I have an 02' WRX. I recently torched an exhaust valve on #1 cylinder. My question is this.... are over sized valves worth the effort and expence. I have to replace at least 1 valve but if the heads are off...why not. If they are a good choice does anyone know how far you can cut the stock seats out with out having trouble? I have seen valve up to 1mm bigger in size, will they fit into an overcut seat?

Second question, thinner head gaskets. I see Cosworth has thinner gaskets availible to raise compression. Can anyone tell me what thickness equals what raise in compression? I would like to pull a little more out of the engine while I am in there. Any info would be great.

Mods are as follows, header, 3" TBE, intake and IC hoses, 565cc Cobb spec injectors, AP stage2, stock turbo, 12lbs flywheel, Cusco mounts,

 

Any help??

 

Hello.....

 

im more worried about how you did that to a valve


there are +1 that cosworth does and they seat the valve



what are you going to do with the car

i mean why do the mods if you are going to do all the head work you are going to need a block

raising the compression means less timing and boost

 

I'm not set on raising the compression, I dont think I would gain a whole bunch with just a gaket anyhow. I am more intrested in the valvetrain. I plan on bolting on a 16G soon but I want to do the heads as long as I have them off.

The valve let go becouse I was sucking air from a bad intake gasket, running lean on that cylinder. I am not 100% sure I dont have any piston damage yet, I havent pulled the heads off. I dont have any smokeing issues so I think it is just a valve problem. That and the poping back through the exhaust is a give away.

I mostly want to know if the stock seats can be cut as far as +1mm or if I am pushing my luck.

 

the cosworth website says that they do it



the headgasket does make enough of a difference

 

Do you mean the Cosworth web site says they can put 1mm oversize valves into stock seat?

 

Any info guys??

 

what im saying is cosworth's web site has the info / or easier call them

http://www.cosworthusa.com/store/pc/...7&idproduct=21