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I was thinking bout doing some head work before I get the new short block. I cant afford to get a full port and polish, but how much would it help to polish the heads myself? Not enlarge the ports really but just smooth out the rough finish from casting? I made 435 with 15 degrees of timing @ 13 psi but cut it off at 6100rpm. I plan to run it to 7000rpm with the new motor . My tunner said the heads get restrictive when you near the 500hp mark. Is it worth polishing the heads? I was thinking bout doin the exhuast manifolds too, as much as possible at least.
 

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It wouldnt hurt I guess. Luckily, I am getting mine ported/polished. My buddy has a GT making 500/500, and he has (Cleaned off) heads, no port, and it works pretty well.

Gains, dont know. Because when he got his motor build he added the supercharger/cams.
 

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No flow gains from smoothing them as they are already pretty smooth.

Intake side cut out the bump in the roof under the adjuster. Cut out the fuel injector vane if you want, its questionable if that gain is still there once the intake is bolted on. Those 2 mods give about 5-10CFM. If you have a pair of brass ones you can straighten out the curved right side wall to where its 1.3" or so of width in the full length of the port. Its alot of grinding though to do that.

Exhaust side you need to lay back the long turn radius just beneath the valve seat and up towards the sides of the guide. Thats about 10CFM there.

Any other gains ain't really happening unless you pull the guides and reshape it all.

Polishing is a waste of time and is bad for your lungs.
 

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If you have the smoothing bit and really want to jump on those heads, definitely do a gasket / port match. That will help flow more than anything.

I agree with the others that its too much time and labor involved, and you just might mess up and take out too much. I have seen someone actually burn through and to fix it, they used JB weld and resanded that. Well, the temps got up and the JB weld developed a pin hole and coolant leaked down into one of the pistons.
Just issues you can have when messing with headwork.
 

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JB weld. EWWWW.

There is a actual epoxy for that. Or a tig welder.

Gasket matching doesn't do a thing unless you blend it back into the runner and clean up the short and long turn radius and the bowl area around the valve. Otherwise you'll just have funnel ports.

I say just sand roll it. It will only take a few mins with the valves out. Other then that it's going to take removing material to see any real gains.

I would smooth out the emmission mark/swirl dam to get rid of the sharp edges to ward off detonation.
 

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JB weld. EWWWW.

There is a actual epoxy for that. Or a tig welder.

Gasket matching doesn't do a thing unless you blend it back into the runner and clean up the short and long turn radius and the bowl area around the valve. Otherwise you'll just have funnel ports.

I say just sand roll it. It will only take a few mins with the valves out. Other then that it's going to take removing material to see any real gains.

I would smooth out the emmission mark/swirl dam to get rid of the sharp edges to ward off detonation.
Agreed on gasket matching being worthless as the gasket area is where the port is already the largest on the 2V head.

Don't touch the swirl dam unless you completely remove it, I lost 10% down low and 5CFM up high by just touching it lightly.
 

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Don't touch the swirl dam unless you completely remove it, I lost 10% down low and 5CFM up high by just touching it lightly.
So which is better to leave them alone or remove them completely?

When you are talking about smoothing out the exhaust radius are you talking about removing material on the deck side or the bottom of the exhaust port? Maybe squareing it up a little next to the valve. If this makes any sense.
 

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So which is better to leave them alone or remove them completely?

When you are talking about smoothing out the exhaust radius are you talking about removing material on the deck side or the bottom of the exhaust port? Maybe squareing it up a little next to the valve. If this makes any sense.
I leave them alone. A blower car seems to live without them fine but an N/A car needs a ton more timing. I haven't seen a back to back removing them only for a blower car to see if it really helps there either.

Exhaust side just beneath the valve has a large protrusion in the bowl. Lay that back and up into the roof and thats 90% of the gains possible IMHO.
 

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if u have enough skill with this kinda thing u can also try to do a little bit of a d shape exhaust port which will help with exhaust flow and scavenging.
 

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Agreed on gasket matching being worthless as the gasket area is where the port is already the largest on the 2V head.

Don't touch the swirl dam unless you completely remove it, I lost 10% down low and 5CFM up high by just touching it lightly.
That's because you don't know how to tune for it.

You have to add timing once you prone it back. You should smooth it out. Removing it totally makes the combustion chamber dead.



This what Foxlake does to theirs. I had to add a couple of degree's at cruise for it. But it helped reduce detonation considerably under boost.

The edges are very sharp to start. Which will cause detonation even in a N/A motor. I've seen it blow the ring lands out of the pistons with reasonable timing on a NA motor.
 

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That's because you don't know how to tune for it.

You have to add timing once you prone it back. You should smooth it out. Removing it totally makes the combustion chamber dead.

This what Foxlake does to theirs. I had to add a couple of degree's at cruise for it. But it helped reduce detonation considerably under boost.

The edges are very sharp to start. Which will cause detonation even in a N/A motor. I've seen it blow the ring lands out of the pistons with reasonable timing on a NA motor.
Have you done a back to back test only changing the chamber to prove this?

The sharp edges of the dam don't cause detonation or they would crumble if they got that hot like the area around the spark plug thread here:



I would think that the dam stays pretty cold with all the air and fuel coming across it on every intake stroke.
 

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Yes I have.
And so has Foxlake, Livernois, TEA, and countless other cylinder head porters. TEA I believe takes it all the way off. And the chamber does require more timing. Everywhere.

Just because the piece didn't melt doesn't mean it doesn't cause detonation.

How did you loose 5 cfm from removing a restriction around the valve? Curious. Because Foxlake has some of the best flow numbers around. And I've talked with Ron at length about this. And they agree it's best to prone it back then knock it all the way off.

How many heads have you tested with different configs on blower cars. I've tested 3 different ones so far. And my friend has TEA heads and I have all the data on those.
 

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Well if you have the data please show the before and after dyno results with the chamber only mod so I can see if its something I want to do.

I did my testing on a flowbench personally and saw the numbers change myself. I didn't think touching the dam lightly would lower flow but I was proved wrong. There is a bit more going on there than flow inhibition, thats why Ford designed it to the shape it is.

I have also tested many of these other heads on the same flowbench. True you get more flow if its completely removed but one of those famous name heads without it only made 5 more RWHP than a stock head on a 300RWHP N/A car even with the 30 extra CFM of intake flow on a local dyno (only change was the heads and the massive amount of extra spark advance needed)

Getting back to the original post, DIY modding of the swirl dam isn't something I recommend and you would have to be very skilled to accurately duplicate the Foxlake shape by hand instead of a CNC. The recommendations I gave are what I found personally on the flowbench myself and what I think an average DIY can do without pulling the valve guides. We can say Foxlake this and TEA that but its a rare DIY that can accurately duplicate that port shaping so why bother.
 

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Were talking boosted cars.

The person who started the thread has a boosted car.

Sorry I don't keep dyno graphs 300 deep on my car(Really only keep the money pulls, lol). Also how are you going to tell if it was detonating in a dyno graph? What is a dyno graph going to tell you about timing and combustion events. Not much. We've pulled my car with stock heads, Foxlake stage 2 heads which had the old combustion chamber design then Ron's stage 3's with more machined off. Then Mike Dez owns the TEA heads that we tested. Mike has tested just about every modular head out. And a bunch on my car.

And your trying to tell me a ported head is worth 5hp over a stock head. No offense but your data is useless if that's what you found. 5hp is barely repeatable on a dyno. We've seen more then that on a chassis dyno.

Flow numbers and HP numbes you've made on big power cars? You've made with your heads.

Was on your website. Your dog is cute.

You hand port all your stuff?
 
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