2G Head, Valve question...

[interex]

I am kind of in a pickle. I bought a Ported head, that is clean as a whistle. It looks great and the ports all look really clean. I turn it over to check out the valve seats and to me it seems that the exhaust valve seats are the exact same size as the intake valve seats. I was told the seats were just 1mm over but this has me puzzled. I have yet to measure anything but is it a bad thing? Will I be able to buy big exhaust valves for this head now? I dunno why anyone wanted them to be so much bigger. I just need to figure this out so I can get my parts ordered and head put together.

 

[delta448]

So you're saying only the exhaust valve seats have been cut oversize by 1mm, correct? But the whole head has been ported?

You can buy oversize valves from several vendors, but take a second and measure everything to make sure of what exactly you're seeing. What are the diameters of the valve seats for both intake and exhaust? A picture would be cool too.

Oversize valves can lead to some great top end performance but can also change the whole personality of an engine. It's not for everyone.

 

[groundPork]

you can either do a quick check with some lapping compound and dykem to see the foot print left on a valve and on the seat to see what it's really cut for. but might just take it to a reputable auto machine shop to have them do a check with over sized valves to go along if you do not have access to that stuff.

 

[interex]

I don't believe the exhaust side is only 1mm over. 1mm is .040 of an inch. Not exactly something you'll really notice with just looking. I honestly think the exhaust side is matching the intake side. Stock is 34mm intake, and 30.5mm exhaust. To me, it looks like they are both 34mm or 35mm. I'll try and get a picture today.

 

[interex]

Okay finally I was able to get some pics and upload them. Let me know what you think of my head and if my valve guide bore looks okay for both intake/exhaust. (also posting an intake/exhaust port pic.)

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[interex]

(note: that is not a hole on the exhaust port, its a shadow of the stud caused by the flash of the camera)

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[90laserRSfwd]

wow... who did that head?

 

[interex]

I bought the head this way for $150 off craigslist. If it's not worth it I can very much take my original stock 2G head in and have it done at an actual performance/head shop.

 

[Freerevving]

Everything looks fine to me... nice port job!

and you stole it at $150