Here you can see a good shot of the intake bowl before any blending. notice the harsh transition at the bottom af the cut.

 

Here you can see the initial grinding to smooth the valve job into the bowl. I am not trying to open up the bowl, or teardrop the guide, or do any major port work at all. I have been doing this long enough that I'm not really worried about nicking the seat. It soesn't take too long with a nice sharp carbide.

 

Have you considered using thin wall bronze liners instead of stock iron replacement guides?

I use thin wall liners on everything..it’s much simpler , less work and you end up with a better guide that’s better for the valve stem.

It’s also a quick an easy way to use a smaller stem valve to reduce weight and increase flow, by putting a 5/16 or 8mm liner in the stock 11/32 guide for an 8mm valve.

either K-line or Rapid.

 

Ok-let me educate you, as I've done Olds heads before myself.



On the first hole you run your valve job and leave it high .005, you then go in and cut the bowl where you want it, you then set the stop and cut the other 3 bowls out, you then you recut the first seat set height, then cut the rest of the seats, thats the best way to do it. While we're on this, rebuilder cast valve guides is not the best way to do this, CHE bronze guides honed to exact size is the best way to do the job. And on that Serdi you better have a perfect round, sized, strait guide and a perfectly sized pilot or you have a less than desirable seat.

 

I use those too........

 

yep…I haven’t used an iron guide since the 90’s on anything.

the thin wall bronze liners also transfers heat better than iron , which is crucial for pulling heat out of the ex valve….that’s where the majority of heat transfer takes place

if anyone is using positive type seals with iron guides on the exhaust in a performance app, they’re taking a chance..unless they up the clearance by another . 001+

 

Nobody serious uses cast guides, in my opinion. One piece CHE bronze guides are the gold standard period, but I also use Klines as well, but they are always honed to size.

 

Now this is random but .... What about the Goodson K liner kit where you size the liner with the ( check ball ) that's meant for the corresponding valve stem diamanter.

 

sizing ***** work fine, as long as the internal dimensions of the guide you’re putting the liner into is parallel. sizing ***** only size at the point of ball contact.

an iron guide can have a twist or bend in it , the ball will just follow that contour and in turn, push out the thin wall liner to that shape …as opposed to a hone which will insure the new liner is straight top to bottom.

so you just have to make sure the old iron guide is reamed straight and true to begin with

 

Thats fine but it still must be honed to size to make it round and strait.