You're correct in some regards, a 4bbl intake with a bigger carb, and a better exhaust will wake that engine up like nothing else. But the 300 simply is just not bogged down with emissions equipment. There isn't that much on there. The pre-emissions 300 was rated at 117hp from the factory. The emissions era 300 was rated at 122 from the factory.
The restrictions are in the intake, exhaust, and the head, which have nothing to do with emissions. Open those up, and yeah, you'll double your horsepower without thinking twice.

I just don't want anyone having any misconceptions about removing emissions equipment on a stock engine and getting anything out of it. It's been discussed over and over and it leads to almost zero improvements, and usually more headaches. I removed the emissions equipment on mine as a half step to a 4bbl setup, and while it was still the 1bbl without the stuff, it was one of the most miserable things I've dealt with. (On a separate note though, I still got it to pass local emissions. )

Unless you're looking to remodify the engine, leave it be or you're just asking for trouble.

 

Thanks 8525ford, it's all about $'s & cents at this point.
Chuck

 

I will disagree.

Removing the EGR system on any engine will increase the amount of volume within the cylinder for air and fuel. On some engines this can amount to 5% of the combustion chamber volume being exhaust.

Junking a smog pump can gain you 2-5 HP. As well as increasing the exhaust flow by maintaing a denser mixture within the exhaust. (Re-burning unburnt fuel in the exhaust reduces the density. Therin creating an unhomogonus mix.)

Cats restrict exhaust flow.

The only smog component that reasonobly wont reduce your horsepower and is a savior to a mechanic is the PCV system.

Evaprotive emmisions though alot of plumming is of no harm either.

I dont advocate junking this stuff as long is it is all in working order and cooperating with the EEC-III. If it is broken in the least, RIP IT OFF! The cost of fixing it VS the gain is pointless. Yes, You may need a new carb at the price of $300. Compared to the $120 for an o2 sensor, $200+ for a cat, or the $100 for an EGR valve. Come on? There is more parts that can be added to this list.

You realy are only talking about a 4-10 HP gain on a 300.

BTW the 300 was originaly rated at 170 gross HP. Thats with an alternator.

 

The 170hp rating is pre-1972 before they switched to net ratings. In 1972 it was re-rated at 114 on the same engine. It got up to around 117 during the 70s. The highest it was ever rated was the emission era, where it rated at 122 (before fuel injection). It probably put out 180 gross in 1980. Completely a moot point.

You're right, you can gain a couple horsepower by removing it. If you look back, I stated that in one of my first posts. About, maybe, 3 - 5hp. However, it usually runs so crummy that all that horsepower is lost simply because unless you convert everything, you can never get it to run right because it was designed with it.

Secondly, as I stated in the above post, the 300 is just not one of those engines BOGGED down with smog equipment. That's what I was getting at. It's not held back, restricted, or bottlenecked by any of the emissions equipment. Sure you can gain a little by removing it, but it was actually at its peak power output from the factory with all the emissions equipment.

Also, as I stated earlier, this is only void if all the emissions equipment works, which is completely necessary with the feedback carb setup. If the emissions equipment isn't working, any feedback carb 300 is going to run horribly. But, to remove it all, you're going to have to convert the carb, distributor, and ignition module to a pre-feedback setup. Again, all custom work.

 

I dont know what 300 your talkin about but i just put a 89 motor that was fuel inj. into my 85 with a clifford intake and holley carb... I must have pulled 2 mile of vac line off the engine. smog pumps, diverter valves, ported vac switches, egr and plumbing, air pipe and plumbing, ALL junk. half the stuff on these engines TOday in 2009 isnt working. its on there and is holding back the motor. ya maybe back in the 80;s when it was new and working perfect it was fine and dandy, but now a days, come on now. dont waste money fixing that emissions junk. if you dont need it, then ditch it.

 

You said it yourself, you just put an EFI engine in. Of course those are loaded. The computer needs it. We're talking about carb engines here.

And moreso than that, we're talking about FEEDBACK CARB setups. You have to either A) Modify them completely or B) put them 100% back to stock. If you don't FULLY do either one, they'll run horribly. And, when you're done, you won't have much, if at all, any more power than it did before the emissions equipment was in there. It'll just be a simpler setup, albiet a more pollutant one.

As for vacuum lines, yeah, even my '81 had a bunch of vacuum lines, valves, switches, etc. But after it was all sorted out, it had a smog pump that tossed in some air, and an EGR that put some extra exhaust back in to cool exhaust temps. Pretty much it. All of those other vacuum lines, ported switches, etc, actually helped the engine to run BETTER. They kept the engine from stalling under certain conditions, warming up faster in the cold, advancing the distributor properly under condition x, y, and z. Just because you don't know what they are doesn't mean they're junk. It just means you don't know what they are or understand how they work.

Also, again, it sounds like you're not paying attention. If you're not going to read everything that's written, don't bother replying. My point is IF it's working, leave it alone. The discussion here is whether or not removing it does anything. The original poster said he no longer had to pass emissions and if it's worth pulling it off. If he was able to pass emissions, it's working, and he should leave it. Remodifying a STOCK system to run without emissions is a LOT of work, leads to a LOT of problems, and produces almost ZERO results. I can't count the number of people on here that I've had to walk through trying to get their engine running again because someone pulled out all the emissions equipment and then sold the truck because they couldn't figure out how to get it running right again. To just pull it out because it's there is pointless and is asking for trouble. Yeah, (as I've said already), if it's not working you're going to have to do something about it anyway. But simply whether or not you should remove it to gain some power is an easy answer, and it's no. Not on a 300. They're not dogged down by emissions.

If you want to talk about remodifying the engine to run with an aftermarket intake and a Holley carb, that is a completely different discussion that has nothing to do with pulling the emissions equipment off a stock engine.


If there's anything worse than no advice, it's the wrong advice. So don't give it out.

 

No there all smogged down bad. all that emissions junk, whether working or not. is still holding back that engine. a 300 6 with all factory emissions still in tact is like Pam anderson wearing bagging sweatpants and a sweatshirt. You got all that potential underneath but your not lettin it show. Its simple if you can spend some money then do it its worth every penny. if not then listen to what know it all said above me, because you cant just remove it and hope its going to run without modifing it. TONS of guys have done this and yea had some headaches but all the problems you have someone will have already went through and will ease your problems.

 

He's not talking about pulling the emissions equipment out of a modified 300, he's talking about a stock engine. It is completely different than if you're going to throw a 4-barrel and a good manifold on there. He's talking STOCK engines. Like AB said, no gains from ripping the emissions equipment out of a STOCK ENGINE.

 

If it is all working top shelf I would use it also.

A de-smoging has to be done right or you gain squat.

Abandoned Bronco is actualy right for the most part and Im the devils advocate here.
I sugest everyone replace theyre carb with two ball valves. One on the air and one on the fuel. You will figure it out.

 

He, my smog does not work and I want to get rid of it. Can you help me? thanks...

 

Hiya xlhr8r.
First things first, you'll need to provide a bit more info.

What year is your truck / engine?
What isn't working?
What is the current state of the engine?
Etc? Etc?

 

Hi ab, '83 f250 4.9, I think it is original, but...
It runs okay at a stand still, but it spits and misses under a load. I've had it for 11 yes, last fall I noticed that the wide open gizmo on the carb was broken, and I repaired it. Since then I've lost about 4mpg, and now it isn't driveable. I thought about getting a rebuilt engine, but no one has one. Whaddya think?...

 

And then the crazy guy with custom efi is looking to install smog equipment...

Egr, evap, cat, pcv, but not the smog pump!

It roars like a lion, and purrs like a kitten. And does so with good fuel economy.

If I would do this again, think I'd K.I.S.S. and use a carb.

 

I have a 1985 F2 50 with the 4.9. I removed the feedback carburetor replace it with one from 1979 which I rebuilt.
I replaced the distributor with a 1979 model and converted to dura spark 2 ignition. I cut out the computer wiring and used
the wiring diagram from non feed back carb set up.
The only emission stuff I have is the smog pump which is for show. And the EGR valve! Runs great now! No more erratic idle!
See my posts

 

What is the "wide open gizmo?" The choke?
Are you sure the choke isn't just stuck shut? (That would definitely kill mileage).

You may simply need a carb rebuild. Or your EGR valve needs to be replaced. It doesn't necessarily mean your emission equipment needs to be removed.


Don't worry about the engine itself until you get it running right. Unless you have a broken valve/spring/piston, or some other damage, a worn out engine won't necessarily have running problems.