vale job (30° cut)

p10driver · Jun 30th, 2003, 03:14 AM

I'am going to cut my valves. But before I can do it I need to know how big should the 45° seating cut remain? Should I do it on both intake and outlet valves?

Lucino200sx · Jun 30th, 2003, 02:28 PM

Please don't attemp to do this yourself.

Unless you have some kind of force induction sys on your car I doubt it will make any differences.
Plus it's expensive.

psuLemon · Jun 30th, 2003, 05:48 PM

unless you have done it before i wouldn't mess with the valve.. and it shouldn't really make too much of a difference unless you have a turbo like lucino said

p10driver · Jul 1st, 2003, 11:59 AM

I know some people with high precision CNC machine. They did it for a friend of mine (VW GOLF). It would cost me about $20 but if they destoy my valves I would have a big problem....

Hm? no difference?? Mike Kojima said:
The quality of a valve job is very important because it can contribute up to 50% of the flow gains that headwork will get you.
????
The head is already ported.

psuLemon · Jul 1st, 2003, 02:29 PM

thats the biggest problem though.. if the person that is doin the valve job doesn't have too much experience then your in big trouble if they mess up.. then you would have to get all new valves which prolly isn't cheap...... what mods do u have done anyways

javierb14 · Jul 1st, 2003, 02:53 PM

yes, a good valve job can benefit a NA engine.

p10driver · Jul 1st, 2003, 03:37 PM

The problem is that i don't know what elese to mod?? head/intake are ported, CAI, 2" free flow exhaust sys ( waiting for some bends to weld my Y-pipe and install my new 4-2-1 header ), Aluminium underdrive pulley. Hm... maybe I should remove my small carb and put on a costuom MPI to gain some real power???

psuLemon · Jul 1st, 2003, 03:38 PM

so if you do the port and polish and do the valve cut.. about how much hp can be produced by doin this.. does anyone know how much for a port and polish

**wes** · Jul 1st, 2003, 09:20 PM

Mild porting on my cylinder head made 6 WHP. The back cut on the valves should be matched to the valve job. The shop did a 3 angle valve job on my cylinder head however we did not back cut the valves because of how small they were. I'm sure it can be done I just chose not to do it. They did mildly unshroud the valves though.

I'm assuming Precision has the appropriate machinery to do this properly?