Port matching?

[tsteiner61]

When a cylinder head is port matched, what does that mean exactly? and what benefits does it give? Just curious..

[Karl43]

Port matching is ususally where you trace the gasket outline on the heads and intake and port it out to match the gasket. This eliminates any mis-match in the port alignment and gives better flow. Any mis-match in the port wall alignment gives a loss in flow energy.

P.S. How is your oily kitchen floor?

[tsteiner61]

Kitchen floor is still a mess. My rug is even worse even since I brought that transmission inside.

[Karl43]

I have to install upper & lower ball joints, inner and outer tie rods on my 68 yellow cuda. I was anti-seizing my tie rod ends at the kitchen table last night and installing them into the new sleeves while helping my oldest son with homework. Tought about your kitchen experience while I was doing it. Luckily did not make a mess.

My friends mom used to use Lestoil to remove the oil from his jeans in high school. Maybe that would work for you.

[dynorad]

There are two reasons why you should not match the openings in the head and intake to to the gasket opening.
The first is that you will never have perfect alignment between the two when the manifold is installed. The mismatch will create a "speed bump" for the air flowing in where the face of the head is exposed, and it will decrease flow.
The second is that mismatch in the opposite direction is beneficial in that it discourages reverse flow.
So what you really want to do is open the head up to the gasket opening, and make the opening in the intake smaller than the gasket opening. I did mine with about .060" per side less than the gasket opening. There may be a different figure that is better.

[tsteiner61]

The reason I ask is because I am considering the Edelbrock heads, for my engine buildup, and the literature says they are CNC port matched. It was just confusing because they didn't say what it was matched to, and I really don't know a whole bunch about cylinder heads.

I'm going to assume they mean port matched to their manifolds.

[onebad440]

The head have the ports port matched to each other (i.e. dimensionally) for equal flow on all 8 runners. The info about the reverse flow sounds like good advice.

Oil on the Kitchen floor.....reminds me of the whole kitchen smelling like carburetor cleaner after rebuilding a carb while watch TV from the dining room table.

[71 scamp]

I've been debating on this all summer, my edelbrock heads are ported and gasket matched to a felpro gasket. My rpm air gap intake is straight out of the box so the ports on my intake are an inch wide and the ports on my heads are an inch and an eighth wide. Alot of people tell me not to match it but some of you with super quick small blocks have said to do it.

[Crank]

I have allways match the ports as close as posible but you just go deeper into the ports to to eliminate the bottle neck or speed bump as you say ,and get them smooth as posible.some people say not to smooth out the port's or runners because it mixes the fuel better .I think that's not true or Bull sht if the ports are set up to create more swirl around the valves and the quench is good all it can do is rev faster and higher .Now between the bowl on the fat side and the port opening is a slite angle on the wall between the hump and the wall needs to be opened up so it's almost a straight shot to the back of the bowl.this will create more air flow to the fat side of the bowl and create more turbulence or swirl to go around the valve and fill the cylinders quicker.now if you don't the air will try to go around the short side of the bowl and kill the swirl and hurt your flow .the air flow will run write into the bottom of the valve instead of twisting around it at a much faster pace . This is anouther reason why you can get more power using smaller valves instead of over size valves and diferent valve angles and types of valves.

[tsteiner61]

Well, I finally got an email back from Edelbrock. They said it was port matched to the gasket (FelPro #1213) and not the manifold. It would seem to me that if you can get a total match you should do it. I think what the others were trying to say is that this is very difficult, and if you're off by just a bit, it's speed bump city, hence port intake man. undersize by just a slice to decrease chance of error.

But what do I know? I was the one asking the question in the first place.

[Jims451]

The part about having the head slightly larger than the intake is pretty good. Most people do not mill the intake manifold so it fits exactly centered with the head ports (the intakes larger bolt holes create some port mis-match.)
Some racers will bolt the heads to an empty block and the mainfold to the heads using the same gasket thickness as the assembled engine, and then blow chalk through the intake and cylinders to mark the port mis-match.

[Hybridized]

With a B/RB block, bolt on the valley pan and see how the intake ports line up with the gasket. Before tightening the valley ban bolts, center the valley pan over ALL the ports to minimize port work. Scribe out the gasket port onto the cylinder head. Then gently massage the excess material away with a die grinder.

For the intake, first address the "bolt slop". Example - Bolt on an intake but don't snug the bolts down. Now move the intake back and forth. It will move up to 3/16". Try a 1/4" long piece of copper or steel tubing between the intake bolt and the intake bolt hole.

Once intake slope is eliminated, cover the intake manifold port face with Prussian Blue (art/paint store) and bolt up the intake. Take car in trying not to move the intake around. Now unbolt and carefully lift the intake.

You now have an imprint on how the intake lines up to the valley pan/cylinder heads. Mark and grind off excess.

If all the intake manifold ports appear to be too high (relative to the valley pan), especially after milled heads, you may want to get the intake milled to fit.

It is a pain to do this, but if you don't, the port match is a waist of time cause the ports will probably not line up.

Headers/exhaust manifolds are much easier to do.

[71 scamp]

Jims451 and Hybridized, I like your ideas, since my engine is assembled I think I'm gonna do the blue ink thing, may as well do it right, winter time ya know.

[Crank]

i 've used siilicone caulk between the head and manifold line them up and scribe a mark in at least 4-spots to line it up .cut small strips of cardboard mike your gaskets then the cardboard strips to match or shims .put the silicone around all the ports and the shims in between line up the manifold with the lines you scribed put a few bolts in and snug it up.NOT tight waight a few hours and pull it appart the silicone will leave a perfect inprint and form a templet the cardboard and silicone will stick together to make a perfect templet for a perfect match.you can buy the silicone in a small tub and you add a hardener to it like bondo it dry's fast and won't stick to the mettle.

[mr.b]

the eds heads intake openings "should" be fine as is. if your looking for big gains measure the opening inside the runner around the pushrod opening. when measuring you will find significant size variations. blueprint these openings by making them all the same size. then take out your desired amount. i took out approx. 100 thous. this was about a 10% increase in cfm. this is serious horsepower gains. air flow is bottlenecked in this area usually.