SECO - Spare parts for MAN B&W, Himsen, MaK and Wärtsilä power plant and marine diesel engines
Experience report – Reduction of spare part costs through the use of our WearResist® piston crowns for MAN B&W marine diesel engines of the series MAN 27/38, MAN 32/40 and MAN 48/60
Today, in our globalized world, the procurement of spare parts for MAN power plant- or marine diesel engines is not a problem anymore. Just fed the search engine with the right keywords and in seconds an almost barely manageable range of various vendors from around the world is presented.
Starting with the engine manufacturers themselves, to the well-known and successfully established traders, the search engine also lists other supply sources as well in quick order. Scrap yards from India up to Asian online-traders are offering all of what you are looking for. From an O-ring via the piston and up to the crankshaft, everything that your heard desires is listed. Cheap and of course in the highest quality! ... that at least is what those suppliers are claiming. Conveniently, sometimes also pictures are provided together with the offered products. You all know these pictures: in a dark and untrustworthy looking warehouse there is a lost, half unpacked piston which is looking sadly to its observer. If you are lucky, and the resolution of the picture is high enough you can zoom into the piston pin bore... as it already looks strange without zoom.
Here, the qualified observer now sees a piston pin bore in which the cutting tool apparently resigned during the finishing process. Massive and non overlookable chatter marks over the entire visible surface of the bore. By drifting the sarcasm a little further at this point, we could highlight one of the advantages of this high-quality “Alibaba-piston”: This piston does not need locking rings to keep the piston pin in position. Once lammed into the pin bore, the piston pin is fixed for eternity. In other words: trash.
Unfortunately, the Internet doesn’t make it always that simple for our customers to make their purchase decision. Foresight and patience are required. Depending on the spare part it will take a long time until customers’ decision can be proven as right or wrong....
But precisely this patience and foresight a customer should have when buying piston crowns. Only after a couple of years in engine operation our customers will get the conformation of what we have promised at the beginning:
A considerable reduction of spare parts costs by using our WearResist® piston crowns.
SECO has been producing and supplying piston crowns in WearResist® Quality, useable for operation in MAN B&W marine diesel engines,quality since 2009. Thus, long enough to prove that the lifetime of our piston crowns is much longer, compared with the piston crowns of our competitors.
A good example therefore are our WearResist® piston crowns for the MAN 27/38 engine. The wear limit for the 1st piston ring groove is specified by the engine manufacturer with 6,42 mm. Our former experience with this piston type shows that - depending on the plant conditions - the standard pistons that can be achieved on the market, usually reach this wear limit after 15.000h. Unsurprisingly cheap piston crowns - made in Asia - are exceeding the wear limit already at 10.000h.
Below an example from our daily practice:
End of March 2016 one of our customers send us cylinder heads, cylinder liners, connecting rods and the pistons of a MAN 27/38 engine for reconditioning. This shipment consists of 3 WearResist® piston crowns supplied by SECO and 5 piston crowns from foreign competitors. Running hours of the pistons: approx. 15.000h.
The decisive factor in the evaluation of a used piston crown for the MAN 27/38 is almost exclusively the wear of the 1st piston ring groove. If the wear limit of this groove, which is predetermined by the engine manufacturer with 6,42 mm is already reached or exceeded, it doesn’t help even though the 2nd ,3rd and 4th groove are still and clearly within the wear limit; which is usually the case.
The following table summarizes briefly the criteria which are crucial for the further use of the crown of this piston type:
|basis of calculation||with of groove at |
|%-usage of |
|wear after |
15.000 running hours
|piston crown 1 SECO WearResist®||6,27 - 6,28 mm||36 %||0,085 mm|
|piston crown 2 SECO WearResist®||6,26 - 6,29 mm||38 %||0,090 mm|
|piston crown 3 SECO WearResist®||6,26 - 6,28 mm||36 %||0,085 mm|
|piston crown 4- 8, foreign competitor||6,60 - 6,80 mm||219 %||0,515 mm|
The above table shows very clearly the customers’ primary advantage by using our WearResist® piston crowns. Taking into account the secondary benefits, the following overall picture is shown:
- reduction of spare part costs
- less piston ring damages
- reduced lub oil consumption
- less wear on cylinder liners
In this case, the pistons that we received for reconditioning, could be returned again to our customer with our WearResist® piston crowns still assembled. Thus, no additional costs for our customer. However, the pistons with the asian crowns had to be disassembled, the crowns scrapped and replaced by new piston crowns from SECO. Certainly, we do not offer those advantages only to the owners of MAN B&W engines; we produce and supply our WearResist® piston crowns also to customers with Himsen H17/28, Himsen 21/32 and Himsen 25/33 engines. Together with our sister company Marine Motor Service GmbH, we also offer our WearResist® piston crowns for MaK and Wärtsilä engines.
Trust our expertise as a manufacturer of high-quality engine spare parts. Give us a chance to convince you about the quality of our products and services. For MAN and Himsen engines we will be pleased to provide you with a corresponding offer for the following services:
- reconditioning of cylinder heads
- reconditioning of cylinder liner
- reconditioning of conrods
- reconditioning of fuel injection pumps
We wish you a nice and successful day!
Uwe Pränger and Jan Michael Rentsch