N217T
N21R7
KAPPO21

They are similar but not the same. N21-7T & N21R7 use the same block and crank. The KAPPO21 has a better crank and block. N21R7 & KAPPO21 use the same piston/sleeve. The N21-7T uses a different piston/sleeve. Same bearings & rod in all three.

Exploded views

http://www.novarossi.it/2012/images/...va/KAPPO21.pdf
http://www.novarossi.it/2012/images/...nova/N21R7.pdf
http://www.novarossi.it/2012/images/...ova/N21-7T.pdf

Hope that helps

It is a commercial thing... No racer would buy an engine saying "basic" or "stock" and no driver (on all levels) with a limited budget will buy high end engines.....
I do run the N21-5T but I do modify them. Out of the box it is already a good engine and after some modding they are as good as any other more expensive engine. The basic engines are made a bit slower through timings, a smaller hole in the crankshaft and missing optical things like a silicone insert.

Thank you my friend for the definitions. I saw the details of each engine but through the pictures i wasn't sure for the similarity of some parts.

Roelof i understand you exactly....... . I need my friend some pictures of your modding. Really if it possible i would be grateful.

About the differences i realised that there is somewhere fake specs on behalf on NOVA.
I mean it is not possible to add at a basic engine some exotic materials and technologie of NASA and still it produces the same HP and RPM.

Something else that i realised is that the expensive motors have installed carbs with single needle on the contrary with basic engines that have two needles.
Could someone explain me the the benefits pastic vs aluminum carb?

Hey bro I just bought a novarossi 35 plus 21 that's going in my gt I really need to get a bigger cooling head?

Hey buddy probably you will find it out earlier than me. In fact my engine is on its way.
But it believe the answers above were enough for me to understand that it would be better to work out with a bigger head.
I recommend to go on with the run in of the engine and then you will see how the performance and temperature are.

I just went through the same thing again yesterday with my XZR speed. It runs too hot with the stock head so I am swapping to a larger one today. It wasnt as hot as my nova but still too hot to tune properly.

Did you have the same problem running without body?
What was about the temperature?

290 body on 210 body off

Hmmm for this season it sounds high with body on. What body did you use? Enough holes on it? Which head did you used as a replacement at OS?
These temps was for Nova as it came from factory, for OS factory or OS with replaced head?

Do you have only an opening in the front window or also one in the rear? (which is needed).

And what plug are you using? The OS XZR wants to have a RP7 or even a RP8 plug (R7), if you are using offroad plugs like a nr 5 or lower then that can also be the cause of the heat.

And sometimes a different exhaust can make a difference in temperature.

legal holes on body, tried with the entire rear window out and it made no difference, enlarged front hole and it made no difference either. I have a Red Alpha head on the OS and A GO engine head on the NOVA. The Nova temps were way higher and that is expected because the head is smaller than the OS head

It actually ran cooler with the rear window solid than without it. I made the window removeable and tried it back to back both ways.

Running a RP7 plug but have an 8 ready for homestead.

All pipes were the same 2050, 2052 and even tried an RB off road pipe

Only thing that brought the temps down was simply a bigger head
I wouldnt think that any small thing would make up 100 degrees!! the NOVA went from 310 to 210 and the OS went from 290 to 230 ish but i wasnt pushing the car nearly as hard as i was the NOVA and the OS was on break in mode with no second gear shifting. I thin it just boils down to needing a bigger head. these engines are designed for Pan cars that have the engine head exposed and GT cars dont. Before i switched to the onroad engines, none of my Off road engines had this problem and with the bigger heads they run perfect. When i went to the bigger head on my NOVA i went immediately one full turn lean on the HSN and it was still a little fat!

Wow well what head will fit my novarossi 35 plus 21?
I don't want to ruin my perfectly new motor :-(

So far all of the bolt circles have been the same, I think the Nokia's are pretty close to the same just get the head off if an off road nova engine. As long as it sits flush with the CC you should be fine.

Any head from a non low head NOVA motor like a PLUS21-4C, P5XLT or P3XS...