Man,... I'm glad I got this plug thing started. You guys all kick butt! Thanks for taking the time to really use your skills and figure this out for us.

I'm feeling better about trying another brand. I do think the recommendation of continuing to use the same plug, or what ever you settle on would be a smart thing. Its nice to know you could use the OS plug, as they are cheaper and more readily available. As for the .003 well I just shimmed my GRP up for 30% and that shim measurement is much much larger than the .003.



You guys ROCK!!

Glowplug temp is detemined by the size or thickness of the wire. The hot glowplugs have thinner wires, so they glow very easily, as where the cold plugs have a thicker wire, that requires more compression, heat or lean mixture to get them going. Thats why the cold plugs idle erratic, but come on hard on the mid to topend, due to the RPM's keeping the heat going on the wire.

Novarossi changed up the system with hot and cold in the same heat range. This is the length of the glowplug body, not the wire size. The difference is how quickly it dissipates heat, but will have the same wire thickness in the same heat range.

So what is the verdict on glow plugs? I just ordered a GRP .21 only to find out that GRP plugs are no where to be found (in stock)... Will the Mugen plugs work? IM guessing so as the motors are close to identical, but at 11 dollars a plug, I don't want to order a bunch and find out that the MR plugs are a no go?

They are considered to be Losi parts:

http://www.amainhobbies.com/index.php/cPath/1_68_880

OD97T work great

I broke in this engine a week ago. It's had about 3/4 of a gallon through it. I love the top end power. I had some problems tuning it. Finally, I changed the plug from a #6 (which it came with) to a #5 and it's been behaving alot better.

I have been using the 7.0 venturi from my MR21 b01a instead of the 8.0 that it came with. Were some of my problems due to changing the venturi? Which venturi did yours come with?

I'd like to see the comparison done with an OD plug, seems to be the closest fit.

I am on my second gallon through a GRP with an O.S. plug. No problems. The only problem I had is that the motor wouldn't start with the GRP plug that was in it. My other buddy's GRP plug wouldn't even glow fresh out of the motor.
There are 3 of us running this setup with no issues.

If you read the "Ask Mike Truhe" forum on Neo-buggy.net he even tells you that its ok.

.

P3's are awesome.

I got 9 minutes exactly during a race with using Tilted Green 30%, OD97T, Dyn 53 pipe in a trugg. Engine was ran in last Friday for a few tanks, and then thrown on the track Saturday, so I am pretty sure I can get 10 minutes once she loosens up a bit and she is leaned down (this was on a track with a LOT of WOT also)

I've got approximately 8 tanks heat cycled through my .28. I've been breaking it down every couple of tanks to make sure everything is wearing well (which it was). So this weekend I decided to take it out for it's first bit of track time. I'm running Nitrotane 30% using an OS P-3 plug with my head shimmed at .5. I chased a tune for the first part of the morning, but I believe it was because the outside temp was rising so fast. The outside temp stabilized around noon at about 90 degrees and I was able to finally get a proper tune.
Good news first: The power delivery for a .28 is as smooth as it gets! It wasn’t overpowering and I didn't feel like it would get away from me as I opened her up. I was definitely happy with the power delivery and this is my first .28
Bad news: Take a look at the pics showing both sides of the piston. I broke it down this morning to see how everything looked and this is what I found on the exhaust port side of the piston. The cylinder is showing wear in the exact same place but I can't get a good pic of that area.
Not sure what my warranty options are here, but I hope I'm able to get the piston and cylinder replaced. It had to happen at the track this weekend because I had it taken apart Friday night and everything looked great.
Any ideas or opinions on what could have caused this?

^^ Looks like there was something foreign in there to do that

Ive got 10 litres on my .21 tuned and i cannot get it up to temp, after a 20 min final on a fast track, its hardly breaking 50C. Im running a 12% oil mix #6 plugs, maybe i have to drop the oil content a little? Ive got the thing absolutely screaming, not loading up and reading the plug and the amount of oil residue on the pipe side of the car its still very rich And every now and again (usually after "Release the cars" ) it will flame at idle, was thinking just bump up the idle but 90% of the time it will idle all day after a warm up Its got me paranoid now

It’s hard to see in the pic, but the marks are from some type of continuous abrasion, just not sure what? The con rod still looks good and where it connects to the crankshaft is still in excellent condition.
The engine definitely runs cooler than most. I’ve heard that Truhe was running between 180 and 200. That’s consistent with the temps I was seeing this weekend on mine.

If your shimming .005, your way too tight on clearance, plus a p3 glowplug on top of that. It looks like the piston got hot at the exhaust port area and dragged on the sleeve IMO.