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Page 2.
Content:
1-Cam timing 2-Milling the head/head gasket part#/racing ignition boxes part#
3-Milling the deck 4-Cooler motor temps 5-High compression motors
6-More air under the tank 7-Porting 8-Ramair 9-Velocity stacks
10-Crankcase relief valve 11-Spark plugs
1
Camshafts timing and power band alterations:
Those figures are for intake cam timing and resulted peak power rpms!
Note: keep in mind that we keep 100 degrees of exhausts timing as a baseline.
From 104 to 105 intake timing: peak@9500-9800rpms
From 106 to 107 intake timing: peak@10000-10300rpms
From 108 to 109 intake timing: peak@10500-10750rpms
From 110 to 111 intake timing: peak@11000-11250rpms
Note: Those are averages and peak power may differ sensibly.
From experiences:
A good consensus would be to set the cams at 108 degrees intake/100 degrees exhausts.
Note: Advancing the intake cam timing too much WILL make a small rpms dip in power bigger!
Doing so is only indicated while using an aftermarket air box (ram air) to simulate hotter cams.
Myself, I'm running a Qbcarbon ram air system with my cams set at 110int/100exh.
But to make the whole thing worth your while, you got to mill the head to get more compression, and that is a whole new world....and jetting headaches**.
**Additional note: the cams timing from the factory can be different than specs;
checking the timing can give you back what belongs to you!
2
Angle milling for a 5 valves head:
Why angle-milling?
Well, it's mainly because of that middle intake valve;
It's the one preventing us to squeeze even more power from our motors!
Removing 0.020" from the head can lead to as much as a 12.75:1 comp. ratio!
There are different ways to get to this:
1-Go for it, remove 0.020" from all the head surface and use a stock thickness gasket;
2-Remove 0.010" from all the head surface and use a YEC gasket
part#4XV-11181-70 (Yamaha race part-you guessed it, 0.010" thinner than stock)
3-THE SAFE WAY: remove 0.010" from the exhausts side, and 0.005" from the intake side
and using a YEC gasket; if you cant lay your hands on one, use a stock gasket(0.025")but
get the machinist to mill 0.015" from the intake side, and 0.020" from the exhausts side...
or 0.005" from the exhausts side and nothing from the intake side
using a Cometic gasket(0.015" thinner than stock).
That's called angle-milling.
Note: Power is made mainly on the exhausts side anyways...no need to feel hardcore on this and destroy an amazing engine!
Contact for YEC gaskets:
YEC racing ignition boxes:
98-01 part #: 4XV-82305--70-00
02-03 part #: 5PW-8591A--70-00
3
Removing metal from the "deck":
This operation consist in mating the cylinder part and the head part on a perfect 180 degrees plane;
Ex.: If you plan on removing 0.020" for more compression, have the machinist remove 0.010" from
the head and 0.010" from the cylinder.
Note: In my opinion, we do not really need to be this paranoid about today's bikes tolerances.
4
Make your motor run a bit cooler with less engine noises:
Let say we want to use MOTUL oil, but we don't want to experience
a slipping clutch and contaminated-beyond-salvage friction plates:
My blend:
2litres of 3100 semi-synth+1litre of 300V full-synth.and top off with 3100 semi-synth.
A good indicator of oil time-changing would be when yourmotor runs hotter, but the exterior temp hasn't
changed; more noises coming out of the motor is a good indication too!
(You may want to check other things though...lol)
Also, there's the radiator content that can be optimized:
WaterWetter is one, as well as changing (diluting) the amount of anti-freeze in your radiator by adding
distilled water only. Evanscooling is another, and so is Engine Ice.
Note: Waterwetter and Evanscooling are accepted for track days as well as pure distilled water;
anti-freeze is forbidden.
Additional note: I got to admit here that my motor was definitely making less engine noises with
running only BEL-RAY full synth. oil.
Info site on WaterWetter: 1
One other thing that you can look into is changing the temp switch on the radiator; the stock piece
start the fan at 105c, and you can easily get one that will start at 92c in some auto part stores;
just find the correct tread numbers and you're on.
5
High compression motor:
Alert: info taken from the internet...
I'm not sure if this setup will result in a time-bomb!
For a 15.0:1 compression ratio:
Reduce deck height to 0.024" from 0.042"(disassembling of the motor required)
angle-mill the head 0.015" intake side/0.040" exhausts side using the stock thickness gasket.
(that is dangerous) I'd be using end-of-spectrum valves clearance on such an engine
(extreme tighter side), my source told me that he's using tight valves
clearance: 0.035"exhausts/0.050"intakes.
Note: It's well-known that most power is made with loose valves specs on 5 valve engines.
WHEW...I WOULDN'T DO IT...UNLESS I HAD A SPARE ENGINE AND MONEY TO BURN!
6
Get more air under the tank:
Note: This is a common modification;
With the addition of a spacer, there is a way to get more air under the tank
(and then in the air box) without sacrificing the look of the bike;
1- Remove tank completely
2- Remove attaching tab (the one that attach the tank to the frame-1 bolt)
3- Find a 1/2 inch spacer to slip between the tab and the tank
4- Make sure to install a seat of some sort between the tank and tab if the spacer is metal; a thin rubber
washer under a thin plastic washer should do it (rubber spacer between tank and plastic spacer).
Additional note: You may have to find a longer bolt to fix things back up!
7
Porting:
Being mild or full-on job, depending on the state of the tracts, in most cases
a porting job does not do big things for the peak HP figures; a sizeable boost
in mid-range HP and torque is, in most cases the result.
Note: It is widely recognized that R1 heads are pretty much closer
to the perfect side that to the perfectible side.
8
Ram air kits installation warning:
On any kits, I strongly recommend that you by-pass the instruction regarding the
routing of the crankcase breather tube into the box; Doing so will pressurized the
crankcase more than you think, leading to the head cover gasket failure.
Instead, plug the small built-in tube on the box, and route the crankcase
breather tube anywhere you like (inside a well-ventilated catch-tank is an idea).
Note: I've blown a valve cover gasket with that initial setup already, so I found it the hard way!
9
Velocity stacks:
There are actually 3 models that I know of:
Ray Stringer-designed shorter than stock stacks for QBcarbon boxes: 1
FactoryPro longer than stock stacks 50 and 59mm length: 1
Note: Both claims gains (2-3 hp); up to you to guess which will work for you; keep in mind that 2-3 hp gains
are typical of the difference between dyno run 1 and dyno run 6 (ex). The first dyno run always makes
more hp.
Shorter, lean the jetting by one main size; higher rpm effect.
Longer, richen the jetting by one main size; lower rpm effect.
Velocity stacks allow you to tune the effective length of the intake tract;
Rule of thumb: Longer= lower rpm effect. Shorter= higher rpm effect.
10
With the above mods, get this:
In my opinion, a must have: This device creates a negative pressure inside the crankcase, theoretically helping the engine spin faster through the rev band.
11
Spark plugs:
No real gains have ever been found on a road bike with so-called race spark plugs;
use the stock NGK CR9E. But, if you really need to brag about how your bike goes
that much faster with race plugs, you better go all the way:
Yamaha R7 race spark plugs: #R017xx
(replace the xx by heat range needed i.e. 09-10-11)
Or, the famous Surface-discharge race spark plugs:
#R0045J-xx (now you'll have something to brag about at around $75/each)
Here's a good informative site on spark plugs (By Gordon Jennings):
Another one:
Can't remember which spark plug you have?