Lincoln Forum: How would you guys open the 99 4.6 up?
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11-13-2017, 07:57 AM #1Junior Member
- Join Date
- Nov 2017
How would you guys open the 99 4.6 up?
I want to open up my 4.6 over the next year or so. I have heard about the short stroke, low pressure, Extremely restrictive exhaust and intake, etc. I think pistons stay but everything else is air game. But I am often wrong on my first dumb assumption. This will be my first build. I am a good shade tree kind of worker. My priorities in order, which may be entirely wrong, Exhaust, intake and tb, maybe headers now, heads, cam, fuel rail, injectors etc, SUPERCHARGER!
She sat for a couple years. I cleaned and replaced basically the whole cooling system, harmonic balancer, etc. I like to clean things then fix them, so new rad cap gas cap, etc. I refuse to do sensors on a dirty system. I yanked and cleaned the injectors, new plugs and coils. 18mpg city sometimes. I can bounce off the rev limiter all I want.
I have been stalking this forum for a bit now. So just want to say thanks for all you have already helped me with and I think this will be a fun year.
11-15-2017, 07:56 AM #2Member
- Join Date
- Nov 2016
to me its all stock. just to be safe
11-16-2017, 04:49 PM #3
I am not at all knowledgeable about tuning the 4.6 2 valve engine, but I would first investigate if it is possible to install the taller 4.6 3 valve engine which starts off with a lot more HP. But the electronics would be different and possibly the transmission so some additional research there.
In order to get more power the exhaust system would need to be opened up and twin exhaust system would be essential. The cats would be enlarged and the connection between left and right exhaust pipes after the cats would be changed from a cross tube (better for stock) to a X pattern which is better for higher rev performance. Mufflers would be changed for less restrictive ones. The cast iron headers would be changed for tubular flowed ones that would not be easy to find and are usually problematic to fit in a performance length in a Town Car.
You may be able to get a PCM tune to take advantage of different settings to improve performance. Such settings may eliminate the need for exhaust improvements or enhance the effect of them. A good shop would be able to help you with exhaust and other tuning to get more power since they would have experience in this area of what works and what doesn't.
To upgrade the intake there are superchargers and turbo-chargers where the turbo-chargers mounting would eliminate the need for a problematic tubular header system. While performance will improve due to the high intake pressures these systems significantly increase blowby of the pistons and increase crankcase pressures that force oil and water and other sludge into the intake. You will probably need a device to catch and hold some of that liquid to prevent excessive liquids from going into intake. You will need high octane fuel and some attention to the PCM tuning to address the huge changes in intake pressures and their effect on the combustion process and ignition timing. Will the composite head gaskets be able to handle the higher cylinder pressures and heat from extra fuel burning.
The alternative to a pressurised intake would be bigger (higher flow) injectors and opened up manifold runners but that is going to need some kind of PCM tuning change to maximise performance and retain some economy in fuel use.
Your maintenance time will increase significantly with most performance add-ons and then you need to upgrade the brakes and suspension and tires to handle a significant performance upgrade.
You need to talk to a real expert on performance upgrades, because speed costs a lot of money, and even more if you head in the wrong direction.