Perhaps that's because those of us who are not as knowledgable of engines and are trying to learn have this 'EPA/emissions screwed things up' attitude shoved at us every time we try to research the issue.Yours is one of the only opinions I have ever read that states differently.I welcome all information but that's what I have thought for years,because that's the most common thread when researching engines of the 60's compared to the engines of the 70's.Also,not to be contrary or try to start an argument but I was 7 yrs old in 1970 and 17 when the decade ended and I don't recall any japanese street muscle cars when I got a '68 Goat in '79.Are you referring to efficiency when you say 'The japanese ate their lunch'? (Meaning hp to cubic inches) All I remember from the jap cars of the 70's are fuel efficient 4 and 6 cylinders whose driver's wouldn't make eye contact at red lights.

Please help me become less ignorant.

-Shawn

 

You are very gracious. I appreciate that.

I apologize for my tone of voice. I live in paradise (Idaho) and I've lived in other places like Chicago and New York City and I appreciate the environment here.

I have been a gearhead for almost 40 years and I've tried to learn as much as I can about how engines work. One of the things I've learned is that the equipment added to engines to reduce emissions always has performance benefits. EGR improves part throttle torque, reduces combustion chamber temperatures. PCV keeps the oil clean. AIR pump keeps the oxygen sensor clean and that helps fuel calibration. Fuel injection improves torque.

I learned a lot by reading Probst's book about Ford EEC IV fuel injection (the EEC IV was used on 5.0's). I read it twice and then reread certain sections again. It was a read education.

Back to the subject. I love the idea of a 5.0 in a F100. The truck is designed to be light weight and the 5.0 is a light, powerful engine. The late 90's Explorer (starting in about 1997) had a 5.0 with heads called the GT40p, also known as an F7TE. Even though it has slightly smaller exhaust valves, the exhaust flows excellent. The chamber is a 'closed chamber' design. High compression, high swirl, high torque design. The chamber design is called a 'Ricardo' design. Clearly Ford's best design. I have a pair in the garage that I'll be putting on an engine out of an 85 Lincoln.

The best mods for a 5.0 are good quality headers. Long tube headers make great torque. Shorties work fine and are easier to install. I'd use the Ford parts.

If you're handy with a computer, I'd suggest tuning the engine's computer. Other than that, the best advice I can give is to make certain that the squish is as close to .040" as you can get it, and that the cam is degreed.

To degree the cam, I have a .pdf file of a degree wheel. You can print and paste it to an aluminum disk. Get a dial indicator from Harbor Freight.

I don't recommend any of the usual underdrive pulleys, throttle bodies, or intake swaps. Too much money for not enough power. I'm hoping to put a 3.25" stroker crank in the Lincoln engine. It's the only no-brainer power improvement that I know of.

Email me at pcmenten at yahoo.com for a copy of the degree wheel pdf.

 

I would like to clarify some things.

"EGR improves part throttle torque" FALSE
The EGR doesn't increase HP or torque. If anything you have less available when it's active since it is mainly used between 2000-3000 rpm (cruise). It does however increase fuel mileage due to the leaner mixture. It is disabled at WOT.

"reduces combustion chamber temperatures" TRUE
By introducing spent exhaust gases into the intake, it leans out the mixture and reduces the amount of NOX gas produced. Which means a cleaner burning engine.

"PCV keeps the oil clean" Partly True
The PCV system removes combustion gases that have slipped past the piston rings. These gases are mainly composed of hydrocarbons (gas) and water vapour. When these are mixed with oil, sludge is produced. Also when there is too much crankcase pressure, the pressure can make engine engine seals fail (ex. leaking rear main seat) and also push oil past the rings which will be burnt.

"AIR pump keeps the oxygen sensor clean and that helps fuel calibration" FALSE
The air pump is used to burn unburnt fuel in the exhaust system. By mixing oxygen with the hot unburnt fuel it ignites (think heat, fuel, air). When paired with a catalytic converter it will increase it's efficiency. Most air pump systems have a line that hooks directly into the catalytic converter. If you pumped enough air at the oxygen sensor you would make the computer see a lean mixture and the engine would run rich.

"Fuel injection improves torque" Depends on the engine and system
With a carburated engine you gain a little more lower-end torque but the EFI makes more higher-end torque. The EFI wins HP hands down. You get better fuel mileage, throttle response and emissions from an EFI engine.

Now a little more on tuning an EFI computer. Speed Density computers can only be changed by a chip (only the Mustang DA1 computer is hackable) and most mass air computers are hackable. The OBI computers are a little easier to use than the OBII computers (96 and up). OBII computers like to have all their sensors and will turn on the check engine light if there are any emission equipment missing. Where as the you can remove the air pump, carbon canister and catalytic converter from a 86-95 computer and it doesn't care. Don't remove the EGR as the engine can't tell it's disabled and will advance the timing causing detonation.

 

Nathan,

EGR improves low-end torque by two means; the addition of gasses to the volume of air at part throttle increases the compression ratio. Higher compression means more power. Also, the open EGR valve reduces manifold vacuum at part throttle, there is less pumping losses.

Look up EGR on the wikipedia.

The ability to lean the mixture is not the intent of EGR.

When the engine is cold, the ECU enriches the mixture (open loop operation) to prevent burned exhaust valves caused by lean mixtures due higher density cold air. Also, the ECU designers exploited this rich mixture together with the thermactor system to help warm the catalytic convters more quickly.

During the cold start sequence, the diverter valve routes the air from the AIR pump through the thermactor ports to help burn the unburned HC in the exhaust ports. This prevents the soot from fouling the oxygen sensors, helps warm up the oxygen sensors, and it helps get the catalytic converters up to operating temperatures.

When the engine reaches operating temperature, the diverter valve switches the air to a pipe that runs to the oxidizing side of the three-way catalytic converter.

Trust me on this. I read the Probst book twice. It's in there. If you insist I'm wrong, I'll go get it and quote chapter and verse.

Maximum torque is produced at a slightly lean mixture. The cylinder-to-cylinder fuel distribution of a carbureted engine varies; some cylinders are richer than others. A modern SEFI engine can adjust each fuel injector for each cylinder, and together with the oxygen sensor, keep each cylinder in the engine at the exact proper mixture.

Most carburetors cannot be dynamically tuned like an electronic fuel injection system.

Also, the intake manifolds on carbureted engines have to be heated (using exhaust gas) to help with vaporization of fuel. Warm air is less dense. Fuel injected manifolds are not heated, so they run a colder, denser air mixture into the cylinder. This colder air can be run leaner without risk of detonation.

I don't know where you got this information. The A9L ECU used to be the favorite ECU for programming. The spark maps, the fuel maps, and the timing of the injector are programmable. The difference between SD and MA are things like where the air density is measured, and how the ECU gets its airflow information. You can convert a MA to a SD and visa-versa. SD is tunable and many people prefer to set up their engines as SD because the MAF of a MA system is a restriction to airflow; an SD setup will make more peak power.

 

I would have to agree with Paul on those points.

 

The computer does lean out the mixture when the EGR is active and it advances the timing. Go disconnect you EGR and go for a drive. It will ping like hell cause it can't run at like 40 degree timing. When you mix an inert gas and less fuel, you get a cooler burn which reduces NOX gas.

On the computers the A9L is a 89-93 Mustang Mass air computer. Only the 86 Mustang DA1 speed density computer has been mapped. The Mass Air flow data tables are more standardized than the speed density. I have a VR1 computer which is unhackable by TweeCer (which supports the most Ford computers than any other software). Where as the chip just overrides the computer's programming. With TweeCer you actually change the factory computer settings. Go look on www.fordfuelinjection.com.

 

My understanding in 1970 Ford got their 302 blocks from Mexico, and the walls are much thicker. Therefore, they had the most HP. What I did was mate a 94 Motorsport fuel injection on top of that with the stock heads, and you really get an increase in horsepower from a vehicle thats easy to crank and fun to drive. I battled with the heads, but the aluminum heads have a tendency to need to be torqued on a regular basis.

 

Whoa this thread is so full of misinformation it hurts.

Lets start with the original question.

Arguably the best all around easily obtainable shortblock setup is the 87-92 HO 5.0 block. Forged pistons, roller cam, decent compression ratio etc. This is a good motor out of the box. The heads are ok but not good. The stock efi is good and reliable and has long intake runners good for torque.

There are lots of good aftermarket aluminum heads on the market in the 1k range for a nice 302 afr 165s are very popular. TFS and Edelbrock also make great heads

I like efi alot but intakes and injectors and tuning get pretty expensive compared to a decent carb and intake.

Non HO motors are not worth messing with unless you just want to use the block.

Speed density EFI goes off of fuel maps and atmospheric pressure. It runs good in stock form but it does not respond to upgrades. It came on 87-88 mustangs(not CA 88s) and mark vii on the HO 5.0s

Mass air uses a heated wire that senses the mass of air going to the engine. This works well with the usual upgrades but when you start getting wild you will start pushing the boundries of the system

Explorer motors are good options as well. They have very good heads from the factory. A great flowing intake and a larger throttle body than stock HO stuff. Explorer motors do not have air pumps and its easier to use regular HO mustang parts for the efi. Explorers use coil on plug ignition and are crank triggered, good things but I have not heard of people using explorer control systems. So you need a ho style distributor, timing cover, wiring harness computer mass air sensor etc. Also the Explorer motor use hypereutectic pistons, decent but not as good as forged. Explorers do not use air pumps. The explorer cam is not great either stuffing in a HO or aftermarket cam is a big upgrade.

A block does not increase hp it can help handle more power. 70 ish and older blocks are heavier and some think that means they can handle more power. I doubt it and its certainly not worth searching out an older block unless you want to meet smog requirements. There is a rare Mexican block there is no rhyme or reason to what it went into but I beleive this to be a better block. it says hencho in mexico on the lifter valley. Aluminum heads do not need to be retorqued on a regular basis.

I run a explorer motor with HO controls and eliminated the EGR, and left the actuator there to trick the computer into thinking its there and I have never had my engine ping, I have seen no negative effects of not having the EGR yes I know what its for and how it works. I just did not like the look of it. A properly function EGR is beneficial and does not rob horsepower but your engine will not ping without it.

An EGR does NOT improve horsepower or torque it improves part throttle fuel economy and lowers NOx emissions. Its essentialy inert gas how would it produce power??

Tuners do not prefer SD and some say in stock form it makes more power, this is not due to the system purely due to timing curves and fuel maps. A9l is just the tune on the computer for a 5.0 5 speed mustang it is the most popular stock tune. Other MA computers are 8ld, a9p, etc they all except chips the same.

An air pump is simply a waste of space, weight, and power. It is purely to help decrease emissions and barely effective at that. Newer mustangs and explorers do not use them. The computer senses the pressure of the air and the temperature so it knows the density. Hence the term speed density. The computer uses the air density and rpm to put in the correct amount of fuel. You will not foul plugs or cause soot on your valves without one.

Getting a chip for a computer or tuning the computer is not going to give much more power for a stock engine. They are a minimum of $400 and will not make the diffrence a intake, tb, or used heads will. The stock HO headers are actually decent as well. For free advancing your timing a little will make more power than the headers or computer tune. And I do not suggest degreeing a cam unless you really understand what it does and are looking for a specific outcome. Certainly performance would decrease on a stock type motor with stock cam. If you are buying aftermarket buy the right cam and install it as the manufacturer suggests.


Gt-40P is the better head but the gt-40 fits all headers well. The performanc diffrence is not much.

What Travis T did is the cheapest way to a 302 with great HP. He should be putting out 300 hp and 340ish tq (at crank) for What, $800 bucks? Plus these motors are relativly new with lower miles. no need to rebuild.

 

You did one of two ways of disabling the EGR. The sensor is just telling the computer, the EGR is closed and it adjusts fuel accordingly. The other way is to use two resistors to accomplish the same thing. The pinging will occur if you just leave the EGR position sensor unhooked then the computer will think it is open when it's not.

Here is some general rules for Speed Density Cam selection:
Requires a minimum lobe separation of 114 degrees
Also no valve duration over 220 degrees at .050

With Mass Air you can run a slightly more wilder cam selection:
Can run most cams with a lobe separation of 112 or more
Valve duration to about 225-230 degrees at .050

 

Wow, I have been driving a miracle for 10 years. If I get time, I will send you pictures of what won't work, but does! Lots of different answers here and everybody is right in their own way. You go to 3 different mechanics with the same questions and you probably would get 3 different recommendations. Good luck, have fun with your car!

 

I have a '71 302 with the 289 heads, not really sure the year of the heads but it seems to fit nice. Not running yet but...Thats just my two cents$