Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec Copper Gasket

Im about to start my 3 liter project but im concerned about the high compression ratio of the hybrid engine. I dont want to worry about detonation in the summer and it looks like the porting the heads evenly would be tough. Has anyone used a thicker copper gasket to lower the ratio, if one is even available. thanks

Tune the engine right and you won't have any pinging even with the high compression.

i got a quote for some copper headgaskets. $130 per head.

The higher compression ratio is the main reason why you would want to build the hybrid 3.0. The higher compression ratio is what gives the SVT more power than the regular SE. This holds true when comparing the SVT to the hybrid 3.0. Like he said proper tuning and higher octane fuel will stop any pinning or detonation you might incur. -Nick

You wouldn't want to use copper head gaskets as a method to lower compression since that opens up the quench inside the combustion chamber (which kills power gains). A healthy powerhouse needs a tight quench area (area where the flat part of the piston meets the flat part of the head). The only correct way to lower the compression without killing the quench is to open the combustion chamber up in it's area or by using a dished piston (that is NOT dished in the area of the quench). Now I'm just giving all this info based on motors that have a quench area in the first place. I've never seen the combustion chamber on my Duratec yet, so I don't even know if it has a closed chamber design in the first place, so if it does NOT, and it is an open chamber design, then it's too late anyways. That would make this engine doomed for building and trying to gain power in the first place. In that case, a copper thick gasket couldn't hurt performance any worse than the open chamber combustion chamber design already would.

Also, I DO recommend lowering the ratio down to at least 9.8 to 1 (with 10 to 1 being the highest) if your gonna run pump gas (92 oct). This is where your maximum power gains will be realized with proper tuning. The amount the timing has to be retarded and the amount the fuel has to be richened in order to counteract detonation will be less power than the optimal fuel and timing curves using the maximum recommended compression ratio. Believe me, I experimented with all this stuff when I used to toy with Stangs a lot. Maximum power was at 9.8
Better breathing is the key to power. (Higher compression too, but only with better gas)

Flat quench area is old thinking for 30 year old small blocks. These 4 valve per cylinder heads have very little quench area and focus more on cylinder filling and air movement into and out of the head more than just old fashioned squish. Believe me, these heads and chambers flow more than small block race heads with very little porting!!!

It's not the heads that are holding these engines back, it's mostly the physical strength of the stock parts that are hoilding big numbers down. Replace the rods with aftermarket ones, then replace pistons with lower CR ones, you're left with a crank with it's power limit of around 400-450 HP (at the crank) if it's going to last at all. Drop about 3 grand and you can have a custom billet crank, then you can really take advantage of some low CR pistons. Otherwise, the only reason to lower the CR is to increase your margin of safety against detonation, not as a power increase.

I just looked at a pic on Warmonger's site that shows combustion chamber on the 2.5 Duratec head, and it still looks like it has quench area to me? Correct me if I'm wrong, but I count 2. One on each end of the combustion chamber. The total area of this is just as big as the quench area that the 30 year 'old' small blocks have. The laws of physics don't change (to the best of my knowledge). Quench is still good to having a more efficient engine. Breathing is a key too, but the main reason these engines have 4 valves is to provide a wider usable powerband (w/ the tuned primary and secondary runners and cam profiles). Many racecars using a tuned-in but narrower powerband still have your good ol 2 valve setup, since they only run at a certain rpm range for the race. He can do what he wants, but you wont see me putting a thicker head gasket on my engine when I do the 3.0 swap (if I do it). I would rather open up the combustion chamber a little, or get the lower CR pistons as a preference.

Yes, but that quench area is a lot smaller then on those older engines. The D-shape is cast into the chamber to aid low speed cylinder filling from the primary intake runner, as you said, but it can be removed from the chamber if the secondaries are gutted to aid better high end RPM breathing for racing applications... Especially to unshroud larger 3L valves in the 2.5 heads.

You're right about the gasket though. The only reason I would be worried about putting a copper head gasket on is if I were worried about blowing out a stock head gasket, which are metal already and can take quite a bit more boost than old fashioned paper or cork steel ring type gaskets before blowing out. Copper gasket on Duratec = wasted funds.