what to do about porting 3&4 port runners

matt1967

Famous Member
I don't want to go to the expense of having a port divider welded into the head, and my teacher isn't shure on what to do about the 3&4 siamesed ports, all he can figure is do a little bowl porting under the valve and call it good. this is a '67 head, any suggestions?
 
Or do the racer's trick when no welding is allowed on the head - install a "fin" to the header flange.
 
No one can say for sure the divider does any good anyway. If it could be proved, it would be very minimal. I wouldn't fret it.
 
I wonder if its main benefit would be to keep some heat off of the lower side of the intake.
 
Was it fitted to the 2V head, when Ford retooled to make that casting? :wink:

I seldom support a "company line" but here it seems well-founded (pun noted).
 
Hmmmmmm, interesting.
I didn't have a divider welded in when they did the build on the 250, it was an after thought. So I pretty much thought I'd be stuck using the stock exhaust manifold until I removed the head to have that thing welded in. Or I even kicked around the idea of welding something to the header that went inside the manifold like mentioned above.

So I guess the question is "how much can or will be gained by dividing the port?"
and is it really necessasary if you are putting on headers?

This is purrrrfict timing for this topic.
 
Linc's 200":g0jf3qob said:
Slickmofo":g0jf3qob said:
is it really necessasary if you are putting on headers?

Might help keep gaskets alive longer

But to remove the head, remove the 2 valves, have the part welded in and machined flat, put the head back on and botton up the whole top end.
My guess; 6-8 hours labor and a good 100 bucks at the machine shop.

Are the header flanges not fitted properly over these ports?
 
My headers went on today and the question of the siamese port wasn't even brought up. 3&4 pipes are welded to a single plate. I don't know anyone with a port divider in Oz. Just doesn't seem to be an issue.
 
:( today, I was porting my head, just finishing up, been coming along nicely until I cut through 1 exhaust runner, and noticed another was almost all the way thru, and with a little poking, it was thru. so I can ither have it welded or buy a diffrent head, so I called around and found a place that might have 1. I asked for a '78 Head which would be better flowing, and have hardened seats arleady, so I wouldn't need that done to the head, like I would this 1.
 
fxp":1hn4y6cg said:
chin up, you learnt something! Nothing beats experience (even bad ones).
I'm not really worried about it, If I can't find another 1, I'll have this 1 welded, it's a minor setback but, next time I'll mic the thicknesses as I'm porting, so I don't repeate this prosess.
 
matt1967,

Keep improving your skills with the grinder on that '68 head but it is truly a dog (lose it). The '78 head is alot better flowing, the '80 might be a touch better... but not worth hunting for.

Don't get carried away with this hogging out the ports crap. It isn't necessary and may even hurt. Just narrow the guides, careful bowl work, competition valve job. Mike has some nice stainless steel proflow valves (1 3/4" intake and larger, 1 1/2" exhaust valves - they have a narrower stem for better flow).

You can unshroud the valves like Fast '64 Ranchero did. He has pics on one of his posts. Be careful and not go wider than the cylinder.

As far as the port divider deal, it has more of a benefit on a turbocharged log because it acts as an insulator. With the extra power the turbo will provide it will be like having a huge blow torch heating up your intake manifold. That's why Ford designed it exactly the way it is. Your exhaust will also be hotter and denser because of back pressure. You don't want it heating up your intake air causing power loss and detonation. You may not notice it with a quick hit of the throttle but stay on it for a full 1/4 mile and the heat will catch up with it.

The trick to installing a port divider is carefully grinding it to fit exact and protrudes ever so slightly and just tack weld it top and bottom where it's vertical - you don't want it welded everywhere, you want separation for less heat transfer.
 
drag-200stang":1smf34af said:
matt1967,

Keep improving your skills with the grinder on that '68 head but it is truly a dog (lose it). The '78 head is alot better flowing, the '80 might be a touch better... but not worth hunting for.

Don't get carried away with this hogging out the ports crap. It isn't necessary and may even hurt. Just narrow the guides, careful bowl work, competition valve job. Mike has some nice stainless steel proflow valves (1 3/4" intake and larger, 1 1/2" exhaust valves - they have a narrower stem for better flow).

You can unshroud the valves like Fast '64 Ranchero did. He has pics on one of his posts. Be careful and not go wider than the cylinder.

As far as the port divider deal, it has more of a benefit on a turbocharged log because it acts as an insulator. With the extra power the turbo will provide it will be like having a huge blow torch heating up your intake manifold. That's why Ford designed it exactly the way it is. Your exhaust will also be hotter and denser because of back pressure. You don't want it heating up your intake air causing power loss and detonation. You may not notice it with a quick hit of the throttle but stay on it for a full 1/4 mile and the heat will catch up with it.

The trick to installing a port divider is carefully grinding it to fit exact and protrudes ever so slightly and just tack weld it top and bottom where it's vertical - you don't want it welded everywhere, you want separation for less heat transfer.

I'll know tomorrow if the yard has a cyl head I can buy, they have a compleate running '78 200 but don't want to break it up, so there searching there yard for another. I was going to get the larger SI valves Mike offers anyway.
 
matt1967 said:
I cut through 1 exhaust runner, and noticed another was almost all the way thru, and with a little poking, it was thru. /quote]

Pictures?
 
Linc's 200":2fu23rhv said:
matt1967":2fu23rhv said:
I cut through 1 exhaust runner, and noticed another was almost all the way thru, and with a little poking, it was thru. /quote]

Pictures?

I'll get some today, I cannot gaurentee my Cheapo camera will take clear pictures, but I'll try.
 
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