Weldman0730

Hey guys, I am new to this forum and would like to introduce myself.

Basically I have recently traded my 2002 ford focus for a 1997 4X4 F150, with a 5 speed manual transmission and a 4.6L V8 engine, because I need a truck where I live due to lake effect snow and my need to haul things constantly. I have owned one other truck, it was a 1994 f150 XL with a 5-speed transmission and the 300 CI I6, which made some monster torque and was overall a bulletproof engine. Hopefully this 4.6L is too.

Basically my question for you guys is what is the best bang for your buck performance wise for the low rpm range, not top end?

Basically what I was thinking was an aftermarket camshaft or camshafts (it is SOHC right w/ 2 Valves?) and maybe a CAI. I already have aftermarket exhaust; so I think this combo will make some noticeable improvement, or would you guys go another way? I am not looking for huge gains, just a little bit more responsiveness and low end torque to make the truck more fun to drive, plus give me something to work on.

Thanks,
Weldman

I also have put pictures on the forum, the tan truck is the one the questions pertain too

https://www.f150forum.com/album.php?albumid=315

Moose08

cant go wrong with a aftermarket throttle body and a air intake for a little gain. You could also throw in a throttle body spacer.

torkum

You are thinking correct for going after the top end, the thing is you have none PI heads and if you change to 01 up PI heads your gonna pick up 35hp. Put some long tube headers, electric fans, and a custom tune and that will give you over 100hp and not worry about the cams [cams are expensive].

Weldman0730

Ok so lets say I go to the junkyard and find each side of the head(2 peices) out of a 99 F150, will they just bolt up, I mean obviously I have to follow a procedure otherwise the timing will be messed up, but I wont have to modify the head any, right? Does it help to machine and port and polish those heads any or are they pretty free flowing?

How about shave the head down for more compression? I know with 4 cylinder engines thats a big power adder.

Also is this the same engine in the Mustangs of the same year?

Thanks,
Weldman

torkum

You would need to grab the intake too because the ports changed. The intake will bolt up and the heads are interchangable from side to side.
PI heads luv to be ported and polished, they respond very well.
I would not shave the heads unless you have too, these are interference motors.
The Mustangs are the same on the heads but different on the intake.

Weldman0730

Well if its an interference engine then Im not going to deck the head and put those valves any closer to the piston, but I will port and polish the PI heads.

You say I could gain 35hp from just this? How about even if I didnt do the CAI or the headers?

Also one more thing, are the headers on this truck fairly restrictive, or are they alright? I have done some research and have gotten mixed results.

Thanks for the help torkum and moose08,
Weldman

torkum

The claims are 30+ hp and 40ft pounds of torque on PIs.
Long tubes gain around 30hp on dyno reports I've seen from reputable builders and shorties are good for about 5hp. CIA are good for 5-7 hp.
If you take this route I would highly recommend a custom tune for maximum performance results.
* I made a edit on the year heads because on the 4.6 trucks Ford didn't change to PIs until 01. To be safe make sure they are stamped with PI on the end.