Head Porting Techniques

[TC]

I've ported a few sets of heads over the years, mainly just your basic port match, bowl blend and short side stuff, but I was wondering if anyone has tried incorporating shapes or patterns into the walls of the runners......or maybe better put texturing the walls of runner.......I've even thought about ways to give the the walls of the runners a swirl type grooving in an attempt to increase port velocity.......So what do you guys think??....

And at that what other porting techniques do you do or know of??.......

[Stich496]

think head porting is going the way off the doodoo
todays heads come cnc machined and most good ones offer cnc ported..
and for the cost of having a guy with a flowbench port your heads, you can bolt on a s/c or turbo and force the air in..
I ported my brodix track ones.. and old iron nascar heads.. looking for the highest flow doesn't make the most power n/a.
biggest spot is the turn near the valve.. I lowered the floor(hit water and welded in material) and roof(epoxy) there..keeping the port about the same size and picked up power,(60hp)but the flowbench showed almost no change( 5cfm) air don't like turns and fuel hates it even more

[JeffMcKC]

Yes, mucho power can be had, I would not get a over the counter CNC if I wanted big steam. Flow numbers are just sales tools its all about the Velocity profile. CNC and Hand tuning is a good way to go if the correct fit is to be had.


I dont understand only a 5 cfm increase and getting 60 hp.

I call BS but whats neeeeewwww about that.


My valve has a turn all the way around it, what one does not?

[TC]

Jeff you ever see guys doing "weird" texturing to the walls of the runners or maybe spiraling grooves that run the length of the runner and into the bowl??.........

[min301]

Mostly it's about blending...not reshaping.

The area around the guide is an area to pick some flow,
as is the area just above the valve, and usually a good spot
to smooth the transition from seat to head, as it can stick out
and cause a bit of bad turbulence.

It will depend on many things, such as the casting being used,
intended use, n/a or p/a, c.i.,etc....

[Stich496]

Yes, mucho power can be had, I would not get a over the counter CNC if I wanted big steam. Flow numbers are just sales tools its all about the Velocity profile. CNC and Hand tuning is a good way to go if the correct fit is to be had.


I dont understand only a 5 cfm increase and getting 60 hp.

I call BS but whats neeeeewwww about that.


My valve has a turn all the way around it, what one does not?

mine I dropped the roof at the turn to the valve and dropped the floor into the water and welded it up.. straighter shot to the valve the port wasn't made bigger.. thats how.. sorry I didn't have the cash to pay someone to do it for me..
60hp is the difference in track times.. no dyno.. as I don't race dyno's

[Huskinhano]

This guy is interesting. www.theoldone.com

[dieselgeek]

Anyone ever hear the wives tale that you should flow a head both directions, and if it's a good port job it'll flow good only in the incoming direction? I was told by a guy who's engines are quite impressive, if it flows the same both ways it's no good. He also said the sound of the head as it was on the flowbench provides clues as to performance, if it's screeching it's got issues.

He said flowbench numbers were only good for advertising, but that he does pay a lot of attention to low lift flow because the engine spends more time during it's cycles at low and mid lift than at max lift.

I know ZERO about head porting but this is what the guy told me, and he's known for doing amazing things with cylinder heads.

[1931s/x]

a friend of mine built his own flow bench, he used to port heads for a guy and did a wet flow setup on this bench, hes got high hopes. for a lot of engines you really can just go buy an out of the box set of heads for more bang for the buck compared to paying him for his time though.

[Barry Donovan]

Yes, mucho power can be had, I would not get a over the counter CNC if I wanted big steam. Flow numbers are just sales tools its all about the Velocity profile. CNC and Hand tuning is a good way to go if the correct fit is to be had.


I dont understand only a 5 cfm increase and getting 60 hp.

I call BS but whats neeeeewwww about that.


My valve has a turn all the way around it, what one does not?

I did just one mm by a drill bit will a ball shaped grinder on the end .I was mad at the alignment revealed by intake gaskets...can't move anyhting, only hand port. No numbers known, it was the beginning of the end of the oem clutch on the very first run onward...gain never died. the whole range.
another consideration, is getting each port the same. the boxer shares one for two...proved it to me, instant self balance

Anyone ever hear the wives tale that you should flow a head both directions, and if it's a good port job it'll flow good only in the incoming direction? I was told by a guy who's engines are quite impressive, if it flows the same both ways it's no good. He also said the sound of the head as it was on the flowbench provides clues as to performance, if it's screeching it's got issues.

He said flowbench numbers were only good for advertising, but that he does pay a lot of attention to low lift flow because the engine spends more time during it's cycles at low and mid lift than at max lift.

I know ZERO about head porting but this is what the guy told me, and he's known for doing amazing things with cylinder heads.

it will do that on its own anyway, as hard as the irons might be..you still got a pressured wind in direction.
aluminum is very responsive...a day driving in the summer.

I bored out exhaust sides to on my egr based engine...the cold starts all the way to warm...a real gain does not quit. numbers don't even matter for the peak..its like giving a fat spot on a cam with the same lift it had before (it would be tricky to measure)

I believe 5 cfm measured and 60hp overall. the stoich is the other part of the mix..you may have gotten it just right..or at least better.

[Beagle]

TC, Smokey's book was pretty good. When I think about all the variables that have to be contollable before you find out if your new technique does anything new or meaningful, it's kind of intimidating. Humidity, temperature, barometric pressure to start, then getting multiple sets of heads and measuring the crap out of everything a billion times at very small increments... maybe if I were getting a salary to do it, but otherwise I can't swing it. I think I would totally get off on it, but it's not in the cards at this point in my game.

Wait - I got it... Dentist drill! You can make your golfball port with swirlies and vortex generators and let us know!!

More seriously though, a 3D CNC modeler and a pile of time might get you a lot of answers.

[TC]

So what kind of results where they looking for when they textured this intake like this?? What will the little dimples do to the air flow??........

[Beagle]

So what kind of results where they looking for when they textured this intake like this?? What will the little dimples do to the air flow??........

Golf balls are dimpled for a reason, but what was the before and after here? Do you not see it because it wasn't cost effective, or because it was not a significant change?

How can you tell without a pile of money in labor and 10x pile of money worth of test facilities, keeping in mind that every test condition has to be identical or your test is skewed.

[CDMBill]

Yes, if intake manifolds were the same as golf balls then maybe it would work. I've seen pictures of the same thing on combustion chambers. If it worked you'd be buying it from the top manufactureres and head porting services now.

For almost any head there reputable cylinder head experts, they aren't cheap or fast usually, and there are guys who sell templates that the DIY guy can follow to get a reasonably well documented result.

On my most recent set of heads i had a CNC program jointly develped by the manufacturer, TFS, and the head porters led by Lem Evans and Charlie Evans who are renowned for theri success with A460 BBF heads. I am extremely pelased with the results given the modest cam and pump gas compression ratio we used.

You can see the CNC "waves" in the port and the chamber and it all seems to work pretty well. I have no reason or basis in experience to think I can do better myself and I wouldn't want to ruin a demonstrably good set of heads that come at a very reasonable price because somebody says I should carve out the short side radius and put dimples in the port floor.

see below. And yes these are for my Hi Po 289 Ford. The manifold was done by Wilson Manifolds, the heads by TFS/Evans

[Stich496]

and that porting cost? ya though so.. I just looked at the 5 intakes I have here they don't have dimples, they have a set of raised lines at the under carb area. that holds a layer of air so that the fuel being dossed at the intakes floor, never get to hit the alum.
even my bbc dart intake that wasn't a cheap intake, but no where near the cost of a hogan sheet metal..
sounds like your top end alone cost more than most very good strong builds cost..