Looking for X Head Picture

[RustyRatRod]

And I can't say this for certain, but I bet the factory didn't mess with 3 angle valve jobs.

Cool new avatar!

 

[PRH]

Same head/port as in post 14, but with a light reconditioning of the seat(stones, 30/45/60), and a Manley 3/8” stem nail head valve without a back cut……. No porting:

Lift——In
.100— 61.8
.200—126.0
.300—178.8
.400—211.3
.450—222.5
.500—224.4
.550—224.4
.600—222.5

 

[autoxcuda]

I have heard the old stocker guys would buy EVERY head they could get their hands on and start testing. Some were just better, some were horrible. IIRC, they ended up which a bunch of “crappy” heads in the end not knowing what to do with them.

The son of Tim Ekstrand that won a couple of NHRA stock class National Championships with a 360 Duster with Bob Lambeck said Chrysler would send them 100's of stamped rocker arms. They would pick out the thickest ones and the ones that had the most ratio. Send the rest back for common replacement parts

Also, there are "good" castings that are sent to select racers. I've seen reference to that in the Chrysler interoffice memo's I have between Bob Tarozzi and Tom Hoover.

 

[Earlie A]

Also, there are "good" castings that are sent to select racers. I've seen reference to that in the Chrysler interoffice memo's I have between Bob Tarozzi and Tom Hoover.

Wonder what would make one of these castings “good”, and how that would be decided.

I wonder about the water jackets in these heads. Which heads are the same? For instance, the X head, the 915 J head and the 587 head look to me to be very similar. As a matter of fact, looking in the 587 intake port the common wall corner of the floor/short turn has a larger hump than the X head. These heads are so similar that it looks like a port mold from the X head was just whittled down in a few areas to make the 587 port smaller. I can even see a different texture to the iron in that one spot. It almost looks like that extra hump of iron was added after the head was cast. That’s a slight exaggeration, but you get the point. I have a fully cut up 587 head. I’m sure I’ll never cut up an X head but it would be a nice comparison. Again, I wonder if the water passages are the same.

I have ported several ports in a 587 head and never hit water. The ports have been made way larger than I thought would be possible. I forget the final volume, but I remember getting flow into the mid 270s.

I also ported a set of late 70s/early 80s smog heads and did hit water - way before I was expecting to. Could have been core shift but I think the water jackets changed in the later years.

Sure seems to me that a 915 J or 587 could be max ported just as far as an X head. In all honesty, with a 2.02 valve job and 15 minutes with a grinder, the other 2 heads could have a way better port than the X head.

 

[PRH]

In all honesty, with a 2.02 valve job and 15 minutes with a grinder, the other 2 heads could have a way better port than the X head.

When you start with a 1.88” valve head, then recut the seat to 2.02, then do the appropriate bowl cut, the short side becomes this tall, steep wall.
Whereas the X head has the SSR tapering down into the bowl, leaving much less of a wall.

My experience has been that it takes a fair amount of grinding on the SSR of the non-X heads with 2.02” installed valves to get to the as cast form of the X head.

 

[Mattax]

When you start with a 1.88” valve head, then recut the seat to 2.02, then do the appropriate bowl cut, the short side becomes this tall, steep wall.
Whereas the X head has the SSR tapering down into the bowl, leaving much less of a wall.

My experience has been that it takes a fair amount of grinding on the SSR of the non-X heads with 2.02” installed valves to get to the as cast form of the X head.

Since its in the casting can I assume that was equally true for non-X heads which came from the factory with 2.02 valves?

 

[PRH]

Same port as posts 14 & 27, now with the bowl machined with a 75* cutter, along with a typical basic bowl blend and some minor touch up of the SSR.
Nothing done to the rest of the port.

Lift——In
.100— 63.0
.200—127.7
.300—180.0
.400—224.4
.450—233.7
.500—235.6
.550—233.7
.600—226.2

 

[PRH]

Since its in the casting can I assume that was equally true for non-X heads which came from the factory with 2.02 valves?

It is.

This is the “cliff” you end up with in a 2.02 J head after the bowl cut is done(this was a factory 2.02 valve head)-

 

[Earlie A]

Whereas the X head has the SSR tapering down into the bowl, leaving much less of a wall.

Interesting. Here's a picture of the SS on my X head. The 75 cut creates quite a cliff on this head as well. Probably not quite as big as a J or 587 cliff would be at 2.02, but still not a nice SS at all.

This is part of the reason I was hoping someone could share a picture of a factory valve job on an X head. I believe on my head the 75 bowl cut is factory. The 65/45/15 cuts are newer. The new cuts are concentric with each other, but not with the 75.

 

[Mattax]

Same port as posts 14 & 27, now with the bowl machined with a 75* cutter, along with a typical basic bowl blend and some minor touch up of the SSR.
Nothing done to the rest of the port.

Lift——In
.100— 63.0
.200—127.7
.300—180.0
.400—224.4
.450—233.7
.500—235.6
.550—233.7
.600—226.2

So even with the X-heads your work seems to reinforce the idea that without some additional work, one can't really get the full potential from a .5+ lift cam/rocker combo with factory 340/360 heads. In fact even a .450 lift gets most of the potential unless one is purposely going higher to get higher lift earlier in the opening.

 

[PRH]

I’ve probably only had 5 or 6 sets of x heads to work on in 30+ years, and none in probably 10 years.
But the way I remember it is, I could easily differentiate the shape of the SSR between the X head and a “newer than X head”(by feel) with a 2.02 in both.

 

[PRH]

I don’t get too worked up about the ports stalling, or backing up some at higher lifts.

There are a lot of really good running cars that are using heads that suffer from it.

I tested a Mullins ported T/A head a couple of years ago.
The porting looked really nice, ports were quite large for a factory head, no pushrod pinch at all.
Flowed 275.6@.600……..and 252.4@.650

 

[273]

Interesting. Here's a picture of the SS on my X head. The 75 cut creates quite a cliff on this head as well. Probably not quite as big as a J or 587 cliff would be at 2.02, but still not a nice SS at all.

This is part of the reason I was hoping someone could share a picture of a factory valve job on an X head. I believe on my head the 75 bowl cut is factory. The 65/45/15 cuts are newer. The new cuts are concentric with each other, but not with the 75.

View attachment 1716445554

I was watching Chris he said he also does a 90 degree cut to throat size, does doing that make sense to you? does seem like it would be a good way to go about it definitely simple, but also heard from Darin he don't make his throat perfectly round it biased to the ssr and center if I remember right.

 

[Earlie A]

It has been my experience that a port that backs up can USUALLY be modified to have a better 'looking' curve. But the curve that backs up will often have more area under the curve in the usable lift range. Increasing the 0.650 flow will hurt the 0.400-0.550 flow.

 

[Earlie A]

I was watching Chris he said he also does a 90 degree cut to throat size, does doing that make sense to you? does seem like it would be a good way to go about it definitely simple, but also heard from Darin he don't make his throat perfectly round it biased to the ssr and center if I remember right.

I watched that video from Chad as well. I was very surprised that he said he used a 90 degree plunge cut to set his throat percentage. Very surprised.

As a matter of fact, I don't even believe he does it that way (all the time). Chad was trained by Darin if I'm not mistaken. And Darin has been teaching the offset throat in his seminars for years.

 

[MOPAROFFICIAL]

Can anyone post a picture of what they know is a factory valve job on an X head? I just picked up a set of 1967 production date heads that are in quite good shape, but I think they may have had 1 valve job. I have 4 angles on the intake and some non-concentricity. I believe the factory valve job would have been 3 angles, something like a 10-45-75. Pictures anyone?

Sometimes there's a bottom cut , 75 or 90 i cant remember, I think 90 though.
Non concentric is the giveaway.

 

[PRH]

Granted this is far from having the two heads on the bench next to each other, but……..

If you look at the point where the bowl cut meets the SSR, you can see there is some of the tapering floor casting visible on the X head, but on the J head it’s a sharp edge.
Also, the bowl cut looks like it might actually be a larger diameter than the J head.
I’m basing that off the length of the 60* cut between the bottom of the 45 and the top of the 75.
The 60 is longer on the J head(and if you cut the 75 more, the cliff gets longer).
Also, keep in mind these two pics are of ports that are mirror images of each other.

 

[MOPAROFFICIAL]

I have notes from a set of X heads I did several years ago.
First test is listed as “OE valves and OE valve job”

Lift——— I/E
.100— 54.6/48.5
.200—117.6/89.0
.300—170.4/117.1
.400—205.7/124.4
.450—216.9/128.1
.500—220.6/129.3
.550—220.6/130.5
.600—218.7/131.7

Impressive exhaust flow huh? lol

 

[MOPAROFFICIAL]

You must have a happy flow bench.

Sorry joke from another thread. I don’t think that’s out of the realm of possibility for a stock x head. Nor do I think the numbers from @Earlie A test are out of the realm of possibility. What is the margin of error on a flow bench in your opinion? Does the same head on a different day repeat fairly accurately?

He sees the same numbers i get on mine.
That other thread i had posted 220, and lone behold...

 

[MOPAROFFICIAL]

Looking at the ports in those old heads it's amazing any of them were considered 'good'. They are all horrible by today's standards. Not really much difference between the X head port, the 915 J port or a 587 port. The X head intake port is about 5cc larger in the bowl and apex area and the 587 has the smog hump in the exhaust port. Other than that they are about the same. All are bad, some are worse.

X vs J, there's a notable difference indeed.

 

[MOPAROFFICIAL]

*Stock class is all about cherry picked cores*

 

[Earlie A]

Granted this is far from having the two heads on the bench next to each other, but……..

If you look at the point where the bowl cut meets the SSR, you can see there is some of the tapering floor casting visible on the X head, but on the J head it’s a sharp edge.
Also, the bowl cut looks like it might actually be a larger diameter than the J head.
I’m basing that off the length of the 60* cut between the bottom of the 45 and the top of the 75.
The 60 is longer on the J head(and if you cut the 75 more, the cliff gets longer).
Also, keep in mind these two pics are of ports that are mirror images of each other.

The throat on my X head is 1.531/1.611/1.650/1.664 with width listed first, then depth parallel to intake flow direction, then two diagonals. 587 head is 1.531/1.572/1.591/1.566. There's a good bit more metal blocking the throat in a 1.88 valve head which validates your point about the short side 'cliff' being higher on the 1.88 heads.

The width of the factory castings is about the same. The extra metal seems to be on the SS as you said.

 

[TT5.9mag]

Looking at the pictures posted by PRH and Earlie A it’s quite astonishing guys go as fast as they do with any of those heads.

 

[273]

I watched that video from Chad as well. I was very surprised that he said he used a 90 degree plunge cut to set his throat percentage. Very surprised.

As a matter of fact, I don't even believe he does it that way (all the time). Chad was trained by Darin if I'm not mistaken. And Darin has been teaching the offset throat in his seminars for years.

Could be an effort reward type deal, get most of the rewards with minimal effort, not every customer is willing to pay for every last hp.

 

[PRH]

Old news for some, but for somewhat related non-X head stuff……

T/A heads