Building 1 engine from several brands parts
 

I just got a box with all my old (broken) engine stuff, it was all examened by my sponsor in the use for devellopment/comparing their engine.If I could build up something for trainig, spare or as a rain engine.

I found the case of my old RB Xenon-R (Sirio based), I know it has runned just 6 or 7 liters before the rod broke. The crankpin was still OK end in good size and no play on the bearings so this must be a good start.

http://www.euronet.nl/users/tooms/ftp/evo5/motor1.jpg

A good looking sleeve of a JP R01 and a fitting piston with a R7 rod must make a fit.

http://www.euronet.nl/users/tooms/ftp/evo5/motor2.jpg

RB dos have some differences comparing standard Nova based engines and one of them is the location pin. A small cut on the opposite side is simple to do.

http://www.euronet.nl/users/tooms/ftp/evo5/motor3.jpg

The hole in the case for the sleeve is 19.4mm while the JP sleeve is 19.5mm, I fixed an adapter to mount the sleeve in my drill station and with a piece of sandpaper I could grind it down to 19.4mm

When fitted it was clear the sleeve was sitting to low so from a 0.5mm thick plate aluminium I made a ring for under the sleeve which did set the sleeve almost to the right height looking through the exhaust.

http://www.euronet.nl/users/tooms/ftp/evo5/motor4.jpg

RB has a crankpin of 5.02mm so a R7 rod with a 5mm hole will not fit. I have a dremel 5mm diamond grinding bit I have used before to do this job. Now it fits like a glove.

http://www.euronet.nl/users/tooms/ftp/evo5/motor5.jpg

In the box also some heads made by my sponsor to fit Novarossi engines. It has an in one piece combustion chamber for a maximum cooling. It did not work that good because the chamber was to small and to much head clearance needed to be used. With a 10mm drill I could make it a tiny bit wider and straighter in shape to get more volume.

http://www.euronet.nl/users/tooms/ftp/evo5/motor6.jpg

While I was busy I just drilled some holes to make it lighter, I did go from 70 gram to 65 gram, not that much and I think most racers do not notice that.

http://www.euronet.nl/users/tooms/ftp/evo5/motor7.jpg

With a piece of solder setted the head clearance to 0.7mm to start with and mounted it all togeather.

http://www.euronet.nl/users/tooms/ftp/evo5/motor8.jpg

OK, the stroke of the crankshaft does not fit the stroke the P/S set needs but 0.1mm difference (16.7 / 16.8) is not a huge difference

Now just to mount a clutch and give it a try.

Awesome!
Let me know how it turns out.I like these experiments.

Do not get this the wrong way, but I would be very surprised if this engine would make good power and run consitantly.
But, you never know.;)

Let us know how it went.

I never said it will be a racing engine but just to save the best engines (JP R09) in the case I do not need them. Last year I mounted a new GRP P/S set in an old JP R01 crankcase. I only needed to drill up the R7 rod from 4mm to 4.2mm to fit the piston pin of a GRP. That engine has already runned a 5 liters and is screaming, not bad for a 80 euro investment while this will cost me nothing.

Maybe next weekend I will give it a try, I will mount a clutch and can make a start in the backyard. You will hear more!

interesting...

Roe's the man, that custom made mrx4x front belt tensioner u sent me last year worked flawless all season...he knows his stuff, id be suprised if it DIDNT run good...lol...

No more stripping belts? :lol:
Yes, that is an easy solution for the frontbelt which should we a standard in the kit, I am glad you like it. In the current days it is a shame that most people can not (or will not) fix problems by creating solutions than only getting option parts. Back in the days that was different, a lot of parts needed to be modified or home made.

This is just a funproject to see if it can be done and so far with simple tooling it is possible. I am sure the engine will run and regarding the current height of the ports I think it will run OK. These are just old parts, there is no investment and so nothing to loose but if it works I could arrange a new P/S set.

hey roe, just curious, how did it work out? and how do u like the looks of the new mrx coming out?

tommy

It did run fine for a short time, the piston did become very loose. In the beginning the piston did feel great but the sleeve was probebly from a broken engine and a tiny bit misformed that the piston did push back in shape.
The 1st impression was OK.

I have pinched it and need to run it in but did not have the time due races and work.