Hi, I have an 89 F250 351w. I've heard of guys removing the smog? What does this do and what exactly are you removing? Does it add power? Thanks

 

It used to be that removing the power-robbing smog equipment from the engine really freed up a lot of power and that thinking continues to this day. Nowadays, the smog is designed to work in harmony with the EFI system and there really isn't much to be gained by removing it. Some of the components in the smog system actually help you save a little gas as well. And some states can give out huge fines for removing it. I believe NJ is one of those states. I'd leave it.

 

Ok thanks for the info. I have another question tho, how serious are vaccuum leaks and what can they affect

 

Do the smog inspections restrict such cams as say a 220/230 duturation 106 lobe seperatoin angle, fast ramp rates, .500" lift?

Say a '96 motor, 302 with that cam do you guys think you could pass a 302 with 450 hp at 6000 rpm?

I think he can still have a powerful Windosor even with teh smog equiptment.

What are your thoughts?

 

Vacuum leaks can affect quite a few things, it really depends on how bad they are and where they are. These newer motors have vacuum lines all over the place so it can be a challenge to pin down the leaks. Are you sure that have some, or are you just assuming or guessing that you do?

There are a couple of ways to look for them. About the simplest is to idle the engine and spray WD-40 or carb cleaner around the area where you suspect the leak is an listen for any change in engine RPM. Others have suggested doing the same with an unlit propane torch. Never tried that one myself.

 

On the passenger side of the motor I found a hose that wasn't even connected. So of course I connected it and I didnt notice a difference in anything. But than again I wasnt sure what exactly it would have affected. I'm not sure if there are any others.

 

Speaking of vacume lines I would get rid of them all. I would run a mechanical advance distributer. Get an Edlebrock non smog intake and some headers. If you are injected I would get larger injecters. I would also replace the rubber intake with aluminum, you will still need about three inches of rubber with hose clamps on one end of the aluminum tubes to attatch to the throtel. At the other end of the aluminum tubes I would attatch some type of an open element air filter.

This is what I would do:
If you like simple better or you want big hp just take off the intake manafold and put on an eldlebrock performer RPM air gap with holley or edlebrock 4 barrel vacacume socondaries 600 or 650 cfm. Large step headers are a big help. More power without more gas. Mallory dual point mechanical advance. THe less vacume lines you have the better. If you really want power get a cam with a fast ramp rate, make sure it is roller if you go too steep on the cam lobe so that the lifter does not burn up the lobes. And if you get a cam for more than 5000 rpm be sure to get some high rev lifters.

I think this is more than you wanted. I am sorry for that but the intake, exaust, and ignition are designed to work with the emissions.

If you are looking for a strong motor without doing too much just get some emissions intake, exaust bolt ons.

 

Hi, I don't know anything about mechanical advance distributors so I looked them up and this is the first thing I found http://www.type2.com/library/electrip/advance.htm Why would aluminum pipes be better than the rubber hoses? Also my exhuast manifold has copper like tubes going into them, so if I got headers what would I do about them?

 

Air is more dense when it flows through aluminum than rubber, the more dense your air gets the more air gets into your intake ports. However the intake port and valve and camshaft. have teh final say in you much air gets into the cylinder.

 

THen go vac advance, I had sugested mechanical because the vacume lines work systematiclly with the smog. I have had alot of trouble with these. THE vacume line on my diesributer is fitting loose which may be why It is running on mostly carburator.

Good work find ing that info.

Now you could just take off you smog pump and exaust manafolds and run large headers and it would probably run good however I did similar to my bronco, I removed the egr from the inake and it ran good but when I hooked the egr back up it ran pour.

Duraspark, Msd, pertronix,Dui are all well like ignition. all electronic adn all vacume I think.

 

I would just run headers then 2.5"-3" steel tubibg straight out of each header with a muffler on each pipe.

 

this would be a big mistake. a truck will get better low end performance running a single exhaust . especially better then what you suggested. 2.5-3" is way to big , would need a cross over and be long running to the back to gain any type of performance. your setup would work in a hi rpm hi hp motor but not a 351w that will rarely see anything above 4500rpms. you also keep pushings carbs when his app is EFI and should stay efi because of smog laws and what not.

also cams with lob sep less then 110 suck in a daily driver and being his is running speed density 114* is the lowest he can run period.

hunter you might go here www.fordfuelinjection.com great site with lots of info.

 

What kind of exhaust would you suggest to run? When I get around to change it I want duals, but I dont want worse gas milage then I alrready have. Thanks for the Info

 

the key to running duals is 1 not use to large of pipe. 2 a cross over is a must not only to equalize the pressure but also helps the scavenging. also running the exhaust all the way out the back either strait or turned would be much better then running it short. I suspect your truck is 2wd as well so the routing should be easy.

duals are really meant for Hi hp applications that need the exhaust out quickly. for a tow rig honestly a set of headers, Bassini offroad Y pipe (no cats) and 3" single pipe with a flowmaster or magnaflow muffler out stock location will give you the best for towing and low end power. and the sound is great also.

 

Its 4wd and that sounds good because im looking for something that adds power and sounds good. What about duals that are 1.75'' or 2". Headers no cats and a muffler on each.