Topic: Cut your own valve seats?

[Grey]

Anybody cut their own valve seats? I found these manual seat cutters that you turn by hand. Cutter is $65
Not sure on the stem guide price. Seeing the prices on the site that people are getting charged for machine work it looks like an option.
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Never heard of a hand tap for cutting seats. Can't even imagine using a hand cutter for seats. Is it made by the same company that makes Slick50? Sounds like it could be. JMO

SEE THIS FIRST.
Honda CB750 cafe SOHC4 Neway Valve Seat cutting.AVI

In the motorcycle world IT IS NORMAL to cut the seats with hand tools.
On the Honda CB750 though the seat has 3 different angles.
The original Honda factory seat cutter had all 3 angles and cut them all by turning the tool 1.5 turns.

Some of the seat cutters offered for sale has three different cutting tools to cut the 3 different angles.

Also on the Honda valves you do NOT grind them at all.
The exhaust valves are sodium filled like aircraft exhaust valves.

No SORRY you do not need a computerized $50,000 tool.

I'm speechless...............well almost.

Im sure that there is a difference....if there wasnt then people wouldnt charge what they charge.

Is there a layman way of explaining the difference though?

Yes the correct way, then the Neway way.

Hey what ever floats your boat. There is much more to valve seat prep than cut cutting 2,3 or five angles. If power and proper sealing is not a consideration then I guess this video valve job is fine for some.

Real good info on the whys,hows and expectations of a good valve job for power. May be over board for most, unless you want the best for power. Does explain the correct way though.

http://www.enginebuildermag.com/Article/16025/the_inside_angle_on_valve_seats_what_you_need_to_know_to_go_with_the_flow.aspx

Using a cutter to do seats. 1st shows cutting seat, 2nd shows how to check listen to what he says.

Ducati 848 valve seat cutting
Ducati 848 valve seat cutting

What the Neway cutter is good for IMO
LAWM MOWER REPAIR : how to cut the valve seats on a small engine

So what do you want your motorcycle engine to be?

[Don R]

I did my own seats on my jr dragsters with a neway. They went like stink for what they were, stock stroke .100 overbore, etc. That said, a proper performance job on a machine would give more consistent results.

[Terry in Australia]

I'm with you Don, if you know what you're doing, the Neway is fine. If you don't, send it to a shop so they can get some return on their 50,000 buck investment. Cheers, Terry.

[MRieck]

You can buy mint, used 3.0 Serdi's with tooling for 15,000.00. That will do just about anything. Smaller units are even less. The Serdi also does more than just valve jobs.

[Grey]

I did my own seats on my jr dragsters with a neway. They went like stink for what they were, stock stroke .100 overbore, etc. That said, a proper performance job on a machine would give more consistent results.

Do you know a guy by the name of Joe Amends? He builds and dyno's Jr dragster engines. Or use to. He's close to you in Bowling Green Oh. A friend of his built the chassis and some were sold thru Summit Racing.

[754]

 Knew a guy that had an bike engine shop that used Neways , said he really liked being able to touchup XR 750 seats at the track.. when you are 1000 miles away from your shop..

[lucky]

I worked at a dealership and this is how we did valve jobs back in those days.
Honda Factory sent us a special tool kit for each motorcycle model.

I am sure there are modern machines that cost a lot more and are more precision.
I wonder what Honda would say about that.

[754]

 Say about that ?? what do you think they are using at Honda..

[scottly]

Knew a guy that had an bike engine shop that used Neways , said he really liked being able to touchup XR 750 seats at the track.. when you are 1000 miles away from your shop..

Did the XR use brass valve seats, or was it the earlier model? Whichever one, the valve clearances had to be checked quite often, as the valves would pound into the soft seats and tighten up.

[MRieck]

Prior to the Serdi the guys I know used Neways to cut the top and bottom angles...they always ground the 45. That's quite a while ago too.

[Rigid]

I was surprised to see the video guy allow the tool to go backwards...what the hey

Yeah I was taught to never run a seat cutter backwards

Neway says to only run it forward.  In my experience, it will chatter and cut too agressively when new, even with VERY light pressure.  The backward stroke is an attempt to limit the aggressive cut of a very sharp tool.  Same idea as a file.  Dragging it backward doesn't remove much material, but it will smooth the surface.  The seats sealed perfectly with a very satisfying contact band.  Lap first, cut lightly, if that doesn't do it, search for a new head.  They are cheap.

[bollingball]

I worked at a dealership and this is how we did valve jobs back in those days.
Honda Factory sent us a special tool kit for each motorcycle model.

I am sure there are modern machines that cost a lot more and are more precision.
I wonder what Honda would say about that.

What dealership did you work at and what years when you used the sodium filled valves. Did you work in sales or put them in the engine? Do you have a part number? I don't want to get the wrong part so please let me know
                                                 Thanks in advance

                                                        Ken

[754]

 You actually run a file backwards ?? Really... fastest way to loose a tool edge known to mam is running backwards.. I personally ca not watch that being done..

 I am not a valve and head person but, in my own opinion, using hand turned seat cutting tools rely  largely by using correct "feel", most fine work does.. Tvery nature of a workhardened workpiece dictates that it will take a firm cut to get through it...
 
 I am not seeing why lapping should be involved before using Neways..

[jaguar]

I worked at a dealership and this is how we did valve jobs back in those days.
Honda Factory sent us a special tool kit for each motorcycle model.

I am sure there are modern machines that cost a lot more and are more precision.
I wonder what Honda would say about that.

What dealership did you work at and what years when you used the sodium filled valves. Did you work in sales or put them in the engine? Do you have a part number? I don't want to get the wrong part so please let me know
                                                 Thanks in advance

                                                        Ken

you really believe/listen to half of what lucky says?