W2 head porting observations help needed!

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replicaracer43

replicaracer43

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So, I bought, and have setup and been playing with my new flowbench, and have ran into a few curiosity's. I have a set of early, 1st design W2 heads (a buddys) that were assembled by a well known, highly reputable shop, but the engine didn't seem to run as hard as we felt it should. These have 11/32 stem 2.05 intake valves, 3 angle valve job, and on my bench the initially flowed 8 cfm LESS than a box stock speedmaster. Down 10 at .300. The bowls look very under sized in my opinion, so, I did a bowl cut, added another angle between the bottom 70° and the blending into bowl. That got me a increase from 217@ .500 to 245.6@ .500 with a peak of 253.4 @ .550
 
My lightly ported econo W2 peak at .295 @ .600. There's a lot more to be had....
 
Then I pulled out a bare, brand new later W2 casting, with the factory out of the box valve job, 2.02 valve, they flow 234@ 500, with no work whatsoever, immediately back to back. I know the actual flow numbers seem low across the board, that could be my bench, but as a comparison, 20 cfm increase seems a step in the right direction, but I feel it needs more. The short turn in the early head has a narrower, more oval shape, where as the later head it looks wider, and a bit flatter. Like to get some opinions from some of the head porters on here, help me go in the right direction @pittsburghracer @PRH @yellow rose @MOPAROFFICIAL ..... ANY advice is GREATLY appreciated!
 
This is the as cast, later 2.02 bowl
20210215_181742.jpg
 
Krooser said:
My lightly ported econo W2 peak at .295 @ .600. There's a lot more to be had....
Click to expand...
I think the numbers seem low overall, that's why I'm just comparing back to back changes, quite possibly I dont have enough air flow source, so not overly concerned about the actual numbers
 
My old 3/8 stem 2.02 valve W2 heads hit [email protected] and fell on their face. A standard 60-45-30 valve job and a what I would call quick porting work they were up over 300cfm. Like I’ve said on W2 post before my econo heads were the number that were prone to cracking, which they did two years later, so I didn’t spend a lot of time on them. I easily ran 9.80’s at 2800 pounds on pump gas (Bp93) on my 408 with a Racer Brown .520 lift solid lifter cam.
 
pittsburghracer said:
My old 3/8 stem 2.02 valve W2 heads hit [email protected] and fell on their face. A standard 60-45-30 valve job and a what I would call quick porting work they were up over 300cfm. Like I’ve said on W2 post before my econo heads were the number that were prone to cracking, which they did two years later, so I didn’t spend a lot of time on them. I easily ran 9.80’s at 2800 pounds on pump gas (Bp93) on my 408 with a Racer Brown .520 lift solid lifter cam.
Click to expand...
I read your posting about those, like I said my overall flow numbers seem really low, which is probably my air source, so I'm just looking at the increase percentage wise, and wondering where to bring to gain a little more. All you guys are way smarter and have way more experience than I do! I'm grateful for the feedback
 
It’s been many many years since I’ve touched one and at least one of my old ones is used for fill outside my shop. If you take GoOD pictures with good lighting I’m sure someone can help you out. Lighting is very important
 
pittsburghracer said:
It’s been many many years since I’ve touched one and at least one of my old ones is used for fill outside my shop. If you take GoOD pictures with good lighting I’m sure someone can help you out. Lighting is very important
Click to expand...
I posted some pics, are they not clear enough? I can definitely take more tomorrow
 
My suggestion would be to buy a few PST test plates for the flow bench.
They will at least let you know where your bench is in relation to other shops.

I don’t have much W2 experience at all, but on one of the ones I had here I noticed there was quite a bit of bias in the intake bowls, which helped two, and hurt the other two.
My recollection is that I’ve noticed they all had that same bias ootb to some degree.
I don’t think I’ve ever done any work on the real early ones(that look like stock heads on the exhaust side of the head).
What cylinder are you testing?
On the ones I was working with, the #1/8 intake port was the best ootb, and was noticeably better than #3/6, which clearly had the bias going the wrong way.

As for the round floor....... I used to see that talked about in magazines/forums...... it’s never worked for me on anything.
W2’s work better for me when the floor appears basically flat(very slight convex as you approach the apex), as viewed from the manifold side.

The SSR on those heads can be pretty fussy.

I wouldn’t expect that really round floor/bowl in the older head to work as is.

The bias is going the right way in the ports in the pics, so you’re good there.

This? No good imo......

5FC83826-3C61-4B03-920C-249D117C608A.png
 
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PRH said:
My suggestion would be to buy a few PST test plates for the flow bench.
They will at least let you know where your bench is in relation to other shops.

I don’t have much W2 experience at all, but on one of the ones I had here I noticed there was quite a bit of bias in the intake bowls, which helped two, and hurt the other two.
My recollection is that I’ve noticed they all had that same bias ootb to some degree.
I don’t think I’ve ever done any work on the real early ones(that look like stock heads on the exhaust side of the head).
What cylinder are you testing?
On the ones I was working with, the #1/8 intake port was the best ootb, and was noticeably better than #3/6, which clearly had the bias going the wrong way.

As for the round floor....... I used to see that talked about in magazines/forums...... it’s never worked for me on anything.
W2’s work better for me when the floor appears basically flat(very slight convex as you approach the apex), as viewed from the manifold side.

The SSR on those heads can be pretty fussy.

I wouldn’t expect that really round floor/bowl in the older head to work as is.

The bias is going the right way in the ports in the pics, so you’re good there.

This? No good imo......

View attachment 1715690700
Click to expand...
The other head for comparison has a much wider, and flatter shape to that short side...my concern is how much material is in there to widen it out without busting through
 
Looking at the pics more closely....... it appears as though the middle of the floor of the old head has been lowered to create that rounded shape...... or its cast that way.
If someone did that, I’d tread lightly trying to fix it.
Seems like an easy way to make a hole.

If it’s cast that way, then you obviously have more material to work with.

Like I said...... limited experience with w2’s, so I can’t speak to what kinds of variations there might be to the ports of the different generations of casting.

You could try filling it with some clay and seeing what happens to the flow.
 
PRH said:
Looking at the pics more closely....... it appears as though the middle of the floor of the old head has been lowered to create that rounded shape...... or its cast that way.
If someone did that, I’d tread lightly trying to fix it.
Seems like an easy way to make a hole.

If it’s cast that way, then you obviously have more material to work with.
Click to expand...
They were completely un ported, just a 2.05 valve seat cut in them
 
Which SM head did you test, and what were the numbers?
Might be able to get some sort of gauge on how the bench compares.
 
replicaracer43 said:
They were completely un ported, just a 2.05 valve seat cut in them
Click to expand...

Okay.
Interesting.
So at some point they decided the filled in flatter floor was better.

If they were untouched, you should have some meat to play with, but I wouldn’t try and duplicate the newer floor shape in the old heads.
I’d shoot for a slightly wider, slightly less rounded floor.
Guide boss could use trimming, size the bowl correctly.

What you’ve done is already a big gain...... so be smart about how to proceed..... and know when to say, “that’s enough”.
 
The sbm head, bought assembled and un ported 2 years ago black friday sale....
.100 63
.200 121
.300 174
.400 208
.500 224
.550 224
 
The early w2, tested 5 mins later, before any work
.100 61.6
.200 117
.300 164
.400 196
.500 217
.550 216
.600 210
 
Looks like the bench reads pretty low.

But, as you say..... comparing before/after, you made some very nice gains.

Question...... you are using an air entry radius, right?
It’s a “must” for the numbers to have any real validity.

Btw...... congrats on the new bench!!

116A80D0-AFB1-4D4D-AB05-E42155A4FFE1.png


96935DB4-A5CB-4CE3-8894-BBBDD5C6EAA2.png
 
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