1991-1996 Buildup Tips
The 91 through 96 has the poorest flowing intake port and smallest valves of all the Escorts although it does respond very well to porting. There is a dog leg in the intake ports of these heads. The whole port is shifted to the left and half the port is filled in to the top of the valve guide. The valve sizes are 1.534" / 1.339". The older heads had 1.652" / 1.459" valves.
The best head to go with is the 1985-1/2 to 1987 engine with carburetor. They bolt up fine, have the smaller combustion chambers and like all the heads, the same exhaust ports and bolt pattern. The intake manifold will not bolt up but can be made to work with a little work. The only other things needed are a cup plug to seal the cam opening where the distributor fits, and the earlier valve cover which uses several bolts around the outside instead of 3 in the middle.
The Escort GT / H.O. engine had a true hemi head and will lower the compression too far if used with your pistons. It would be very expensive to put larger valves in the head because the seats have to be removed and the head machined for larger press in seats. The seats are way too thin to cut and install a larger valve in them otherwise.
Valve size isn't everything. When we got our first 2nd Gen Escort, a 1998 SPI (110hp), an old 1991 SEFI (88hp) that we have was 2 full seconds quicker 0-60 mph than the 1998 (both automatics). The 91 was 100% stock with the exception of the removal of the inlet tube below the air box and a hi-flo air filter. The car also had well over 100,000 miles on it at that time. The 91 ran to 238,000 miles on it and was still running fine with no engine or transmission problems. The car was finally sold as it had a lot of minor problems not worth fixing.
The 91-96 engines make good torque but will be down 15-20 horsepower (everything else being equal) due to the head design. Porting this head will help a lot. I would guess at about 145-155 HP with the #1C1C84C cam & kit with a good header and the throttle body and air flow meter modified. Doesn't sound like a lot but it's almost double the power of the stock engine.
The bottom end of the engine is reasonably strong for street use. Limiting the engine speed to 6,500 rpm, it should last. We have never had a lower end failure on a street engine running it no harder than this. Keep in mind, detonation will kill any engine.
One of the first things you should do is remove the restriction at the end of the air cleaner assembly. If you look at it you will see the inlet is restricted in size. This limits how much air the engine can breathe. Take off the chamber (black plastic box) under the air cleaner assembly. This will allow it to draw air through 2 openings instead of one.
Also go with premium synthetic oils and fluids when you change them.
A good start for modifications would be with the ignition system. A coil-pack, spark plugs, and wires will get the job done. Our wires have only 1/7 the resistance of new factory wires and the coil puts out over 25% more energy. We sell a dual gap plug re-gapped to work with our wires and coil for the maximum spark. This results in more torque, a smoother running engine especially at idle, and better fuel economy..
If your engine shows signs of running lean (surging and misfire) at part throttle, it can benefit from a Adjustable Fuel Controller.
Our 50% underdrive pulley, #1H6U82C, is a good addition to any engine. It's worth up to 3/10 second in the quarter mile. It also helps with a noticable savings in fuel economy as there is a lot less drag on the engine from the accessories, especially while running the air conditioning. The most performance you can get for the money, and it will pay for itself in fuel savings.
If you have an automatic transmission you should look at the Transmission Controller does the same and keeps the torque converter locked any time the trans is in high gear. This lets the trans run cooler and provides a boost in fuel economy on the highway. A simple adjustment will make the automatic transmission shift firmer and save wear. If you have a manual trans, a simple Shifter Bushing kit will firm up the shifter. And when it's time to change your clutch, you should go with a good performance setup. Ours have almost double the holding power.
The early 90's Escort 1.9L's had a very restrictive air flow meter. It has a center port that measures only 1.500" diameter. Later models (1993-96) have a much larger air flow meter. The way to tell is look at it from the end. If it has a small round port in the center and a screen, it's the early model. The later model has a vertical divider in the center and has no screen.
A way to increase airflow as long as the electronics work with everything is to change a few pieces to later model ones. You will need to remove all the ductwork from underneath it the air filter box. This is a major restriction. Just unbolt everything under the air box and pull it out. Also use a high flow air filter like a K&N. Here is the combination that will fit:
The air flow meter is much larger and will flow better even if it has the cross tube. You need the rubber air tube because the air flow meter is larger on that end. You will also need the end of the wiring since it is slightly different. Then just cut & splice the wiring. It will bolt to your air box.
The throttle bodies from 1991-96 are all 40mm. The 1997-up are 44mm. This doesn't sound like much but is about a 24% increase in flow area. The throttle body is almost a direct bolt-on. If you have an automatic transmission use only the 1997 throttle body from an automatic. It's the only one that has the provisions for the transmission throttle linkage, the lower cable.
* Air tube from a 1994-96 1.9L Escort
* Air flow meter from a 1994-95 (OBDI) (1996 was OBDII compliant)
* Throttle body from a 1997-up (1997 only with auto trans)T
Next you priobably should have the head and intake manifold ported. Changing the head to the earlier head mentioned above first would be better, and then have it ported. With these modifications a reprogrammed computer chip and a larger throttle body and modified air low meter will be need to get the most out of it. You could expect power to be in the 160-170 range ( with the earlier ported head and proper computer tuning) and with a turbo or supercharger, well over 200. Keep in mind that the more power the engine makes, the harder it will be on internal parts and on the drivetrain.
The 1996 and later OBDII cars are more sensitive to any modifications and changes. They will need computer reprogramming with almost any internal modifications. Spark plug wires, plugs, pulleys, air filters and intakes usually will not have any negative effect on how the engine runs. Cams, porting, a header, larger throttle bodies and air flow meters will usually not run right, or to their full performance abilities with a stock computer.
Let us know if we can help you with your project.