hey, so ive got a '93 f-150 with the 300/6, and im attempting to squeeze a little power out of it. its got efi, a k&n cold air intake(with a custom made cold air box), and a 2.5 inch exhaust with a dynomax muffler.
so my plan is to first change the exhaust out with dynomax headders, a magnaflow cat, and a gibson dual sport, side exit exhaust pipe.and then im going to remove the old clutch fan and install a flex-a-lite, twin motor electric fan. then i guess jet makes a performance chip that supposedly creates up to 30 extra horsepower.
any opinions would be much appreciated, as well as any more ideas on how to free up more power, without gooing inside the motor it-self.

ps. it's a 5 speed standard.

 

hate to say it buddy but its about as good as its going to get without going into the motor. You have a low lift cam with a low-flow head, a perfect combo for big torque at low rpm. Getting air in and out a little faster with mods youve already done can help a little, but its still a truck cam and a truck head. The only way to make more power is to move the power peak up (in terms of rpm), and the only way to do that is to ditch the stock cam and port the head, gasket match everything, and maybe bump the compression. No matter what intake and exhaust setup you do around the stock head, the torque and power peaks will stay roughly where they were stock. To sum up, you have to mod these engines from the inside out to get any really noticable difference. If you wanted, you could increase the airflow to the engine without going into the engine by forcing air in with a turbo, but chances are your engine has quite a few miles on it anyway and youll end up blowing gaskets and having mega computer issues since youre SD. Welcome to modding a 300. You could squeeze out 200 NA hp with the stock crap, but if youre looking for 250 or more, youre throwing pretty much everything in the trash.

the chip is a waste of money. Leave the computer alone for now

 

thanx 4 the help torx. what head-cam set-up would yoiu suggest? i think that a turbo would be a whole lot of work for a few extra horse, seeing how i could only add a few( maybe 5) lbs of boost without lowering the compression. what do you think of a head-cam set-up with a head shim?
or do you think a supercharger would be the answer?
motor has 183,000km

 

well, how much power are you looking for?

 

Pretty much everything torx said.

My two cents;


The 300 is best used as a medium duty daily driver. It's a good engine. It's solid, can get decent mileage, and move when you need it too. But to hot rod it would take a large chunk of change. If you don't want to mess with the internals of the motor, and can afford the extra fuel costs if you drive highway, change out your gear ratio. I went from 3.08 to 4.11 and I think I was fastest thing around from 0-30. You could even go to 3.73 and open up the exhaust and it would run fairly decent. You'll never get a lot of speed out of it though.

Don't get me wrong. The 300 moves a truck just fine. All of it's power is in the low end. It's not meant to move fast or rev like a V8 or V6. The 300 has a 4'' bore and 3.98'' stroke. Maximum hp is 145 @3,200 rpm and 265 ft lbs at 2,000 RPM (correct me if I'm wrong). A solid motor, but I'd rather have a 302 or 351C for speed.

 

bills prety much right.if u want to make a hot rod w a bunch of aftermarket stuff u might as well get a 302 or 351,or if ur gonna work and beat the **** out of it ur better off sticking with what u have and not doin too much to it

 

As stated the "performance chip" is nothing more than a couple cents part that tricks the eec into adding more fuel...complete waste of your money....youll end up bitching about how bad your fuel economy is more so than praise the HP gain.


Some people actually think headers is a good idea and have gained noticable hp, so if you have the dough to blow, why not? Just remember, when you install headers, youll have to have an O2 bung welded in, as well as a bung for the EGR downtube, and it would be a very good idea to use some sort of flex line for the EGR downtube, as that sucker is a sumbitch to connect sometimes.

I went a cheaper route adding an electric fan to my truck and as far as Im concerned, it was the best modification I made, even better than headers, but there is a slim chance my mechanical fan was faulty, although, the truck only had 40K on it when I added the fan, and the fan seemed ok when I took it off, so...I dunno...in any case, my mpg magically went up 1-2...could have been a fluke, who knows.

If your willing to do the research and understand how to make a speed density system happy with boost, I think 5 lbs would be great, if you look at those that have done it, your talking a substantial TQ increase. Its easier said than done, as most modifications are but its not that complicated to do.


Now this is my opinion and my sole opinion, if I were you, Id research what it takes to control an efi system, and what modifications you would need to make your specific engine/efi system work with major modifications, if you feel its a bit much for a modified six banger, Id save my money.

Ive done the modifications your suggesting, less the eec trick aka "chip" and while the truck has enough pep for a daily driver, has more than enough umph at high mph to get someone in trouble...what its not is a power monster...If your serious about making power and having good fuel economy....you should seriousy explore some of the v8's that are out there today, and I wouldnt limit myself to ford, Id look towards the GM line....the idea that V8's are less reliable, provide less mpg and dont have off idle power, is a thing of the past.

 

Whatever you do if you want some torque, Don't go with a 302.
They just don't have the torque down low that a 300 has.

 

They'll pull just as much as a 300; just not as easy in the low end. The thing about it is this, a 302 doesn't mind revving.

 

gotta remember the 302s powerband isnt as good as the I6 but the engines both have nearly the same peak torque

 

When it comes down to it, they're both great motors.

If only Ford could have combined them. We would have the perfect motor. Speed, power, fuel economy, loooong lasting life.

Mmmm, power.

 

Closest to that would be:
The 400 is 4.00bore x 4.000stroke
The 300 is 4.00bore x 3.980stroke

 

That's what I was thinking, actually.

What kind of mileage does the 400 get? Can't be worse than the 300! Ha

 

buddy has one w a 4 spd an its not good

 

My stock 78 f350 with the 400m and a fresh tune up got 13.8 mpg highway at 65-70 mph.
my truck now has a stock 390 FE and over the last 400 miles it got 12.6 including alot of city driving.
I'v never had a 300 I6 what is it's mpg like.