Replacing Vs. Upgrading...
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Posting Guru
Joined: Apr 2003
Posts: 1,153
Likes: 1
From: Venezuela
Replacing Vs. Upgrading...
Subject: F150, 1991, 300CID, E4OD, 4WD
Hi there, recently my 300 is getting a bit tired, has some blow-By and is going to need an overhaul, basically I need hear your opinion about this 2 options...
1º Repair my actual engine using a performance camshaft and other parts to obtain 190 - 200 HP
2º Replace the whole engine by a 4.2L V6, 2000 - 2006 used know good, this is supposed to provide as stock performance 210 - 215 Hp, 255 - 265 Lbs, isn't it?
This truck is used to pull a fishing boat & trailer (1800 - 2000 Lbs) every weekend is drive between 100 to 500 Miles. Variable speed between 50 - 70 MPH
Any comments will be appreciated...
Hi there, recently my 300 is getting a bit tired, has some blow-By and is going to need an overhaul, basically I need hear your opinion about this 2 options...
1º Repair my actual engine using a performance camshaft and other parts to obtain 190 - 200 HP
2º Replace the whole engine by a 4.2L V6, 2000 - 2006 used know good, this is supposed to provide as stock performance 210 - 215 Hp, 255 - 265 Lbs, isn't it?
This truck is used to pull a fishing boat & trailer (1800 - 2000 Lbs) every weekend is drive between 100 to 500 Miles. Variable speed between 50 - 70 MPH
Any comments will be appreciated...
Postmaster
Joined: Dec 2006
Posts: 3,603
Likes: 10
From: Spokane, WA
A stock rebuild with a cam upgrade that is computer compatible would probably be the simple course. I don't think you can get 190-200 without going to a carbed set up.
There is a big thread here somewhere on using a Crane Cam 503901 that seems to be quite popular. Do some searching and you will find it.
There is a big thread here somewhere on using a Crane Cam 503901 that seems to be quite popular. Do some searching and you will find it.
Last edited by Harte3; May 25, 2007 at 11:59 AM.
Thread Starter
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Posting Guru
Joined: Apr 2003
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From: Venezuela
Thanks for your input. I guess reach 200Hp with the stock computer is not going to be easy and maybe imposible, but how much you think can reach with cam, inyectors, pressure regulator and maybe a throtle body??
In the other hand, I have read about the computer used on 4.9L 1996 can be flashed to accomodate better calibration, maybe changing the computer and some electricla stuff can obtain a few more horses....
Any more comments will be appreciated...
In the other hand, I have read about the computer used on 4.9L 1996 can be flashed to accomodate better calibration, maybe changing the computer and some electricla stuff can obtain a few more horses....
Any more comments will be appreciated...
Posting Guru
Joined: Apr 2005
Posts: 2,246
Likes: 2
From: Hawkeye Country
rebuild your 300 and dont look back, 4.2s are a joke. you'd spend all kinds of money to put the v6 in there, only to spend more money a week later when your tearing it out.
a half dead 300 is still twice the engine a 4.2 is.
a half dead 300 is still twice the engine a 4.2 is.
Thread Starter
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Posting Guru
Joined: Apr 2003
Posts: 1,153
Likes: 1
From: Venezuela
Thank you guys for your answer lines.
I know install a 4.2L will be a lot of job, specially because this configuration was not originally designed to be accommodated on a 1986 engine compartment.
4.2L can give more 200Hp as it comes from factory and the 300's need some mayor modifications just to reach that power BUT the 300's is over the earth from the 60's and have proved to be more than just a "Reliable & long lasting engine"
Since I'm getting every day less and less free time, it seems to me I have to go with the 300's and make the modifications recommended, because this is going to take almost same down time to make a standard overhaul.
I got a very interesting information from a Forum guy who answer me to my email after I sent him a info request. I'm going to share with all you guys, please see next post...
I know install a 4.2L will be a lot of job, specially because this configuration was not originally designed to be accommodated on a 1986 engine compartment.
4.2L can give more 200Hp as it comes from factory and the 300's need some mayor modifications just to reach that power BUT the 300's is over the earth from the 60's and have proved to be more than just a "Reliable & long lasting engine"
Since I'm getting every day less and less free time, it seems to me I have to go with the 300's and make the modifications recommended, because this is going to take almost same down time to make a standard overhaul.
I got a very interesting information from a Forum guy who answer me to my email after I sent him a info request. I'm going to share with all you guys, please see next post...
Thread Starter
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Posting Guru
Joined: Apr 2003
Posts: 1,153
Likes: 1
From: Venezuela
This is from BigBlue pencil...
Hi, Javier.
Most of the shortcomings of the original 300-6 (horrible intake &
exhaust manifolds) were adressed with the EFI setup. What remains is:
Horrible exhaust
limited head breathing
cam retarded 4 degrees.
tiny injectors
The horrible exhaust topic has been beat to death in the inline forums.
The recommended fix is to remove both catalytic converters and replace
them with a single, modern hi-flow cat. Get a Catco brand "universal 3
way + air" 2.5" converter and install it. That will make a huge
difference. Second is the factory muffler. Get rid of it and replace
it with a generic high-flow turbo muffler. Some people also remove the
soda-straw tailpipe section after the muffler and have the exhaust exit
in front of the rear wheel. This makes a difference as well. You don't
need a large exhaust; the factory pipe diameter will suffice. 2.25 or
2.5" maximum, and a single exhaust works best on these trucks. They
just don't breathe much. The factory Y-pipe is very good. Keep it, if
you can. All the exhaust parts you can get from Summit Racing.
Converter = $60, Summit-brand turbo muffler = $20. If you can weld it
yourself, great. If not, call a few different muffler shops and find
one that will weld in your muffler & cat for cheap.
The easiest way to address limited head breathing is to add a cam. The
Crane 503905 is the most popular cam for these motors. It gives you
twice as much lift and more duration. On the thread, you'll notice that
nobody says it looses low-end torque. True, the longer duration should
affect torque, but the cam brings the timing +4 degrees, which increases
torque. People have noticed that if anything, there's a net gain in
off-idle torque. Get a new set of lifters as well.
Ford used itty-bitty little 12-lbs high-pressure injectors on this
truck, and they just can't deliver the fuel to run this motor hard.
Ford also used a fixed-pressure regulator, so an injector swap requires
a regulator swap. The 4.9 regulator is a different mounting pattern
than everything else, but the inner workings are the same. The best
thing to do is get an adjustable pressure regulator for a 5.0L Mustang
and make a collar out of thick sheet metal for it that will go over the
regulator body and provide screw holes to match the 4.9L regulator
mount. You'll probably have to cut the mounting ears off the Mustang
regulator. Use 14 or even 19lb injectors, whatever brand you choose.
Accel is the cheapest, and often not the best. OEM Mustang parts would
be good. Check eBay for Mustang parts. Tuning the pressure is going to
be the tricky part here. The EECIV computer has some amount of fuel
trim, but it can't compensate for the huge flow increase, so you're
going to have to cut the pressure down. Search the Inline 6 forum for
"fuel pressure regulator", and see what other people have done. You'll
need to be able to read the computer codes;
http://www.therangerstation.com/tech_library/OBD_I.html has instructions
that I used to pull codes on my old 88 using a paper clip and the
"service engine" light on my dashboard. It becomes second-nature after
a few tries. Using a fuel pressure gauge (basically a tire gauge, but
meant for fuel- it fits onto a tire valve stem that's part of the fuel
rail), with the key on, but engine not running (fuel pump on), adjust
the regulator to about 40lbs of pressure. Then start the engine and let
it warm up, at least 10 minutes. It'll be really rich and run poorly.
The EECIV computer is dumb enough that it won't start "learning" right
away. The check engine light will come on, and you'll have a code in
the computer for HEGO-RICH. Here's where I'm not familiar with the
system: I believe that when you get the fuel pressure into the right
range, the check engine light will go off, which means you've hit one
extreme of the computers fuel trim ability. Remember this fuel
pressure. Keep going until it comes back on and the engine starts to
stumble- you now hit the other extreme of the computers trim ability.
Remember this fuel pressure too. Then set the fuel pressure regulator
to a pressure halfway between these two. In searching the forum
threads, you may find someone who's already done this and can just tell
you what pressure to set the regulator at with your larger injectors.
The EECIV computer is dumb and limited. It's not supposed to run well
with the cam- it doesn't know how to account for the increased airflow.
However, you should be able to play with the fuel pressure regulator to
compensate for it. Whoever started the cam thread you mentioned has an
EFI six with the cam, and it runs fine for them. You should replace the
timing gears as well if you swap the cam. The recommended upgrade is to
the steel gearset used on older carbureted engines. The caveat to this
is that the steel gearsets are said to interfere with the knock sensor
used on the EFI engines, and can cause your ignition to be retarded.
Search the forums for this. You can always just get new composite/fiber
gears, which is what your truck already has in it.
With the better exhaust and cam, it'll certainly rev higher. The EFI
motors are supposed to rev to 3500 well. If yours is fading at 2800,
I'd suspect a plugged exhaust. No matter what other mods you do, fixing
your exhaust will be neccesary. Replace the cat, muffler, & tailpipe
first, and see if that improves your power enough. Factory HP for EFI
motors is about 150. The cam should get you to 200, I believe, with the
better exhaust, larger injectors and the adjustable pressure regulator.
The forums are your friend. There's alot of experience there from
people who have actually done this stuff.
Good luck!
-Devin
Most of the shortcomings of the original 300-6 (horrible intake &
exhaust manifolds) were adressed with the EFI setup. What remains is:
Horrible exhaust
limited head breathing
cam retarded 4 degrees.
tiny injectors
The horrible exhaust topic has been beat to death in the inline forums.
The recommended fix is to remove both catalytic converters and replace
them with a single, modern hi-flow cat. Get a Catco brand "universal 3
way + air" 2.5" converter and install it. That will make a huge
difference. Second is the factory muffler. Get rid of it and replace
it with a generic high-flow turbo muffler. Some people also remove the
soda-straw tailpipe section after the muffler and have the exhaust exit
in front of the rear wheel. This makes a difference as well. You don't
need a large exhaust; the factory pipe diameter will suffice. 2.25 or
2.5" maximum, and a single exhaust works best on these trucks. They
just don't breathe much. The factory Y-pipe is very good. Keep it, if
you can. All the exhaust parts you can get from Summit Racing.
Converter = $60, Summit-brand turbo muffler = $20. If you can weld it
yourself, great. If not, call a few different muffler shops and find
one that will weld in your muffler & cat for cheap.
The easiest way to address limited head breathing is to add a cam. The
Crane 503905 is the most popular cam for these motors. It gives you
twice as much lift and more duration. On the thread, you'll notice that
nobody says it looses low-end torque. True, the longer duration should
affect torque, but the cam brings the timing +4 degrees, which increases
torque. People have noticed that if anything, there's a net gain in
off-idle torque. Get a new set of lifters as well.
Ford used itty-bitty little 12-lbs high-pressure injectors on this
truck, and they just can't deliver the fuel to run this motor hard.
Ford also used a fixed-pressure regulator, so an injector swap requires
a regulator swap. The 4.9 regulator is a different mounting pattern
than everything else, but the inner workings are the same. The best
thing to do is get an adjustable pressure regulator for a 5.0L Mustang
and make a collar out of thick sheet metal for it that will go over the
regulator body and provide screw holes to match the 4.9L regulator
mount. You'll probably have to cut the mounting ears off the Mustang
regulator. Use 14 or even 19lb injectors, whatever brand you choose.
Accel is the cheapest, and often not the best. OEM Mustang parts would
be good. Check eBay for Mustang parts. Tuning the pressure is going to
be the tricky part here. The EECIV computer has some amount of fuel
trim, but it can't compensate for the huge flow increase, so you're
going to have to cut the pressure down. Search the Inline 6 forum for
"fuel pressure regulator", and see what other people have done. You'll
need to be able to read the computer codes;
http://www.therangerstation.com/tech_library/OBD_I.html has instructions
that I used to pull codes on my old 88 using a paper clip and the
"service engine" light on my dashboard. It becomes second-nature after
a few tries. Using a fuel pressure gauge (basically a tire gauge, but
meant for fuel- it fits onto a tire valve stem that's part of the fuel
rail), with the key on, but engine not running (fuel pump on), adjust
the regulator to about 40lbs of pressure. Then start the engine and let
it warm up, at least 10 minutes. It'll be really rich and run poorly.
The EECIV computer is dumb enough that it won't start "learning" right
away. The check engine light will come on, and you'll have a code in
the computer for HEGO-RICH. Here's where I'm not familiar with the
system: I believe that when you get the fuel pressure into the right
range, the check engine light will go off, which means you've hit one
extreme of the computers fuel trim ability. Remember this fuel
pressure. Keep going until it comes back on and the engine starts to
stumble- you now hit the other extreme of the computers trim ability.
Remember this fuel pressure too. Then set the fuel pressure regulator
to a pressure halfway between these two. In searching the forum
threads, you may find someone who's already done this and can just tell
you what pressure to set the regulator at with your larger injectors.
The EECIV computer is dumb and limited. It's not supposed to run well
with the cam- it doesn't know how to account for the increased airflow.
However, you should be able to play with the fuel pressure regulator to
compensate for it. Whoever started the cam thread you mentioned has an
EFI six with the cam, and it runs fine for them. You should replace the
timing gears as well if you swap the cam. The recommended upgrade is to
the steel gearset used on older carbureted engines. The caveat to this
is that the steel gearsets are said to interfere with the knock sensor
used on the EFI engines, and can cause your ignition to be retarded.
Search the forums for this. You can always just get new composite/fiber
gears, which is what your truck already has in it.
With the better exhaust and cam, it'll certainly rev higher. The EFI
motors are supposed to rev to 3500 well. If yours is fading at 2800,
I'd suspect a plugged exhaust. No matter what other mods you do, fixing
your exhaust will be neccesary. Replace the cat, muffler, & tailpipe
first, and see if that improves your power enough. Factory HP for EFI
motors is about 150. The cam should get you to 200, I believe, with the
better exhaust, larger injectors and the adjustable pressure regulator.
The forums are your friend. There's alot of experience there from
people who have actually done this stuff.
Good luck!
-Devin
Trending Topics
More Turbo
Joined: Jul 2005
Posts: 579
Likes: 7
From: Auburn, CA
Very nice post, thanks!
Is replacing the OEM cat with the Catco an easy job or does it require fabrication beyond simple welding/cutting?
Vince
Is replacing the OEM cat with the Catco an easy job or does it require fabrication beyond simple welding/cutting?
Vince
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