98UAGT

So I had bought PI heads and cams, and when I got them they were trashed. One of the valve guides was broken, and the cams were pitted out. It looked as if they had rust on them (maybe leaking coolant and water) and someone tried to powerwash them. And something had been in the engine they came from because there were huge spots where there had been piston-to-head contact. So I just bought a set of SVO heads instead! I was reading the Sean Hyland 4.6 book and he claims those are the best heads for 4.6s. There is a chart in there with serious fact to back it up to: the SVO intake outflows the PI all throughout lift on the intake side, and outflows PI exhaust after.100 lift. Anyways, what I am getting at is does anyone have these heads? I am going to poo myself when I put them on because just looking at the heads the valves and ports are HUGE!

98UAGT

Sorry couldn't find the book to list the REAL facts, but I just found it. The intake valve is 46.83mm, and the exhaust is 35.88mm. It has a 173cc intake port, the largest of all the 4.6 heads. With .500" intake lift the NPI flows 156 cfm, the PI flows 156 cfm, and the SVO flows 193 cfm! At .550" the SVO flows 203 CFM. On the exhaust side, at .550" lift the NPI flows 117 CFM, the PI 136 CFM, and the SVO 141 CFM. So there is data to back up the fact that the SVO heads are definitely the best heads for the 4.6. The only downside to the heads is that it will only accept the NPI intake or the SVO intake, in which the Bullitt intake was designed after. So now I am after an adapter plate for the PI intake I have sitting in my garage. I know Livernois makes them, but I think you have to buy the whole set (intake and adapter plate), which I don't need to do.

BCisme

ported PI heads flow better than that. but you can port the SVO heads as well i'm sure. with a set of cams and a good intake you should be able to break 300 rwhp with full bolt ons and a good tune. good luck.

kubball2005

Just cuious, but how much did the heads and cams cost ya?

sweet99

Interesting, a google search had this on the first page. Ford ran the last of these heads back in the winter of 2009, January or so and sold them out rather quick. I'm looking for a good set now. I have a set of the Windsor PI Heads and PI cams to sell also.
I also run an SVO intake, $1950. for the complete intake and install kit. I had to drive 800 miles round trip as the seller would not ship nor separate and I also had to take 24lb. injectors, the SVO ECM(sold that), a set of 3.73's(sold) the SVO TB, throttle cable, inlet tube, SVO strut tower bar(might sell). Since it was 3 years ago I have forgotten most of it. Oh, a set of Sean Hyland #2730 cams and a set of PI heads. Rear differential Ford synthetis oil and additive, all synthetic.
More I can't remember. I was offered $500. back then when I simply mentioned the purchase and it was not for sale. It would be ebay goods most likely, especially because almost all of the install kit is there, EGR tube/valve. I need a set of heads with a chamber close to the 51cc chambers the SVO's have. My 11.2:1 static compression is just a bit too high with 43ccchambers Hope the heads worked out for you. Limited to .532" lift but that is fine for a 4.6.The last run sold at $440. each bare. Mark