okay here the situation...1993 F150 extended cab 300 I6 EFI STOCK with Cali emmisions!

i wanna put some gadgets on it.
here's what I want on it:
cams
headers
dual-rear exit 3" exhaust system
4bbl carb
K&N air filter
new spark plugs + distributor
maybe a perf. mod chip

all these things are stuff i heard u can do with a engine....i have no kind of direction on this.

is this possible with the 300?
how much!!!
and is it safe for the engine?

 

Dont bother with the 4 bbl carb, because there is to much electronic stuff to do away with including the efi system, being yours is late model, besides the efi packs enough power. there is headers and cams avalible for this motor, just check cliffordperformance.com, everyone on here knows clifford has eveything for inline sixes, every thing you can do do this motor is safe if done right, the price depends on how much work you plan on doing, oh, by the way dont run a 3 inch exhaust you will lose to much back pressure,
i think 2 1/2 is the largest exahaust you can go on a 300 six.

 

I have been looking around I have had several persons tell me that you should combine your Clifford Performance headers into a single 3" single exhaust. Run this through a high flow catalytic converter and on out to the end of the bed. This will give you a boost in your trucks top end power and still maintain the low rpm torque. I'm talking to CP about this and I'll find out what they think. I'll let ya know as soon as they get back to me!!

 

I have been looking around I have had several persons tell me that you should combine your Clifford Performance headers into a single 3" single exhaust. Run this through a high flow catalytic converter and on out to the end of the bed. This will give you a boost in your trucks top end power and still maintain the low rpm torque. I'm talking to CP about this and I'll find out what they think. I'll let ya know as soon as they get back to me!!

 

Actually the guy who posted before I did is correct. You will want to use nothing bigger than a 2.5" exhaust pipe and make it a single exhaust pipe. DO NOT GO DUAL EXHAUST WITH THIS ENGINE!!!!!!

 

I'm just curious, but why not go with true dual exhaust off a split manifold? Is it because there isn't enough back pressure, or is it the sound, because I plan on going true duals, with 2.5"s, and twin thrush glass packs. If this is a bad idea, I'd really like to know!

Chris
1982 F100 Flareside
300" T18 4speed
Blue & Silver

 

I'm just curious, but why not go with true dual exhaust off a split manifold? Is it because there isn't enough back pressure, or is it the
sound, because I plan on going true duals, with 2.5"s, and twin thrush glass packs. If this is a bad idea, I'd really like to know!

The are a few to several reasons why you shouldn't put a dual exhaust on your truck:

1. Inline 6 engines like the one you and I have in our trucks aren't big enough to truly justify a dual exhaust. They don't produce enough backpressure as to gain any true performance from a dual exhaust.

2. Putting a dual exhaust on this type of engine does not sound very good. Even though it will sound pretty hearty if your engine is in good condition, you don't want to drive around in a car that sounds like a overgrown bumble bee. Seriously, the engine doesn't sound good with a dual exhaust, even a single exhaust "without" a good muffler sounds kinda of funky. A good sports muffler changes this however.

3. Being that this type of engine came with a single exhaust originally. Most states emissions tests won't let this vehicle pass a visual inspection. Noticed I said visual. By all means your truck could put out damn near no pollutants but because you changed it from a single to a dual, your out of luck. There is another post somewhere in the Inline 6 message board that discusses this dilemma.

4. If you do go with true dual exhaust, meaning two catalytic converts and two glass packs. To retain the needed backpressure so your truck's engine doesn't loose its torque; you will have to go lower than 2.5" exhaust. You'll need to drop to 1.5" or 1.25". Dual exhausts really evacuate backpressure. You don't want to do it to the point of having practically none though.

5. A single exhaust off of a pair of Clifford Performance headers (part# 53-0016 w/Smog hookups) and a single 2.25" exhaust will make this engine scream! It's a good thing because this type of configuration gives you nothing but power. It gives a little boost to low end torque, but there is diffenent boost in the upper rpm range. You can't loose with this exhaust setup.

 

The are a few to several reasons why you shouldn't put a dual exhaust on your truck:

1. Inline 6 engines like the one you and I have in our trucks aren't big enough to truly justify a dual exhaust. They don't produce enough backpressure as to gain any true performance from a dual exhaust.

2. Putting a dual exhaust on this type of engine does not sound very good. Even though it will sound pretty hearty if your engine is in good condition, you don't want to drive around in a car that sounds like a overgrown bumble bee. Seriously, the engine doesn't sound good with a dual exhaust, even a single exhaust "without" a good muffler sounds kinda of funky. A good sports muffler changes this however.

3. Being that this type of engine came with a single exhaust originally. Most states emissions tests won't let this vehicle pass a visual inspection. Noticed I said visual. By all means your truck could put out damn near no pollutants but because you changed it from a single to a dual, your out of luck. There is another post somewhere in the Inline 6 message board that discusses this dilemma.

4. If you do go with true dual exhaust, meaning two catalytic converts and two glass packs. To retain the needed backpressure so your truck's engine doesn't loose its torque; you will have to go lower than 2.5" exhaust. You'll need to drop to 1.5" or 1.25". Dual exhausts really evacuate backpressure. You don't want to do it to the point of having practically none though.

5. A single exhaust off of a pair of Clifford Performance headers (part# 53-0016 w/Smog hookups) and a single 2.25" exhaust will make this engine scream! It's a good thing because this type of configuration gives you nothing but power. It gives a little boost to low end torque, but there is diffenent boost in the upper rpm range. You can't loose with this exhaust setup.

 

Some interesting info in "Advanced Engine Technology" by Heinz Heisler regarding exhaust on the in-line six-cylinder engine:

"...if the exhaust manifold is divided into two halves so that cylinders 1-2-3 feed into one exit passage and cylinders 4-5-6 feed into another, then with a firing order such as 153624 [which the Ford 300 I6 has], there will be an equal Thus, there will be no exhaust period overlap. exhaust discharge interval from each outlet passage every 240 degree crankshaft rotation. Subsequently, there is no exhaust gas interference in either of the divided manifolds and, by the time the gas has traveled to where both downpipes discharge into one common intermediate pipe, any exhaust gas interference this far downstream will be at a minimum." (page 283) Apparently the stock exhaust on the 90s 300 I6 is pretty good. Heisler goes on to say that for high performance it may justify having long branch pipes of equal length in groups of three, but nowhere does he ever mention dual exhaust for the I6. According to Heisler, with a set of tuned headers of two three branch pipes, the interference of pressure waves can be used to improve the extraction of the residual exhaust gases from the cylinder towards the end of the exhaust period.

Hope this is of some use to all you folks who are modifying their exhausts.

 

Thanks alot guys for giving me those reports on the dual exhaust. I'm glad I'm not going with them, every thing that you guys said made perfect sense! Now what about if I had a split manifold, with a single exhaust pipe from the manifold to a double pipe muffler, what would happen then? I still would like to have the "fake" dual exhaust go out under the steps...
Thanks again guys! :-)

Chris
1982 F100 Flareside
300" T18 4speed
Blue & Silver

 

Hell go for it as long as you maintain backpressure. I plan on just putting a dual piped exhaust end cap on my exhaust. You can find some nice ones at Summitracing! It could affect the sound of your exhaust however. I don't know what it would sound like though!