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What's the difference between the Novarossi ...TGC and ...TGH plugs? I have a plus-4.

The differrence in the plugs is the opening that the filament sits in. The TGC plugs have bigger opening which allows for easier tuning I believe. Both plugs can be ran in your motor though. C5 or C6 will work depending upon the climate you are in.

So I have a Plus-4 BTT engine that Ive run around 1½ gallons and Im having some issues with it I gotta say. Ive ran OS in the past with no issues at all, but Im really struggling finding a tune on this engine.
The problem seems to be like. First of all it takes forever for it to heat up, I have to warm it up in the pits for like 5 minutes first and then drive an additional 3-4 laps before it stops bluddering on the straight.
After its heated up properly it runs but still feels like its running a bit rich, however, the temperature is good and feels like I cant really run it leaner cause itll get too hot.
So today I was fiddling with it alittle and decided to try and lean it alittle, what happend was that it randomly stalled 3 times within 2 tanks of fuel, just for no apparent reason but it ran much better and had much more power.
I richened it alittle again and changed the plug to a 7 instead of a 6, just to be able to drive. And it didnt stop but at the same time I drove almost 6-7 laps with it feeling rich on the straight, not super rich but you know, some what reduced powerwise.
After those 6-7 laps it started to run better while it got hotter until I ran out of fuel and decided enough for today.

Now Im hoping someone can shed some light on why its acting like that. Im not an expert at tuning engines, but normally I just have a hard time getting the idle right but the idle isnt the problem here, so it feels like its not a tuning issue but Im not ruling it out either.
I should also say that its been acting like this since it was new, so its not something thats suddenly appeared. Its always been difficult to find a good tune and always taken a really long time to heat up and always been feeling rich even if its been okay temperature wise.

sounds fat on the bottom

Hi

I would say too rich on the top...

Whats too hot? Everything is relative.

One way to set the HSN correct:
Stay with the #6 plug. Lean the top until you can hear the engine runs "clean", when you run WOT in the air (e.g. preventing nose landing). Start rich and go from there with small adjustment at a time.
After that you can fine tune the LSN and idle speed.

People who don´t know the potential of these engines, often sets the top too rich and too lean in the bottom, and think they have a very powerfull engine. They are only watching half of the power of them... ... and has flame-outs...

Take your time alone on the track, so you can hear your engine. Once you know how the engine should sound and feel, you will not have future issues.

Even though my P5 wasnt too bad for me since it was my first Nova, but two things really helped me out a lot. first was this video with bernard from racing experience, the second was the tuning bible. Houston had made it clear that once you go OS plug, Stay OS plug, but it is fine to switch between OD and Nova Plugs. Here is the link for the video
http://www.neobuggy.net/modules/news...p?storyid=7253

As I said if I lean it it stalls randomly. The only way I could prevent it from stalling was to richen in both top and bottom and increase the idle a bit.
It does feel like the idle is too high now though as I get a bit of an unstable idle.
Its also weird because Im not getting much more than 7 minutes on a tank, which is way too low, causing me to believe that its still running rich, so why is it flaming out randomly when I lean it.

And I know how the engines are supposed to feel, Ive been doing this for many years, but Ive ran OS engines in the past and theyve been much easier to tune. Everything tells me that its running rich on both ends, but as I said, if I lower the idle and lean it on both top and bottom itll flame out randomly.
And I put the 7 plug in because it was very hot outside and I figured itd reduce the temperature somewhat.

you want a 5 or 6 nova plug and or a od97t noting eles.
sounds like you got to cold plug and to make power you got lean the motor out. so try a warmer plug

Id say mine takes about a lap to get warmed up after warming it up before hand. I think on the bench you want it to get to at least 180. If it just stalls while going wide open then its too lean, if when you let off for a turn the idle is probably too low. Your problem before seems to be just too rich in general. How deep are your needles from flush right now? Also how hot is it before and when it was stalling? Its not uncommon for the engine to read 270-300 with an exergen temp gun when it goes all the way to the plug. The engine is not necessarily running hot but the temp gun goes all the way to the plug so it will read hotter than other engines. What is the temperature outside while running?

I had a 6 plug in it, thats when it kept stalling. It ran with the 7 but not well.

New heads will temp around 270-290 when properly tuned

Reason: the new heads put the temp probe teally really close to the glow plug

Use c5tgc for most all conditions , use c6tgc when you are running in low humidity above 95°

yep to cold of a plug so the motor idles weird.

Well mine was more around 250ish, cause thats what my OS engines have been running at with the same tempgun. But yea maybe youre right the Nova engines heads are more open where the plug sits so it might be measuring against the coil.
And now that I think about it the times its stalled have been when Ive let go of the throttle so the idle was probably a bit low, I did increase that though but I think I overdid it alittle.
Guess Ill put a new 6 plug in it and see if I can lean it on both ends and then maybe decrease the idle just alittle from my previous adjustment and see where that takes me.

I dont have the car inhere so I cant see what the needles are like, but I know the lowspeed is probably a millimeter or so in from flush.

Usually my low is about flush or slightly in or out and the high speed is about .5mm in. You might be way too lean on bottom and too rich on top.