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Discussion Starter · #1 ·
Been a while since I've done a port matching job, although I've recommended it plenty. The whole job took about 2 1/2 hours, including the manifolds, which needed a lot of work.

Engine is out, and the owner wants a performance upgrade.

You can see here from the soot line, even the stock manifolds (log type) have better openings than the heads. You can also see the huge lump inside the port, for the un-machined Thermactor injector.

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Another view-

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Since the owner wanted to retain the manifolds, here they are opened up to the full size of the gasket pattern. Not only were they smaller than the gaskets, they had a core shift problem that had two ports on each manifold 3/16" offset compared to the heads. I fudged a bit on the upper left corner, due to how narrow the manifold flange was at that corner, due to the relief for the injector. The manifolds were smoothed about 1 1/2" inside, to improve flow, and remove rough casting flaws.

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Then I moved on to the heads. The rough, constricted openings had to be smoothed on the right side, and opened considerably on the other three sides. And of course the huge Thermactor lump had to go. On the manifolds I cut all the way to the gasket. The Sharpie line on the heads will only be cut halfway to the gasket, to avoid exhaust hitting a ridge at the opening. I have used the flange bolt holes on the manifolds and heads to align the gasket.

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After opening up, and removing the Thermactor lump. The whole pocket has been smoothed, to remove numerous lumps and roughness-

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Here's the completed heads.

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A week later, the engine is assembled-

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Very nice! Be sure to let us know the owner's thoughts after he gets to drive it!
Would hipo manifolds help that much in lieu of the stock manifolds? Probably a bit spendy with the h-pipe upgrade and all...
 

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Awesome, thanks for showing this. How much did it cost to have the rest of the machine work done on the heads - valve guides, new valves??, etc??
 

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Wow, great write-up! I'm still pondering what to do about heads and watching you guys port and polish your own stuff has me thinking I can do it too :).
 

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Sorry, my photos are in reverse order.

So right off the bat you can see I went big, and yes, I did ruin 1 head by porting into the water jacket.

As 22GT did, I also used the exhaust gasket as my guide. I matched the gasket to the exhaust first to make sure it was aligned, and then transferred the opening to the heads. I went high and removed not only the exhaust bump, but also much of the area where the valve guide drops down. This is not recommended for a street engine and you do not do this at all for the intake side. I used the sanding rolls and cleaned up the valve pockets, and smoothed out the combustion chamber just a bit to help remove any potential hot spots.

This type of work is not easy, and I spent a couple of weeks with the carbide burr and maybe 100 or more sanding rolls of various grit. I searched the internet and found this article by Article by Mark Reams that I used as my guide. Again, I did cut into the floor of one port too much and hit the water jacket. Though I did try to weld it up with special high nickel wire, it did eventually fail and I had to replace the head.

Not shown is the intake port matching. Very little was needed there and I only used the sanding rolls to clean up the intake ports. There is an entire section on intake port airflow velocity that I am not even going to attempt to get into here.

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As I understand it, if you smooth the ports too much you lose turbulence for air fuel mixing. No?
 

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Great write up. I have always thought that everybody doesn't need 500 or 700 horsepower potential heads. Some people still just want a mild performance increase on their stock engine. Your customer was fortunate to have found you with the skills to do this. It has become something of a lost art unfortunately.
 

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As I understand it, if you smooth the ports too much you lose turbulence for air fuel mixing. No?
This is the exhaust side, so not an issue. And I wouldn't say its a lack of turbulence that causes the issues, moreso its a lack of charge velocity. Just increase the flow demand with a larger cam and more rpm's to bring back velocity.
 

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Discussion Starter · #13 · (Edited)
Very nice! Be sure to let us know the owner's thoughts after he gets to drive it!
Would hipo manifolds help that much in lieu of the stock manifolds? Probably a bit spendy with the h-pipe upgrade and all...

I'm sure you'd get a bit more power with HP manifolds, if for no other reason than they have bigger inlets than the standard ones.

Awesome, thanks for showing this. How much did it cost to have the rest of the machine work done on the heads - valve guides, new valves??, etc??

No cost for the above, I'm afraid. They were all well within limits, disassembly was done only as a precaution due to the millions of metal chips created by the work.

Nice work and thanks for the detailed share. What AC bracket is that for the Sanden AC compressor?

Classic Auto Air daily driver. The included shims were useless, and it required a bit of a tweak for perfect alignment. Looks good now, though.

This is really neat, but I'm drooling at that last shot of that clean shop full of Mustangs. :)

That's actually less than half the shop, and yeah, he keeps the place pretty clean, even on the body/paint side.

Wow, great write-up! I'm still pondering what to do about heads and watching you guys port and polish your own stuff has me thinking I can do it too.

The first time I did it I'd never even seen it done, just a few magazine photos. Practiced on a pair of 69 302 manifolds from the parts bin. Somebody got a really nice set of used manifolds after I put them back.

So right off the bat you can see I went big, and yes, I did ruin 1 head by porting into the water jacket.

Well, you, sir, went for the gusto, with a full porting and polishing job. The results are impressive. Have you had it on the dyno? That I'd like to see. Only time I have seen a bigger port is on the Crane Fireball head, which was a Ford Service Replacement head with HUGE ports opened up.
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As I understand it, if you smooth the ports too much you lose turbulence for air fuel mixing. No?

No. If your carb isn't cutting it, the passages are not going to fix the problem.

Great write up. I have always thought that everybody doesn't need 500 or 700 horsepower potential heads. Some people still just want a mild performance increase on their stock engine. Your customer was fortunate to have found you with the skills to do this. It has become something of a lost art unfortunately.

True. All the magazines go straight to buying Acme Super Heads. (d'ya think the advertising has something to do with it?) Since I wasn't actually enlarging the ports beyond the original design, There was virtually no risk of water jacket intrusion. All I did was remove the excess material from the opening, and the Thermactor lump, which is solid, in this case undrilled. Even if it was drilled, though, you can flatten it out with no real risk. Getting decent street performance from these heads is not a problem (and much more satisfying than spending a grand or two) to get a smooth, powerful cruise night rocket, or even autocross machine.

This is the exhaust side, so not an issue. And I wouldn't say its a lack of turbulence that causes the issues, moreso its a lack of charge velocity. Just increase the flow demand with a larger cam and more rpm's to bring back velocity.

Also quite true. The intake passages in the stock iron heads are usually pretty good. All I did with these was pass the burr over the surface to ensure there were no big flaws or casting flash interrupting the flow. There weren't, it only took me 2-3 minutes to be sure of the intakes. The smallblock exhaust ports are the real weakness of these heads, the sand core for the original version in 63 was, to be kind, indifferent. They got worse every year, especially after provisions were made for the Thermactor system, whether it was the Windsor or Cleveland style. And I've seen smallblock heads with a horrifying amount of casting flash right at the opening.

Frankly, I'd do this even to a stone-stock 260 2V engine, I consider it part of proper assembly. This engine received a cam somewhat milder than the C9OZ-C, but much more open than the stock C3AZ-V.

The only dyno results I've ever seen for this simple port-matching work was a 67 289 2V, converted to 4V, and a C9OZ-C cam. I did one port while the owner watched, then he went home and did the other seven. After assembly, he had it put on the dyno, and it turned 323 hp at 5300 rpm.
 

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Very nice! Be sure to let us know the owner's thoughts after he gets to drive it!
Would hipo manifolds help that much in lieu of the stock manifolds? Probably a bit spendy with the h-pipe upgrade and all...
As a side note, I installed the HiPo exhaust manifolds when I switched to Gt40p heads. I don’t really port them, but the inside was extremely rough and bumpy. I spent some time to make it smooth.

At the exhaust side the walls can be as smooth as possible to increase the flow. Don’t do a mirror finish at the intake side.

Great work!
I’m curious about the feedback from the owner. Before and after dyno results would’ve been great.


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Been a while since I've done a port matching job, although I've recommended it plenty. The whole job took about 2 1/2 hours, including the manifolds, which needed a lot of work.
This brings back fond memories. When I took my junkyard 351 to the machine shop I asked the fellow about doing the porting. He explained what to do inside the valve areas and around the ports. I made a jig to hold the heads and rigged up a shop vac to pull all the removed debris out the other side of the port/valve I was working on. I did both heads - took a few days to get both heads done IIRC. The machinist actually seemed a bit impressed - and I had a lot of fun too. Thanks for sharing that!
 
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