Ported Iron Head Flow - Good or Bad?

[Nick Micale]

Do these have the EGR passages filled like the Champion ones? Us poor souls in CA still have to smog and having a working EGR sure helps.

If the EGR passages in the iron heads were filled, Papa Lou would ban me from California!

For those fortunate and do not have to deal with those restrictions, I do have a set of fresh Champion iron heads available.

 

[Pierre]

For over 20 years I have been dealing with modified iron, stock turbo heads to optimize air flow and performance.

I have seen many flow sheets and numbers from around the country, and there is a large disparity of the numerical data so it begs the question to determine "what are good flow numbers for iron heads"?

Since my project of having the TA alum head porting CNC is now done, I moved on to determine the "best" iron head porting and still have it affordable.

My baseline is a fresh Champion iron head which is considered a benchmark for iron head performance in the turbo Buick world, and is considered max flow for an affordable iron head.

My plan was to bring the Champion head and a stock head to a good friend of mine that owns an engine auto machine shop, and is really an expert in performance head work of all brands.

I asked him to replicate the Champion head and provide me with flow numbers on each. The valves are the same in each head, the flow machine, adapters, operator, temperature were all the same and testing on both were done within the same hour so we could eliminate as many variables as possible.

Here is the results:

Champion Head:

intake exhaust
300 cfm 164 139
400 cfm 185 148
500 cfm 179 148
600 cfm 179 154
Max 185 154

AZGN Head:

300 cfm 166 145
400 cfm 176 148
500 cfm 179 154
600 cfm 182 154
Max 185 154


The cfm at .400" number on the Champion head is not a typo, but a disturbance in the passage air flow?

More details on our heads will be available shortly on my web site, and shipping for these heads will commence in about a week.

nick do you do porting and polishing ? or just sale heads ready to go?

 

[chris romani]

nick do you do porting and polishing ? or just sale heads ready to go?

This post is from 2016

 

[TIMINATOR]

I know this is an old post, but let me offer a few insights on the subject.
Even an expert porter has difficulty replicating someone else's port.
If they want to have their port work outflow someone else's, either consciously or unconsciously, they won't do their best to replicate what someone else has done. That's only one reason why CNC scanners and machining centers exist.
Small nuances in ports may have much larger effects than apparent, especially if the original porter is more knowlegable than the "replicator."
If you want to KNOW what someone else's head can do, rather than guess, buy his product and measure it on the same flowbench as your work, under the same conditions.
That being said with no malice intended, let's move on to "trends."
#1. intake porting gains are more important to horsepower production than exhaust port gains, more so in unboosted apps, but still a true statement.
#2. The valve is at max lift only once per operation. The valve is at low and midrange positions twice per operation.
#3. The valve can never flow more at any lift than it's radial distance from its outer edge to the chamber or cylinder at that point. This is called shrouding. Unshrouding the valve to the chamber helps the flow everywhere in its lift range above the shrouding distance.
#4. Proper porting assumes the port does not end at the valve seat, but extends past the valve head into the cylinder.
#5. At what depression in inches and temperature were the flow #s generated at?
#6. What cylinder bore size was the head flowed on? Standard? .060" over? Stage II?
#7. What valves were used? Stock, oversize, swirl polished, undercut stem? Back cut? Other tricks that I'm not gonna mention?
Now you can make more sense of flow chart numbers, but only if you have ALL of the information.
TIMINATOR

 

[Pierre]

If the EGR passages in the iron heads were filled, Papa Lou would ban me from California!

For those fortunate and do not have to deal with those restrictions, I do have a set of fresh Champion iron heads available.

Price and location please

 

[chris romani]

Price and location please

Pierre are you following this the post your reading from Nick is from 2016 he’s not on the board anymore as he has fallen ill.

 

[Pierre]

O sorry to heard that. I’m a bit newbi on this page

 

[TurboTGuy]

The unfortunate part of all this, is Nick has fogotten more than most of us will ever know about these cool assed cars.

He has a couple of guys still running Arizona GN, but his knowledge and insights are, and will be missed by all of us.

I just hope his final days are enjoyed with Terri, his kids, and those who know and love him.

 

[chris romani]

Agreed, I never met him or had any business dealings with him I am in N.Y. but his Tech Posts over the years where excellent.