VFR400R NC30 engine build

[micpec]

Nice aim and project, Rhory! I will be following this thread too.

Not kidding, but i was thinking the other day about what sort of work load comes with an NC-engine rebuild, and also what tools are necessary to perform this. I never done or tried this on an NC-engine myself. But I do have rebuild a classic '69 Puch MV50 moped I owned in my younger years (sold it, never mind what these costs nowadays ). One day I decided to dismantle the whole moped, and started from a bare frame for some nice paint work and so on. On some moment I then decided to rebuild the complete engine with 3-gears and that with literally zero knowledge or experience. It took me approx. 6 months with just a handful of simple and cheap tools and gears and a small copy of the genuine works manual. Best advice I have it to just try this engine rebuild and learn from the aspects while doing it...with the Haynes manual of course. Any gain knowledge is a plus!

[banoffee]

nice one. have rebuilt several car and 2-stroke bike engines over the years but not one of these yet. can see that I might do so some day if I keep the NC long term so will keep an eye on your progress. good luck

[MexicanGringo]

If your lucky you'l have this to marvel at, hopefully all intact as well.. The crank case was a proper bastard to separate though, most probably have to use a careful, sharp wedge at the corners.. And even more lucky if you get a smiling mandela too... http://i530.photobucket.com/albums/dd34 ... nktemp.jpg

[royster81]

the casings where split before ewhen the first knackkered crank came out and yeah it did look like that but unfortunately it wasn't all in one piece.

i have the wait to the weekend before i can start taking images of the stuff we're getting up to.

[viper_biker]

Go ahead lad, get it done.

[vfrman]

Yes, get it done, and then send it to me! Better still, I will come and collect it. I need a track motor.

[royster81]

Enough chatting , lets get this thing started.

Last night my mate Stu called up to get this underway.
First before we go buying new shells and bearings i need to figure out what rods i'm going to be using, what shells and bearings are going to be needed to fit the choosen rods and to get things ready for cleaning. We started off with the bench like this. the two cranks at the back are soon to be made into lamps as they are the knackered ones.

The crank that came out of it, think it'll regrind ?

And a not so hot looking piston,i guess i'll not be using this again.

The rods were picked as the Haynes suggests with them being matched weight wise, from the codes on the rod, and it works out i'll be fitting 4 B2 rods. why am i telling you this ? Well i need the get the codes from the casings , the crank and the rods to order the right bearings and shells and from what i remember it works something like this.
You get the code ( four letters) stamped on the casings and the codes printed on the crank to tell you what main shaft bearings you need, my casings are BBBB

( I'm not sure if it's easier to see in one picture or the other so there's both )
Next you use the number printed on the crank, mine is 2121

So i need a B2,B1,B2,B1 bearing ,which if you consult the Haynes is brown,green,brown,green.
Next is the rods, Etched onto the rods is a codes, as said i'll be using four B2 rods, meaning the weight codes are B and the bearing codes are 2, and if you look at the crank again and use the letter this time, AAAA and use the number from the rods,2222, i need four A2 bearings, so again back to the Haynes and they are 4 green bearings. I'm only going by the Haynes manual here is if it's wrong tell me before i go any further please, this is were some NC30 motor build history comes in very handy. So anyone care to correct me please ?????
As said before we had looked into it before to see the original fault so we were starting off with this .

The heads never came with the bike and the knackered crank,rods,pistons are all removed in this.
After pulling the sump off we were greated with this view, here's a snap to show you how empty it is.

Next we split the casings. if it hadn't have been so late at night i would have started cleaning them and getting them ready for the rebuild but 00.30 on a school night is late enough for me.But here's some sexy pictures of the casings open and the 'box hanging out of her ..... NICE.

Stu holding a selector fork up.

And the 'box as it normally sits on the motor.




spendometer
total£120

[MexicanGringo]

Yup as per the haynes the crank web number is the main bearing journal size, crank web letter is the conrod journal size, stamped crankcase letters are the housing sizes, letter etched on conrod is the weight and number is the size, select conrods & bearings as per haynes tables and suggestions..

Make sure to also check conrod side clearance, pin size, small end size, ring-to-groove clearance, ring gap, bore ovality if possible & oil clearances once bearings are selected, pretty much do all the checks in the haynes...

[montsta56]

Great Thread Royster .
I'm currently building a "full Fat" Engine for my race bike so I'll be following this thread very carefully.
First Question as I plan to get my rod's balanced does this negate the rod markings??.
If that makes sense??

[MexicanGringo]

A rod is given a weight marking so it can be grouped with a complementary rod, and the set of two should then be balanced in relation to that crankshaft pin. If 'balancing' involves removing/adding material, then youd need to know what weight to balance to,honda's specifications for grouping rods should be within vibration tolerances