Taking off all the computer stuff from an 83 Olds 307. Just rebuilt a 77 Olds carb for it and put on a new vacuum advance HEI dist.

Wondering if I should just plate off the EGR port. Also wondering on the PCV valve if I should just put a breather in its place. Then there will be breathers on both valve covers.

I'm just looking for simplicity. Not necessarily the absolute perfect, from the factory tuning, etc..

If I put a new EGR valve on (the old one is no good) - Do I just run it to manifold vacuum and that's it? Autozone sells from them for $47 and they are the same part number for CCC vehicles and pre CCC.

I've heard the 307 is specifically designed to be ran with an EGR and if you take it off the engine will run hotter and leaner? Not sure how true that is. If anyone has any hands-on real world experience with it.

Thanks!

 

You can buy or fabricate a cover to block the EGR. The PCV (positive crankcase ventilation) valve is not 100% necessary for the operation of the engine, however is does create a negative pressure inside the engine that keeps your blowby in check and recycles internal crankcase fumes. Its a good idea to use one and it does not effect performance.

In addition to removing the EGR, remove all the miles of unnecessary vacuum lines.

 

This is a small sample of what has been removed LOL

Also - I broke the old distributor housing removing it. Going in the trash, so doesn't really matter..but it was froze in there pretty good.

I'd like to get all the ECM wiring out of the way.. Looks like it could be a pain getting it through the firewall.. I may hack it out once I get this new setup running.

 

I have eliminated the EGR valve on a few early 5A 307's and a 260, all with aggressive timing thrown at them. They worked fine, especially with the slightly richer 350 carb you are throwing on, I did the same. Here is the block off plate on my 260.
https://redirect.viglink.com/?format...RBlockOff.html
As said, leave the PCV intact, otherwise pressure might push out a gasket.

 

10-4

Yea, I found that link online..Looks like the only place that carries the EGR block off. Crazy you can't find them on eBay or Summit, etc... Ah, the challenges of owning an Oldsmobile versus a Chevy.

I've got a plate of steel that should work pretty well. It's only 1/8" thick, but I'm hoping that will be OK. I'll make the gasket out of hi-temp gasket material and copper coat it. Imagine I'll need shorter bolts as well.

 

Don't do that. The PCV valve sucks the blowby gasses back into the engine to be burned. Without it the gasses will get into the cabin and choke you. Been there, done that and won't do it again.

 

There were lengthy discussions in the performance community when PCVs were introduced in the 1950s. I recall reading a dyno test article in Hot Rod or some similar magazine on an engine with and without PCV. There was no change in power or fuel use at full throttle, with or without PCV.

The test also looked at fuel consumption at road load. The difference between PCV and no PCV was minuscule, but the average run showed that the PCV gave a tiny decrease in fuel use per horsepower.

Fun71's advice is spot on. Do not put open element breathers on your valve covers or you will breathe blow-by each time you go to full throttle. Keep the breathers connected to the air cleaner housing.

 

Appreciate all the input on PCV.

I cut out the EGR block off today. Turned out pretty good. A little concerned it's only 1/8" thick and it is actually aluminum (didn't realize that.. Thought the metal I had was steel). Hopefully it will hold up good enough.. Will put copper gasket spray on the gasket also when I install.

Hopefully I'll be able to start the car here in the next few days. Hard to find enough time to actually make any progress..

 

Your plate should be fine. When I've had problems it's actually the gasket blowing out due to exhaust pressure. Maybe poke around and see if there's a Felpro replacement gasket that's like exhaust manifold stuff?
You can also post a parts wanted. Those plates from with the base Edelbrock intakes, so I'm sure there are several floating around in the bottom of folk's junk piles. Hell, if need be, I've got one on my parts car that I'd be happy to pull.

 

I appreciate the offer! Hopefully I'm all set with the one I made. Also - In case anyone is wondering what belt size you need for air pump delete (with A/C) - I believe it is Duralast 15530 (53").

That's the measurement I came up with - Also if you look up a late 70's Oldsmobile with A/C, but without air pump - That is the exact size (I could not find those options on an 83). I haven't bought or installed it yet, but pretty confident that is correct.

 

Well - It runs! I'm pretty excited. Took a few minutes of adjusting the distributor to get the timing close so it would fire up, but running pretty good as far as I can tell. Will spend some more time this weekend getting it dialed in. Check engine light is still illuminated unfortunately even with all the wiring removed.

I attached a couple photos. Does it look like my distributor is off a tooth? I'm able to get the timing correct where it is at, but seems turned clockwise just a touch further than it should be. Rotor was facing very close to where the old one was at removal. Should have just enough room/clearance for the vacuum line on the distributor.

Also - Does anyone know what I need to do to retain A/C? I did not try to turn it on. I know it goes through the ECM (for some reason).

 

re. your AC question, In some cars the AC control is not part of the ECM but a separate computer system under the dash. You may not have to get a shop manual to figure it out. Here is a link to a quickie bypass of the AC computer, Kinda corny presentation but it might work:
https://diy-auto-repair.wonderhowto....switch-401445/
Jerry

 

Yea, I have the chassis manual - but it is actually incorrect about a couple things. I think A/C going through the ECM may be one of them. It shows the A/C connector going into the ECM harness for my vehicle - but it does not. So I have a feeling I may not have to do anything. I'll try it out this weekend and find out.

 

Unless you remove and replace distributors often, it can be difficult to get the correct engagement between the cam gear and the distributor the first time. You have to guess how much the rotor will turn as you push down after the teeth engage.

On 1965 FI Corvettes you had to have the vacuum advance in a small area, otherwise it would hit the ignition shroud or shroud support when you tried to get the timing correct.

Each time I removed the distributor it took me a few tries to get the distributor to engage the correct tooth. (And then another few tries turning the oil pump until the distributor would engage the pump drive. Thankfully, pump drive alignment on our Olds is less worse.)

You may be experiencing something like that. However, as long as you can time it correctly while accessing everything you need to, go with what you have.

 

Yea, I'm going to stick with where it is. I've got clearance for everything - Only problem is the 12V lead for the distributor is barely reaching where it needs to be. I'm going to have to splice and extend that wire a couple inches so it isn't straining as much. The plug is broke anyways, so it needs to be done.

I just think it's really weird the vacuum advance is where it is on an Oldsmobile. I'm sure there's a reason - but I can't imagine why it points toward the rear of the engine (as opposed to a Chevy). Also - I had to break the old distributor removing it. It was lodged in there ridiculously tight. Even getting the new one in - I had to tighten the hold down to get it seated (I oiled it with the o-ring prior to install).

 

The factory vacuum advance usually has a 90 degree vacuum hose attachment nipple.

 

not just a fuelie.any corvette with the distributor cover had this issue.i know i have one on my 66 chevelle with a corvette 3x2 intake.it's also a pita to get the coil wires and tach wire connected too.

 

Well - I did end up having to move the distributor over a tooth.The vacuum advance was hitting the firewall right where it needed to be (wouldn't have been able to hook up the vacuum line). Wasn't a huge deal to move it over - luckily went smooth.

Put the lockup kit in the trans today. That was a very messy job. Didn't finish everything until late tonight. Will drive it tomorrow and see how everything works.

 

One additional comment on the PCV, the valve does nothing at wide open throttle. The system relies on manifold vacuum of which there is none when the throttle is fully open. That is why Oldsmobile ran a pipe from the breather to the air cleaner housing (or two on the W machines). The airflow in the air cleaner would draw the cranckase fumes from the breather through the carburetor under high load condition providing some crankcase evacuation.

Removing the EGR from a carbureted engine is probably okay unless you live is a state that still tests emissions on older cars. Don't remove the system on the fuel injected Oldsmobile engines used in Cadillacs from 1975 to 1980. These were open loop fuel control systems that were calibrated with the EGR functional. Removing the EGR will cause them to run lean and hesitate because there will be more air replacing the inert exhaust gas that was supposed to be there from the EGR system.