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I do not have the OEM parts, but I bought a complete setup on eBay. So no harm in modifying them.
If I could just get the two vanes out without smashing them up, the thing would freewheel and I'd be done! I'll see if my buddy has a bearing puller that might work.
I wasn't stoked about the notion of just smashing up the vanes with a chisel, so I pulled the back bearing out (took a long time, walking it out a little bit at a time on each side with a slide hammer):
Anyway, that allowed me to remove all the guts entirely. Now I'll have to "plug" the lines somewhere so that exhaust doesn't back up into the pump, unless someone knows there's a check valve in there already somewhere?
My concern is that I've never had an AIR pump before, but this one is too hard to rotate by hand. You can do it with a wrench, but it's very stiff. And that's just the front bearing, there are no vanes in here any more!
Is that normal, or has this pump got some kind of front bearing issue?
Should rotate freely. Bearing is binding. They rotate easy even with the vanes still in there.
The trees can be blocked with inverted pan head screws per my earlier post. Pull out the extension tubes from inside the exhaust manifolds (If they are still there). The pan head screws make up the dimensional clearance left by the missing tubes and also block the heat. The threaded ends of the screws point inside the trees but are not screwed in or attached in any way. No harm and invisible. Just slip them in there before installing the trees.
Most original pumps I have come across were seized.
My two 69s have the original pumps, both were seized when I bought the cars and I gutted both of them. It took all but 15 minutes but i just smashed the fins. And it will spin more free and look correct. Functional pumps cause backfires and make the engine run like crap at idle. Who cares about the horsepower loss, its the backfiring that made me want to inable the system.
Instead of welding the exhaust manifold holes closed, a less expensive way is to weld closed the ends of the trees(smog pipes) that screw into them. The repro smog pipes are less expensive than than the repro exhaust manifolds.
Last edited by ed427vette; 02-02-2018 at 01:29 AM.
I would do this ^^^ as well...I would not touch the OEM parts if they are original to the car.
On a side note, on my 78 L-82 when I removed all the AIR parts and the OEM stock exhaust manifolds, all of which I still have in storage, I was shocked at how far those innocent looking AIR ports in the manifold extended into the exhaust manifold itself AND extend way into the exhaust port of the head. There is no way that all that hardware directly in the middle of the exhaust stream does NOT create restriction and turbulence......It's not just about the HP to turn the AIR pump which is minimal but more importantly those exhaust port extensions......If you are looking to streamline the exhaust flow, those port extensions must go.....................
Most of the emissions hardware back in the 60's/70's was worthless and extremely crude and often ineffective, that includes the EGR valves that so many tout as harmless to performance.....NOT ( not one engine builder I know will support running an EGR to "cool" the intake charge with 500 degree recycled dirty exhaust gas in place of cool clean air). The only emission piece I would support, and ONLY if necessary, to pass emissions would be a high flow cat. A proper running high performance Gen 1 SBC/BB will run relatively clean if tuned properly.
The Hedman #68301 headers that I installed on my '80 L48 (back when I still had to pass emissions) had the tubes welded into the tops of the exhaust pipes. They did not extend into the exhaust tubes. Even Hedman must have realized that projecting into the tubes had to steal some flow. They were issued a CARB exemption for their headers with these A.I.R. tubes. I still run them but removed the air pump and put iron caps on the top tubes (1 per header). When the headers finally fail (they are now 18 years old - Jet Hot coating), I will probably go with HTC-coated (no A.I.R.).
01-27-2018, 12:59 PM
