Fellas,

Should I port match the intake with heads? any significant difference in performance?

Iron or Aluminum heads? Stock or aftermarket?

No It's not worth the time in a stock engine

I feel very that every performance enigine that will COMPETE should have the ports matched ! heck the intake is just an extension to the head port! IF you pay attention to all performance TIPS AND TRICKS you just may win the race , if not the other guy who paid attention to detail will win. Do you want to loose ? EVERY LITTLE DROP COUNTS !!! THATS MY .02CENTS.

I did mine, but wouldn't do it again, might as well take a **** before you race for the amount of time it would take off your time. I'm a firm believer that if you want to go faster, lose weight in the car and gain cubic inches.

this is what i am building,

454 .30 over
049 pocket ported, 2.19 1.88 oval heads
9.7 to 1 JE pistons
stock rods
steel crank
performer rpm air gap oval ports
770SA holley
60204 voodoo cam


its mild, so i was just wondering if i should port match the air gap with the heads? or just throw the air gap in from the box?

I have no experience with it, but most of what I've read says you won't see any difference on a timeslip by port-matching.

If you have a Performer 2-O the runners are sized for the truck peanut port heads. Marketing....covers the truck guys and daily use/milder street applications. For some added performance, I have it on a relay from the Eddy intake designer that if you open the runner to just below standard oval port size....30 horse gain. The runner sizes nearer the plenum are large, just the area near the mating flange to the heads is necked-down. Get the die grinder out! This puts you into the Perf RPM category.

The Rpm Air Gap Intake ports are smaller than the 049 ports. It fits without a problem.

Little confused, my machine guy says i will gain some ponies if i port match them, he will charge me an extra $50 to match the intake with heads. he says at least 10-15 more ponies if i do this.

I always heard that if the ports on your head are smaller than the ports on your intake, it's well worth the effort to open up the manifold. The incoming air is highly disturbed when it hits the edges of the head as it goes into the combustion chamber.

If the ports on the head are larger than the manifold ports, you might be better off just leaving it alone.

Again, just what's been passed on to me and it seems to be logical.

Little confused, my machine guy says i will gain some ponies if i port match them, he will charge me an extra $50 to match the intake with heads. he says at least 10-15 more ponies if i do this.

It depends on the intake but for the most part I agree with Bryce, in most cases you will see little to no gain.
I have no experience with the Performer but if in fact the 2.0 intake is "necked down" to peanut port size & the upper part of the runners are larger like the Perf RPM then I would expect a gain but 30HP??
Maybe in certain applications but for the most part I doubt it

But the question was about the Perf RPM not the Performer.

While I have no direct tests with the RPM,
I have done back to back "port matching" on the Vic Jr & Super Vic on Big blocks with AFR heads & seen absolutely no gains that I could measure.

If you are doing the port matching yourself go for it but I would not recommend paying much just to have port matching done unless you are having the complete intake done to a specific head / engine combo.

That said, for $50 go for it, you will sleep better :D

Yes it's worth about 15 horse power.

I figure it falls in the *can't hurt* category. Never seen it hurt anything......

If the guy really takes the time to match the ports....NOT just the gasket...$50 is a bargain. Ask what you're getting for your bucks.


JIM

Yes it's worth about 15 horse power.
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Like I said, it will make you sleep better & I agree it "can't hurt" but 15HP in most cases is crap,,
In my experience it ain't gonna happen except in magazines 9 times out of ten unless you have a huge mismatch or the intake is larger than the heads
Then quite possibly yes there is power to be had
And of course doing the complete intake, especially the plenum is a whole nuther story,,,;)

But I have port matched a fair number of intakes & seen little to no gains on the dyno.
Looks impressive though,, so it must be worth something,,,,,, :p

i will measure the heads see if they are smaller or larger than the intake ports, and if they are larger, then i will leave it alone, if not, then port them. :thumbsup:

It makes NO DIFFERENCE WHATSOEVER until the actual IMPORTANT part of head porting is ALREADY accomplished. Once the bowls are blended, the throats opened and contoured, the guides smoothed and airfoiled, etc. etc. etc., THEN AND ONLY THEN, it might maybe possibly make a difference sometimes. But in the VAST MAJORITY of all engine combos, that point isn't where the flow restrictions are, and therefore, messing with it doesn't DO anything at all beyond the "esthetics" of the heads before they're installed (in other words, it's monkey spank).

no difference if the manifold ports are smaller than the head ports?
Why?
I'd think the airflow zooming down the manifold and hittingthe edge of the head would be horrible for flow...

As an example, in my current motor, the heads are milled .040". It's enough that I had to hog out the manifold boltholes to get the bolts in. The manifold still fits perfectly, the heads are just a lil lower than they used to be. I'd guess I have a sizeable step in the roof of the ports, and that it is hurting my performance badly...

Comments?

no difference if the manifold ports are smaller than the head ports?
Why?
I'd think the airflow zooming down the manifold and hittingthe edge of the head would be horrible for flow...

As an example, in my current motor, the heads are milled .040". It's enough that I had to hog out the manifold boltholes to get the bolts in. The manifold still fits perfectly, the heads are just a lil lower than they used to be. I'd guess I have a sizeable step in the roof of the ports, and that it is hurting my performance badly...

Comments?

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Umm
I believe you have that backwards :)
If the manifold is smaller & the head is bigger where is the edge?

But I think I know what you are saying & that is not what I said & I don't think anyone else did either
In fact that is pretty much what I stated, I prefer not to have a step in the wrong direction

And I do not think anyone has said it is a bad idea to port match just that it is not going to make any difference in most cases.

On yours, if there was a mismatch why wasn't the intake side of the head addressed when the chamber side was cut?
It should be standard fare unless of course the customer does not want to pay to have the intake side of the heads cut,,,,
And usually only 40 thou will not cause much mismatch unless the block happened to be cut too.

As has been stated, it may make you sleep better but do not expect much performance wise :D

=
Like I said, it will make you sleep better & I agree it "can't hurt" but 15HP in most cases is crap,,
In my experience it ain't gonna happen except in magazines 9 times out of ten unless you have a huge mismatch or the intake is larger than the heads
Then quite possibly yes there is power to be had
And of course doing the complete intake, especially the plenum is a whole nuther story,,,;)

But I have port matched a fair number of intakes & seen little to no gains on the dyno.
Looks impressive though,, so it must be worth something,,,,,, :p

Considering the above mans decades expereince and his current shop I believe what he states is just about law.

Statments of 15hp and even 30 hp gains?! If this was actually true, intake porting would be known as the best bang for your buck upgrade one could do; and aftermarket intake companies would offer CNC options for them. Id bet if there was any gain its on high RPM motor with tall single plane manifolds on race/non street motors; and Id guess the only power increase acheived is through moving the RPM up a little bit (200-600 rpm)...maybe for a whopping 1-3 hp gain. Not flaming anyone, JMO.

Hey..style counts right?


I think many many years ago....Hot Rod played with it on a 454/425 HO motor deal. Not really a on of HP...but they went through the excercise and managed to find 2-5 HP maybe...but again...in my experience that's within run to run variations....not enough to get all excited about.

OK..we all agree..it looks pretty...and it can't hurt!

Now where are all the guys with the rectangular port intakes bolted on oval port heads and *running fine*????

JIM

I think I saw some neat stuff somewhere showing the boundary layer that exists on the wall of the ports that actually extends out from the wall a fair amount. The fact that the *real* airflow is not running right against the walls allows for a little mismatch.


But again....sure looks pretty and it can't hurt!

JIM

We put a Chevy rectangular port intake, with the divider removed, on a mild 1974 454 smogger. Talk about port mismatch. It had the Cam Dynamics 272 Energizer cam and headers along with 3.55 gears. There was enough bottom end torque that even 275 X 60 Dunlop GT Qualifiers didn't work all that well. Still went 102.4 mph at 3900 pounds with driver. Not earth shattering but there was no fine tuning what so ever and a rooky driver. With just a little more cam and tuning, the car would have probably been in the 12s while breaking just about every rule in the book. Not bad for $1000 tied up in engine and add ons.

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Umm
I believe you have that backwards :).
Indeed, appears my typing was backwards.... my thinking was not.
Nice to know it's not that big a deal.

Here is a mismatch that works very well. A chevy rectangle intake on a chevy oval port head. Did it for years, tried various other intake's with no gain in performance. Still not a bad option in most cases.

Ask Wolfplace Or Any Other Engine Builder, If You Have A Perfect Match From The Heads To The Manifold It Will Not Be A Perfect Match At Engine Teardown.

Here Is Whyfirst, You Port Match Everything Perfect Then Put The Engine Together,all Done, Right? Yes,but After Heat Cycles I Have Seen Edelbrock Intakes Shift Around Then When You Look Down The Runners They Dont Line Up One One Side,there Is A Hair Restriction.

My Suggestion Would Be To Make Sure The Head Is A Hair Larger So This Does Not Happen

Also, We Port Match The Water Pump To The Engine Block,we Have Seen Times Where There Is A Restriction Here. Be Sure To Check And See If You Water Pump Mates With The Block Correctly At Your Next Engine Build.

Here is a mismatch that works very well. A chevy rectangle intake on a chevy oval port head. Did it for years, tried various other intake's with no gain in performance. Still not a bad option in most cases.

why does this work? Is the volume in the intake the biggest performance factor?

a rectangle intake on an oval head works better than oval/oval when the heads outflow an oval port manifolds capabilities

540 said it well.

"I think I saw some neat stuff somewhere showing the boundary layer that exists on the wall of the ports that actually extends out from the wall a fair amount. The fact that the *real* airflow is not running right against the walls allows for a little mismatch."

B/c flow velocity at the wall is ZERO.

A flow graph look's like a great big "U", fastest in the middle and zero on each side.

pdq67

a rectangle intake on an oval head works better than oval/oval when the heads outflow an oval port manifolds capabilities

Do you know where to find flow numbers for intake manifolds?