I'm looking at the cut-away and see what you mean. The short side protrudes into the path the gas would like to take, so needs to be cut down a bit. But, on the other side there is plenty of room and little, if any, cutting needs to take place.

As for the guide, I'm not not planning to take any of the guide itself away, but smooth the edge a bit. What I did on the cut-away was too much. In fact, I only showed the one with the least metal taken away as the others were over the top. Anyway, thanks, I'll take it easy.

And I, too, over-think things. That's how I got to tapping and filling the AIR port when everyone I found on the web said don't bother. And, once I did it I realized there's really no easy way to fill it in a way that for sure won't fall out - which could be bad news depending on where the filling went. So, I think I'll pass.

But, if flow between the cylinders is a concern then a rod could be driven into the drilled passage that runs the length of the head. The passage measures .500" so you might get a 1/2" rod to seal if fairly well, but it wouldn't be perfect. Perhaps using high-temp Loctite?

Well, I finished the porting and polishing today. But, I should clarify that everything I read, and especially David Vizard's book How To Build and Tune for Performance with Economy, says that you should not polish the intake side of the heads as you need roughness to help economy on a carb'ed engine. So, while I've cleaned up the intake side slightly, I've focused 95% of my efforts on the exhaust side. While I've put lots of pic's in my album on porting the heads (Ford Truck Enthusiasts Forums - Gary Lewis's Album: Porting D8OE Heads), here's before:
https://www.ford-trucks.com/forums/p...ictureid=79389

And, here's the result:
https://www.ford-trucks.com/forums/p...ictureid=79726

I also lapped the valves to their seats, and here's one of the reasons:
https://www.ford-trucks.com/forums/p...ictureid=79715

And here's what the seat looks like after having been lapped with the valve:
https://www.ford-trucks.com/forums/p...ictureid=79723

And, here's what the valve looks like after lapping, with the shiny part being the surface the machinist ground, and the dull part being lapped:
https://www.ford-trucks.com/forums/p...ictureid=79724

So, my question to you is how should I document what I've done? Do I put on my web site and we put a link to it somewhere? I think that's the best way since I have quite a few pictures and a lot I want to explain.

Anyway, your thoughts?

Intake ports should be rough, as in coarse sanded.

Exhaust ports should be as smooth as possible to help flow and reduce the amount of heat transferred to the head.

Did you use sanding rolls or just burrs?

Valve seats after lapping look normal for a standard rebuild. For performance, I would have cut the seat down to about half of what you have there.

Swirl polishing the valves helps too.

Burrs on both the exhaust awa the intake. Then, on the exhaust I used a rough and then a smooth stone in the die grinder, followed by sanding drums in the Dremel.

And, I worked the short side of the exhaust as best I could, but that's difficult since you are pretty close to the seat when doing that. Thanks for that tip.

Edit: Forgot to comment on the seats. Yes, I understand they could be narrowed. And, a back-cut could be taken on the valve. But, I'm gonna stop here for reliability.

Exactly. For a daily driver, there is no need to go that far. The narrower seat does not last as long either. But if you have to take your heads to have the seats recut, then widening them is only a few more $$$. And then larger valves.....

I don't bother with stones. I go straight from the burr to rolls.

Glad to see you stopped from lapping too much. Seen too many that have a groove in the valve face from lapping. Too much lapping also makes the seat rounded and will not last.

How much stem clearance do you have?

Haven't measured the stem od nor the guide id, although I can do that. What should I have?

And, btw, the engine I "melted" had heads that had been reworked about 2k miles before. I'm not using them since they are D7's with rail rockers and also may be cracked from the heat, so I went w/the D8's. Anyway, the machinist for the D8's but on Felpro's black umbrella valve stem seals while the D7's have a seal w/a band that holds it to the guide. It looks like a better seal, so should I reuse them or is the umbrella fine?

Gary, would you mind adding that cross-section view of the exhaust port to your album? (Ford Truck Enthusiasts Forums - Gary Lewis's Album: Porting D8OE Heads)

Thanks!!

Umbrellas are ok for stock, but I always use banded. I never reuse seals. Would you reuse a rear main seal? Front cranksnout seal? They are not that expensive.

Put a valve in the head, without spring/retainer/etc and rock it in the guide. Grab the tip and see how much the valve moves laterally in the guide. If there is more than just a hint of play, it is probably too much. The exhaust side will usually have more play. I have found this true regardless of make or model. Honda A18/A20 heads are really bad about exhaust guide wear.

Too much side play will allow the valve to seat on an angle and not directly on the seat. This wears the seat and valve face. Also wears out the stem seal quicker.

Anafiel - I've added the cross-section and made it the album cover. However, it isn't the one that I'd put the red lines awa the arrow pointing out the AIR port. I could put that one out there, but I'm thinking about doing another one that shows the curve that I tried to put in there on the roof to get the exhaust gases to starting bending before they hit the exhaust manifold and have to bend quickly. Would that help?

Stang - Good point on the seals. And, I'll check the valves for rock, but I'm very sure there is none given how they fit today when I was lapping.

Anything, and everything. Helps to visualize the project. Sometimes I can look a dozen pics of something, and just not get it until the very last pic. That last angle could be the kicker.

The cross-section you had was one of those kind of pics, and if you have more like you said above, the more the merrier.

Thanks for the time you've taken with documenting this project. It's helped me, and I'm sure it'll help others. Good job, dude!

Speaking of cross section..

Any chance you could cut it the other way through a pair of ports?

I've added this, which is intended to show what I intended to grind out:
https://www.ford-trucks.com/forums/p...ictureid=79743

But, I apologize for the wiggly line. Anyway, if you could see another cross-section just a bit further in and right at the back side of the AIR bump you'd realize that the bump sits in the middle as an island. My intent was to take the island out and leave what would have been the roof w/o the island. So, I ground the bump until I got to the back side of its vertical passage and went just a bit further, sorta like the red lines show.

Stang, I'm not understanding where you'd want it cut. Try me again?

Am I the only one to rate this thread 5 stars???

When done perhaps Chris can sticky this to the top of the page.

As far as exhaust movement between thermactor ports, a few of the porters over on 460Ford and the old Network54 suggest just pumping them full of silicone caulk.
Sure it will char on the surface, but if any comes out it's only going out the tailpipe anyhow.

Jim - Thanks for the kind words. But, it's the help from the rest of you, and particularly Stang, that has made the difference.

As for making it a sticky, maybe Chris could change the title to Porting D8OE Heads when the time comes to ditch the "documentation" part. And, we could put a link to the writeup I'll do on my website in the first post so people can find it. I do think it would be helpful to explain my intent for the porting, which was more efficiency than power, as that changes where you spend your time, and I'll do that in a page on my website.

Re the AIR ports, I suppose it wouldn't hurt to pump them full of high-temp RTV. Most comments I've read say not to bother, but you never know about the source of comments you read on the Internet. The RTV approach is about the only thing I can think of that is safe, since the cast iron of the heads is going to expand away from anything you screw or drive in there, ultimately allowing it to fall out. And, since it is above the exhaust valve there is the possibility it'll come into the cylinder. I'll think about that. Thanks again.

As I said Gary, this was in regard to porting D3VE 460 heads. But the idea is the same.
Certainly the vast majority of the heads don't get hot enough to disturb the silicone, just the area right around the exhaust ports.
Doubt it could "fall into" the cylinder. Whenever the exhaust valve opens there is a lot of pressure on it's way out.

Carry on.
This is a GREAT thread! :-X22