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Headwork Winter Project

2M views 21K replies 174 participants last post by  Jan Okal 
#1 · (Edited)
Hey there guys, thought some of you might find this interesting…

I’m doing some headwork on my 2003 R1 over winter. I own a bike shop in the UK and it’s getting up to the quiet period for me and I have been planning to do this for a long time.
Because I own a bike shop I obviously have access to the workshop, tools and resources to do work like this and it got me thinking, what I can do to my engine to make it the way I want with the minimum amount of money spent. I’m on quite a tight budget (owning a bike shop hasn’t made me the millionaire I hoped it would but I wouldn’t change it for the world!). I have a list of things I plan to do which I’ll go into in a bit.

Firstly, I’d like to say thanks to a few people on here who’ve helped me out already with the info/specs I was missing and given me some great advice as to going about things. They know who they are. Also, thanks to the people who make this great source of information possible, the guys who run this forum. :beer

For future readers, please check out this thread also as it contains some very useful info on tools I use and additional information from other users.

http://www.r1-forum.com/forums/showthread.php?t=185329 Thanks to BSR-1 for starting that thread.
 
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#41 ·
I think this is a bullshit statement. I can't comment directly on the HP differences between stock and re cut angles, but a knowedgable guy I know dismisses any real gains.

I can comment directly on HP differences.

A good seat prepartation is about much more than than sealing the valve to the seat itself. It is all about flowing more air when the valve is JUST beginning to open and close. I have seen unreal gains on the flow bench from seat prep only. Granted this is at partial/ low lift, but anytime you are flowing more air earlier, you are already subject to a power increase. Period.

If the stock yamaha seats are so good, then why would yamaha offer a seat cutter in the race kit? It's because a stock seat has flow and seal, but economical. A real seat must be perfect, regardless of cost. This takes much more time, more machining, and is thus more expensive.

This is fact, not question. If stock seats are so good, why on earth do real race (F1, NASCRAP, etc) teams spend millions on the machines that cut them? You can absolutely rest assured that an M1 doesn't run the same seat profile that the stock R1 does. (and yes, I am aware that they are completely different motors.)

To say stock seats offer the same performance as well prepped seats is ridiculous. It's like saying the stock suspension is as good as a well prepped Ohlins suspension.
 
#42 ·
i had to go to doctor at lunch, then to yamaha shop for headgasket, then to get meds, then wife ran out of gas(shes a blonde) so i didnt get measurements on gasket. but i have brand new stock on and the 2 halfs at house. i will check them later and let you know.
 
#43 ·
I can comment directly on HP differences.

A good seat prepartation is about much more than than sealing the valve to the seat itself. It is all about flowing more air when the valve is JUST beginning to open and close. I have seen unreal gains on the flow bench from seat prep only. Granted this is at partial/ low lift, but anytime you are flowing more air earlier, you are already subject to a power increase. Period.

If the stock yamaha seats are so good, then why would yamaha offer a seat cutter in the race kit? It's because a stock seat has flow and seal, but economical. A real seat must be perfect, regardless of cost. This takes much more time, more machining, and is thus more expensive.

This is fact, not question. If stock seats are so good, why on earth do real race (F1, NASCRAP, etc) teams spend millions on the machines that cut them? You can absolutely rest assured that an M1 doesn't run the same seat profile that the stock R1 does. (and yes, I am aware that they are completely different motors.)

To say stock seats offer the same performance as well prepped seats is ridiculous. It's like saying the stock suspension is as good as a well prepped Ohlins suspension.





I hear ya Scooter. I know my statement was a generalization, as was yours. I'm definitely not saying that all stock seats are great. I meant that specifically, the stock R1 seats are pretty good and as long as the seal is perfect, they can make great power. Is that to say that there is no gain to be had by recutting the angles? No way. But just like it always comes down to: price:performance. Are re-cut seats worth the cost on a massaged R1 versus well sealed stock ones? I am leaning towards no. What do you think the HP gain would equate to? Everything else being equal (including seal).
 
#44 ·
more cuts on seat, the better the flow. how much.. i dunno. but it must be worth something if all superstock and supersport guys do trick 5 angle jobs on them. has to be for good reason. now will it be enuff for what he needs?? prolly not gonna notice much difference on stock motor. but one with more compression and different cam timing... its sure worth shot. i would love to see dyno on bone stock motorcycle, then one on same bike with multi angle valve job. then same bike with set of high compression pistons in it. but dont guess anyone has those lying around anywhere.
 
#45 ·
I do agree about the valve seat debate, it would be a great thing to have a multi-angle seat. Unfortunately, in the constraints I've got, I doubt it's going to happen. I phoned a friend of a friend, the nearest person I could find today who can do seat machining without charging me the earth and he's going to phone me back with a price and time quote. I will say though, besides satisfying my curiosity as to the price, I think it's going to be out of my reach. I'd rather put the money towards having my suspension re-worked as I feel it would make the bike better to ride for me than the few hp I would gain with a better seat setup. I'm doing this work now because I know I will benefit on the road and track. I base this on the fact my favourite and regular road I ride has very many corners I can exit in second or third on full throttle, bike feeling perfect. More power would be a use to me there, then I'm sure next winter's project will be chassis orientated to make better use of the extra power available.

I'm very much pro for having the valve job if you are in a position to do so but at this moment and for a while, I'm afraid I'm not. Much the same story regards pistons. Sure, some lighter, better made and stronger ones would be great but I'm not ruling them or the valve job out. Definitely not. I can always do them at a later date, it doesn't cost me anything other than gaskets to have the motor to bits again at a date when I can afford to carry on with more work.
 
#46 ·
i had to go to doctor at lunch, then to yamaha shop for headgasket, then to get meds, then wife ran out of gas(shes a blonde) so i didnt get measurements on gasket. but i have brand new stock on and the 2 halfs at house. i will check them later and let you know.
LOL No problem mate, sound's like you've had a fun day! Thanks in advance.
 
#47 ·
Awesome info guys. Subscribed.
 
#48 ·
Funny you mention that as i just dropped my G1K head off today at the welders. I am having him weld up the ports in the exhaust for the pair valve crap. Just trying to make it as perfect as I can.

Problem with having the seats cut is it's an average of $300. Thats a good bit to tack onto a motorjob without and decisive information as to how much it's worth in terms of power.
 
#49 ·
i had to go to doctor at lunch, then to yamaha shop for headgasket, then to get meds, then wife ran out of gas(shes a blonde) so i didnt get measurements on gasket. but i have brand new stock on and the 2 halfs at house. i will check them later and let you know.
martinc has that info......and a lot more, already avaliable on his site. much good reading on there people.:fact
 
#50 ·
Are re-cut seats worth the cost on a massaged R1 versus well sealed stock ones? I am leaning towards no. What do you think the HP gain would equate to? Everything else being equal (including seal).
Look at it like this: everybody has heard the clique about a motor being roughly comparable to an air pump. The easier the pump can move air, and the harder it can squeeze it, the more output it has. Many tuners look to cams for increased airflow. The reason? They go in quick, require little teardown, they do move more air (so they can make more power), and are somewhat profitable. It's the easy way out.

The problem is that cams usually sacrific a good bit of lowend to gain topend.
More power, but only on top. For a basic shop tuner, this is the easy, profitable way to tell a guy he just bought more power.

Good valve jobs can provide the same effect, but across the entire rpm spectrum. No losses anywhere. I.E., NO COMPROMISE. More power, all the time. More time, more effort, harder and more tedious work. And it requires specialized exspensive equipment to do. Not perfect for a shop owner. This is REAL reason many tuners don't do it or recommend it.

The process costs about the same as the cams, (maybe slightly more) since there is more labor, (you must pull the head) but fewer parts to buy. Full on port work will cost more, but the thread starter indicated he was doing his own, so this is not a factor in this example.

High velocity ports work by forcing air to move faster than in the stock port, resulting in more inertia. When the intake valve shuts, the faster moving air doesn't want to stop, and pressure builds at this point. This is termed interial supercharging. If the valve doesn't open before the pressure dissipates, the effect is lost. The window to use this pressure increase is small and easily lost if all the pressure isn't emptied into the cylinder quickly.

The reason a real seat works in this application is due to the fact that a prepped seat flows better WHEN THE VALVE STARTS TO OPEN, right when the pressure is at it highest in the "high velocity" intake tract. I've tested examples (with convention port work) that had 35 and 40% flow gains at .050" lift. This is more airflow and it equals more power. It doesn't require a larger port to get more air into the motor during this phase of the valve opening, it requires the valve/ seat combination to work better. This why I stress seat work. A machinist that knows what he's doing ALWAYS removes as little as possible from the intake tract during a good port job, instead relying on the seat to make the real difference in the flow curve. (Unless he's building a no holds barred drag motor that always operates in the top 15-20% of it's rev band. Somewhat different story)

The CFM under the curve is the TOTAL air moved through a head during the entire cam movement, not just at peak lift. If more air enters the cylinder during the opening and closing of the valve, the higher the cfm will be, even if the peak cfm is the same. Keeping the port small does help bottom end, so keeping the port small, but increasing flow at part lift raises power at no loss.

Thats why seat work is important. It's simple physics. I'm not trying to bash anyone here, so please don't take it that way.
 
#51 ·
:thumbup

It's cool man, I like a good debate. You definitely made good points and I agree with your theories. Cutting the seats would be more effective than cams. I just don't agree that lapping the valves (properly) is of little benefit, or inapplicable on our bikes.
 
#52 · (Edited)
Valve lapping info:





A gain in midrange HP, or "torque" is often better than top-end gains.
Besides the obvious gain of more initial speed on the "dragrace" out of
turns, the advantage is really due to the drafting factor.

If your bike is equal to your competitor coming out of turns, but faster on
top-end, your competitor can easily equalize the advantage by drafting.
Then it becomes a braking battle, which can end up slowing your lap times,
and effectively turn your advantage to zero. But, if you can pull some extra
bikelengths out of the turns, then the draft is broken, and as long as your
bike is at least equal on top end, the other guy has a much harder time
getting close enough to challenge you on the brakes.

That's why I like smaller ports ... the biggest advantage is often that they
gain on top, and midrange. If they gain on mid, without losing top-end, your
still getting the bulk of the advantage...

If you get the valves to seal perfectly, the bike will make the best
possible power out of corners. This is because a little leak is a lot !! The
high combustion pressure will find any leak, so you've got to get them
perfect. This is the secret to getting a good drive out of corners, and a
lot of tuners don't realize how important this is. When you've got slightly
leaking valves, it often doesn't show up on the peak dyno readings.

But...

When you're at lower rpm's exiting corners there is more time for the
pressure to leak out than at max revs, so the real power loss is in poor
acceleration !!!

The best way to do a valve job is to use very fine (400 & 600 grit) valve
lapping compounds, and lap in the valves. Don't re-cut the seats to radius
them or add extra angles. The stock angles flow the best !!! The lapping
compound I use is Clover brand, and the fine grades that I recommend
are available through MSC Industrial Supply -- phone number
(800-645-7270). This isn't the same as the Clover lapping compounds
commonly available, as they are much finer. Unfortunately, this product
is only available in large cans, which is more than the average enthusiast
will ever need -- but it's really not that expensive once you discover that
this is by far the cheapest power gain money can buy.

Especially don't be tempted to use the rough lapping compounds (usually
packaged in tubes) which are commonly available at auto supply stores.
Although they will work quickly, they leave deep grooves in the valve seat,
and wear into the hardened surface layer of the valve. Both of these problems
will soon lead to compression leakage after the engine has run a while.

400 grit lapping compound:
(1lb. can $16.00) part # 00274001

600 grit lapping compound:
(1lb. can $25.00) part # 00276006

1200 grit lapping compound:
(1lb. can $40.00) part # 00265801

{Note: the 1200 grit is much more expensive, and if you decide it's too
much, just skip this step. The 400 & 600 are the most important}

Rolite Polishing Compound -- I tried to find a website for it, but no luck.
Anyhow, it should be available in hardware stores. The last time I bought
it, it came in a silver tube with blue writing on it.


Update: here is a place that sells the Clover compound in 4 oz. quantities
for anyone who doesn't want a 1lb. can.
http://www.utsupply.com/viewprodtable.asp?CategoryIDSS=30


The Lapping Process -- Start with the coarser 400 grit compound, and use
only small "dots" of lapping compound about 1mm apart around the sealing
face of the valve. (Using any extra will just make more of a mess.) Be very
careful not to get any on the valve stem, or into the valve guides -- as
valve stem and guide wear is something that you want to avoid at all costs
!!) The action is to rotate the lapping suction stick back and forth about 8
times until the grinding sound and feel goes away, then without removing the
lapping stick, just lift the valve slightly and tap the valve on the seat 2
times, then go back to rotating about 8 more times. (The tapping brings some
of the "grit" back onto the seat, and the grinding effect becomes effective again.)
After about 3 of these cycles, the grit in the compound is done. Clean the valve
and seat off with paper towel.

After lapping the valve with the 400 grit, use 600 grit in the same way to
smooth out the small grooves caused by the 400 grit. Never use 400 grit
twice in a row, or the grooves get too deep to smooth out with the 600 grit. The
way to do it is 400-600-400-600 etc... Check for leaks as outlined below after each
400-600 "lapping cycle" until the valves are 100% sealed. (I've found that it usually
takes two or three 400-600 cycles, but always check for leaks after each cycle,
since some valves will lap in after just 1

cycle. The idea is to lap the valves as little as possible and still get a
perfect seal. Excess lapping will only sink the valve seat and lower the
compression ratio.

Checking For The Perfect Seal -- I do this as I'm working on each valve, and then
mark the valves as they pass this test. Be sure not to mix up the
valves, because each valve will only seal correctly with the seat it's been
lapped to !! Set the head on the bench with the combustion chamber side up. With
the seat and valve absolutely clean, install the valve in the head,
without assembling the springs. Check the seal by setting a super bright
light on the combustion chamber side, then look into the port. You want
total darkness, so in multi valve heads, put in all the valves for that
port. Once your eye adjusts to the dark, rotate the valve and you can see if there
are any light leaks. Light from the "blind" side will reflect off the
valve stem. You'll be surprised at how many professional valve jobs leak
when tested this way !!! Note: the area around the valves and seats must be cleaned
of carbon, or it will block the light. It's best to do this before
you begin the lapping process.

Once the valve is sealed, I use an extremely fine (1200 grit) lapping
compound and lap the valve in using one lapping cycle to get rid of the 600
grit grooves. (Almost impossible to see, but even at a microscopic level,
the valve will still leak under the extreme pressure of combustion.)

With the 1200 grit lapping compound, the finish effect is almost complete,
only there is still a gray band left on the valves and seat. For the final
step, finish with 1 lapping using metal polish to actually polish the valve
and seat. This is done for 2 reasons -- to make the metal to metal contact
as perfect as possible, and it also removes any traces of the abrasiveness
of the lapping compound. The brand I recommend is Rolite. This product isn't
like the chemical type for polishing silverware, but rather the type that's more
like toothpaste, with a extremely fine grit to it.

You only need to use the 1200 once and the Rolite once. (Also, you won't
have to recheck the seal, as with the 400 & 600 grit lapping cycles since
these compounds are so fine.) Using these last 2 compounds might seem like
a waste of time, but it's all about doing an outstanding job, and one where the
power will last as long as possible.

Thoroughly clean the head and valves, and assemble them with the utmost
care in a super clean workbench environment. All it takes is 1 grain of dirt or
grit between the assembled parts, and all that work will be ruined the first time
the engine is started.

As you can imagine, I ALWAYS recommend using an air filter, since 1 lap
around the racetrack with open intakes will suck in enough dust to un-do the
polished finish on the valves.

Be sure to check all the valves for "cupping" of the sealing area. If the
valve looks like it's worn, even a small amount, you should replace it. For
example, most older Yamaha (FZR600-FZR 400-FZR750) valves I've seen need
to be replaced.

The good news is, once the valve seal is perfect, they will last a lot
longer. The heat from the leaking valves is what makes them leak worse and
worse, until they eventually wear out. Surprisingly, all the engines I've
ever worked on leaked ... brand new and straight off the assembly line !!

Keep everything in the engine super clean, I can't stress that enough !!! Be
extra careful with the lapping compound, as it can do serious damage if it
gets in the guides, or anywhere else in the engine.




(Courtesy of Pat McGivern (Motoman))
 
#53 ·
it comes down to his statement of " stock angles flow the best" this i would question ? as no-one would disagree with the 70 lines saying a good finish is important.
 
#54 · (Edited)
r1scooter, you yet again make a great case and fantastic explanation of your thoughts on valve jobs.

But damn, you just make me want to do more things now! LOL I must admit, I was expecting and am hoping the high velocity port work to be of benefit when the revs are a bit higher due to the increased pressure built behind a closed inlet valve. This is pretty much what you have described if I have read it correctly. We'll soon see when I have finished and the bike dyno'ed. I can understand the gains from speeding up gas velocity at lower rpms but am interested to see if the gains from the increased pressure at higher rpms will out-weigh the losses from not having the physical size of the original ports.

I'm sure no-one is thinking you are bashing them by explaining yourself. I'm sure I speak for other when I say I always look forward to yours and anyone's explanations of their thoughts.
 
#55 ·
fiveoh, a very interesting read about valve lapping. I was always taught to use acetone (as I think you mentioned before) to check for leaks, I've never done it with light like that.

I must admit though, that after reading r1scooter's thoughts on valve seating, especially when taking high-velocity porting into account, I have to disagree with Motoman's view of stock seats are best. You have to take advantage of any amount of valve lift, no matter how small. The better you can make the seat flow, the bigger the advantage.

I'm looking forward to getting my stock seats as good as yours looks unless my guy comes back with a ridiculously cheap price for me!

Top info, many thanks :thumbup
 
#56 ·
:thumbup

It's cool man, I like a good debate. You definitely made good points and I agree with your theories. Cutting the seats would be more effective than cams. I just don't agree that lapping the valves (properly) is of little benefit, or inapplicable on our bikes.
I think we're actually debating two different items. You-sealing, me-airflow. Airflow means nothing with a high leakdown %. I'll never argue about that.

I guess what I'm saying is that lapping a valve may seal fine, but a real seat job seals at least as well, AND gets you more flow without any compromises. :thumbup
 
#57 ·
-- you just make me want to do more things now! LOL

It's always cheaper to do it right the first time than to do it over the way you wish you had in the first place. Ask me how I know!:lol
 
#58 ·
I think Motoman's statement would be accurate if it was amended to say "The stock angles flow the best !!! (in consideration of Yamaha's mass produced engine.)"

just poking fun...

My belief is that a multi angle valve job is best, at least five cuts, to be followed with proper valve lapping by hand. I have never assembled an engine with a fresh valve job without first lapping the valves. And yes, a brand new motor as well as an older motor in good mechanical condition will benefit from hand lapping.

I'm getting the crazy urge to go pull the head on my bike now! Lol. :sneaky
 
#59 ·
Hey guys, I just called back about the qoute for a valve seat job.

I was told it could be done for £180 (about $340) and would take between two and three weeks to turn around. He did say that was 'cheaper' for me because I knew his mate but I didn't want to be rude and ask how much cheaper! I've not got a problem with waiting (would rather not to mind!) but unfortunately that puts it way out of my budget.

The guy that I spoke to was very helpful. He told me that they use a Serdy(?) machine if that means anything to anyone. He was also honest enough to tell me that my model R1's seats are quite good as standard. He said I would benefit from a 5-angle job at all rpm's but didn't want to be pinned down to any estimates over hp gains considering the rest of the work I was doing. Another useful nugget of info he gave me was that high-velocity porting works very well for road bikes in his experience although they don't do it as a service as it's too time consuming compared to a regular port job which they have the experience to do quite quickly. Also, most of his customers are 'fickle' (his word) and are mainly interested in peak power gains.

Damn, postman was supposed to deliver more rotary tool bits for me this morning but typically, didn't... I'm sure I can find other things to do today :)
 
#60 ·
My very limited experiences with the high velocity porting is that it will result in much better and broader midrange and throttle response, at the expense of a few HP up top.

R1Scooter: I am interested in what you said about high velocity porting. You made it sound as if it were done to build up a pressure behind the intake valve so that when it opens it would immediately start to cram in air. My understanding that the real benefit to high velocity porting is that you will (through high velocity) pull in more air between BDC and the time the intake valve closes. It's my understanding that this is the "free" supercharging effect that high velocity porting gives you.

On a completely gear headed note...I have a spare R1 head. I would love to see the difference in power with stock seats and seats that have been prepped. I would be interested enough to put this head on my bike, dyno it, send it to R1Scooter so he can cut the seats to his liking , pay him for his time, then reinstall it and dyno it again.

this would be a several month project to be sure, but I would love to see the difference in real world power between prepped and unprepared.

The head I have is ported, but not epoxied.I just cleaned it up the best I could like I did my G1K head.

Right now I hand lap all the valves i install. It's the only way i have to insure a good valve seal without spending allot of money on something that sounds great but I am not sure of the actual performance gain.

You know when I talked to Lee at Lee's performance he mentioned that he noticed someone sunk the valves into the head (I think he said ten thousandths) I was too embarrassed and excited to tell him I lapped them and other wise they were dead stock.
 
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