T should be the heat treat on the material. 7050 is stronger, but I don't know if it's a viable option to use in nitro. 7075, although rare, is much more common than 7050.

You want it strong and also with some flex. The R7 rods are a kind of 7075 which is an easy to get material, it can also been seen how it oxidises by the nitro. The best option seems to be 7068 but is so far I know not that easy to get.

How would I know when I need to replace a conrod? Is it just something that needs to be replaced after break in then every 2 gallons or is there signs that tell me it's time to replace?

The Novarossi Rods are extremely strong and last a good while. Personally I tend to change the rod after the first 2 gallons and then every 4-5 gallons on a 21 engine and after the first gallon and then every 2-3 gallons on a 12. However I have had engines run over 6 gallons perfectly fine on a rod without any issues.

I need some help on understanding how to choosing the right plug, instead of being told what plug to use.


For e.g, my engine is a Keep on 9 XLS, temperature is around 25 to 35 degree celcius. 25% nitro. How should I choose?


1. Hotter plugs for colder days or the other way around?


2. Hotter plugs burn oil more efficiently than cold plugs? If my engine is running rich, will it become relatively leaner i I switch to a hotter plug? And what will be the consequences?


3. For this engine, I was told to use the C8TGC and it's running fine. What will happen if I switch to C7TGH?



Thank you for your time.


Ted

The best plug for that engine in the ambient temps you have and 25% nitro is C8TGFB. Just run that plug you don't need to consider anything else unless you go down to 16% nitro and the temperature falls below 20 degrees then you could consider a slightly warmer C7TGFB plug. Don't get overly concerned over plug choice as you've only got 2 options really for onroad.21. My advise is run the C8TGFB 99% of the time and if you get a really cold day you could goto the 7.

On.12 size engines we run C6TGFB almost exclusively unless it's really hot outside or you are running 25% fuel then we consider going to a C7TGFB.

In a nutshell the higher the number the colder the plug. Higher the nitro content the colder the plug. The hotter the ambient temperature the colder the plug. The opposite in all cases the hotter the plug.

My advise is stick to the 8 and concentrate on tuning the engine correctly and you'll be fine.

By the way the 'C' plugs are for offroad engines and shouldn't be used onroad. The engine will run but it isn't ideal. You should be running either the old C8TGH or the new (and much better/stronger) C8TGFB.

http://www.novarossi.it/2012/index.p...s/on-road.html

http://www.novarossi.it/2012/index.p.../off-road.html

The high end Novarossi engines are very tight shimmed so it needs to run an 8 plug, going to a 7 will blow the plug.

Many things can contribute to rod life expectancy. The most beating a rod will take is on a poorly planned break-in, heavy on and off throttle, and over revving of the engine.

In a very nicely broken in engine, my experience let's me believe 4-7 gallons depending on actual usage. Up to 10 gallons has been seen but is rare and more common in lower rpm/hp engines.

In a heavily raced engine and/or rough break-in, without heating the head to a proper temp, I'd say from immediately after break-in, or 1-4 gallons is the spread. Immediately for break ins with excessive starter running and getting caught in pinch often without actually starting.

Rule of thumb is always replace it if over revved, overheated, and abused excessively out of normal use. This is a great insurance policy. Not saying you will have trouble immediately, but a stretched out/brittle rod wil snap much sooner.

Would you risk a 500 euro engine over a 40 euro conrod?

is there other variants of the Novarossi R7 rod? If my engine comes with a R4 rod, can I replace it with a R7 rod? Is the R7 rod considered an option part?


Thank you.

The R4 is a lightweight rod

Thank you Roelof. By light weight, means it's better in performance but less in durability than the R7?

Good question, I am not the one to search the limits and like to replace the rod after a 5~7 liter use. So far I have no issues with the R4 rod replacing it at the same time as I do with the R7

Here you can see the differences:
R/C Tech Forums - View Single Post - Novarossi Ielasi Tuned Engines - Official Thread

And yes, lightweigh should mean more performance but placing a R7 rod I did not notice a thing.

This is funny. By accident I came accross some old version R7 rods new in bag, the R7-11. On top of the bag a R4 rod, looks the same.
The only difference is te groove on the side of the pinholes.

So it seems the R4 is based on an older model R7.

Anyone have a 35 plus collari WC09 edition gold cooling head they'd be willing to sell me? I just need the cooling head as I've been trying to find one in good shape to replace my damaged one.