I can't believe anyone would port match an intake without having the the intended long motor in front of them. Quite often manifolds are machined crooked, so when you put them on otb the top of the port is higher than the other side. 2nd lesson here is ALL the manifold tests you’ve seen in magazines and RUclips are a 100% waste of time. It's not a matter of saying the manifold is port matched... it MUST be port matched to the exact long motor It's being tested on. What we really need to see is OTB intakes and then port matched and show the dramatic differences in hp. People spend a lot of $$ on heads, but have no qualms in blocking off half the port with an intake manifold.😮. Thanks Eric for bringing this fact to life. Keep up the great work.
The only way to find this stuff is to test. So cool I wondered about alignment but never really took the time to check. Little cameras on a lead are cost effective now. I have one ordered to look through the motor and see how things look when assembled. I think the camera was like $60. Thanks for the info and results.
An old NASCAR engine builder taught me how to port match and always said the roof of the port is more important for alignment and overall power production.
So now match and test the new Victor Jr and see if it will match the old one? I've been known to mock up my engines and blow some spray paint down the intake to verify the port match is correct and mark the head for correction. Now that you can buy a video scope and look into each port, all the way to the valve, it's a lot easier to confirm the port work is correct. Enjoy your videos and appreciate you taking the time to make them.
We use spray dykem at work with the straw and a long piece of PVC hose, plug the end, but take a fine pic and poke multiple holes around the circumference of the tube the last inch, then feed it down to where we have alignment issues and spray it , does a decent job of painting the joints that need to be dressed more. Sounds complicated, actually pretty simple. Then verify with bore scope we hit everything that needs material removed, tear down, finish matching and reassemble.
Excellent as always!!! Of course I watch whole nine yards.. cover to cover!!. Always something new to learn. After port match on both. Never thought to put camera down the intake to double check??. Makes I guy feel dumb for NOT double checking??..😮??.. thanks for your time Sir!!!..
Darin Morgan addresses this in his video.any miss alignment at top of Port is far worse than bottom of Port. Because velocity is much higher at the top.as I'm sure you know
Eric this is the exact reason why our Aussie SBC Intake Manifold "Iron-Hide" has the first inch of the runners cast small. It forces the engine builder to match the intake to the port correctly. It gives a lot more flexibility for the porter to get the alignment they desire. Should've showed it in this video for reference.
Wish more manufacturers would do that here in the states, the market spent so long catering to the diy crowd that they got away from the practices you use.
@@b.c4066 when I started designing my intake I wanted it to have features that set it apart from the rest on the market. I now design all my intakes using the same design approach for better freedom with port matching.
Hey Eric, Tim here, i've been anal about pirt matching, since the late '80's, yes, had sucess.....but never shot a light down the intake port, to see the LOCATION!!!.....i assumed, i'm portmatched, i'm good to go....this is just an AWESOME vid, explaining, and showing data, that even an older fart like me, learned something, makes me wanna chk out my Poncho intake to head port LOCATION, as i port matched it yrs ago, and have the same basic combo i've run for almost 20 yrs.......i need a tenth, and 1.5 mph to net 10:90's.....i shud look at my port match LOCATION!!!......SUPER cool!!!.....i'm all spun up now....haha....LOVE IT!!! TY SIR!!
Flexible bore scopes are cheap now days, no reason to not verify your work. Anyone messing with high performance engines should have one in their toolbox. Very helpful for troubleshooting stuff.
Well done Eric. Am not surprised though that it picked up 10 hp with the correct port match alignment. My engine builder friend here in Australia always checks this fitment , he says it’s crucial to gaining correct hp and flow through the head. Makes all the difference!! Awesome video loved it! Jon from down under
Cool test man it makes me think how bad my engine was I had a bad ported manifold with only a small flat tapped cam and man I go so much ho potential I can't wait to run it after your improvements to it
Been running this with a 1 inch spacer on my 406 sbc since 1998.Port matched and this manifold is AMAZING!..Swapped out the heads with AFR’s and port matched.Wow sucker pulls hard with plenty of torque down low all the way to 7500.Would never switch it out.
So you need to know what block decking has been done by a customer if you’re going to sell him heads and manifold with a port match. Great video, thanks!
Best to have the actual engine, with heads bolted in place to get things exactly matched. Vizards books give good info for port matching your intake to your engine.
We saw the same mismatch of ports on the victor jr Intake to the promax 215 project Heads. The corner radius of the port in the head was smaller than the intake manifold. And it still made the most power.
I used to use a pin like that. I bolt it all together on the block with the gaskets used, hg down to like 45, and torque intake all the way down, then drill.
So I have an old set of 882 Chevy heads, that imported. Import matched them to fit a 1206 gasket. But I basically glue the gaskets to the head with small plastic bushings on the bolts that fit the gasket bolt hole to center the gasket on the port and center the gaskets on all the manifold bolt holes. It means I don’t let the gasket slide around when I mount the intake manifold. These heads also have not been milled. I run an Edelbrock sy1 cross ram. Pretty sure I looked down the port to verify the ports were ok. I did not touch the manifold ports since they were fairly large.
Forgive me, I thought port match was to get the manifold to the height (and fore and aft) that the ports line up. Gasket match is just matching the head and intake to the gasket.
I have had a couple rec port bbc over the years respond very well to a intentional missmatch at the floor. I always assumed it was kicking fuel into the airstream with minimal flow disruption. It would be interesting to see you test this with either a slight step on the floor. Or a fuel ramp ground on a 45 at the floor gasket area.
I guess I already knew one thing: do not get a cnc "gasket match" option on a head. They don't have your block, your intake and that leaves... a pile of assumptions [I hope they aren't steaming] in place of a mock up. Great video - looks like some wet flow characteristics were unveiled that a flow bench would miss.
On a 90° V8 you can remove the exact same amount of material off of the intake flange of the cylinder head as was milled to keep the port alignment close to correct, that way you don’t have to modify every intake manifold that the engine will see throughout its life, this doesn’t always work out because some intake manifolds will not fit or sit too low but it’s easy enough to get thicker intake gaskets to raise the intake manifold up and a lot cheaper lol
You can end up with a thing where the intake doesnt fit between the valvecover rails and you have to feed the intake in from the end, over the China wall. You are 100% correct though.
@@timothybayliss6680 and you are also correct on certain small block Chevy heads and big block Chevys,I remove a little bit of material from the valve cover rail usually doesn’t take very much just enough to be able to get the intake off and on, but yeah it’s not a lot of fun when you run into that problem when you just laid down all the silicone on the china wall lol 😂
I think the differences are going to be greater the more there is a demand for airflow out of the intake manifold and at power levels I’m not sure you would see nearly as much of a gain but that’s just a theory something that would be difficult to test, on another note I think the next cork in the system is probably the Camshaft because it’s making very impressive power for a 406 on pump gas
at 18:08 you mentioned a fixture to cut them off. I'd like to see it. cause i have Bridgeport knee mill. so i can compare set-up . Time consuming. sometimes i get 20.00 swap-meet intakes. that someone used an angel grinder on . surprisingly only took .008" to clean-up. now it looks like a 150.00 intake.
Now if you bias the ports higher instead of lower, you'd gain some more. I've done gasket matching on stock type heads with emphasis on port alignment, and had excellent results. Once you've milled the heads that much, your kinda screwed. Higher ports are always better.
So you got the port matched right, instead of just a generic gasket match,. Like so many posts from speed talk I have read "each combo is different, test your combo and dial it in" cool stuff Eric.
Lol. Back in the 80s my brother and me shaved the crap out of a set of heads. Learned the hard way about port location . Gasket match and port match are 2 different things.
Left out oops, I gasket match my heads, and port match my intakes. This is so simple to do - With matched heads on block a small dab ( tiny, just enough to hold gasket) of silicone on the ends of intake gasket. Line up ports let dry. Before putting on intake put 4 more dabs of silicone in intake side gasket. Let dry. Take thin scraper blade under gasket ends on heads side and cut silicone. Lift off intake and you have perfect port location to match too.. That's my hillbilly gasket/port match method. Lol.
I’ve had that very same problem with my 327 with 461 heads. Used a 69 z28 manifold off of ebay and couldn’t get it aligned like I wanted. Used a 1205 and 1206 gasket and still working on it. Might have to mill the intake?
This is why used intakes may be useless if they have been gasket matched or port matched. Used parts and new parts have gotten retarded for prices. And the new victor jr makes less hp than the old school one.
I'd say they make less power because they intentionally ship them with less material removed, so the end user can properly match them to their combination. It's easier to remove material than it is to put it back. Their vic jr is then effectively a viable option for more customers. Engine builders know this, and deal with it. It's the street strip and diy crowd that complains and expects perfect fitment and interchangeable parts like OEM stuff is, that's easy to do when you make 300,009 of the same engine. The aftermarket has to try to please everyone with a broad range of products, it's up to the end user to adjust and verify final fitment, especially for a performance application. Trouble is most enthusiasts do not own a flow bench, Dyno, or mill to do the final fitment that Eric did and verify the results were positive gains. Make sense?
Is it possible the heads outflow the Vic Jr enough that it is now a choke point? It might be interesting to see each intake flowed with the head on the bench?
In scored an old ford one at the ford fest swap meet this year. I was pumped. Just saving money for heads, should be getting them here in a couple months.
Eric I'm watching your video when you discover the LS3 heads have a wider chamber than the bore. My question is, you pointed out later on that the liberty heads had the intake valve moved over closer to the exhaust. Would you think that the liberty heads have a smaller chamber across. That is nasty with a wider chamber than bore.
You wouldn't think it's so good just by looking at it from the outside, that's for sure, I'm sure the runners in the manifold look better on the inside than the outside if you get what I mean.
I don't think it was a surprise. We're all human and simple things can be forgotten or overlooked. You got to realize all the work that Eric is doing on this dyno session in a short time limit.
@WeingartnerRacing comments like the one above stating that they can't believe this was a surprise for you are why I hate the internet. People are too quick to criticize. Thanks for the videos and keep up the good work.
This is kind of a weird video.. I have always assumed port matching meant PORT MATCHING! so what you're saying is port matching is just port "sizing". To me Port matching has Always meant lining the ports with each other in the individual situation.IE Bolt on the manifold, mark the port alignment within the intake as good as you can (very hard with a dual plane.. but doable ) and grind either the head or the manifold .or adjust with gaskets or milling. I can't believe you haven't already been doing this EVERY time.. So its kind of a language thing, port sizing is what most people do..port MATCHING is too hard for most.
I do port match on every Manifold that I port for a customer. But just dynong different Manifold out of the box. I am not going to port match every Manifold. Because if I do, then it’s only matched to one set of heads and I am testing multiple sets of different heads.
So, what you're saying is that your entire set of SBC intake manifold tests are useless, since you didn't make sure that the intake port heights matched up to the heads on the engine?
No. All the intakes were exactly as they would come if you bought them. So if the port alignment sucked when I had them it would for everyone else too. I knew some were worse than others but I never altered it to keep all tests the same. I now only altered one that was the worst to see the effect.
@@WeingartnerRacing - but if your goal was to test manifolds against each other, each one should have been massaged so that the ports aligned with the heads. I realize that's not possible with a borrowed manifold, but it kind of makes me not really have much confidence in your results.
My goal was to test each out of the box to see how they did. Just like an ordinary consumer would. If I modified each one to make them perfect that would be lying to people. People would would think a certain manifold was good go buy it then not get the same result I would. Sure they could spend the money to have it modified but the majority of consumers don’t. Milling the manifold cannot be done at home in your average garage.
I can't believe anyone would port match an intake without having the the intended long motor in front of them. Quite often manifolds are machined crooked, so when you put them on otb the top of the port is higher than the other side.
2nd lesson here is ALL the manifold tests you’ve seen in magazines and RUclips are a 100% waste of time. It's not a matter of saying the manifold is port matched... it MUST be port matched to the exact long motor It's being tested on. What we really need to see is OTB intakes and then port matched and show the dramatic differences in hp. People spend a lot of $$ on heads, but have no qualms in blocking off half the port with an intake manifold.😮. Thanks Eric for bringing this fact to life. Keep up the great work.
The only way to find this stuff is to test. So cool I wondered about alignment but never really took the time to check. Little cameras on a lead are cost effective now. I have one ordered to look through the motor and see how things look when assembled. I think the camera was like $60. Thanks for the info and results.
Buy a cheap borescope. You could check every port every time.
An old NASCAR engine builder taught me how to port match and always said the roof of the port is more important for alignment and overall power production.
So now match and test the new Victor Jr and see if it will match the old one? I've been known to mock up my engines and blow some spray paint down the intake to verify the port match is correct and mark the head for correction. Now that you can buy a video scope and look into each port, all the way to the valve, it's a lot easier to confirm the port work is correct. Enjoy your videos and appreciate you taking the time to make them.
We use spray dykem at work with the straw and a long piece of PVC hose, plug the end, but take a fine pic and poke multiple holes around the circumference of the tube the last inch, then feed it down to where we have alignment issues and spray it , does a decent job of painting the joints that need to be dressed more. Sounds complicated, actually pretty simple. Then verify with bore scope we hit everything that needs material removed, tear down, finish matching and reassemble.
A little attention to detail, and you have almost 10 hp. I better pull my carband have a closer look. Thanks for sharing!
Excellent as always!!! Of course I watch whole nine yards.. cover to cover!!. Always something new to learn. After port match on both. Never thought to put camera down the intake to double check??. Makes I guy feel dumb for NOT double checking??..😮??.. thanks for your time Sir!!!..
Darin Morgan addresses this in his video.any miss alignment at top of Port is far worse than bottom of Port. Because velocity is much higher at the top.as I'm sure you know
Eric this is the exact reason why our Aussie SBC Intake Manifold "Iron-Hide" has the first inch of the runners cast small. It forces the engine builder to match the intake to the port correctly. It gives a lot more flexibility for the porter to get the alignment they desire. Should've showed it in this video for reference.
Wish more manufacturers would do that here in the states, the market spent so long catering to the diy crowd that they got away from the practices you use.
@@b.c4066 when I started designing my intake I wanted it to have features that set it apart from the rest on the market. I now design all my intakes using the same design approach for better freedom with port matching.
Hey Eric,
Tim here, i've been anal about pirt matching, since the late '80's, yes, had sucess.....but never shot a light down the intake port, to see the LOCATION!!!.....i assumed, i'm portmatched, i'm good to go....this is just an AWESOME vid, explaining, and showing data, that even an older fart like me, learned something, makes me wanna chk out my Poncho intake to head port LOCATION, as i port matched it yrs ago, and have the same basic combo i've run for almost 20 yrs.......i need a tenth, and 1.5 mph to net 10:90's.....i shud look at my port match LOCATION!!!......SUPER cool!!!.....i'm all spun up now....haha....LOVE IT!!! TY SIR!!
Flexible bore scopes are cheap now days, no reason to not verify your work. Anyone messing with high performance engines should have one in their toolbox. Very helpful for troubleshooting stuff.
@@b.c4066 GOOD idea, i wonder if Horrible Freight got a cheapy, that wud work....TY sir!!
Well done Eric. Am not surprised though that it picked up 10 hp with the correct port match alignment.
My engine builder friend here in Australia always checks this fitment , he says it’s crucial to gaining correct hp and flow through the head.
Makes all the difference!!
Awesome video loved it!
Jon from down under
The biggest news is that how far that manifold came in the pack & how simple it could be. When it swings at 10hp, I call that a gain. Excellent work 👍
They must cast & machine manifolds based on stock deck height & a certain compressed head gasket, again great job
Not many would take notice of where the port's line up, thanks for sharing, all the best to you and your loved ones
Awesome video, the videos have been improving & so has the information. Thanks 👍👍
Cool test man it makes me think how bad my engine was I had a bad ported manifold with only a small flat tapped cam and man I go so much ho potential I can't wait to run it after your improvements to it
Outstanding information, thanks Eric.
Been running this with a 1 inch spacer on my 406 sbc since 1998.Port matched and this manifold is AMAZING!..Swapped out the heads with AFR’s and port matched.Wow sucker pulls hard with plenty of torque down low all the way to 7500.Would never switch it out.
So you need to know what block decking has been done by a customer if you’re going to sell him heads and manifold with a port match. Great video, thanks!
Best to have the actual engine, with heads bolted in place to get things exactly matched. Vizards books give good info for port matching your intake to your engine.
We saw the same mismatch of ports on the victor jr Intake to the promax 215 project Heads. The corner radius of the port in the head was smaller than the intake manifold. And it still made the most power.
Thanks for sharing Eric, we appreciate u
I used to use a pin like that. I bolt it all together on the block with the gaskets used, hg down to like 45, and torque intake all the way down, then drill.
Great info eric i know lots of peoplie just slap stuff together and leave hp on the table
So I have an old set of 882 Chevy heads, that imported. Import matched them to fit a 1206 gasket. But I basically glue the gaskets to the head with small plastic bushings on the bolts that fit the gasket bolt hole to center the gasket on the port and center the gaskets on all the manifold bolt holes. It means I don’t let the gasket slide around when I mount the intake manifold. These heads also have not been milled.
I run an Edelbrock sy1 cross ram. Pretty sure I looked down the port to verify the ports were ok. I did not touch the manifold ports since they were fairly large.
It goes back to running bbc rec port intake on oval port head. Creating a venturi at the head, speeds up the charge filling.
Forgive me, I thought port match was to get the manifold to the height (and fore and aft) that the ports line up. Gasket match is just matching the head and intake to the gasket.
Dang it. I noticed mine a while back were off a bit. Missing hp's!!! Great information
I have had a couple rec port bbc over the years respond very well to a intentional missmatch at the floor. I always assumed it was kicking fuel into the airstream with minimal flow disruption. It would be interesting to see you test this with either a slight step on the floor. Or a fuel ramp ground on a 45 at the floor gasket area.
I guess I already knew one thing: do not get a cnc "gasket match" option on a head. They don't have your block, your intake and that leaves... a pile of assumptions [I hope they aren't steaming] in place of a mock up.
Great video - looks like some wet flow characteristics were unveiled that a flow bench would miss.
You should get Cnc gasket match head but not manifold. It’s easier to correct a manifold.
On a 90° V8 you can remove the exact same amount of material off of the intake flange of the cylinder head as was milled to keep the port alignment close to correct, that way you don’t have to modify every intake manifold that the engine will see throughout its life,
this doesn’t always work out because some intake manifolds will not fit or sit too low but it’s easy enough to get thicker intake gaskets to raise the intake manifold up and a lot cheaper lol
You can end up with a thing where the intake doesnt fit between the valvecover rails and you have to feed the intake in from the end, over the China wall.
You are 100% correct though.
@@timothybayliss6680 and you are also correct on certain small block Chevy heads and big block Chevys,I remove a little bit of material from the valve cover rail usually doesn’t take very much just enough to be able to get the intake off and on, but yeah it’s not a lot of fun when you run into that problem when you just laid down all the silicone on the china wall lol 😂
I think the differences are going to be greater the more there is a demand for airflow out of the intake manifold and at power levels I’m not sure you would see nearly as much of a gain but that’s just a theory something that would be difficult to test, on another note I think the next cork in the system is probably the Camshaft because it’s making very impressive power for a 406 on pump gas
Do you do air flow testing with the intake manifold bolted to the head? How does it compair to the flow numbers of just flowing the head?
This is great info , free hp, long live the 2975 though. thx Eric !
at 18:08 you mentioned a fixture to cut them off. I'd like to see it. cause i have Bridgeport knee mill. so i can compare set-up . Time consuming. sometimes i get 20.00 swap-meet intakes. that someone used an angel grinder on . surprisingly only took .008" to clean-up. now it looks like a 150.00 intake.
more flow at the top so a little low better than high
Thank you Eric.
Now if you bias the ports higher instead of lower, you'd gain some more. I've done gasket matching on stock type heads with emphasis on port alignment, and had excellent results. Once you've milled the heads that much, your kinda screwed. Higher ports are always better.
So you got the port matched right, instead of just a generic gasket match,. Like so many posts from speed talk I have read "each combo is different, test your combo and dial it in" cool stuff Eric.
Great video.👍
Great video.....thanks
Yep . Excellent
Lol. Back in the 80s my brother and me shaved the crap out of a set of heads. Learned the hard way about port location . Gasket match and port match are 2 different things.
Ps. Thnx for all the great videos and work. I always learn something..
Left out oops,
I gasket match my heads, and port match my intakes. This is so simple to do - With matched heads on block a small dab ( tiny, just enough to hold gasket) of silicone on the ends of intake gasket. Line up ports let dry. Before putting on intake put 4 more dabs of silicone in intake side gasket. Let dry. Take thin scraper blade under gasket ends on heads side and cut silicone. Lift off intake and you have perfect port location to match too.. That's my hillbilly gasket/port match method. Lol.
I’ve had that very same problem with my 327 with 461 heads. Used a 69 z28 manifold off of ebay and couldn’t get it aligned like I wanted. Used a 1205 and 1206 gasket and still working on it. Might have to mill the intake?
I am seeing that the Intake manifold has Oval bolt holes yet, so aligning the manifold on the heads is also as important.
This is why used intakes may be useless if they have been gasket matched or port matched. Used parts and new parts have gotten retarded for prices. And the new victor jr makes less hp than the old school one.
I'd say they make less power because they intentionally ship them with less material removed, so the end user can properly match them to their combination. It's easier to remove material than it is to put it back. Their vic jr is then effectively a viable option for more customers. Engine builders know this, and deal with it. It's the street strip and diy crowd that complains and expects perfect fitment and interchangeable parts like OEM stuff is, that's easy to do when you make 300,009 of the same engine. The aftermarket has to try to please everyone with a broad range of products, it's up to the end user to adjust and verify final fitment, especially for a performance application. Trouble is most enthusiasts do not own a flow bench, Dyno, or mill to do the final fitment that Eric did and verify the results were positive gains. Make sense?
It would be interesting to see if you could replicate the results of the old victor jr with a new victor jr port matched and textured the same
Is it possible the heads outflow the Vic Jr enough that it is now a choke point? It might be interesting to see each intake flowed with the head on the bench?
I’m still looking for an old victor jr, since I bought a newer one at the swap meet, brand new two years ago for $175.
In scored an old ford one at the ford fest swap meet this year. I was pumped. Just saving money for heads, should be getting them here in a couple months.
Eric I'm watching your video when you discover the LS3 heads have a wider chamber than the bore. My question is, you pointed out later on that the liberty heads had the intake valve moved over closer to the exhaust. Would you think that the liberty heads have a smaller chamber across. That is nasty with a wider chamber than bore.
I don’t know I didn’t measure but I think it’s the same width
If you had the dyno motor in a vehicle, at what rpm would you shift it at?
7200
Port location > match. Get both on point = racecar
You wouldn't think it's so good just by looking at it from the outside, that's for sure, I'm sure the runners in the manifold look better on the inside than the outside if you get what I mean.
Have you tested plenum TURTLES?
Yes watch my other videos.
To clarify this is the book called “Final 2023 Book” ?
I always though that was part of engine building. No engine bolting on parts
So you're saying that the Trick Flow R is a great manifold after all.
But they would probably all get better if they were milled properly
@shelbyavant5081 yes probably. It's good to know
I definitely wouldn't say this discounts any of Eric's work, but yeah the trick flow did have an appreciable improvement
I sure am disappointed in the moderately ported 2892 that you were dynoing a while back. Maybe it was badly aligned as well?
The 2892 are usually high and need milled.
I can’t believe this was a surprise for you!
Not this much power. I haven’t ever seen a dyno test showing just this.
I don't think it was a surprise. We're all human and simple things can be forgotten or overlooked. You got to realize all the work that Eric is doing on this dyno session in a short time limit.
@WeingartnerRacing comments like the one above stating that they can't believe this was a surprise for you are why I hate the internet. People are too quick to criticize. Thanks for the videos and keep up the good work.
If your mixture hits a mismatched roof it will head down to the floor real quick and become useless on most people's port finish.
This is kind of a weird video.. I have always assumed port matching meant PORT MATCHING! so what you're saying is port matching is just port "sizing". To me Port matching has Always meant lining the ports with each other in the individual situation.IE Bolt on the manifold, mark the port alignment within the intake as good as you can (very hard with a dual plane.. but doable ) and grind either the head or the manifold .or adjust with gaskets or milling. I can't believe you haven't already been doing this EVERY time..
So its kind of a language thing, port sizing is what most people do..port MATCHING is too hard for most.
I do port match on every Manifold that I port for a customer. But just dynong different Manifold out of the box. I am not going to port match every Manifold. Because if I do, then it’s only matched to one set of heads and I am testing multiple sets of different heads.
So, what you're saying is that your entire set of SBC intake manifold tests are useless, since you didn't make sure that the intake port heights matched up to the heads on the engine?
No. All the intakes were exactly as they would come if you bought them. So if the port alignment sucked when I had them it would for everyone else too. I knew some were worse than others but I never altered it to keep all tests the same. I now only altered one that was the worst to see the effect.
@@WeingartnerRacing - but if your goal was to test manifolds against each other, each one should have been massaged so that the ports aligned with the heads. I realize that's not possible with a borrowed manifold, but it kind of makes me not really have much confidence in your results.
My goal was to test each out of the box to see how they did. Just like an ordinary consumer would. If I modified each one to make them perfect that would be lying to people. People would would think a certain manifold was good go buy it then not get the same result I would. Sure they could spend the money to have it modified but the majority of consumers don’t. Milling the manifold cannot be done at home in your average garage.
So.. does that mean all your previous manifold comparisons are null & void?
No. They were all tested the same way. Making them all perform the way they came. Some would do better with milling.