Hi, I'm new to this site, just looking for a little help. I recently purchased a new daily driver, an 85 Caprice, 305 LG-4. It was in pretty rough shape, and so far I've replaced the Q-Jet with an Edelbrock 500 cfm, replaced the radiator, and few other things; my question is about the exhaust. The vehicle is definately not emissions legal, there's no EGR or smog compressor, and the AIR has been completely removed from the exhaust manifolds, and each hole has a bolt jammed into it ( I say jammed because the bolts are pretty clearly the wrong thread size, they're all angled slightly). I'm trying to figure out why the guy I bought it from did this, and if it has any effect on the engine's performance.  I don't really know anything about emissions or AIR, so any thoughts would be greatly appreciated. Thanks.  

People do stupid things, by disconnecting the AIR many people think this is a route to more horsepower. This is like peeing in Lake Erie to watch the water level rise. All this thing does is supply air to burn any fuel in the exhaust that wasn't consumed in the cylinder. It takes all of 2 or 3 horsepower if that to run. However, it's obvious that you don't live where an emission test is required so I wouldn't worry about it. If you want to clean the look up retap using a suitable size pipe thread tap and install 8 brass pipe plugs, probably 1/4 to 3/8s NTP will do the job. EGR systems can cause all kinds of problems as they fail, mostly related to lean running. If it fails closed then the carb is supplying more mixture by volume to the cylinders, problem is the carbs wasn't jetted to do this so the engine falls lean, combustion goes hot, pinging and run-on occur. This problem exacerbates itself because there is so much under carb exhaust heat applied to these engines that when the mixture goes lean the hot spot gets even hotter driving the mixture to loose density and power falls off and the engine tends to overheat because of the high temps in the crossover passages heat up the coolant which further drives cylinder temps up making pinging and run-on bigger and bigger problems. This mess just feeds on itself over and over again.

Since you don't have an emission test just leave the EGR off. However, there's some tricks you can do to make the engine run better. First is to get the carb jetted right, along with this get the automatic timing advance corrected to come up faster. If you're willing to put a few extra bucks and effort into it, pull the intake and have it cleaned as the hot spot is probably plugged with carbon by now. Then put it back on with a manifold gasket that restricts the amount of exhaust gas that can flow under here. Cutting that in half in cold country and by 2/3s in the southwest works fine.

If you have to pass an emissions test, then probably all the missing stuff will have to be put back on, I'm not sure that's worth the cost or effort unless you find a wrecking yard donor.

Bogie

Well, fortunately, I live in emissions-free southern Minnesota, so I'm alright on the EGR and stuff. Thanks alot for the info, there just one more thing I'm wondering about; the left rear freeze plug leakes, it's not too bad but it's still a leak. I've heard that when one freeze plug starts to leak the others are right behind it. Is this true? and how hard are the plugs to do on a 305? As always, any help is appreciated. Thanks.  

The soft plugs rust out from the inside. When one is leaking the others usually aren't far behind. Since you have to drain the coolant, you might just as well do all of them you can reach. Some people recommend replacing them with brass rather than steel. Brass will probably last a little longer but they're expensive. The factory steel ones lasted 20 years in an engine that probably never saw a coolant change, so this is a pretty good indication that steel is sufficient and less expensive solution. A lot of shops put a bead of 3M gasket cement (known as elephant snot where I live) around the plug upon installation. This helps to lock the plug in position and prevent any leakage around the plug. Then of course you refill the cooling system with a mixture of antifreeze and demineralized water in a ratio appropriate to Minnesota winters.

When you get the old plugs out you may find lots of rust and gunk in the bottom of the water jackets. Just take a garden hose and blast this stuff out. Yeah, you're gonna get wet. Don't bother with cooling system cleaners, this stuff is ineffective in the block and often uncovers leaks in the radiator.

Bogie

Thanks for the advice Bogie, I'll try it this weekend.  

The holes in the manifolds for the air injection are tube thread. Tube plugs are easy to find anywhere weatherhead fittings are sold.The thing would have a little better gas milage and better response if everything was put back on but only like 7% better.If it still has the original distrubitor without vacuume advance and centrifical advance the computer is most likely not giving it any advance.This would make it run kinda flat.Anytime there is any sensor disconnected  the computer will go to a pre program  closed loop I think .At this point the timming does not advance.You could try to put it back to O.E.M if you can find a donor car without a lot of rust on everything under the hood.Or seal up the exhaust make sure the converter is not plugged and get a older style distrubitor.Oh yeah if you have a O.D trans or a lock up torque converter without the computer working in open loop the trans will not work right in 4th or lock up converter.  

I seem to have not ben reading all the answers posted.Sometimes I differ with OldBogie and I dont mean too.I just found this site with people of the same interest as mine.I just want to help by saving time and imforming from my trial and errors.I have never got involved with a serious restoration or a big block for that matter.My two best friends are profesional mechanics and seem to be clueless about many things we talk about but are up to date on many things I am not in a wider variety.Sorry Old Bogie  

Gearman, you lost me. Your correct about the AIR holes being conventional tube fittings. When I recommended redrilling and tapping, I had assumed (and we all know what ASSofUandME means) that the bolts probably stripped out the original threads and that would require a fix. However, if the original threads are undamaged, your recommendation works without the hassle of my so called "solution".

Good shoot'n

Bogie

If it still has the factory distrubitor I would get a new one for a non computer engine.Or a used one in good condition will do. Dont assume that a vacumme advance on it means it has centrifugal inside.I saw one in a 87 suburban that had vac advance on it but was also computer controlled.Set the timming at like 6-8 deg.This should wake it up. If it still has the comp.dist. in it it is more then likely set at odeg. and not giving much advance.I think a hei module does change the timming somewhat on its own as it will change the dwell a little bit with rpm. But that alone is not gooing to cut it. Go for some hooker headers with 1 1/2 primary tubes. After the headers use 2" tubes or better yet see if u can fab up a 2 1/4 -2 1/2  single system. If you run duals you need a H pipe (balance tube). This will help with the torque . I did not have one on my malibu. After putting one on a over cammed truck I had I could not believe the difference it made.The truck had no bottom end untill I did that.I ran a TRW cam 204,214 degrees 420" 442" in a 83 malibu 305 G (L69) police had G ,rare.Acutally the vin said H but the heads were smaller cc with 184 intake valve.And when I pulled em the pistons were flat tops = 9.5:1 in my book L69.put hookers comp headers ,valve springs ,performer intake ,modified the Q jet and it would spin one tire 100'.It felt like 100 more ponies but in reality 220 net . 273 gears did not help ,on my watch 0-60 in mid 10 sec.Before it was like 14.Good luck of course the malibu was 3380 lbs. But you have a lower first gear then my th350.  

I'm sure getting a new distributor will make a ton of difference, i'll try and see what I can find off a donor at the junkyard, I don't know how willing I am to spend $100+ on a new one for this old beast just yet, but I will get it taken care of. As for the non-computer controlled, I had the misfortune of experiencing a computer failure first hand this past week, as I was pulling away from a stop light, as soon as I hit the gas and got above 5 mph, the torque converter locked up on me. Until I got home and took a look at it, as soon as the vehicle started to move, the converter would lock up, but it always unlocked at a stop. I got home, and look at the computer and all the connections seemed fine, so I just spliced the pink wire going to the transmition and put it on a toggle switch. Now, when I want the converter to lock up, all I have to do is hit a toggle. Was this a good idea? Also, does anyone know what kind of cogs I'm running in the rear of this beast? I'm trying to learn as much as I can about B bodies, now that I have one, and am growing pretty fond of it.

Thanks again,

Brian

I had the same thng on a 86 cavalier . It was a th125 transaxle ,mine would work fine untill it got hot then it would stay locked up. The slippage and heat from the high stall speed factory converter worried me. Besides that I think the cogs were like 3.73 and that did not help at 65-70 mph. Anyway after talking to a local mechanic who told me to leave it unplugged or rebuild the trans I went to the switch thing also. If  I turned it on before it was in third gear it would allmost bark the tires when it hit second.Does yours shift hard? I worked at NAPA at the time and knew we sold a TCC solenoid  under our ATP line. It was cheap with my discount. I changed it it has a little O ring on the end of it that was swollen on the old one and causing it ti get stuck in its bore. I changed the whole thing anyways. On that trans the valve body is on the side of the trans so it is a little harder then yours to pull the pan. I would think you have a th700r4 or the 2004r  .I am not saying your computer is not causing this ,hell I am suprised it was locking up at all with your computer running in closed loop. But if you change fluid some time think about it. You could put a timming light on it and run the rpms up a little and see if it moves . If it does your computer is still dooing its job there too. You  may not be that bad off  and dont need the used dist. From my experience if there is a trouble code or sensor not hooked up you loose tour lockup and your timming advance.But i have ben wrong many times before. Allmost foregot my converter worked fine after I changed the solenoid.

Yeah, it's a 700R4, and honestly, I'm not sure if it's the computer or not, but the shifts are factory-smooth when I don't have the converter locked. When I lock the converter, the shifts are rougher, but at a much lower rpm then usual, and she jumps like hell if I'm not giving it a decent amount of throttle. But I never lock it up until I'm in 4th gear and going to be there for a while. Right now, I'm perfectly fine with just hitting a toggle when I need to, but I may get to looking at the transmition soooner or later, but then then again, I'm running on 173k of wear and tear. On the other hand, I'm pretty much sure there's no timing advance , because I can sure hear it and feel it when I stomp it down (however you wanna describe flooring a 305 in a 5000 pound car), so I'm thinking just going to a vacuum advance from a donor is the easiest option right now. I like this car alot, but I didn't pay much for it, and with as many miles as it has, and looking at some of the work the guy before me did to it, I'm not willing to invest a whole lotta money at this point. I'd be a lot more willing if 80s B-body restoration were a lot more popular, but I don't see that happening for while. Anyways, always looking for tips, comments, help, or just general info about this thing, 85 Caprice, 305 LG-4, 700R4, all pretty much stock except for the carb.

Thanks again,

Brian

I had a 78 caprice a few years ago . I drove it through the winter and pulled the enngine and some other parts for mu malibu. It cost me 500 and had a good inspection sticker and a strong virgin engine with 78k. 350 with a th350 .I think it got around 14 mpg .It had full power and every option so it was nice to me. It had bran new tires and new coil springs all around . I think it had like 2.41 gears but would still spin em. I kinda miss that old car but my s10 does get 35 mpg highway now.