Contour Enthusiasts Group Archives Forums Modifications Duratec Performance ported and polished heads

You read my mind. I'm thinking that would be good to do with the 3L swap. Kinda the same philosophy as tranny work. Since its out and in pieces, why not. I had asked earlier in the post about downsides. Will this decrease the life of the engine in any way?

The $650 I quoted was for both heads, an entire port and polish job abd a three angle valve job included.

I think no one is replying because the answer is no. It just aids in breathing. Thier is a lot of metal left in the casting process that can be removed. Just to expensive to do in a factory and also we own mass production vehicles.

So, in your opinion would it be a worth-while step when doing the 3L swap?

Just a couple of points.There is NOT a lot of material on the intake ports,this is one of the thinnest areas on the head.The inside of the combustion chamber can be milled 'lightly' to smooth it out and some heads have a cast in 'tongue' between each intake and exhaust valve, this can be removed.On the valve job its the 'back angle ' of the valve that needs to be modded to reduce reverse flow.If you have any data on the Cosworth 2.0 cylinder head you should use that as a guide for mods to the Duratec,works quite well.As a final point ,ALL the combustion chamber volumes must match AND the port volumes,if you want to do it right.regards Terry Haines

I have ported and polished heads myself on three separate vehicles and I have had mixed results. I have grown up in an automotive/mechanic family and been around cars since I was very young. The first car I ever did was a 2.8V6 for a friend that had an X-11 citation. It was a H.O. V6 (for its time, and old when I did it) from the mid 80's. All I did was widening, smoothing, and polishing. Since it was never dyno'd and it was with an atx, all I can say is that the power was smoother over all. Then next engine that I ported was the 2.7L inline six cylinder from a 1982 BMW 528e.
That engine still impresses me. It was tuned multiport fuel injected for its time and had semi-tuned cast iron exhast manifolds. I widened, reshaped and polished the exhaust ports only on this head. The intake was already large and very smooth for a stock casting. The low end torque jumped so much that I was completely amazed! The car that took off like a 4 cyl. until it readched 3000rpm now took off faster than my SVT! It still has the stock exhaust which other than the manifolds basically sucks. Of course it did not improve the top end above 3000rmp (which was already good but nothing like the svt), and it made the overall torque curve very flat. Made the car much more driveable and enjoyable. The last engine I did was 1 yr. ago and it was the ford 351W in a 91 bronco. Nice results, and an overall increase in power.

As far as the SVT. I would leave the intake side of the heads alone if you have an E1 SVT since they are supposed to already be done. But from my experience with the exhast port widening and porting on the last 2 vehicles is... Go for it... I plan to do mine sometime this year. As far as reshaping, don't do it unless you are experienced, but widening and polishing is easy enough for anyone who has done an engine rebuild and some other kinds of creative fabrication.

warmonger

Terry,

Wouldn't it make sense on a 3.0 L conversion to use the 3.0 heads with their larger heads and ports as a starting point for a port and polish job? Don't forget that the 2001 Taurus/Sable/Escape have the same water pump drive off the back of the head as the 2.5 does.

If available, the SVT cams would of course be preferred.

I have asked that question myself, why downsize with a 2.5 head,david z any input?

Compression maybe? Adding 2.5L heads to the 3.0 block as we know raises compression = more power?

Think it's possible to get 230 wheel hp with a port and polish job on the 3.0 heads, with headers and some intake mods?

Stock 3.0 Duratec has 200 horses, correct? That's say a 60hp at the wheel increase just by doing a P&P, and adding some bolt-ons? (the bolt ons add what, 15 wheel hp?) That possible? (dunno how much power the SVT cams would give you)

So at this point the consensus is to use 2.5L SVT heads on the transplant. Can more power be had with the 3.0 heads?

John

I was under the impression that the SVT heads made the cr way too high and have had to be m/c? am I dreaming this !!!!