AFR Heads

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Here's what I know about the AFR head. I checked them out at a trade show a couple of months ago and took one picture. The first picture shown below is the AFR head. The reason I took the picture is because of the short turn machining. The blue arrow points to the 'cliff' that was left after the valve job. The top of the cliff is a sharp corner. No way that head is flowing 260+ without work. I was quite shocked a company would take that to a trade show for show and tell.

The AFR head is a Speedmaster casting. To my knowledge there are two foundries in China repopping the SBM head, SM and ProMaxx. The ProMaxx head comes from the Steven Sun foundry. I don't know the name of the SM/AFR foundry. I suppose there could be a third, but where would their heads be sold? Would have to be in the States.

The second picture below shows the same view as the first picture, but this time a SM head. Note there is no cliff. The cliff on the AFR could just be a core shift issue. I've experienced core shift in both the SM and the ProMaxx heads in areas other than the short turn.

The third picture shows a ProMaxx head on top of a Speedmaster head. The differences between the two castings are obvious. The exhaust port face is the quickest way to differentiate between the two castings.

Again, the AFR head is a Speedmaster casting. A bare AFR head is $130 more than a SM head and I think the SM would flow better OOTB. I see no reason to buy a (bare) AFR head. Wait for Black Friday and save another 40% on the SM.

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The couple of things I noticed that make them desirable in my eyes is the slightly smaller chamber than the SM heads, and that they are set up for 8mm valves ootb.
 
turboking15 said:
The couple of things I noticed that make them desirable in my eyes is the slightly smaller chamber than the SM heads, and that they are set up for 8mm valves ootb.
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I didn't notice the 8mm valves. Now that you mention it, it is obvious in the pictures. Unless AFR is re-cutting the deck I doubt there is any difference in the chamber volume. I'll go measure the SM chamber just for kicks.
 
With Ferrea valves the SM chamber measures 60.5 cc. The Ferrea valves have a thicker margin and less dish on the chamber side than Speedmaster valves. Different valves can easily make 2-3 cc difference.
 
After looking at the chamber pics EA posted, here’s my take on what’s going on with the way the bowl cut intersects the SSR……

If you look at the proximity of the outside of the 45* seat angle, and the OD of the seat insert, you can see how much closer the top of the 45 is to the edge on the AFR head.
The “valve job” appears to be “bigger”.

If you size the bowl appropriately for the larger diameter seat OD, the cutter used for that will remove some material from the SSR area……and leave the cliff you see in the pic.
The same thing happens when you install larger diameter valves.

That is my assessment……..going by pics I’m looking at on the net……..and not having the two heads side by side on the bench to measure and compare in person.

That being said, I’m doubtful I’d get the same flow numbers they’re publishing, on my bench……..if the production heads actually look like that.
As for ex flow, AFR typically tests that side of the head with a flow tube attached.
But even with a tube attached, the ex numbers look pretty lofty for a head like that with zero porting.

175cc As Cast Flow Chart
.200.300.400.500.550.600.650
Int136190234252257259262
Exh117156182186190201203
 
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You might be right on the larger OD seat angle. If AFR had the 8mm guides installed at the foundry, they specified their own guide. If they specified their own guide they could also specify their own valve job.

Or, if they bought the heads with 11/32 and replaced the guides, they would have had to redo the valve job themselves. So either way a different valve job than SM is quite likely.

And I agree that the exhaust numbers are more representative of a minor port job. But you could also get there with a really good valve job and a tulip valve.
 
In my mind the 200+ From the untouched exhaust port is just not a number I think I’d see on my bench(even the cnc SM only went 188).
But that’s an illustration of why you can’t really compare numbers from different benches.

This is my point of reference for non-cnc’d SM heads:

C93B40CA-C989-4C7C-9CE7-529638BF90E7.png
 
PRH said:
In my mind the 200+ From the untouched exhaust port is just not a number I think I’d see on my bench(even the cnc SM only went 188).
But that’s an illustration of why you can’t really compare numbers from different benches.

This is my point of reference for non-cnc’d SM heads:

View attachment 1716366564
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Went back through my exhaust port tests. Looks like Edelbrock, SM, ProMaxx are all in the 165-175 cfm range on my bench OOTB with no porting. When ported 220-230.
 
I ripped a set of Trick Flows off, for waaay better flowing Eddie's(ported by a genius. And flowed.) If the AFR are a China casting, I'd stick with Edelbrock.

Just watch Eric's YouTube video flowing the TF's. They did NOT flow as advertised. I doubt the AFR' do. Weak as their numbers are......

I've been down the head rabbit hole, probably farther than most. Nothing other than ported W2's or something exotic has come close to my OLDER Edelbrock castings.

I think if good old Pittsburgh Racer were here, he might agree.
 
Ironmike said:
I ripped a set of Trick Flows off, for waaay better flowing Eddie's(ported by a genius. And flowed.) If the AFR are a China casting, I'd stick with Edelbrock.

Just watch Eric's YouTube video flowing the TF's. They did NOT flow as advertised. I doubt the AFR' do. Weak as their numbers are......

I've been down the head rabbit hole, probably farther than most. Nothing other than ported W2's or something exotic has come close to my OLDER Edelbrock castings.

I think if good old Pittsburgh Racer were here, he might agree.
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Based on track results, the Bloomer heads blow every one of these heads being discussed out of the water, easily. And in several cases, people have actually taken good Eddie heads and Trick flow heads off and swapped on Bloomers and picked up significantly, back to back.
Speaking as a person who owns a set, the casting quality is outstanding. Nicer than my eddies I had previously were
 
B3422w5 said:
Based on track results, the Bloomer heads blow every one of these heads being discussed out of the water, easily. And in several cases, people have actually taken good Eddie heads and Trick flow heads off and swapped on Bloomers and picked up significantly, back to back.
Speaking as a person who owns a set, the casting quality is outstanding. Nicer than my eddies I had previously were
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The casting is just as nice as a speedmaster, because thats what those heads are. With a seemingly well developed port job.
 
I don't know kind of look like a breathed on speedmaster with some engraving possibly, flow numbers are within the same range depending on the bench?
 
Looks like another Edelbrock head rip off and the flow numbers look like I have seen them before.. cough cough
 
fishmens67 said:
They did on every other bench including PBR's.
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Go back and read through his posts. He reported that the flow numbers out of the box on the head he tested were inconsistent, with one port even falling very short, relatively speaking, from the others on the same head.
 
Bobzilla said:
Go back and read through his posts. He reported that the flow numbers out of the box on the head he tested were inconsistent, with one port even falling very short, relatively speaking, from the others on the same head.
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This is correct. PBR and I both had the same experience and pretty much the same flow numbers on the TFs. One port would flow 285 with lots of turbulence/separation. Another port would flow 295. I have had one port on one test reach 300. I believe that John could spend 8-10 minutes working on a port and get it in the 300-305 range pretty consistently.
 
I have read several of NC Engine Builder's responses to the Bloomer head controversies and I can't see where he has said anything that puts him in the 'hater' category. I just don't think he's in the 'believer' category yet. Let's get a set of Bloomers and a good set of PBR heads in a showdown. That would sure sway me one way or the other. Just not enough info yet. A 190cc TF head developed for a 340 engine against a 208cc Bloomer is hardly a fair fight.
 
Earlie A said:
I have read several of NC Engine Builder's responses to the Bloomer head controversies and I can't see where he has said anything that puts him in the 'hater' category. I just don't think he's in the 'believer' category yet. Let's get a set of Bloomers and a good set of PBR heads in a showdown. That would sure sway me one way or the other. Just not enough info yet. A 190cc TF head developed for a 340 engine against a 208cc Bloomer is hardly a fair fight.
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They definitely should be compared to others porters done to a similar level.
 
Earlie A said:
I have read several of NC Engine Builder's responses to the Bloomer head controversies and I can't see where he has said anything that puts him in the 'hater' category. I just don't think he's in the 'believer' category yet. Let's get a set of Bloomers and a good set of PBR heads in a showdown. That would sure sway me one way or the other. Just not enough info yet. A 190cc TF head developed for a 340 engine against a 208cc Bloomer is hardly a fair fight.
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The Bloomers are 200cc
They are absolutely a fair fight against anything that isn’t offset.
As people have said, all they are is a speedmaster head with a good port.
All standard port heads were developed for stock stroke stuff. So was the offset W2 and W5 stuff.
 
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