64LikesOS FS26S-C 4-stroke development
06-03-2019, 10:53 PM
#1966
I chose poor wording for my previous post. Airplane engines aren't tuned absolutely lean, they're tuned relatively leaner than car engines. Airplane engines are tuned much closer to an ideal air:fuel ratio than car engines are -- something they can get away with because of the adequate cooling provided by the propeller..
And how the rod and bearings are lubricated is the way how the piston ring is shaped, acting as a kind of oneway valve it will push some oil on the sleeve down into the crank case.
06-04-2019, 04:43 AM
#1967
Tech Fanatic
Some food for thoughts...
One thing to remember is that a larger engine needs less oil to cover the internal surfaces based on that the volume increases quicker than area.
There is only so much space available between parts so more oil might not help much at all, but instead an oil with stronger film might be needed, or making sure it's not diluted with too much fuel.
As the power goes up you just can't compensate enough, take an example of say lawn equipment or a moped engine that can run happy for many years on 2% mineral oil, and then you have something like a gokart engine that runs maybe +5% of the best synthetic oils and still wears out in no time.
At some point it just gets ridiculous to try and compensate and you just have to realize that nothing last for ever, or at least spend the money where it matters.
Regarding propeller cooling, if the prop is 100% efficient it wouldn't cool the engine, the speed of the airplane would, but that's just theoretical.
One thing to remember is that a larger engine needs less oil to cover the internal surfaces based on that the volume increases quicker than area.
There is only so much space available between parts so more oil might not help much at all, but instead an oil with stronger film might be needed, or making sure it's not diluted with too much fuel.
As the power goes up you just can't compensate enough, take an example of say lawn equipment or a moped engine that can run happy for many years on 2% mineral oil, and then you have something like a gokart engine that runs maybe +5% of the best synthetic oils and still wears out in no time.
At some point it just gets ridiculous to try and compensate and you just have to realize that nothing last for ever, or at least spend the money where it matters.
Regarding propeller cooling, if the prop is 100% efficient it wouldn't cool the engine, the speed of the airplane would, but that's just theoretical.
06-05-2019, 06:32 AM
#1968
Ten t
So much to update on but ill make this quick. Got a chance to get my .91 thumper into my 2.0 truggy. Clutch still needs work, new shoes are on the way. Also forgot I put buggy diffs in truck so gearing is all funky at the moment.
Also got a chance to get MINI truggy started. This is a losi ten t with a .30 thumper conversion. Engine, servos, clutch are done. Still needs custom intake, fan and throttle linkage set up yet. These have been some really awesome projects to work on. There is a shit ton of machining into these trucks. It's all worth it in the end to see them running around the track.
06-07-2019, 12:05 PM
#1969
Very first drive of mini truggy with .30 thumper. Still a good amount of work to do yet
https://youtu.be/Y924DvyNSM4
https://youtu.be/Y924DvyNSM4
06-07-2019, 12:06 PM
#1970
https://youtu.be/Y924DvyNSM4
06-18-2019, 01:59 AM
#1971
I wish I had time to work on my 4-stroke Revo. I barely have time to take a dump between work and chores and taking care of the baby. I wish he'd get to where he can sit up and crawl around so I wouldn't have to stop what I'm doing every 10 minutes to move him around so he doesn't get bored. People say babies start getting into way more trouble when they can move, but at least I could sit in one spot and work on stuff while I keep an eye on him. I've got a puppy training collar all ready to go so I can discipline him with the push of a button whenever he gets near something he shouldn't touch. If that doesn't work I'll upgrade to an invisible fence.
06-18-2019, 02:02 AM
#1972
No, with both engines to get the best they do run the same air/fuel mixture ratio but because an airplaine engine has a smalle carburator (+/- 4 to 5mm instead of 8 to 9mm) they will get a total less mixture and so with that less oil if you use a car fuel.
And how the rod and bearings are lubricated is the way how the piston ring is shaped, acting as a kind of oneway valve it will push some oil on the sleeve down into the crank case.
And how the rod and bearings are lubricated is the way how the piston ring is shaped, acting as a kind of oneway valve it will push some oil on the sleeve down into the crank case.
06-18-2019, 04:16 AM
#1973
06-23-2019, 06:29 AM
#1974
Tech Fanatic
Awsome man !! I always hoped that one of the manufacturers would develop a 4 stroke similar to what motor cross did. With electric taking over, I’m sure it will never happen. Your custom creation is Awesome!
07-03-2019, 09:48 AM
#1975
Thanks for the kind words guys, haven't got any more uodates yet. Ill keep working to improve performance of these engines and vehicles.
07-06-2019, 07:43 AM
#1976
Test fitting body
07-06-2019, 01:17 PM
#1977
Tech Initiate
That thing looks great! I really like the look of the beadlocks. Not practical for racing, but I doubt these trucks would be that good of racers anyways. I finally got the magnum .52 running consistently today on he bench with the trx 3.3 carb. I expected that it would be a pain to get it started like it was with the stock carb but it fired up almost immediately. It spits a little fuel back out of the carb when running. Is this a symptom of being too rich? Could definitely use a heavier flywheel too but I’m just happy that I finally got it running well. It sounds sooooo nasty too. Hopefully it’ll be in the buggy soon
07-06-2019, 03:14 PM
#1978
The spit back out of the carb is normal. My air filters get pretty wet with fuel. Its not a problem.
07-07-2019, 02:05 PM
#1979
Same here, fuel soaked air filters.. Just wonder how much better fuel milage we could get without that happening.
07-10-2019, 01:05 AM
#1980
Wouldn't an extension on the carb inlet fix that problem?
Anyway, the fuel economy shouldn't be affected, because the fuel evaporates easily so the fuel that soaks into the filter just evaporates and gets pulled back into the engine along with the air.
Anyway, the fuel economy shouldn't be affected, because the fuel evaporates easily so the fuel that soaks into the filter just evaporates and gets pulled back into the engine along with the air.