Old head new valves

[hubz91talontsi]

Ok so im going to try to use my hold head on my build...Do you think 1mm over valves will keep me away from a 3 way valve job?
What is the purpose of 1mm over valve's?
Head in the car can't be that bad considering that i daily drive the car.

 

[tkelly27]

You don't want a 3 angle valve job? That helps flow.

The point of bigger valves is to open of the valve seat so you have a bigger hole in the head. I'm not even sure if it will work, but if it does, it would be a foolish decision to upgrade the valves and not have them machined.

 

[mach4g63t]

The head uses 3-angle valve jobs from the factory. It's just the fact that a large majority of the heads most of us are still using are very old, thus the seats are rather worn out. So, a lot of times, a refresher cut on the existing 3-angles is beneficial.

Also, you need to have a machine shop over-size the valve areas for the 1mm valves. It's not a simple drop in job. Also, as beneficial as 1mm oversized valves are, a lot of companies who provide them in their built heads don't really deem them necessary until you're making well over 500 hp.

 

[hubz91talontsi]

Well obviously im looking for the cheapest price. What an average price for a 3 angle or 5 angle?

 

[mach4g63t]

That depends on your local machine shop. I've seen one Machine shop out here do headwork for x-dollars, while another one will with or for twice that. It's different. Call your local machine shops and see what they say. There is no real standard.

If you're really wanting to put something in your head that will add to the reliability and performance, skip the oversized valves for now, and get a set of Brian Crower Springs and retainers and just head the head cleaned up. That will help you safely bump your redline up to 9k... IF you have a turbo that can flow that high into the RPM range.

Otherwise, if you're just sticking with a regular street build, don't worry about it. It all depends on how far you want to take your build in the future.

 

[tkelly27]

Cheap and +1mm valves don't really go together. The price changes from town to town.

I don't really think you need bigger valves. Unless you have plans for a much bigger turbo. There are plenty of people making huge hp numbers on the stock, unported head. Others on ported head with stock valves. There are so many other places to find power.

 

[Defiant]

Ok so im going to try to use my hold head on my build...Do you think 1mm over valves will keep me away from a 3 way valve job?

That's a half-millimeter size change. Do you realize how little that is?

What is the purpose of 1mm over valve's?

You're asking that question? What's your purpose in wanting to have them? For your case, just tell people you put them in.

Head in the car can't be that bad considering that i daily drive the car.

You won't know until it's off. However, lifespan for aluminum castings from the nineties is probably a few hundred years, or until overheated.