubricator reservoir driven by the rear end of the magneto with a single pipe heading off to the mains (I assume) but there are grease nipples on the casing too  :-\. It is 1.5 bhp @ 750 rpm. What colour should it be ? I see traces of a very pale green. The big end seems to have a might too much play on it. Still has compression although it feels weak but that may be because I am used to my Lister diesel.
Title: Re: Petter M
Post by: Blue on March 10, 2016, 02:41:27 AM
O.K. Got it all stripped down now. The mains are grease lubricated via nipples but the big end is oil lubricated from a calibrator unit. Unfortunately that system has not been working too well and the small end has about 1mm play in it. The big end bearings are loose in the rod and I will have to put shims in to get the clearance right. One grease seal has broken and allowed grease into the crankcase which then combined with some carbon and blocked the oilway to the big end. Does anyone know if these seals are available? I have been trying with a bit of 1/4" shaft packing with no success but would really like to replace all four of them having now seen what can happen when they allow grease to pass. They are 1/4" square material and run against the crankshaft whilst sitting in a pocket on the side cover, the inner seals are 1 5/8" inside diameter, 2 1/8" O.D. and the outer seals 1 1/4" I.D. & 1 3/4" O.D. What are the originals made of, leather? Any help would be appreciated.
Title: Re: Petter M
Post by: dieselgman on March 10, 2016, 02:58:45 AM
We are not well versed with the old Petter designs but do have a huge archive of what remains of the old Petter documentation recently rescued from L/P Americas attic. Lister bought out Petter in the 1980s thereby becoming Lister/Petter.
If needed, and time available, I could try to dig up something for your model.

Title: Re: Petter M
Post by: listard-jp2 on March 10, 2016, 08:08:38 AM
OP, I suggest that you contact a UK ebay seller that goes by the name of  "rattlenackers" on eBay (note spelling).

His proper name is Mac McGowan, and he remakes some of the faster moving spares for that engine, and he may well be able to help you out.

Here is an example of what he makes, and subsequently sells on ebay:
Title: Re: Petter M
Post by: Blue on March 10, 2016, 05:06:33 PM
Thanks for the replies. I have sent a query to rattlenackers. I am amazed that there are not more folks out there as I read somewhere " The Petter M is one of the most collected engines in the UK" Hmmm. I am making new gaskets today ready for when I do find out what those crankcase seals are made of and can start rebuilding. Also have to drill out a stop stud on the carb that has broken off. All in all it is very well preserved and the quality of parts, even nuts is evident. Nuts are heavy and finished on one side only leaving the full face to carry the load on the other. Some places are still shiny as they were when fitted in the 1930's. Impressive. Thanks again for the replies any and all information received is useful. I am off up to the UK later this month so can pick up any parts I may find necessary.

All the best, Blue
Title: Re: Petter M
Post by: richardhula on March 10, 2016, 10:08:43 PM
Not sure about the Petter M but was intrigued to find that two stroke diesels always have a downward force on the piston. This lead to lube issues with plain little end (wrist pin) bearings. Needle rollers were considered but Kromhout followed by Gardner adopted the rolling bearing below.

Title: Re: Petter M
Post by: 38ac on March 11, 2016, 12:19:04 PM
Hi, Sorry but somehow I have overlooked your post and questions until this morning,,

 I also have have a few old Petter engines , mostly S types  and with information this side of the big lake being sparse I found some people that can help with most any Petter question at the Internal Fire Museum. Roland Craven who posts as "Petternut" can help you with about any question on your M type. 


Link to IFM website (
Title: Re: Petter M
Post by: Blue on March 12, 2016, 10:57:01 AM
Have signed up to internal fire but have to wait for approval before I can post anything. Thanks for that. My Petter M small end bush is phosphor bronze so has a modicum of natural lubrication and has a cup built into the connecting rod to catch any flying oil. All seems a bit hit and miss but I suppose it must have provided sufficient oil to keep it going. New bush currently being made. The gudgeon pin showed some signs of damage but only to the lower surface. It is held in place by a locating bolt so can't rotate and I was a bit confused by the marks but decided to leave well alone as the upper working surface is just about perfect. There is a sump drain plug so I guess all those drops of oil from the 'Calibrater' (every 5 seconds) that lub the big end collect in the bottom eventually and need removing occasionally. Hopefully I will soon be O.K.'d to access Internal Fire to see if I can pick their brains too. Many thanks.
Title: Re: Petter M
Post by: Blue on July 02, 2016, 02:43:50 AM
Never did hear back from Internal Fire (ho hum) but job completed now and returned to it's keeper looking and running rather better than when it came to me. That needle is very sensitive, it only takes a fraction of an inch to go from backfiring to four stoking.