T/A heads

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I thought I was getting a set of basically stock heads, but this is what showed up.
They’re going on a fairly mild mannered street build with ex manifolds.
Before they showed up, I had it in mind to do some mild porting and have the heads in the 240’s range.
So, the one head is basically there....... I’m just going to try and make it not drop off so fast.
If you look close at the pics from Head B you’ll see not only is the backside of the intake guide boss boat tailed, but the leading edge has been ground to a point.
I’m not really a fan of sharp edges on the leading sides of things in intake ports, so those will be getting rounded over.
Also, the places in the port where the porting meets the untouched areas, the transitions aren’t very smooth, so those will be getting dressed up.

These heads will be getting hardened ex seats installed, which I don’t have here yet, so I won’t be doing any work in the bowls until after they’re installed and the seats have been recut.

After that happens I’ll lightly clean up the entire port, tweak the short turn, and retest.
Then, I’ll know how much work will have to be done to Head A to make them more of a matched “pair”.
 
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Hyper_pak said:
Can these numbers be compared to other head flow values? I know each bench varies, but were these done at a standard pressure? I have seen some slant six flow numbers and was wondering if it's apples to apples. Thanks for the data.
Click to expand...

As stated in the posts, the flow data is for 28” test pressure.
Not converted...... the actual test pressure was 28”.

As for comparing to numbers from other benches/sources....... frankly, it’s not a good idea to assume it’s “apples to apples”.
 
I’m just about finished with this second set.
The “ported” head had the pinch opened up way more than necessary for this build, and also have quite a bit more work to the intake guide boss than I would have done.
Especially on the curved wall side.
They had it trimmed down enough so you could get a 1/2” burr down in between the guide and the curved wall.
I “prettied” the intakes ports up on that head. How much of those 4 ports were worked on varied from hole to hole, so I just kind of finished them off.
I also got rid of the peak at the leading edge of the guide.
After installing the ex seats and re-cutting the intake seats and bowls, a fair amount of additional blending was done there, along with a reworking and rolling back the SSR.
The port openings were “close-ish” to the std intake gasket, but weren’t very uniform, so I brought them all out the the gasket size.
The ex ports just got the new seats blended into the bowls, and then the rest of the port very mildly “cleaned up”.

This is head “B” after the ex seat install, seats recut, bowl cut, and the tweaking of the ports:

Lift—— in/ex
.100— 63/46
.200—131/98
.300—192/131
.400—236/149
.450—252/156
.500—261/162
.550—257/166
.600—253/168
.650—252/172
 
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Head “A” only had some minor bowl work done to it before I started in.
It also got hardened ex seats installed along with the intake seat and bowl being re-cut.
The PR pinch on this head hadn’t been touched, whereas in the other head it was blown out pretty good.
Certainly way more than would be required for these flow levels, and way more than I really felt like doing on this head.
I opened the ports to the gasket, and removed enough of the pinch so it didn’t “look” too much different than the other head.
Basically, I made them 1.050” wide....... about .100” wider than I’d do for this type of job where I wasn’t using T/A heads.
(The port I tested on head “B” was already 1.150”+ before I dressed it up).
I also didn’t remove as much from the guide boss on the curved wall as the other head(can’t quite get a 1/2” burr in there), nor did I take quite as much from behind the guide to make the boat tail as pointy.
To make the appearance of the two heads similar, I knocked some of the peak off the boat tail on head B to match this one.
The ex ports were done the same way as head B.

These are going on a hot street build with ex manifolds and a cam very similar to the MP 528 cam(which would also work fine in this motor).

Lift—— in/ex
.100— 63/47
.200—130/99
.300—192/131
.400—237/148
.450—255/155
.500—259/159
.550—251/162
.600—253/165
.650—254/168

At least as far as the flow bench is concerned, at these flow levels, the big PR pinch seems to be worth basically nothing.
I normally get a std head PR pinch into the .960” range when going after this much flow.
The limiting factor for flow still ends up being the SSR.

Since this isn’t a race car where max power is the top priority, and these aren’t run of the mill J heads that are easily replaced...... I’m erring on the conservative side on how much I’m going to lay back the SSR.
Looks like 255-260 is where these are gonna be.

If I’d have had two unmolested heads to start with....... they would have rec’d less porting, and flowed less.
 
PRH said:
I’m just about finished with this second set.
The “ported” head had the pinch opened up way more than necessary for this build, and also have quite a bit more work to the intake guide boss than I would have done.
Especially on the curved wall side.
They had it trimmed down enough so you could get a 1/2” burr down in between the guide and the curved wall.
I “prettied” the intakes ports up on that head. How much of those 4 ports were worked on varied from hole to hole, so I just kind of finished them off.
I also got rid of the peak at the leading edge of the guide.
After installing the ex seats and re-cutting the intake seats and bowls, a fair amount of additional blending was done there, along with a reworking and rolling back the SSR.
The port openings were “close-ish” to the std intake gasket, but weren’t very uniform, so I brought them all out the the gasket size.
The ex ports just got the new seats blended into the bowls, and then the rest of the port very mildly “cleaned up”.

This is head “B” after the ex seat install, and the tweaking of the ports:

Lift—— in/ex
.100— 63/46
.200—131/98
.300—192/131
.400—236/149
.450—252/156
.500—261/162
.550—257/166
.600—253/168
.650—252/172
Click to expand...

Pics or didn't happen. Haha
It's buzzing round on a riding mower when someone's already done the weed whacking. Jk. Still takes skill as it could still be easily wrecked by another novice.
The chamber seat edges rounded help low numbers. I've removed them and sometimes see a - effect as well.
Wish they all could be T/A heads.
You can spend the time and get the port pretty big....but then you're fighting the air speed @ the push rod pinch.
Just another reminder that the mopar production heads are still contenders.
Half inch between the guide and bowl, that's common practice. I have not gone wider than that at near the roof cause the potential rust pitting on cooling jacket side. I treat every cyl head as if is the last in existence..so not trying to hit water.
Nice seat/angle widths, very important.
What is the air speed near the spark plug/exhaust side of bowl and directly across from that?
Thanks for sharing.

Ps, I quoted your post before you edited it and added the paragraphs below the numbers.
 
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Head A:

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Those TA heads look about and flow the same as some I ran many years ago in my Dart.
Flowed 253 at 25” with a stock valve.
The other day I had to clearance a little more for pushrods. So I did a smidge more work on these.
It’s a stock stroke 360 so no need in a max effort.
Critique away.

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Definitely an older mill.
Click to expand...

Probably....... and maybe missing a few carbides.

The surface is very course.
They’ll be getting cut before they leave for sure.
 
Well, this second set is ready to get shipped off.

Spring pads cut for dual springs, guides cut for Viton seals, flat milled, jet washed, and assembled with inner springs removed for cam break in.

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famous bob said:
was wondering if u were going to do the guide bosses ------------
Click to expand...

I wanted the flow to be pretty close between the two heads, and you’re not going to end up close to 260 without doing that.

Had I started with two untouched heads, for this build I would have been shooting for mid-240’s.
I could have gotten there without doing much to the guide bosses.

Since they were whittled down pretty far on the one head, that kinda dictated the course of action on the other head.
 
As I mentioned earlier, these heads had paint everywhere.
Before I started working on them, I bead blasted the paint out of the chambers and runners.

I installed the ex seats afterward, then machined the seats and bowls before starting in on making iron filings.

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Thank-you for posting all these pictures! It gives me a pattern to follow if I haven't hogged them out past this point already.
 
They’re already assembled, so the photo ops are over.

Pics of short turns are pretty much useless IMO.
Unless the SSR protrudes fairly significantly into the bowl, you can't tell by looking at them if they’re good or bad.

Tweaking the peak in a way which could be worth 10cfm or more, after the numbers have started to back up, won’t show up at all in a pic.

Even when I’m doing the work....... I don’t look at it...... it’s done be feel.
If I could tell by looking at it if it was good or not....... I wouldn’t need to flow it.

The bottom line for this style of head is...... at least with all the ones I’ve seen and done....... it comes down to how far you dare push the SSR back.

And this is why I find it much easier to get higher flow out of X heads.
The as cast SSR is laid back more....... so if you remove the same amount of material from that area of an X head and J head....... you end up with the X head having a lower and more laid back SSR....... which translates to higher flow with the way I port them.

As always......YMMV

If you blow up one of the intake port pics, and flip it over..... you can see the turn from that vantage point.

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Everywhere you’d want to grind........to improve the SSR form, to help with the flow staying connected as it makes the turn........ there’s water on the other side of where you’re grinding.
 
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PRH,

I am very impressed and thanks for sharing all the pics. I have a set of T/A heads that need this kind of work. pm sent.
 
A little addition to this thread....

Over the last 4-5 years I’ve had 5 sets of T/A heads come thru the shop.
Seems like none of those sets saw “quality” machining in their last trip to the shop.

I just shipped off another set that had the same experience.

This set had ex seats installed that had a noticeably too large ID, and a lack of any kind of blending to help that situation out.

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Those seats are also a larger OD than what I prefer to use for these heads........ and since they weren’t pounded out, and had no evidence of anything leaking from something bad going on behind the insert, I left them in and blended the big ledge away.

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As can be seen by the pics, these heads had 1/2” OD bronze guides installed.
They were pretty worn out, so they got replaced.
As many of you probably know, stock SBM heads don’t have an abundance of spring installed height.
They also dont have a bunch of retainer to guide clearance.
The replacement guides on this set of heads had the new bronze insert sticking out above the top of the original guide boss by about .060”.
Several of the hard plastic umbrella seals were split, and the tops of the guides were shined up.
I suspect there might have been some mild contact going on there.
I spot faced the original guide boss down and replaced the bronze guides.
I made it so the top of the new guides were about .100” lower than the original boss.
With only the 1/2” guide sticking out above the spring locating step...... it makes for an easy positive seal install.

The other thing I noticed was that most of the chambers showed evidence of the combustion leaking past the gaskets.
There was a very odd pattern to the head surfacing, so I suspected I was going to find an issue with how flat the head was.


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