Roelof

The hotspots are seen with the Flash models which seemed to use a different piston material that day. The solution was to add 2 or 3 lubrication holes right onder the exhaust port.

But so far I have seen the damaged pistons when using a low oil content fuel, when using 12% or more oil with the break-in and 10% oil with racing nothing went wrong with those pistons

Brian Bosley

iTrader: (13)

Is the nova 16607 replacing the 16605 bearing for the mito 12 wc (prior to dec's release)

beebone

The old Flash models got no problem can run until it die. But I got 2 Mito 21 with identical piston material, all of them got hotspot and very pinch after more than 3 litres fuel, I'm using Runner Time 25% I think should be safe enough. Not sure about the price and material matter compare with old models.

Dougie1986

Hey Dan, I am currently running a Nov mito gt5. It's originally a 2016 spec. However, I recently bought the 2017 conrod,position and sleeve pre broken in from rc target. I am running the Nov 41032 manifold and tesla .21 efra 2139 pipe.glow plug #8. I live in Jamaica and it's HOT. I'm using 20% bryons nitro gas. I haven't played with any shimming.

My problem:

Ever since I introduced the 2017 parts to the engine. I have been struggling with temperatures. At factory mito settings the engine is very rich and the temp is 240-250 plus the car is lazy. So I try to lean the car out in hour increment. The high speed needle hasn't passed 3hrs or 1/4. The low speed needle hasn't passed 2hrs. I'm getting lots of smoke. Yet, the temp is about 300-310. The engine sounds ok... no cracking, no high revs when I come to a total stop...

Should I ignore the temps? And place my attention to the sound and smoke?

Btw it's about 2 months since I introduced the 2017 parts and used about 2 gallon of gas.

Please help

dan_vector

iTrader: (27)

Don't rely on temperature to set your engine. It is just a guide. I always think that if you have smoke out of the corners then the engine is not critically lean.

If the engine has a stable idle and doesn't scream when entering the pits for example then it is unlikely that the engine is lean. If it sounds set right then it most probably is.

The biggest telltale is the condition of the plug after a run. If the element looks wet and shiny the engine is running well and is not lean. If the element is dry or looks dull or worse still broken then the engine is lean (getting leaner as the condition deteriorates).

I don't know what that tesla pipe is but the best pipe I've found for the engine is the Novarossi 2015 with the 41032 manifold (if you can run a 2-chamber pipe then the 9886 pipe with the same manifold is even better).

I'm not sure exactly what the Tesla plugs compare to (I know they are NR plugs but there are many versions of NR plugs). I use the NR CT7 or CT8 if it is really hot out on 25% nitro. I run 16% nitro most of the time due to UK national rules and so run CT7 99% of the time.

The engine is fine on the stock shimming on 20-25% nitro.

I take it you have cut body engine cooling holes in the rear window as well as the side windows and windscreen?

Dougie1986

Ok. noted. my rear window is fully cut out.

Update: i added two copper shims which i had to remove because the engine started to stall. even with 1 shim it was still stalling.

Today the environmental temp was around 95-100 degree. with the car in the sweet spot meaning smoke(on the straight and in the corners) and sound good while pitting engine dies down to normal idle in no time. my temps were 350-370 degree. i am still using the 20% nitro gas. i even replaced the plug with a new NV #8

Everything seems good with the engine except the temp. when i put a little water on the head. it sizzles and evaporate in no time.

i have a race coming up next weekend and its for 1 hour. i am afraid the engine will flame out on me. is there any internal parts you think that could be causing this issues? now that i think about it from i introduced the 2017 sleeve, piston and conrod i have been having this temp problem. should i go back to the 2016 elements?

Julius

Tesla plugs are os based.
Rp6 or rp7 should be ok

dan_vector

iTrader: (27)

If you take off the head is the piston surface and underhead clean and not pitted? If it is then the engine is not lean.

You can try going back to the 2016 piston/sleeve but I would not be overly concerned if the engine is running well and you have plenty of smoke out of the corners and it isn't blowing plugs then the engine is not too lean.

ralphierace13

iTrader: (5)

use someone elses temp gun to double check 370 is way too much I don't believe at 370 u are seeing smoke and no nova plug will withstand 370. maybe u would get away with 370 on a os plug but deff.. not nova!!!

again double check with another temp gun....

dan_vector

iTrader: (27)

Temp is overrated. The CT series of Nova plugs are very good. OS plugs are no better. Don't get wound up about temp - it really isn't everything! If you are tuning an engine based on temp alone then you don't fully understand how to setup an engine!

If the engine is running well and not killing plugs then it isn't lean.

Oh and by the way GT engines will always run way hotter than an engine in a 1/8 car like the 988 because it is inside the body with lower airflow as well as it pulling a car which is 1 KG heavier!

ralphierace13

iTrader: (5)

I don't care what series nova plug I ran them all and they still suxk!! I know gt runs hotter but u are still not getting no where near 400... just because its a gt don't give it a pass to run at 370!! lol same laws of physics still apply!!

dan_vector

iTrader: (27)

Ok pal.... CT series plugs don’t suck but yeah whatever.

ralphierace13

iTrader: (5)

danny don't get mad at me I love u!!!

mustangkillaz

iTrader: (3)

Nova plugs have never been my most durable. They've been ok, but are defiantly more sensitive to temp and set up than others.

dan_vector

iTrader: (27)