Topic: Valve Grinding

[Big Jay]

Most of the money being spent on these engines to get max power are from the three quarter midget race car crowd.

Jay

[MRieck]

I believe and really I'm not surprised at how much one can spend on a sohc motor...carbs,head,rods,crank and so on...but why?..

I enjoy giving guys on 600's fits.

[scunny]

So- when I put in my new valves I get new seats cut, then do I lap them in

[cd811]

what I did...I try to lap first...if it won't seal, ya gotta cut or replace with new seats

[Sam Green Racing]

I believe and really I'm not surprised at how much one can spend on a sohc motor...carbs,head,rods,crank and so on...but why?...in my opinion, if you want to max out on speed why not get something modern...they come stock and fast...if ya want more, put money in one of those...for ex.,I can buy some smoothbores for my sohc for around$400 then boots for $200 to adapt...that kind of money and thinking is just out of my league...I just like the thinking they had in the early 70's with a few modern(and cheap) ideas here and there

Carl, you have spent a lot of money and a lot of time creating  your masterpiece of a masterpiece. you now have what you wanted to create and it's very nice to, but it's not everyones cup of tea.
Some people prefer to spend their money on their motors to make them faster, not wanting a new bike.
Do your own thing.
 If we all had the same idea on how a bike should look and perform, it would be a dull world.

Safe riding Bro.

Sam.

[MRieck]

I believe and really I'm not surprised at how much one can spend on a sohc motor...carbs,head,rods,crank and so on...but why?...in my opinion, if you want to max out on speed why not get something modern...they come stock and fast...if ya want more, put money in one of those...for ex.,I can buy some smoothbores for my sohc for around$400 then boots for $200 to adapt...that kind of money and thinking is just out of my league...I just like the thinking they had in the early 70's with a few modern(and cheap) ideas here and there

Carl, you have spent a lot of money and a lot of time creating  your masterpiece of a masterpiece. you now have what you wanted to create and it's very nice to, but it's not everyones cup of tea.
Some people prefer to spend their money on their motors to make them faster, not wanting a new bike.
Do your own thing.
 If we all had the same idea on how a bike should look and perform, it would be a dull world.

Safe riding Bro.

Sam.

That's right Sam....we would all be driving 4 door black cars. BORING!!

[Big Jay]

So- when I put in my new valves I get new seats cut, then do I lap them in

Have you changed the guides? The guides in older rocker arm motors are usually worn out. If you just replace the valves (why are you doing this?) you can lap them in and see if there is pitting in the seats which will prevent seal. If there is, and the guides are worn, you would need to replace the guides because the modern seat machines can not locate correctly on a worn out guide hole to cut the seats concentric.

Good luck

Jay

[scunny]

I am replacing the valves since I have the motor apart and it looks as if one exhaust valve isn't seated properly due to being bent or abused by the PO. I've never tried to start the bike, I decided to refurbish what I can. I will have to look into the guides tho.
cheers for your concern

[crazypj]

In this day and age, valve seats are machined using very sophisticated machines that cut all or the angles and radiuses at the same time, and do it concentric to the valve guide. The machine head floats on air to line up perfectly with the valve guide centerline.  No one grinds seats anymore or uses the hand cutters.

Check it out;
http://aperaceparts.com/headwork.html

Jay

Serdi make a hand  setup, cuts all 3 angles at one time. Only problem is the cost (about $1600 US) Neway also do hand cutters, I prefer them as you can set seat widths and positions but they take a lot longer to use and get right. A Honda set is about $1500 US but they are available individually.
PJ

[cd811]

that right sam...I agree 100%
like I said ...it's just my opnion...I'm expressing MY opnion...not preaching
btw...I aint your brother...I got one brother and he's an #$%* like me
like they say over ther...cheers

[Sam Green Racing]

Carl, don't worry about being a #$%*, I won't hold it against ya. 

Where abouts is Hollandale, is it close to where the three state borders meet ?

Do you have a drag strip close to you ?

Sam

[kaceyf2]

No one grinds seats anymore or uses the hand cutters.

Great, NOW MY NAME IS "NO -ONE" is it?
Oh the sweeping generalisation of it all!!!!   These "old girls" are up to 37 years old, and I can assure you that "doing it by hand the old fashioned tried and tested way"
"watching carefully with eyes and FEELING with ones hand CERTAINLY IS DONE THIS WAY TODAY!"  And rightly so, There are three different stones that are used with the valve seat grinding tool (and are blue, (37.5 degrees) pink, (63.5 degrees) and white (45 degree finishing stone) furtheremore, the tool has a pilot bar that (together with a little oil)slips down the valve guide to locate the stone being used EXACTLY where it is required..
You must also posses a stone dressing tool to dress the cutting stones each time they are used!  This is the traditional way to do it, it is tried and tested, and used by succesive race champions of the 30s,40s,50s,60,s 70s,80s,90,s and so on....
Of course, you have to know what you are doing, of course you need skill, patience and a dedicated knowlege of motors and the basic engineering principles behind them, but hey, that can be learned with either a lifetimes devotion to the subject  OR you can "take it to the man at the shop with the new fangled machine thingy that OH so costs so much it must be good" (AND pay $400+dollars through the arse for the privilege)  but what you cannot do, is say that this "IS THE ONLY WAY ITS DONE TODAY" because it aint, and yes it is a slow and painstaking job to do it by hand, but, its satisfying,rewarding, and the results are outstanding, both in performance and in fuel consumption (being good of course) and you can sit back when the jobs done, knowing that not only has it been done well, with care and individual attention to minute detail, but that "NO ONE ELSE HAS DICKED WITH YOUR MACHINE!" rant over....

[MRieck]

Like Jay said....it doesn't cost 400.00(by a wayyyyyy long shot). It's (a Serdi) more accurate and consistant. Most people used to use Neways to cut the bottom and top angles and ground the 45 with a stone if that helps you. No one uses Neways etc anymore(unless you are touching up a 45 on a lawnmower engine).

[Big Jay]

No one grinds seats anymore or uses the hand cutters.

Great, NOW MY NAME IS "NO -ONE" is it?
Oh the sweeping generalisation of it all!!!!   These "old girls" are up to 37 years old, and I can assure you that "doing it by hand the old fashioned tried and tested way"
"watching carefully with eyes and FEELING with ones hand CERTAINLY IS DONE THIS WAY TODAY!"  And rightly so, There are three different stones that are used with the valve seat grinding tool (and are blue, (37.5 degrees) pink, (63.5 degrees) and white (45 degree finishing stone) furtheremore, the tool has a pilot bar that (together with a little oil)slips down the valve guide to locate the stone being used EXACTLY where it is required..
You must also posses a stone dressing tool to dress the cutting stones each time they are used!  This is the traditional way to do it, it is tried and tested, and used by succesive race champions of the 30s,40s,50s,60,s 70s,80s,90,s and so on....
Of course, you have to know what you are doing, of course you need skill, patience and a dedicated knowlege of motors and the basic engineering principles behind them, but hey, that can be learned with either a lifetimes devotion to the subject  OR you can "take it to the man at the shop with the new fangled machine thingy that OH so costs so much it must be good" (AND pay $400+dollars through the arse for the privilege)  but what you cannot do, is say that this "IS THE ONLY WAY ITS DONE TODAY" because it aint, and yes it is a slow and painstaking job to do it by hand, but, its satisfying,rewarding, and the results are outstanding, both in performance and in fuel consumption (being good of course) and you can sit back when the jobs done, knowing that not only has it been done well, with care and individual attention to minute detail, but that "NO ONE ELSE HAS DICKED WITH YOUR MACHINE!" rant over....

Yes, we all used to do seats that way. We also used to hone cylinders with a device that fits in a drill motor, before power stroke honing machines were available, etc. I didn't mean that "no one" in the world still did this stuff the old school way. Sure some still do. Some still even hone cylinders with a drill motor, etc.

But if you ever saw a valve seat done on one of these "new fangled thingies" you would just throw your hands up and shake your head. Try doing a full radius valve seat with your stones.

Old technology is never better.

By the way, the latest technology is machines that CNC valve seats with a turning tool instead of forming. You can simply program any seat contour you want and it will machine it.  At $100,000 a pop I don't thing you will see any of the motorcycle people using this for a while.

Jay

[scunny]

bugger, and I was planning on using my old drill operated honing device. maybe those new thingys haven't made it to this fair land yet.
keep up the good advice gentlemen, it's a long time since I've stripped a motor and they were a bit newer then.
cheers

[cd811]

hollandale is fairly close to the ms. river in central ms....yes we have a drag strip...I've never run there except at night(in my youth) until the cops run us off...dam I didn't mean to stur up a head rework hornet's nest...sounds kinda like "what oil do ya use" discussion...lol.. to be honest I'm not really up on these new seats your discussing...I use to do some 3 degree gringing back in the ages on a lot of atc 90,110 185 amd 200...this modern stuff is out of my league...now porting I can do well on bigger stuff