cadillac 500 head issues

[70_boosted]

so i have been porting out my heads, well atleast starting with the ext, tho the exhaust has the same ordeal as all the old v8 engines. how can i go about filling these in? 3 out of the 4 have the pin hole and the other has the large port that needs stuffed, whats my best option?

can only work so much in the one port with the large opening, the rest i think i could get away with some hardening steel buddy and blending smooth once dried and hardened, what you guys think?

 

[cking894]

Take a look at this web site. I didn't have time to find the post about the smog plugs that I read a while back. http://www.cadillacpower.com/forum/viewforum.php?f=9

Here is a post on porting and polishing 500 heads. http://www.cadillacpower.com/forum/viewtopic.php?f=3&t=14508

They are a great bunch of guys over there and are really knowledgeable on the big block Cadi engines.

Keith

 

[zzrodder]

Honestly, there is practically no performance benefit in plugging the smog ports unless you are building an all-out drag motor, in which case it's more cost effective to go with the aftermarket aluminum heads by Bulldog.
If you are just trying to block the flow through the ports to the intake manifold, just slip sheetmetal pieces in between the intake gaskets and the manifold. To plug the smog ports at the ends of the heads, just go to Napa and get some 5/8" frost plugs (or are they 3/4") and bang them in.
The biggest benefit to flow that you can do with porting is to smooth the transition from the valve seat to the port wall so there are no lumps protruding out from the port wall right below the valve seat. Don't try to round off the short side radius close to the valve as a sharp turn there benefits flow.

 

[70_boosted]

That is what i did and just cleaning it up now aftershaping down the valve guide protrusion. Blended that in to create a cleaner flow. Polishing but not mirror, and gasket matching the ports. Think they will flow, along with the mts springs, rockers here soon and gonna have valve and seats double checked once all porting done. Ill leave the exhale x overs alone.

 

[70_boosted]

here is a quick shot of the polishing up the ports after the rough cutting...