Cylinder Head Port Matching At Home. How hard is it?

Status
Not open for further replies.

MrSony

Geezer
Nov 15, 2014
7,042
7,276
113
Des Moines, Iowa
It's something I've always thought about doing to my Buick, but I never had the chance. Well, now that chance has come up. My Th350 exploaded in September so come Spring time the Regal will be back on jacks in the driveway getting a good once over. Along with rebuilding the TH350, I thought I'd dig back into the motor and see what's up, do a general inspection, that sort of thing. It being my very first, and so far only multi-cylinder engine rebuild I'm curious to see how it is on the inside 5,500+ miles later. I will be getting a TA performance aluminum intake that was made on a CnC machine, so the ports are as neat as can be. I want to take my stock cast iron heads to that level as well, and clean up any little bumps or casting flash I can see in the ports. It's free hp. The Buick heads have a lot more nickle than lets say a Chevy head, so they are in a sense hardened. What kinds of tools/bits and other things would I need to do this? Have any of you done this, or should I just sack up and pay a shop to do it for me? How much should it cost?
 
It's not too bad. You mainly need to be careful to stay away from the valve seats or you will certainly be taking them to a machinist. Best advice I can give is to just try to remove any casting ridges/flash and leave the main shape of the port and bowl the same. If you do reshape, really think about how the air will flow and not just about increasing the size. Remember you can always grind off more but can't put any back.

You will need a die grinder(preferably straight rather than a right-angle), a compressor you're willing to punish, a set of abrasive rolls and maybe a few round carbide bits which can be bought at harbor freight or online, eye protection, hearing protection, and a good light to inspect. You will also need a valve spring compressor to disassemble the heads.

There at some good videos and articles online of you look around.
 
Taking them to someone to have them ported professionally is a $600-800 task in my neck of the woods. The issue is that there are not that many people around that are competent at it.

Gasket matching is overrated. The issue is that by only matching the gasket you create a pinch inside the runner that is worse than a smaller runner for a longer length. The goal is to not create any pinch points inside the head. This is most easily done by keeping track of the cross sectional area and making sure that it stays the same from the intake gasket surface area to the short turn radius. After that's completed clean the casting around the guides.

The ultimate goal is to get an intake that is ported to matched to a set of heads which essentially, becomes an extension the head runner by maintaining the same cross sectional area and shape characteristics. I know little to nothing about Buick heads, but I'd find some info somewhere before I began taking a die grinder to mine.

Good luck - Jim
 
  • Agree
Reactions: Rktpwrd and drogg1
I use a dremel tool and a 1/4" ball nosed double cut carbide burr. These cut cast iron like butter.
Double cut makes chips that don't stick into your skin like single cut burrs.

You can pocket port a couple sets of heads before the iron shavings shavings short out the dremel tool. Then you send it back to dremel and get a new one for $30.

for match porting the intake ports, I use posterboard. Line up with bolts in bolt holes. Press the posterboard to intake to make and inpression. Cut out ports with an exacto. Like up the cut outs on the heads with bolt holes and scribe the opening for blending.

If you are going to pocket port factory heads, get a 3 angle valve job on them with a deep throat cut and have the factory valves back cut as required. Then you can just blend in the machining iinto the port and remove any casting flash.

stay away from the valve seats and it would be very hard to screw anything up doing this.
 
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor