Posted this in the Inline Six Forum, but I didn't get much of a response, so...
I had planned on swapping a 351 in place of my 300, but now I'm thinking that I can get all the power I need (not want, need) out of a 300 for a lot less money. I'm want to keep it EFI (it's a 91), and I was wondering what I could do to it. I see a lot of guys with big carbs and intakes, but like I said, I want to keep it EFI. I read on another site about using a 302 or 351 throttle body, will this work or is this some kind of redneck engineering? I already have a K&N FIPK, and I've heard they work better with Mass Air. Is there a way I can convert my 300 to mass air? Lastly, what kind of (mild) head work has anyone found to work well? I want a good improvement in power, not a race truck, so I don't want to go crazy with they heads. Thanks for listening.

 

You are heading down an uncharted path. Nobody hops up the efi 300 six much. Like you found out, some hop up the carb version, but this is definitely not cheap, and is still not a popular thing to do. If you learn allot about motors, and make some decisions on your own as to what will work, you probably will succeed in making more power, but this will not be a "buy a package and bolt in on deal" like they have for the v8's.

 

> but this will
>not be a "buy a package and bolt in on deal" like they have
>for the v8's.

Exactly why I want to do it :7

 

There is no way, no how that you will easily make as much power with that engine. It will never outperform a healthy 5.8. The most you will want to do is an exhaust, port/polish the heads, and larger fuel injectors. However, those last two mods are difficult on a speed density truck. You'll need a 300-400 dollar custom chip in order for it to work. The 14# injectors you have make the 300 a tad lean to meet emissions, so by changing them to 19#s there is power there. However, these mods arn't cheap. I'm sorry but, nobody replied in the six forum because, this engine can't be easily modified. It's nature is for work, not speed or any kind of extra power. It's built the way it is and thats it. MAF would be extremely difficult to change over to. They don't make a conversion kit for it, you would have to find a 96 OBD-II system and change it all over, major major PITA. They don't make a supercharger or a turbo for it, it's not easy to even figure out how to put one on. They've been trying for months and nobody can do it for some reason. You could put a 50-75 shot of N2O on it and have some fun with it but, you arn't going to get very far for your money. All of these mods I talked about, are $$$$$$$. Back to the drawing board my man.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin

 

That sucks. I figured it'd be hard, but a fun project. I'm still trying to figure out what I want to do. I'd like to put a 351 in, but cost... Oh well, I might just wuss out and do that. Thanks for the advice

 

try clifford preformance, i know they like the carbed engine better, but they could help you out quite a bit i would think. they may be able to ghet you a comp for ur tranny so u can change your engine to carb and then start with all their tricks. check em out at http://www.cliffordperformance.com/

1977 F250 460
C6 Hedman Headers
Dual 40 series
edelbrock performer
holley 4160
msd 6a and blaster coil

 

Clifford has some expensive parts, and again, you will still never get the six to make you truely happy. It'll pull anything but I can run faster than it. 351 is gonna be cheaper/easier in the long run, it's not that bad. Find a used engine and hook it up.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin

 

If you can change you motor over to carb what i have say will help you out a lot. 1&2 high compresion(like 13-14:1) on propane(a place called Trev's Automotive in Lethbridge Alberta Canada that loves to build up these motors) then a quality 4 barrel intake and good carb then dual exhaust and high quality headers along with getting the heads worked on to make them work with the high comp., then a good cam and all the necassary bolts, blueprinting, etc that goes along with any engine build. Hope this help , if you want i can get you the number to that engine shop (they also build up 350jp windsors for $3500 canadian not smog leagal though i think.


Cody, Coutts Alberta

82' Flareside: zoom zoom doesn't even begin to describe it, 2/4 Drop, Soon to have 325hp 351 Clevo (maybe more,in a 3600lb truck)Backed by a C6 with a 2000 rpm stall and a 3.50 9 incher, American Racing AR-23 (series 23) wheels, Upgraded interior, Sony Xplod stereo

 

Thats a waste, just get a V-8, the I-6 has 160hp, that needs to go. I had a 300, my new truck has a 302 and i'd never go back. The 302 is 5 seconds faster to 60.

Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin

 

I wish I could build the 300. I love that engine. You just can't kill them if you're good to them.

 

>I wish I could build the 300. I love that engine. You just
>can't kill them if you're good to them.



They're even hard to kill if you aren't so good to them...:P If you haven't been disuaded by the foregoing, then by all means take the road less traveled. It's free to read and ask questions and learn (ok, inet access costs...) There are a few folks around that love the sixes and don't feel that performance is only for V8s. It's easier and cheaper with a V8 because that's what everyone else is doing. Of course if you're after easy and cheap there are options other than the F150.... Like the saying goes: "Cheap, fast, or good - pick 2... 'Cause you can't have all three."

 

We have talked about this before somewhere on this board, and I made the comment that I think building a six would be neat. If you wanted attention when you lifted the hood, you would get it with a built up six. Like was said before, everybody builds a v8. And a six with true dual exhaust is supposed to sound neat. But I don't know about the efi. That is a hurdle that may be insurmountable.

 

It CAN be done, the most i've seen out of a six is 217hp, but somewhere i've seen someone say it can make as much as 500, but thats really unfeasible. I'm not really trying to discourage you, i'm just trying to inform you. I had an inline six myself for a year and 1/2 before someone totalled my truck, I replaced it with the 302 truck below and it just doesn't compare. The inline six will kill the 302 in longevity and low end power, but the 302 will smoke it in acceleration. The 5.8L has a similar horsepower curve as the 302, but the torque curve starts MUCH lower and is much more flat, the 5.8 makes 5 more hp than a 302, but the torque is what makes the difference, the 5.8 has a lot more low end then a 302. All I can say is the six has it's limits, i've seen one go 500k miles and another 475k. You just can't make it go fast, its just, to hard and to much money for it to be worth it. I love to see people take the other road, and go where no one has before and be original, but, theres a point where you have to stand back and say, well, what i'm getting out of my money isn't a whole lot, and go back to the drawing board. If you want, you could replace the six with a bored/stroked 460 out to 514ci and run with the 1500hp monster trucks that go 0-70 in 5 seconds .


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin

 

I don't know whether you are trying for acceleration or pulling power but I have a 300 in my 86 4WD (factory carb not EFI). I first got a set of Clifford headers and put in a true dual exhaust. That alone increased my mileage from 8 mpg to 14 mpg (3.73 gears with 4 speed with "granny" low). I then installed an Offenhauser intake manifold and a Holley 390 cfm four barrell carb and a K&N air filter.
No I won't out accelerate a 302 or a 351 but I will put it's towing capabilities on a par with both of them( the 360s,390's and above will out pull me I would imagine). Anyway, I am extremely happy with my 300 and it sounds great when that 4 BBL kicks in through the K&N eventhough I have non performance mufflers on it at present.
If you are going solely for speed and acceleration, then a v8 would be your better choice but don't neccesarily give up on your 300 if you want good all around longevity and pulling power.


1986 F150 4WD 300 cu in
1998 F150 4WD 4.6 L

 

Do a search for straight sixes on the web, I ve read articles where they are getting around 500hp. You can definitly build a 6 to beat an 8 but its goin to cost you big. You could have a nicely modified 8 for the price. If you want to do it to be different but still have decent power do it.