What's new
Old Chevelles

Welcome to OldChevelles.com, built by Auto Enthusiasts for Auto Enthusiasts. Cars are not our only interests so please feel free to post about any subject the community might enjoy or you just feel you need to air.

We respect free speech and constructive dialogue however we don't allow threatening talk against members, nudity, or pornography. Threads are monitored and trolls are not tolerated.

This site is completely free and there are no costs. Please enjoy and provide feedback.
  • We've enabled the website app for anyone who wants to use it on a mobile or desktop device.

  • We've changed the header logo to display our Member's Cars.

    If you'd like your car to show up there, go to the forum Site Bugs & Feature Requests and post your image in the "Member's Car Pictures for the Header Logo" and we'll add your car into the lineup.

Thinking about porting my heads

The 1969 396/427 "063" ( I think 215 and another head are same) heads are 100.9 cc Semi open/closed chambers that IIRC Edelbrock copied their 100 cc BBC head to help raise comp. on low comp. 454's, I had a set I used sanding cones to smooth everything but I left chambers alone as PO done something but I did have 1.88/2.19 SS valves & new guides and a good VJ done and the engine really was fun after that, I did buy an Isky piston notch tool to cut the radius on the dish piston valve relief wider for the 2.19 int valve & deeper for the .533 lift cam but ended up $1,100 in iron heads :( Not including the Isky tool
The key to remember is the Eddy heads have a way better port and chamber over the old 063/215's to start with.
 
I can't remember if the chambers on my 063's were touched by the PO but the ports were and I went over those to make them even smoother, I should have went over the chambers too but can't remember why I didn't? I did the cam upgrade first and it was ok with the 148? PP heads but after the 063 it was better but I also went from an Eddy 2.0 to an Eddy AG with center divider cut down 3/8" to 1/2"
 
Looks great man!
Thanks, those heads are on the engine in my avatar. It's a 468 with a comp roller cam, hyper pistons, complete engine. I built it for a guy and then he bailed on the project so he lost all his money in it. I may take it to the dyno later this year to see what it makes on the pump as I have nothing to put it in right now.
 
So when doing this, what do you look for? How do you know what to do or how much to take off?
How important is it to make all the runners the same size?
What happens if you take off too much of one quench area, does it cause an imbalance or combustion difference?
 
I have been watching David Vizard videos and Mark Jones as well for that information. They both go very in depth. Highly recommended!!
 
So when doing this, what do you look for? How do you know what to do or how much to take off?
How important is it to make all the runners the same size?
What happens if you take off too much of one quench area, does it cause an imbalance or combustion difference?

So here's what I do, I get one port done the way I like it and if all looks good I do the other 7 ports. Must work ok, the stuff I did to those 062 Vortec heads got the car to run 10.90's and I 'm not one to worry too much about every little cc on the heads. I know some guys work them over and blueprint their heads and they mat get like an extra 10hp but since I am just testing stuff most of the time my junk works well for me. After all it's not like I'm building an LS engine, lol.
 
I've done one set of BB rectangle & a set of 305 head, couple of bowl ports.
I always tried to do each port one part at a time, then reposition & do another.
No A/B testing though.
 
How do you know when to stop?
Some will say when the port is big enough but got be it's when the port and bowl is the right shape. The one key component that a lot of guys forget is the all important valve job. If you spend any money first spend it on that.
 
How do you know when to stop?
I've never ported one strictly for racing. My emphasis:
1) I streamline the valve guides. 2) Blend the radius under the valve seat where it transitions into the port. 3) Doesn't hurt to polish the combustion chamber a little, just don't enlarge it unless on purpose.
Vortecpro also points out where to slightly enlarge inside the port , in and around the valve guide.
If you do those 4 things it should really do well.
 
I've never ported one strictly for racing. My emphasis:
1) I streamline the valve guides. 2) Blend the radius under the valve seat where it transitions into the port. 3) Doesn't hurt to polish the combustion chamber a little, just don't enlarge it unless on purpose.
Vortecpro also points out where to slightly enlarge inside the port , in and around the valve guide.
If you do those 4 things it should really do well.
So basically take the valve guide area and make it oval with a point.
 
I start at the vertical centerline and blend it back toward the valve on both sides of the guide
I guess if I look at a couple of pictures and make them match I could get close to how they are supposed to be.

I suppose you gasket match the head to the intake? Do you then make the runner the same width as the gasket/intake?
 
I guess if I look at a couple of pictures and make them match I could get close to how they are supposed to be.

I suppose you gasket match the head to the intake? Do you then make the runner the same width as the gasket/intake?
I've read that gasket matching is a waste of time. People run square port intakes on oval port heads ? But I'm not trying to get the last .01% either.
The vertical part in the center is the shape I'm talking about for a valve guide
Vortecpro doesn't enlarge the entire port; he enlarges places inside the port on one side of the valve guide.


1651066739671.png

Here is vortecpro :
 
I've never ported one strictly for racing. My emphasis:
1) I streamline the valve guides. 2) Blend the radius under the valve seat where it transitions into the port. 3) Doesn't hurt to polish the combustion chamber a little, just don't enlarge it unless on purpose.
Vortecpro also points out where to slightly enlarge inside the port , in and around the valve guide.
If you do those 4 things it should really do well.
While I agree that some polishing can help on the exhaust side, the intake side of the chamber needs to be rough to inhibit fuel wash. For me I now use the Chad Spier method of a burr finish in the chambers. When I took off the peanut port heads to swap over to the L-29's I noticed that the intake ports and chambers were the cleanest heads I have ever run with hardly and carbon build up or fuel wash with the rougher surface. I am convinced the burr finish works, that's why I try to do all my intake manifolds with that finish.
 
Top Bottom