Valve job

[xmetallicaxguitaristx]

Ok so, lets just say I have free access to a valve grinder/valve seat grinder :D

What type of valve job gives you the best performance without just being overkill and not getting much more out of it? IE like 3 angle, 5 angle, really those are the only two I've heard of, but obviously it would get to a point where the time it takes to do doesn't match with the performance increase (extreme example but it's like doing a 10 angle valve job or something.. lol know what I mean?).

[IwannaCamarosoBad]

Re: Valve job

Ok so, lets just say I have free access to a valve grinder/valve seat grinder :D

What type of valve job gives you the best performance without just being overkill and not getting much more out of it? IE like 3 angle, 5 angle, really those are the only two I've heard of, but obviously it would get to a point where the time it takes to do doesn't match with the performance increase (extreme example but it's like doing a 10 angle valve job or something.. lol know what I mean?).

Not a clue as to what you just said

[bigbrian442]

Re: Valve job

A 3 angle will do wonders on stock heads. Make sure you also back cut the valves. More then that on stock heads would be overkill.

[xmetallicaxguitaristx]

Re: Valve job

That's the thing they aren't stock.

[bigbrian442]

Re: Valve job

Then you may want to use a flow bench and find out how many angles the heads like. Start with a 3 and see if you get any substantial gains going to 5. I doubt a 5 angle will hurt flow and if it doesn't cost any more might as well do it anyway.

[IwannaCamarosoBad]

Re: Valve job

Then you may want to use a flow bench and find out how many angles the heads like. Start with a 3 and see if you get any substantial gains going to 5. I doubt a 5 angle will hurt flow and if it doesn't cost any more might as well do it anyway.

Can someone explain this to me? It sounds interesting

[xmetallicaxguitaristx]

Re: Valve job

lol I don't have a flowbench or access to one and I definitely don't have money pouring out of my *** because I'm only 18. I am still trying to get all of the valvetrain stuff. Otherwise I would have been done with this long ago.

[bigbrian442]

Re: Valve job

Can someone explain this to me? It sounds interesting

Air flows around a radius much smoother and more easy than it does a sharp corner. Think of a stock valve seat that looks like a slash \ / . It has a sharp corner on the cylinder side as well as the port side. The extra angles in a 3 or 5 angle valve job reduce the sharpness of the corners and make it more like a radius. The more angles the more like a radius it gets. Also the stock valve seat is very wide. You can use your angles to make it narrower, in turn that also helps flow. The more narrow your valve seat, the sooner it's going to wear out and need to be freshened up.

A flow bench measures the amount of air that flows through the port. You can then measure the fruits of your labor to see if your work has given you any gains. More air = more power. There are also equations to figure your potential horse power by how much air the cylinder head flows.

[bigbrian442]

Re: Valve job

Then do as many angles as you feel comfortable doing. The biggest gains will be from going from stock to the 3 angle, So that should be the minimum.

[RadRacer]

Re: Valve job

I'd do a 5. It's not going to hurt the flow any, and it'll probably be abit better then 3, since they're not stock heads. But, anything will help.

[ssms5411]

Re: Valve job

Mine right now their doing 3 angle for the SI valves and bead blasting the heads with a .010 milling.

[Meatyshells]

Re: Valve job

i had mine milled .03 with a 3 angle valve job