Wasp .26 not sounding so good

[Shogun1122]

I bought a wasp .26 about 3 months ago and ever since i have had it, it has allways made a funny sound when it ran. Even through the breakin process where the engine never got over 230F it has made a funny whurring shound. It sounds like it might have been metal on metal but the engine was new, so i dismissed it as it being the standard sound of this new engine. The engine has allways had good power, wheelies and crazy fast, but now i have noticed that the sound is getting louder and the engine is starting to run hotter. The hotter the engine the louder the sound or vise versa, i can't tell. The sound get so bad at around 260f, that i can't take it any more and i shut it off. And the last time i shut it off it sounded like it came to a screeching halt. Not good!

So get this, i open the engine thinking i am going to find a seized piston or a trashed bearing. Guess what i found, nothing! the engine had good compression, the piston moved freely throught the stroke and the bearing looked good. I am almost upset that i didnt find anything wrong cuz now i dont know what to Fix.

Does anyone have any idea what might be wrong? Please i need help. And sorry about the long post.

 

[vbgagnon]

could you have a air leak, is your flywheel rubbing on something, does your pipe have a leak? It could be a number of things check the chassis so nothing is rubbing our could be rubbing and go from there.

 

[alkyula]

overheating/worn clutch bell bearings? when mine went out it made a wirring sound.

 

[olds97_lss]

Maybe your running to hot of a plug and getting pre-detonation. The hotter the engine gets, the earlier it will be firing which would explain it getting worse as it warms up.

Maybe try a cooler plug.

What fuel/plug are you running?

The only reason I say anything, is I noticed my 21 really "pinged" when I ran an OS A3 (hot) plug in it. Then I put a #8 (medium) and it runs perfect and the pinging went away.

 

[petal2thametal]

umn i think you dont have to worry about the heat. 260f is normal for some engines.in fact the range should be between 220 and 260f so nothing wrong with that.

 

[olds97_lss]

I don't think he's worried so much about the heat, but rather the noise that exponentially grows louder as the temp goes up.

 

[Shogun1122]

Yea its not so much the heat that I'm worried about, its the metal on metal sound. I know that 260F is not that incredable high.

I run a medium plug with 30% nitro, i know i should probably be running a cold plug with the high nitro content, but i have run cold plugs before with the same results. If i keep the body off and i run it on a cool day, the engine will run well at around 200-215F and the noise is almost unnoticeable. But as soon as i put the body on, which has holes cut for ventalation, the temp gets to like 230F and starts to rise. at that point no matter what i do ( take off the body, richen the mixture) the temps rise and wont go down till i shut it off.

Are the clutch bell bearings moving when the truck is still, because it still makes the sound while at idle.

The funny part (or not so funny actually) is that the last time i used it, i stopped the engine by pinching the fuel line. I swear that the sound it made was metal screeching, way bad! I want to say that there is not enough oil getting to the bearings or something. I dont know if that makes sense or is even possible.

How many sets of bearings are there in an engine, maybe there is one that i havent found.

 

[olds97_lss]

The only time the clutch bearings are spinning is when the clutch isn't engaged or slipping, so to answer your question, yes.

Do you have some lower % nitro laying around? It still sounds like a weird detonation thing to me, but I've been wrong many times. You'd be surprised what 30K RPMS sound like with wierd detonation. I mean, it runs so fast that it sounds almost like a constant ppppppppppppppppiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinnnnnnnnnnnnnnnnnggggggggggggggggggggggg. Kind of hard to get the point accross.

The reason I ask if you have different fuel is that from what I've read, if you run over 20% nitro, you need to add head shims to most if not all engines. If you don't, you get too high of compression which creates adverse effects and/or noises. Did you install an extra head shim?

 

[Shogun1122]

I have not added an extra head shim. Maybe that is my problem. I know how hard it is to understand a noise over text but ill give it a try also. It sounds like "Schwee Schwoo Schwee Schwoo" Like something going around and around that is in time with the RPMs of the engine. Just writing it on the keyboard makes me kringe.

I dont have any different nitro b/c all i have ever run on this engine on anything but 30%. I had a S25 that i started on 20% and then switched to 30%, but it didnt make that sound.

Ill buy a quart and try some of the 20% see it that fixes it.

 

[olds97_lss]

It's worth a shot. Why do you run 30%? Do you race or bash? If you bash, you should stick with 20%. It runs about as cool, is cheaper and is easier on the engine. If you race, then get some shims and try it out.

I was kind of hoping someone else would step in and help with this as I only use 20% fuel which most engines are built out of the box for. I'm a basher only. What I said about higher nitro causing higher compression and needing shims is from what I've read about it. So I can't be real sure. It just sounds familiar is all.

Good luck.

 

[StrechM]

Actually the engine will run slightly cooler using 30% nitro content. You will have to lean it less to get power out of it. I would try the additional head shim to give it the additional clearance needed. You may see a slight improvement in performance. When I had purchased my first picco .26 I emailed one of the Orion sponsored racers to get his feedback on the subject and his response was 30% and the head shim.

 

[alkyula]

out of curiosity....would adding an extra glow plug washer do the trick? of course if it makes a diffrence afterwards you can do it the right way and add a shim..but wouldnt adding an extra plug washer lower compression also? i realize you have to be careful as there wont be as much thread to torque down the plug with.

 

[StrechM]

No, do not add an extra glo plug whaser. That will not enhance the performance. I'm not sure that the engine would run.

 

[olds97_lss]

Actually the engine will run slightly cooler using 30% nitro content.

This is why I said this:

It runs about as cool,

I just wasn't sure how much temp diff it gives you. I knew it ran cooler, but if he isn't racing, is it really worth the extra $ and need of more precise tuning?

As for adding an extra washer on the glowplug, I wouldn't do it. It won't give you near the extra space adding a head shim will. Besides, it will recess your plug up into the head which like stretch said, will hurt your performance.

 

[Shogun1122]

Thanks for all the info guys, it really is helpful. I think that i will try the extra shim and a cold plug. If that dosent work then ill go back to 20%. And if that dosent work ill get a new piston, sleeve, and bearings and send it into eb mods and have them trick it out.

 

[Dedreun]

Shogun1122: I have not added an extra head shim. Maybe that is my problem. I know how hard it is to understand a noise over text but ill give it a try also. /b/ It sounds like "Schwee Schwoo Schwee Schwoo" Like something going around and around that is in time with the RPMs of the engine./b/ Just writing it on the keyboard makes me kringe.

That`s called the Leslie effect.
Do you have a vented flywheel and/or clutchbell?
If so that could also be causing it.

 

[Robie6]

nitro is in fact "a cold burning fuel" now get this, a company up the street from me sells racing fuel & the owner mixes it for the gear heads round town. I was asking him about making my own fuel mix for my r/c trucks & he told me by the time I buy pure nitro-$150.00-5 gal, methanol, caster & synthetic oil it would cost me more per gal. then to just buy a gal. at the LHS. Running 30% doesn't mean your going to run a hotter engine if you take into account everything else that happens in a running engine. In my 1/2 ass way of thinking if ya run 30% fuel & add a .005 or .010 head shim the engine is pushing out more hp without doing more work or taking a beating like a engine running say 20% fuel with only 1 shim & high compression.

 

[woody]

You know guys, I have the same problem. Although, the only times I have the sound is when I gun it. You know, giving it full throttle. This is only when the temps are up like 240 or so. I mean it is a weird sound, just like Shogun mentioned, "Schwee, Schwoo, etc!" I was thinking it was something tearing up in the transmission. Nope, broke apart the transmission, looked perfect!! Then, I thought how about the diffs?? Broke them down, they were a little worn. Shimmed them, and put'em back together!! That was'nt the problem. So, what to think now?? I run a strobe slipper, and I noticed some wear on the slipper pads, namely on the one closest to the transmission. I trimmed off the excess wear materiel, and cranked down the nut a little tighter. I think this might have done it. The Wasp .26, has so much torque down low. I had the slipper nut tightened all the way down, with a 1/4 - 1/2 turn back off, just like the guys at UE say. So, when I tightened it all the way down, no more noise. But, I do still get the wear on the same slipper pad like I mentioned. Hey Shogun, what slipper/clutchbell combo are you running?? Try tightening down the slipper, and see if that makes a difference. Sorry for the long post!! Just my .02

woody