Pistons.

[Highlander]

You will all remember by saga with new pistons when rebuilding my minor engine. I have in front of me the box, in yellow and Hipolite PEP pistons on the side. The label states:- 4 MORRIS. Ref 11580/ PEP 040" + 1.016mm. original bore 2.2441"/57mm. These were sold to me as Morris Minor Pistons 1932. They looked to me, a non engineer, the same as the pistons I took out of my Minor. The piston rings were (looked) the same. I know now that the gudgon pin hole was not the same. About a quarter of an inch lower. What are these pistons? Anyone can have them for a pie and a pint. No gudgeon pins.No rings.
Highlander.

[1936morriseight]

Highlander,

Your Hepolite 11580 pistons are for 918cc Morris 8 hp Series E 1939 to 1952 which includes the early 1948 to 52 sidevalve Morris MM Minor - the Alec Issigonis designed car.

Jeff
1936morriseight

[g4pyd]

Hi, Where did you get the replacementss from?
i need four 30+ for my sv minor engine.

Colin

[Highlander]

Colin. I used my old pistons. I only bought the new ones as the price was the same as re-ringing my pistons. Sorry I cannot help. Highlander.

[Tony Gamble]

Colin

Come and see me re pistons. I have some +30 both new and good used.

Give me a ring on 01757 270308 - you can remember the way to Selby.

Tony G

[parthmehd]

Well, I am looking for a set of pistons too. If you have found a set of replacements by now, could you guide me to the supplier ? If you have not found a set yet, I will keep you posted on any progress in my search. I have a 1934 Morris Minor SV which needs a new set of pistons. You can contact me on parthmehd@yahoo.com

Regards
Parth

[D Johnson]

Hi i was looking for pistons last year. tony leslie homesdale sevens does JP pistons from australia he can order any size you want.

David

[parthmehd]

Thanks everyone. I am in the process of getting in touch with JP Pistons !!

Regards
Parth

[Toby]

Can you let us know how much they want for a set please.

[parthmehd]

Sure. I have already started some correspondence with JP Pistons. Will surely let you know once they tell me.

[parthmehd]

Hello. I finally got a set of pistons, standard size, made by JP Pistons but sourced through Barry Walker who was confident of getting me exactly what I needed. The price as quoted by JP Pistons comes to around 55 pounds per piston (including ring and pin). Thanks for your help !!

[Jpallis001]

Any Piston experts out there? - I have a set of standard 4 ring Pistons that I am about to fit to my re-lined/re-bored block. I have just read this in the Pitmans Motorist Libray, Staton Abbey (7th Edition) -- "The early engines and post-war minors were fitted with three-ring pistons(two compression and one oil control ring) whereas the Series 1 and subsequent engines have an additional oil scraper ring on the skirt.

The three-ring type should not be replaced by the four-ring design, as the effect of the additional oil scraper will make the cylinder walls too dry"

Has anyone run these pistons without the bottom scraper ring? or do the run OK with all four rings in place?

[ian judd]

My pistons have the bottom ring removed. Apart from anything else, leaving it on creates a good deal more friction, and probably does make the bore too dry particularly with a 'new' engine. Of course, they should be 3 ring to start with, but with a 4 ring piston you have the option of adding the bottom ring after many thousands of miles and it has started to use oil a bit. Bore wear, despite modern oil, is more rapid than on modern engines due to the lack of an air filter.

Regards,
Ian

[Jpallis001]

Thanks Ian - From my local conversations, it does appear that on some engines (they were generally talking old Wagons though) is was the 'practice' to leave the groove empty on the new engine with option to fit the additional scraper when needed. Ewan69, on the PWN Forum, reports that he has succefully run an engine with the forth ring in place. I have tried fitting with the 4 rings in place, and yes there is a lot of friction when turning the crank - will be a lot of work for 6v starter!

I think that I will remove the fourth ring and get on and put it together. I have owned a 1957 Morris Minor since 1972 and have rebuilt the A Series engine many times in 300,000 miles. I did expect this engine to be much the same in the rebuild department - not so! In the early days with my post-war Minor everything was available from scrapyard; today everything is available 'new', next-day. I have always been used to putting the engine together rapidly; I am finding pre-war minor more leisurely in the rebuild department!