krokodyl

Hello all I have a caldera 3.0 with a sh.18 engine. I have never tooken it apart. 10 months after i got it the dngine is blown. Or atleast i think so because before when it shut off it mada a loud clang. Also i have only put 3 quarters of a gallon which seems like not very much. Any idea why it couldve happened? Sure i didnt use after run oil or tune it perfectly but still... I have NEVER left fuel in the carb. Last thing, You guys are probably wondering, HOW ON EARTH DID HE ONLY BURN THAT MUCH FUEL? Well im mainly into planes but i want something fun to do when i cant go to the field.

flyinwalenda

My Feedback: (5)

Well it is a redcat so not the best quality to start with.
Did you break the engine in properly ?
You mentioned not tuning it perfectly so I can imagine you ran it too lean.

krokodyl

Yes i broke it in properly. I dont think its was lean. It sounded fairly rich plus there was tons of smoke.

nitrosportsandrunner

no after run oil isn't a good thing. Did you oil the air filter? Is there a filter on the fuel line? Dirt in either the air or fuel can wear down the engine faster.
While the SH engines are not bad, they are certainly not high quality. You have to figure, how can redcat sell a RTR nitro for $200 when other brands start at $350 for a RTR nitro?
But then, I have heard of people with higher-end brands only getting a gallon threw their motors before they broke.
Pull that motor apart...not very hard to do. Maybe it snapped the rod...maybe you heard something that isn't engine related?
Lots of smoke should mean you didn't run it lean or too hot. But running a engine TOO rich isn't good for it either.

Oh, you mentioned that you heard the noise when you shut it off. I would think if a rod or something inside the motor were to break, it would happen while at high RPMs...not when you were to shut it off.

krokodyl

Ok thank you guys. Also the clang happened every time it shut off. It started bogging at half throttle no matter what i did with the needels. Ill take it apart and giv it a look. I know redcat nitros are not the highest quality but i did hear that the sh and nitro star are almost identical.

nitrosportsandrunner

I can recall some of the engines Ive had making a slight metalish noise when I shut them off. I thought it was the clutch/spur gear stopping suddenly.
If needles didn't fix the bogging at half throttle, maybe the glow plug? It sounds like you had it tuned rich, but if that were the case then leaning out the low speed needle should have fixed it bogging at half throttle.

krokodyl

Yes well right now i cant get the engine to start at all. I think the glow plug is ok because it does glow. Possibly its because i was using a drill to start it? The reason for that was because the pull cord kept poping out then the spring snapped.

nitrosportsandrunner

may sound strange, but a glow plug can glow when tested, but not once in the motor (at least not very well)
Ive had it happen. truck wouldn't start, checked glow plug, looked good, messed with other stuff...and then threw in a new glow plug just for kicks...engine fired right up. But it is usually true that if you can test it and it glows, it is good.
using a drill to start it shouldn't hurt it or keep it from starting...unless your drill wasn't turning fast enough.
there should be 4 or 6 screw that hold the head (heat sink) onto the motor. you can pull the head off without removing the motor. This will at least let you see the top of the piston, the head gasket and a good portion of the cylinder wall.

krokodyl

ok ill do that first. I know for sure my goow plug is taking power inside the engine because my glow driver sais power us going through.

krokodyl

Also if i was to replace the engine i would like to have it as a gasoline motor. However im not sure if there are car engines that would fit.

krokodyl

Ok so i took out the cylinder. It seems to be ok but it is black on the bottom. The piston is ok or atleast from the top.

collector1231

My Feedback: (1)

Is there any wear on the sleeve?

krokodyl

No there doesnt appear to be any damage on it, it is black on the bottom

collector1231

My Feedback: (1)

Sleeve, not the piston. What it could also be is that its hydrolocking after every run. Smaller engines typically do that for some reason.

krokodyl

Yes it is the sleeve thats black. I wasnt sure which one was the cylinder which one is the sleeve. Ill check soon to see if its hydrolocking.

krokodyl

Oh and i think i just realized the compression is low. Before i was unable to turn the starter wand. I am now able fo turn it quite easily. All the screws and gkow plug are tight.

1QwkSport2.5r

You got any pictures of this black sleeve? The only time I've seen or heard of an engine wearing out in less than a gallon is if it was ran too lean and overheated a bunch. Too rich and the engine takes forever to break in. Most RTR engines aren't machined very tightly so they tend not to be real "pinchy" and thus rich running doesn't bother them too much. Poor quality fuel can aggravate a poor tune. What fuel and glow plugs do you use? Fuel with too little oil or poor quality oil will not lubricate well enough and can cause erratic running and excessive heat. Also, different fuels have different oils in them and as such each fuel will smoke differently. Fuels with all synthetic oil tend to burn more gray and fuels with castor oil in them tend to burn more blue (smoke color). Just because you had a lot of smoke doesn't mean the engine was running properly with adequate lubrication. I'd highly suggest finding out what oil is in your fuel and if all synthetic, add some castor oil to your fuel. Adding 6oz of oil to a full or nearly full gallon of fuel will raise your oil content by 3-4%. I'm a big advocate for running extra oil for break-in - to the tune of 16-20% oil. After a dozen tanks or so, switch to a normal running fuel with about 11-12% oil works well for me. A quart bottle of airplane fuel would fit the bill nicely. It's messier, but the engines last much much longer. I run SH based engines, Traxxas, and a few HPI engines which all are known for being "cheapies" and having inherent flaws, but they all run and run. I tried "race" blends - 30% nitro 8% oil in the cheapies and didn't like the results. The crankcase was bone dry inside at the end of the day when set to a nice clean running tune. Using 11-12% oil left some oil inside. If you use some castor in your fuel, you don't really need to use any after run oil as the castor has a chemical affinity for metal and sticks to metal like no other oil available on the market.

My last jug of break-in fuel that I mix myself was 18% oil which was an 80/20 blend of castor and synthetic respectively. The idea is you can run a leaner needle setting to get the engine warm enough but still keep it well lubricated. ABC engines really run better and cooler with castor oil in the fuel because it has better heat transfer properties than synthetic oil does.

I've been running nitro for close to 20 years and my method has yet to fail me in that time. I have some "cheapie" engines with over 15 gallons through them and they still have enough pinch to push the liner up when the engine is turned over without the head on.

Just my over complicated opinion. YMMV.

krokodyl

gphoto2://[usb:001,003]/DCIM/127___10/IMG_3636.JPG
gphoto2://[usb:001,003]/DCIM/127___10/IMG_3637.JPG

Here are some pictures. I am using byron gen 2 race fuel. Its 20 percent nitro and 12 percent oil. The smoke apears to be white not blue.

Anthoop

We can not see those pictures.

When you click "reply to post" there are a number of icons above the box that you type your post....if you click the one that is third from the right "insert image" it allows you to upload a picture from your computer to the forum....then we will be able to see.

krokodyl

ok there it is.

1QwkSport2.5r

It could be the lighting, but that liner looks like it's nickel plated and not chromed. Is the whole liner inside and out all the same color metal (except for the black areas)? The areas that are black is a little darker than normal, but regardless, those are stains from the fuel. The fuel is corrosive and etches the liner a little bit.

krokodyl

Yes the inside looks ok. However now i have another issue. I took the starter plate off to see if every thing is ok there and pushed the hex in since it came out a bit. Now i cant turn the hex at all. This means i cant test the engine. I now have 2 problems. :-(

flyinwalenda

My Feedback: (5)

You may not have re-assembled it properly,one-way bearing isn't seated properly or has failed.
Check the drawing :
http://www.himotoracing.com/product/...74/details.php

krokodyl

it seems tat it is assembled properly. The only thing i did to it is take of the top blue part and the sleeve. Then i took off the starter plate. Im starting to think the crankshaft mightve broke.

Anthoop

If the hex came out far enough then the one way bearing holder can drop out of alignment....you can wriggle it back into place but if it was me then I would just take the backplate off and have a look in there to check....only four screws to remove and easier to reassemble the hex/backplate/one way bearing all in one unit and then fit it to the engine.