Deanwvu

I am new to nitro RC. I know relatively nothing about nitro engines.

As an aside, anyone know a nice online FAQ or guide to nitro engine care??


Anyway, I notice that whenever I run my truck, even for just one tank, there is alot of unspent fuel kinda "splattered" on and around the engine... Does this happen often?? Actually, i dont know if it iw unspent fuel, or if it is leftover lubricant fromt he fuel mixture... I find I have to clean up around the engine each time I run.

Are these engines naturally dirty? Or, do I have a leak in my system? If all of my fuel is not being ignited, do I need to adjust the engine accordingly?

Again, would like to know how to tune my engine... link, anyone??

Thanks!!!

schmidty

If it is coming out of the bottom of the carb then you might have a leak. if it is coming out of your pipe your engine is just rich, but it sounds like you have a leak, if its getting all over your car.

HyperDrive

You may find that the rubber gasket is split or perished at the manifold. This will cause oil to splatter around the engine and chassie.
Also make sure the engine head is on tight and the plug is screwed down.

SkrapIron

Part of the problem with Nitro engines, is that the castor oil ( or other lubricant used in their formula ) is not completely combustable. After the nitro methane and methyl alcohol are ignited, the unburnt oil is vaporized, and is what lubricates the internal components of the engine.
The pressure of the exhaust stroke then forces the vaporized oil out of the exhaust pipe. That oil will settle anywhere it can. It does lead to a tremendous oily mess, especially when combined with dust ( YUCK!)

You can control the volume of unburnt oil in the exhaust, by leaning out the mixutre. The problem with that is, if you run the engine too lean, it will sieze up, from lack of lubrication.

pro_steve

i once had fuel spraying out by the backplate i had some new bearings machined and that seemd to stop it

motohead279

i just broke my enginbe in last night and notice the same that there is a lot of spray coming from the exhaust. after I fully break it in, what type of settings are reccomended?

I have a Force.28 main screw right now is set at 4.5 right now, low end adjustment is at 3.5. Any suggestions?

pro_steve

way too rich

plaidfish

and how do you know that??
just curious as I see a lot of people from all over the world stating their needle settings like it will be the same everywhere......is there a universal setting I am unaware of???

Engrose

Do you have a Force .28 engine?

kx250ryder

There is no right setting. You are trying to maintain a controlled explosion. The ammounts of outside forces that act on this are staggering. You have altitude, humidity, temperature amongst others. Not to mention the manufacturing differences between engines, all of this adds up to the fact that no two setups are alike. The best thing to do is get yourself a temperature gauge and have at it.

**NOTE** When making adjustments, keep in mind that this isn't your Chevrolet. The slightest wiggle of the needles can make a difference on this scale. Most suggest making adjustments in "hours" or 1/12 of a turn at a time. I would suggest less if you have a steady hand. Allow about 30 seconds in between any adjustments to fully realize the change in mixture (unless of course your engine temps are high, then adjust more quickly to prevent damage). Take all temperatures from the glow plug for consistency.
HSN= High speed needle
LSN= Low speed needle
MSN= Middle speed needle (leave this at the factory setting until you have mastered tuning of the above needles)

1. Warm up car with break in settings (you may have to lean slightly as in some weather conditions brake in is too rich to even start).

2. Run a couple of tanks like this to fully warm up the car, even the chassis should get hot (if temps get above 250, richen the HSN slightly).

3. Once the car is warmed up, start tuning your HSN to get between the 230-250 range. You will notice a higher pitch exhaust note, as well as a reduction in the ammount of smoke as you lean the engine out. There should always be a some visible smoke while the engine is accelerating, except maybe at the uppermost RPMs.
4. Once the engine temperatures are in the proper range, adjust the LSN for acceleration. Again, there should always be some visible smoke when accelerating.

5. To test the LSN setting, pinch the fuel line right next to the carb nipple. The engine should not immediately rev up. There should be some delay between the pinching of the fuel line and when the engine revs up. This number will vary somewhere between 1-3 seconds depending on conditons.

6. Re-check the engine temperatures to make sure that leaning the LSN has not raised the engine temperatures outside of the 230-250 window. If so, richen the HSN to keep temperatures in the 230-250 range.

7. Leaning the LSN will increase the idle of the car. Make sure to re-adjust the idle screw so that the car is idling as high as possible without moving.

8. Repeat as needed with changes in weather, smoke, or sound of the engine (too high pitch = lean, too low pitch = rich).

Perform this ritual at the beginning of each day of driving, and if there are any change to the conditions in step 8. All of the above seems really annoying at first (especially if you come from electric R/C with no such ritual) but it becomes second nature in no time.

plaidfish

DING DING DING.....
WE have a WINNER!!!!!!!

motohead279

one thing being a fookin newbie is knowing the difference between rev pitches, like what seems high and low. For me I guess just playing with it, and hands on.


Just to clear that up... I meant playing with the car... [8D]

kx250ryder

Use the temp. gauge to get the car close. You will start to get used to the sound. Once you have been tuning for a while, you can skip the gauge alot of the time, maybe use it to start the day, and just sound from then on.

OFNA's new PCR gauge is really small, easy to read, and fits right in the glow plug hole in the cooling head, so you don't have to worry about not aligning it and getting a wrong temp reading. I try not to plug brands, but this one works damn good for the money.

For other parts ideas for new comers (I had to learn the hard way) see my other rant here:

http://www.rcuniverse.com/forum/m_3311337/tm.htm