Prechamber spark plugs for biogas CHP unit - aftermarket plugs any good? 2

[USAeng]

We have (3) MWM V12 TCG 2016 engines at our plant that take prechamber spark plugs. A good deal for the OEM plugs is about $475 each. We go through about 48 plugs per year burning clean biogas.

We wonder if anyone with similar application has had good luck with aftermarket prechamber plugs? I see they can be had in the range of $200-300.

Thank you for any info

 

[Hoxton]

1. At three sets of plugs per year, your gas is not "clean" to MWM gas standards!
2. When you chose to use cheaper components to "save" money, please remember the difference between value and cost....


Have you discussed this with MWM? What was their advice?

 

[USAeng]

We have (3) V12 engines - We go through 48 plugs which is (1) set for each engine per year and then a few extras here and there.

Of course MWM will tell you to use their plugs

Thanks for the reply though

 

[TugboatEng]

What is going bad on your plugs? Are they breaking, fouling, or just plain wearing out?

 

[Lou Scannon]

You can be assured that MWM has made every effort to make their OEM spark plugs as reliable and durable as possible, while achieving efficiency and emissions targets. If they are not reaching the expected replacement interval, I suggest you get in touch with your MWM dealer about the problem.
It is highly unlikely that any aftermarket spark plug has been developed and validated for your application as extensively as the OEM plugs. In addition to shorter operational life (before full load or idle misfire become issues), aftermarket plugs may well have an adverse effect on efficiency, knock margin and/or emissions.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[catserveng]

I have had both very good and very bad experiences with aftermarket prechamber plugs. If you work with reputable suppliers, like Altronic, Mootortech and Woodward you may find that you may be able to reduce your costs somewhat. In my own opinion it sounds like you are getting pretty good life, assuming these are baseload or continuous run units at around 8000 hours/year, right?

How are you determining "end of life"? High voltage or energy levels, low cylinder temps, misfire or detonation? What kind of load factor are you running? If you talk to a "good" aftermarket supplier he should be asking you those kinds of questions.

I was recently involved in a project to evaluate some Woodward plugs, we had two engines with similar service histories and got about the same number of hours at the same load factor. So far about 8 months into the evaluation the aftermarket plugs have performed as well as the OEM plugs at a cost per plug savings of about 15%. We had to make a slight change to the air/fuel setting, and the displayed ignition energy was somewhat different. Units were tuned to the same emissions output and were running on pipeline gas fuel.

The reality is there are only a few companies that make the prechamber type plug for industrial engines, such as Woodward, MHP, Denso, NGK, Altronic and Bosch. In some cases the OEM will go to a manufacturer for a plug, the manufacturer goes thru the effort to come up with a good one, and then the OEM chooses another that works almost as good for a few bucks less a unit.

I have a number of customers using Motortech products, here in the USA and in Europe, they are not significantly cheaper but there is some cost savings and their technical assistance has been very good.

And every once in a while an OEM has problems with their plugs, a few years ago when I was still in the CAT family we had a run of plugs with the prechambers coming off in certain applications, someone decided to make an engineering change that didn't work as expected.

Hope that helps, MikeL.

 

[dicer]

So is MWM a part of caterpillar?

 

[Hoxton]

Yes

MMM is a brand name, essentially now, Caterpillar Energy Solutions gmbh is the company in mannheim

 

[CWB1]

MMM is a brand name, essentially now, Caterpillar Energy Solutions gmbh is the company in mannheim

Slightly incorrect. MWM was bought by Cat Electric Power Division but remains an independent operation with two different brands (both blue and yellow), two sets of dealers, and customer support/experience that can vary quite a bit from what is typically expected of Cat. They are not either of Cat's "regular" engine divisions so design, standards, backwards compatibility, etc are all different. Not trying to nitpick bc technically you are correct, but like any other large corp things often vary significantly division-division.

 

[Hoxton]

They are as independent as CAT lets them be ..........

 

[Lou Scannon]

Which is likely to become less and less as time goes by...

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz