It's a long way to 920 type(rary)

Hello there,
I wish to keep you posted about the evolution of my 920 with big valves.
The way is mutch longer then I expected
I spend a lot of time to shim the beehive springs to 93 pounds, but this is done!
Yesterday I received the parts from Jim Schmidt.
The pistons are on special order, so it took some time to get them it and to be coated.
I received also the fluted bolds and studs, PCV valve; gasquets and more as you can see on the foto above: mecanical art! Great job Jim!



Here above the foto of the new Maney cylinder with Nicasil coating.
BTW, when you make your budget for a 920 and big valves, you have to double
the original budget to come to the reality, you must rebalance the one piece JS crank to the new pistons weight, you must change the shells on the Carillos longer rods, you must
aquablast the cases, cylinder, head, Nicasil coating, rebuilt the oil pump, pay the machine workshop, the 31% custom fee, the UPS transport and so on and on.....
The last thing I discoverd was wear on the BSA followers and blocks, better to change it after +25.000 Kms, I will also change my old JS 2 cam for a new JS 2 Smoothramp cam.
Luckily, Fast Eddy sold me a brand new JS 2 Smoothramp cam and followers blocks for a good price, thanks Nigel!
I ordered new followers from JS engineering.
At the moment my cylinder head is at the machine shop to put the Timeserts
I hope to start the rebuilt of the engine this week, and have the bike ready to break in in tree weeks
Keep you posted
Yves

I think it was Phil Vincent who said "horsepower is expensive!"

Glen

worntorn said:

I think it was Phil Vincent who said "horsepower is expensive!"

Glen

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My wife has said the same thing , several times
Craig

Wives can be expensive as well...so I never got married.

very nice Yves. Will dyno your finished bike? I'm pretty curious as to how much more horsepower you'll make.

Jagbruno said:

Wives can be expensive as well...so I never got married.

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Of course you will never be married Bruno, in Belgium you must have a dick from more as one inch, ,that's why I am not married to, but when I was a Boy Scout my Totem was "concrede dick"
Yves

o0norton0o said:

very nice Yves. Will dyno your finished bike? I'm pretty curious as to how much more horsepower you'll make.

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Me to!
Like every time I make changes on th engine I go to the dyno, I don't expect mutch top horse power but I mutch stronger mid-range
Yves

Looking good Yves. I’m jealous of the quick progress you’re making!

Happy to help out with the cam my friend. I know you’ll put it to good use !

One of the best quotes I ever read on the advent of HP...

If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower.
Mark Donohue

Yves, your upgrades are going to make you smile. Its fun to follow, please keep us in the loop of your upgrade process.

Yves, as I also run the BSA style lifters in my race bike, how come so much wear in this area on yours?
I have had 4 seasons of racing and the engine apart 3 times in that period, no noticable wear so far.
What oil were you using?
Nigel, what did you replace your hardware with that you passed onto Yves?
Regards Mike

Brooking 850 said:

Yves, as I also run the BSA style lifters in my race bike, how come so much wear in this area on yours?
I have had 4 seasons of racing and the engine apart 3 times in that period, no noticable wear so far.
What oil were you using?
Nigel, what did you replace your hardware with that you passed onto Yves?
Regards Mike

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I haven’t ‘replaced’ anything as such. My 850 still has the JS1, I was going to try the JS2 in this engine, but don’t really know when, and kinda think I’ll leave it be as it’s a pretty damned good all round package as is, so Yves need seemed greater than mine!

In the 920, I’m going to try a Webcam 86c/12c... which I anticipate will work well with the 2:1 pipe Mike.

Brooking 850 said:

Yves, as I also run the BSA style lifters in my race bike, how come so much wear in this area on yours?
I have had 4 seasons of racing and the engine apart 3 times in that period, no noticable wear so far.
What oil were you using?
Nigel, what did you replace your hardware with that you passed onto Yves?
Regards Mike

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Mike,
The wear was not that mutch, but I see that one of the stem of the followers was bend, not mutch, maybe .001mm and I find micro- scratches on the stellite.
This bend make that the follower must go in the hole from the block where is was in for 25.000 kms, no possibility to put him on another place.
You will say: don't worry about that, but I always search for perfection, and at the end if you find 85% of perfection you can be happy no?
I am using Denicol racing Oil so far, and I will change for Red LIne motorcycle oil, 20/50 or 20/60 in the summer. the problem with the Red Line, on the can there is a warning: don't use this oil for brake in! I send a mail to Red Line and they says to use mineral oil for brake in????
I change my oil every 1.500 kms and the oil filter every two oil changes.
Yves

Brooking 850 said:

Yves, as I also run the BSA style lifters in my race bike, how come so much wear in this area on yours?
I have had 4 seasons of racing and the engine apart 3 times in that period, no noticable wear so far.
What oil were you using?
Nigel, what did you replace your hardware with that you passed onto Yves?
Regards Mike

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The fact that I was using a JS 2 cam can maybe explain the wear, I hope the JS 2 Smoothramp will help to solve this small problem.
Yves

Lineslinger said:

One of the best quotes I ever read on the advent of HP...

If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower.
Mark Donohue

Yves, your upgrades are going to make you smile. Its fun to follow, please keep us in the loop of your upgrade process.

Click to expand...

Posting a tread on Access is a wonderfull thing! I always learn something from other members.
yves

Brooking 850 said:

Yves, as I also run the BSA style lifters in my race bike, how come so much wear in this area on yours?
I have had 4 seasons of racing and the engine apart 3 times in that period, no noticable wear so far.
What oil were you using?
Nigel, what did you replace your hardware with that you passed onto Yves?
Regards Mike

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Stan Keys is also running the new JS2 smooth ramp cam. He won the championship in Bears class ARHMA racing in 2017.

Thanks Yves, sounds good.
I use Driven oil (Joe Gibbs) designed with high zinc content and for flat tappet motors.
I use this for break in
http://www.drivenracingoil.com/dro/br-break-in-oil-15966html/
And I use this after break in.
http://www.drivenracingoil.com/dro/hd50-synthetic-15w-246html/
Regards Mike

Brooking 850 said:

Thanks Yves, sounds good.
I use Driven oil (Joe Gibbs) desighned with high zinc content and for flat tappet motors.
I use this for break in
http://www.drivenracingoil.com/dro/br-break-in-oil-15966html/
And I use this after break in.
http://www.drivenracingoil.com/dro/hd50-synthetic-15w-246html/
Regards Mike

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The break-in oil is intresting, the second one is similar to the Red Line
The good thing: there is a dealer in the UK, I will contact the UK dealer tomorrow
Thanks
Yves

Lineslinger said:

One of the best quotes I ever read on the advent of HP...

If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower.
Mark Donohue

Yves, your upgrades are going to make you smile. Its fun to follow, please keep us in the loop of your upgrade process.

Click to expand...

Lineslinger Thanks for that link

More eye candy from Yves.
Thanks for sharing...
A sign I saw years ago in speed shop...

"Speed costs money, how fast do you want to go?"

Looking forward to the porogress.

olbbeezer said:

Lineslinger Thanks for that link

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MichaelB said:

More eye candy from Yves.
Thanks for sharing...
A sign I saw years ago in speed shop...

"Speed costs money, how fast do you want to go?"

Looking forward to the porogress.

Click to expand...

This is my problem: when I have one $ in my pocket I spend two $
Here is what I did to day:
The whole day at the machine shop, we put the tree Timserts in the head, to do that we mill a little from the casting on the top of the head and we make a piece of 1:2" tick of steel plate and we sunk the allen bolts in the steel, after this we where sure that the surface of the head was paralele with the machine work plate, we tchek it and it was perfect: les as .001mm
This plate was very helpfull to keep the head on the work plate, then we made a stem that was going straight in the old hole, we align the CNC machine and take the stem out so we can made a perfect centered bore for the timserts, and the result was there, the alignement from the cylinder and head was perfect.
After the timsert, I made the mesurments between cylinder and piston skirt, the machine shop have a pressurised room to do the mesurments (to keep dust out)
We use a tool with tree points to mesure the cylinder, this tool give precicion of .001mm, the bore was exacly 80.995mm with a ovalitation of .005mm witch is nearly perfect when you know that a hair is .03mm.
Then we did the mesurment of the piston, at the end of the story the clearance between piston skirt and cylinder was .12mm, I send a mail to JS to know if this is OK?
Tha antsword from JS is this is OK, without the coating on the skirt the clearance should be .15mm, just be carefull with the throtel in the begining (that will be the most difficult part of the whole story)
the last thing I did on the machine shop was to make the mesurment of the gap on the top piston rings, must be 0.3mm and I find 0.25, so I take a diamaond file and file it to 0.3mm.
Jim Schmidt say there was no need to do that, but sorry Jim, here in Belgium we have no file to fill up the gap...
Keep you posted
Yves