N3W2R/C

are there any long term affects of running your truck too rich?

michelob78

You will ruin the connecting rod if it's too rich, if the top of the cylinder never expands the connecting rod gets alot of un-needed stress usually makes the bushing to the crank egg shaped or plain sloppy.

nicholsm04

My Feedback: (-1)

Yah, so just tune right, and u wont have any problems. Doesnt have to be perfect, just somewhere in the ballpark.

rscharp

You will immediately notice that your oneway bearing will slip also.

MBX5T Maniac

My Feedback: (-1)

running the engine too rich is said to be worse than running it too lean. A little richer than perfect is best for normal use, so the engine lasts longer

bentgear

Running the engine rich will have no negative effect..........if the temp of the engine is high enuff to allow the sleeve to expand and not cause the piston to drag. In fact, except for the fact that performance would be way down, engine life would most likely be longer.

On a new engine, running very rich and not allowing it to come up to temp does put a lot of stress on the rod, it also causes a lot of wear to the top of the piston and sleeve as they scrub together.

As far as the one way slipping, a lean setting using 18% oil might be putting more oil in the crankcase than a rich setting with 12%.

Ed M.

nicholsm04

My Feedback: (-1)

Well, close enough, its still smartest to tune the engine correctly lol

bentgear

Yep!

MBX5T Maniac

My Feedback: (-1)

When I say too rich, I meant that the engine wouldn't be getting up to running temp. This is bad for the engine

lloydy

Your glow plug wont last as long, and the engine will become encrusted with carbon deposits. These are usually easy enough to fix but just something to think about.

binaryterror

Actually too rich is a huge problem.

Compression is higher when rich, meaning alot more wear on the conrod and its bearings.

Also tell me why over rich increases engine temps bentgear...it matters very much to be able to tune correctly...

Too rich is really hard on an engine, more so than you might think.

Haldir

Atleast get your temperature up to 200 degrees.

N3W2R/C

ok i was just wondering thanks

bentgear

If you are so rich you are raising the compression by leaving too much oil on top of the piston then you are past the point of just being rich.

I fully agree that it matters very much to be able to tune correctly. But, I have never found a two stroke or four stroke engine in an airplane or wheeled vehicle that did not cool down by setting the needle richer. If by going to a rich condition you are raising your temp then you better start looking at some other problems like the blend of fuel you are using or stop making full turn adjustments on the high speed needle.

But not nearly as harmfull as being too lean!

Ed M.

jefx

I've never seen an engine get hotter from being too rich.

But this does raise the interesting topic of "fuel rich or oil rich". By running with too much oil, you are actually running with a lean condition. Oil is not combustable, so the more oil that's in the fuel means a higher air to (combustable) fuel ratio. It is entirely possible to burn up an engine by having too high of an oil content.

But since r/c fuel is pre-blended, most people will never experience that problem.

dustin7837

My Feedback: (1)

I've been into 2 stroke dirt bikes for quite a while now and I am in my second year of petroleum engineering tech. and I can tell you that the older bike engines are very similar to the RC nitro engines. Lloydy has it right. It takes a certain amount of air to burn a certain amount of fuel. If you add more fuel it takes more air, simple right? if you get too much fuel into your cyllinder (AKA running too rich) it takes more air to burn that fuel than can fit in the cyllinder during one stroke. This causes incomplete combustion which results in less power, less mileage/runtimes, and also deposits from the un-combusted/semi-combusted hydrocarbons can build up and cause wear on the piston/sleeve. On a bike or even a diesel truck you can tell when this has happened because the engine will start "knocking", especially when cold, before the piston has expanded. It is probabaly impossible to tell when a nitro RC is knocking being that they are so small and loud.
IMO the best way to run an engine for anything other than racing, is to tune it perfectly and then richen it just a LITTLE bit to improve engine longevity. If racing, tune it a bit too lean. running lean though will reduce engine longevity because of lack of lubrication, internal temperature, and running lean makes each combustion more powerful so eventually your piston top can get worn badly. I've seen some bikes that were tuned so lean a hole was made right through the top of the piston.[X(]

binaryterror

Yup, I meant that too rich adds both fuel AND oil into the same size cylinder and now the same parts have higher forces against them...