Help: Novarossi JP Modified RX21 R1 Long Stroke Replacement
#1
Help: Novarossi JP Modified RX21 R1 Long Stroke Replacement
I'm lookng for the replacement of the Novarossi JP Modified RX21 R1 Long stroke engine. I'd like to buy one now. I have one but need to buy a piston and from what I have heard its gong to be almost impossible to find. This engine was supposably ahead of its time about 10 years ago with 11 ports on the engine sleeve. I'd like to find out any information possible about what would be able to replace this engine with same or even better results on the race track. Looking for a top notch on-road .21 engine. Any information would be appreciated.
#2
While finding that EXACT P/S may be difficult, most Nova P/S sets should fit it and perform just fine. I suspect a Kangaroo set would run great in it.
#3
Do you know which model # kangaroo would be sweet? Or even which kangaroo motor model # would be a great replacement so I can buy a complete engine for this up coming yr? Thank you for the quick responce.
#4
Tech Champion
iTrader: (3)
#5
Depending your budget I would advise to take a look at the Novarossi 35-plus-21 (non-Collari), it is a fraction more expensive than a Kangaroo but it is a beast of an engine
#6
Tech Apprentice
I'm lookng for the replacement of the Novarossi JP Modified RX21 R1 Long stroke engine. I'd like to buy one now. I have one but need to buy a piston and from what I have heard its gong to be almost impossible to find. This engine was supposably ahead of its time about 10 years ago with 11 ports on the engine sleeve. I'd like to find out any information possible about what would be able to replace this engine with same or even better results on the race track. Looking for a top notch on-road .21 engine. Any information would be appreciated.
#7
Thanx for the help guys i'll keep doing some research on the 35plus..
#8
The Kangaroo is based on the same model as the JP R01, Novamega EVO5, 321 and many other great engines we have seen in the past years. There are no specific Kangaroo models you must use, all will fit. If you want to go cheaper even a P/S set of a N21-7T or a N21-5T will make a direct fit.
Depending your budget I would advise to take a look at the Novarossi 35-plus-21 (non-Collari), it is a fraction more expensive than a Kangaroo but it is a beast of an engine
Depending your budget I would advise to take a look at the Novarossi 35-plus-21 (non-Collari), it is a fraction more expensive than a Kangaroo but it is a beast of an engine
The R1's have a diff sleeve to the 321 engines. From 321 onwards all later model sleeves are the same. N21 7T is similar to 321.
#9
All current Novarossi sleeves are 19.5mm in diameter and all are 16.2x16.8 bore/stroke. The only uge difference is the 3mm or 2mm thick upper edge and even then with the right button head and the right amount of shims you can make it all fit.
Other difference in onroad P/S sets is the height of the exhaust port, that can differ from 7 up to even more than 8mm but mostly they are 7 to 7.5mm. Even if you buy the same P/S set the exhaust can be different, nothing to worry there, it will determ the balance between top RPM and bottom power.
Last year I bought a cheap offroad JP P8 P/S set (2mm edge) and placed it into a JP Eagle which normally has a sleeve with a 3mm edge, the original Eagle button head needed a 1mm extra shim but I used an old button head.
The funny thing is that all Novarossi engines I have seen the intake ports are always on 65 degrees timing. As it was an offroad the exhaust needed to be raised with at least 1mm and the engine is still going strong.
I have builded many engines combining sleeves with diferent crankcases and realy, there is no special story with the sleeves.
Over here the Kangaroo is about 350 euro and the 35+ about 420 euro, for the 70 euro I would go for the 35+
With the upcomming season our club will be running the N21-5T engine. Ofcourse I turned this engine inside out but we are amazed how this engine is configured for just 129 euro. It is almost timed as a Kangaroo and for the modders it is easy to get more out of it. Also here yhe P/S set does cost 100 euro and yje whole engine (special club price) is 129 euro..... The choice is simple
Other difference in onroad P/S sets is the height of the exhaust port, that can differ from 7 up to even more than 8mm but mostly they are 7 to 7.5mm. Even if you buy the same P/S set the exhaust can be different, nothing to worry there, it will determ the balance between top RPM and bottom power.
Last year I bought a cheap offroad JP P8 P/S set (2mm edge) and placed it into a JP Eagle which normally has a sleeve with a 3mm edge, the original Eagle button head needed a 1mm extra shim but I used an old button head.
The funny thing is that all Novarossi engines I have seen the intake ports are always on 65 degrees timing. As it was an offroad the exhaust needed to be raised with at least 1mm and the engine is still going strong.
I have builded many engines combining sleeves with diferent crankcases and realy, there is no special story with the sleeves.
Over here the Kangaroo is about 350 euro and the 35+ about 420 euro, for the 70 euro I would go for the 35+
With the upcomming season our club will be running the N21-5T engine. Ofcourse I turned this engine inside out but we are amazed how this engine is configured for just 129 euro. It is almost timed as a Kangaroo and for the modders it is easy to get more out of it. Also here yhe P/S set does cost 100 euro and yje whole engine (special club price) is 129 euro..... The choice is simple
#10
Yep that is what I was refering to, 3mm edge which came out 321 based engines. Very interesting to get a 5 port to move.
How quick was the Eagle with the off road piston and sleeve?
How quick was the Eagle with the off road piston and sleeve?
#11
In the attachement some current engines I have seen in the last months and some older ones I am working on (several parts to one engine)
The N21-5T blue head is the older version, the AMCA clubmotor is the latest purple head version and compare its timings with the faster ones in the list. Taking away 2 degrees on both opening and closing side of the crankshaft makes it a Mega MF modifid spec crankshaft