Spark plugs fooling, is it simulated at all?

Voxen

Hi,

So I flew a lot my Commander since purchase and I never experienced spark plugs fooling yet. Engine run tests always give more or less the same RPM drops on magnetos, with no particular engine rumble due to a dirty plug.

I tried to let the engine run on ground for one hour full rich, does not change a thing.

With my A2A Comanche doing that will produce spark plugs fooling pretty fast, that’s why I’m wondering if this is really simulated or not.

Thanks!

Black Square

Spark plug fouling has been a staple feature of my aircraft for five years, and can be found in the list of features in every manual or store page. The sounds and added effects are new to the 114, and I've ported them back to all my other reciprocating engine aircraft since. You can look at the spark plug illustrations on the engine visualizer for red to see the amount of fouling, as illustrated in the manual. As long as the cylinders are cold, you should see fouling in a few minutes with full rich mixture and low idle power settings.

Voxen

Good to know. I’ll do some more tests then.
And sorry for writing « fooling » instead of « fouling ». English is not my native language, at least I learnt something from this topic

rinkerbuck

You ported the new fouling behavior to the older aircraft like the Piston Duke already, so we should notice the RPM drop not being 100% normal every time? Was there a patch? haven't seen any notices of one.

jmarkows

The fleet-wide summer updates haven't dropped yet, no. I think I read TBM is first up "in a few weeks."

Teritio

That's interesting. I've tried fouling the sparks several times, but I've never been successful. I don't have a Commander 114 yet, but I tested it today on a Baron and Bonanza with the following settings for 10 minutes:

OAT -8C, Alt 2900, RPM 600, Mixture full rich, Coldest CHT 106C

No fouling whatsoever. Aren't these conditions enough to foul the sparks? I use MSFS 2024 version.

Teritio

@Voxen have you tested that again? Because no matter what I try in the Baron and Bonanza, I can’t get any fouling.

Voxen

Same for me. Whatever I do there is no plug fouling so I don’t even run the engine tests now. Top bad.

Black Square

@Teritio @Voxen I wanted to test this for myself before I said anything, and I'm currently watching the fouling variable tick up under those exact conditions with the release version of the Bonanza. I know the 114 is working, because I routinely encountered fouling while recording my aerodynamics video. Feel free to take a look at the variable, if you can. It's L:var_engineFouling.

Voxen

@Black-Square Thanks for confirming it works. What would be the best conditions to make plugs fouling happen quite fast?

I'm so used of A2A Comanche spark plugs fouling happening very frequently that maybe I have the false impression that it does not work on the Commander 114.

Teritio

Yes, it works – I’m testing it right now, though the process is slow. I’ve been experimenting with this variable manually, and the effect starts to become noticeable around a value of 7–8, so reaching that level will take a really long time.

Teritio

And another test under different weather conditions - it seems that the outside temperature is the most important factor, and even a closed engine cowl can have a significant enough effect to prevent fouling. In this test, the right engine ran at 1,000 rpm on a full-rich mixture with the cowl closed and managed to reach a temperature high enough to stop and burn out the fouling. It seems to me that you’d have to really mistreat the engines for this to become a serious problem. Sorry for the spam, but I'm really happy to be able to see how it works and what effect it has on the engine.