Question on port matching

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Dan the man

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I'm trying to educate myself on engine building. I'm reading what I can get. My question is, is port matching worth it on a mild build? I've read on it and some people say that it is while others say it's not. So I thought that I would ask guy's that have the experience on the matter.
 
I do it on heads that I use for myself. It seems like I get a couple mpg more, but far from scientific. I only clean up the bowls under the valve, do a good valve job and mill the heads. not sure what causes what effect. It seems like it all adds up to a better running engine.
 
There is an engine masters episode about this tonight, on my cable m/t channel. Eric Weingartner has a you tube video too.
I do it, cause I can, but to be honest, I don't think it's worth much, UNLESS... you have an intake that is badly misaligned or bigger than the entry into the head port. Hitting a ledge in the port, really disturbs flow (big port rat intake, on an oval port head, is a good/bad example).
 
If you have everything apart, then I would just because it's really not that hard.
 
A lot of people think it's as easy as laying a gasket on the intake and exhaust ports and scribing around the inside of the gaskets, and grinding until you met the lines. Unless you take the time to create and establish a reference so the intake and gaskets will align to match the head and intake as well as the exhaust, you may not be helping your situation by doing it. On the other hand, if the ports are badly mismatched, and you know how to correctly position and align the gaskets to the head and intake, and exhaust, and create a way to keep all those components aligned when you install them. Then yes, it can be a benefit.
 
CNC-Dude said:
A lot of people think it's as easy as laying a gasket on the intake and exhaust ports and scribing around the inside of the gaskets, and grinding until you met the lines. Unless you take the time to create and establish a reference so the intake and gaskets will align to match the head and intake as well as the exhaust, you may not be helping your situation by doing it. On the other hand, if the ports are badly mismatched, and you know how to correctly position and align the gaskets to the head and intake, and exhaust, and create a way to keep all those components aligned when you install them. Then yes, it can be a benefit.
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Simply work from the head. Means the gasket and intake bolts to the head, then the head is the reference point.
 
Dan the man said:
I'm trying to educate myself on engine building. I'm reading what I can get. My question is, is port matching worth it on a mild build? I've read on it and some people say that it is while others say it's not. So I thought that I would ask guy's that have the experience on the matter.
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Port matching is just preventing a mismatch between the head and intake. It would be interesting to see dyno results. It can't hurt but how much it helps remains to be seen. Even a slight increase in power is a plus and it just costs a little time as long as you already have the tools.
 
toolmanmike said:
Port matching is just preventing a mismatch between the head and intake. It would be interesting to see dyno results. It can't hurt but how much it helps remains to be seen. Even a slight increase in power is a plus and it just costs a little time as long as you already have the tools.
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I have a feeling there will be dyno results on tonight's engine masters episode. (I haven't seen it).
 
I may be wrong but it is my understanding for best flow that you should try to taper the intake tract from the carb to the head in a big to little scenario? Meaning the port cross section should be larger at the carb end, and taper to the intake exit to the head. The gasket makes a nice template to harmonize the intake and head. Then the port in the head should taper down ( I think it physically has to because there isn't room) but you don't want any bubbles or big spots along the way. Is this simplistic thought process correct or way off?
 
I will add, all 3 of my Edelbrock intakes (RPM, RPM Air-Gap, Victor) had MAJOR core shift....I had to go ham with the grinder to get the ports in the same ball park as the heads. Just my 2 cents.

Edit: I really like how the Edelbrock intakes perform, but the QC is lacking.
 
The better the alignment the more power that can be made. An offset of parts will loose power and Efficiency. Now the big thing here is, “How Much?”

This is a number I can not name on any build. But this is also an item that pays a dividend the higher up the power scale you travel. So a lot of this is build dependent. Will a 8-1, 318 suffer a 40hp loss, no, it won’t. Will a .750 solid roller 408 be shorter on power, than if you had port matched it? I’m sure it will be.

Eric W’s youtube showed how he did it. I would suggest a look. The way I go about it is to fit the intake with the gasket being used to the heads on the block being used. I also have a small camera with a flexible neck to lead down dual planes and the tighter turning runners of a single plane. Then I can see how that alignment is and then make a scribe mark later. If your heads are bare, call it a plus to look the other way.

I do not port match every build. I don’t see a need for it on lower power builds or when I booting up stock intakes to stock heads with small cams. I’m pretty happy when the intake runner is smaller than the heads port on most stuff. The other way around is not good IMO.

Its small potato stuff that is OK to do. Small potato stuff added up over a build equals something noticeable.
 
A Weiand Action+ on a set of 318 heads no need to bother, but on a set of 340/360 heads, definitely a case of “really off” and requires some work. The actual runners are fine, it’s the abrupt tapering down of the roof of the runners to the smaller port opening that is horrendous. A rough sketch for those who haven’t laid eyes or fingers on one of these:

32926F8F-7DC3-4CC9-AA19-232F7E502639.jpeg
 
I had a pair of CNC Speedmaster heads and an Edelbrock Torker 2 manifold using Felpro 90109-1 intake gaskets. The gasket matched the head perfectly an was quite a way off on the intake. I'm sure it helped but no quantifiable numbers either drag strip or Dyno.

Cley
20200326_182204.jpg
 
89on35s said:
I had a pair of CNC Speedmaster heads and an Edelbrock Torker 2 manifold using Felpro 90109-1 intake gaskets. The gasket matched the head perfectly an was quite a way off on the intake. I'm sure it helped but no quantifiable numbers either drag strip or Dyno.

Cley
View attachment 1715849281
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I'm sure it helped a little, but it wasn't critical in your case, cause the intake was smaller than the head.
The other way around would be bad.
 
Agreed but I can't help but think any mismatch would cause turbulence. I am no expert, just what makes sense in my brain.

Cley
 
Post 13. I have struck this with aftermarket intakes. You line the ports up on one head, & find the ports on the other head misalign by 0.100".
 
Bewy said:
Post 13. I have struck this with aftermarket intakes. You line the ports up on one head, & find the ports on the other head misalign by 0.100".
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89on35s said:
Agreed but I can't help but think any mismatch would cause turbulence. I am no expert, just what makes sense in my brain.

Cley
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As long as the intake is smaller than the head port, it’s OK. Not great, but the reverse is really bad.
 
What J par said in #53. I've always heard its a benefit at higher rpms.
 
Dan the man said:
I'm trying to educate myself on engine building. I'm reading what I can get. My question is, is port matching worth it on a mild build? I've read on it and some people say that it is while others say it's not. So I thought that I would ask guy's that have the experience on the matter.
Click to expand...
Read more and study any and all pictures you come across, doesn’t matter if it’s dual plane, single plane, high dollar port work by experienced porters, or intakes for other makes. There’s endless pictures of ported intakes out there. Books as well. Study what you can on plenum work, the roofs of the runners as they enter the plenum/opening, the inside wall of each runner, and how to gasket match, how far up to go with the specific intake you may decide on. On a cleanup and/or “applying the basics” some may need more attention, some not so much. If you’re starting out you are not going to be hogging out anything, welding, using epoxy etc. Just employing the basics.
These two books are only an example, great reads and reference sources with some good pictures for understanding the areas to focus on.

7E7FC2C8-3CD4-42D4-86D3-1C2AE80166D4.jpeg


6F2301C2-BFEA-42CC-A98C-EF0760567394.jpeg


54BBF598-7A97-4E2F-BB01-AB951B318611.jpeg
 
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