JB

Found a numbers correct smog pump and diverter for my big block & I thought I would gut it, repack the bearings, block the vacuum line and run it just for appearance. Got the back off, but I can't figure out how to disassemble it any further. I'm trying REAL hard to be gentle with the plastic fan on the front, as I've seen these white fans alone go for over $100 on ebay, but I don't see any way to get the fan off.

Any hints?

JB

page62

No, but we'll be happy to come over and drink your :cheers: and supervise as you struggle with it!
:jester

Jim Shea

DON'T TAKE THE FAN OFF!!!!!
The bearing behind it is sealed and you won't be able to put any grease in it anyway. Just take the vanes out from the back side. There is a bearing and a race on the back cover that you could grease if you want to.


[Modified by Jim Shea, 5:30 PM 5/8/2004]

JB

Page, you'd watch paint peel if there was beer involved! :D

Jim--If the front bearing can't be serviced, I may have bought into a numbers matching paper weight, since the thing's frozen solid, even with the back cover and and spindle off. I see the vanes inside the cylinder that's inside the outer casing, but I don't see any way to get them out. do I have any recourse here except salvaging the diverter and finding another pump that's not frozen?

JB

trw

JB

Usually its the vanes that lock up. Break the vanes off and see if it turns.

I have heard you can replace the front bearing, but I'd try the vanes first.

Terry

JB

I gotta say I don't see how breaking the vanes will make any difference. The pic below is the pump with the back off. There's a cylinder inside the outer casing, and there are what look to be rubber vanes/wipers sticking through slots in the cylinder (you can see one sticking through the side of the cylinder to the lower left). Inside the cylinder the vanes are attached to those things with the holes in the middle, and the shaft on the back cover goes through the center of the holes. I assume since the bearing is inside the opening in the cylinder that the cylinder is supposed to turn. The vanes are completely loose and I can poke them through the slots so they go completely inside the cylinder, so I don't think they're whats' frozen.

Am I understanding the operation of this thing right?






[Modified by JB, 6:21 PM 5/8/2004]

Wrencher

Jim's right, it's almost always the vanes (they interlock and slide through each other). Yours is mighty ugly, but anything can be fixed. Why not pick up another one (or three) off of some junker and become an expert on those? That way you'll do yours right.

Where are the relevent numbers? In my experience almost all the pumps in that era were the same so most parts should be easy to exchange. As far as running it empty, that works great. Good luck.

Hans

JB

I think that's right good advice, and I think I'll go haunt ebay and see what I can pick up. The important number other than the part number (which is the same part number for a lot of cars) is the date code, which is stamped on a machined half-moon area on the ridge on the bottom of the pump casing. The fact is that there are only two parts that I can't replace with parts from any old pump: the outer casing and the white fan on the front ('69 was, I believe, the only year with a white fan).

What I'm worried about right now is that the front bearing is seized. The vanes seem completely loose and I can't see how they could keep it from turning unless I'm missing something. If I understand the operation of this thing, the drum that the vanes are in turns inside the casing, and the the vanes, which are on an offset shaft, move in and out of the slots on the drum as the drum turns. I can shift the vanes around freely in and out of the drum, but the drum itself is completely immobile. What worries me is that I'm thinking I've got to get the fan off to remove the drum and the front bearing, and I can see no way to do that without breaking the fan, as the fan appears to be press-fitted to the hub that the pulley bolts to. Anybody know how to get the fan off in one piece?

JB


[Modified by JB, 9:54 PM 5/8/2004]

Jim Shea

Back in the 1960s, as an engineering student, I worked on the air pump development program at Saginaw Steering Gear Division. I am trying to remember how the pump went together. According to the service manual, the internal pump parts are not replaceable. In fact, there is also a picture of the plastic filter fan being cut off and destroyed to get it off of the hub on the front of the pump.

With respect of the rotor being seized. You might try some penetrating oil. The part of the housing at about 9:30 in your photo is called the stripper. It separates the intake from the discharge sections of the pump. It is very close tolerance to the rotor. I believe that the stripper could be corroded to the rotor. Try the penetrating oil at that location.

One thing that I can't remember very well. I thought that the rear bearing was part of a round plate that was bolted on the back of the rotor. Removing the bolts allowed the rear bearing and plate to be removed and then the vanes would slide up and out of the rotor. I don't see any bolts holding the bearing and plate. I don't see how the plate and bearing comes off so that the vanes can be removed. Maybe the early production pumps that I worked on had the bolted plate and bearing.

One last thing, the bearing on the front of the pump, (behind the filter fan), is locked in place by injected plastic. You will need an arbor press to remove the bearing from the housing. You will have to press on the bearing from inside the housing.

They really didn't make the pump serviceable.

JB

Oy. May have bit off more than I can chew here.

There are definitely no bolts and the back of the rotor drum is one piece as far as I can see, so I'm at a loss to see how the vanes can be removed without removing the rotor altogether. Destroying the fan would definitely ruin much of the value of the pump. I'm bummed.

Thanks for your help, Jim.

JB

hunt4cleanair

JB:

You might consider having it rebuilt by a reputable company like Hodel and make if functional! A.I.R. actually enhances performance and especially for a gas sucking big block that needs the extra O2 squirt that comes from A.I.R.

That way you save the fan, parts work and it improve performance.

JB

Yeah, that's what I'm thinking at this point. Gotta say I don't see how the AIR system could aid performance, since the air's injected into the exhaust. Doesn't harm performance much, but I don't think it helps.

Thanks, guys.

JB


[Modified by JB, 9:20 AM 5/9/2004]

Corey_68

:nonod: Sorry, it was one of the first things pulled off the car.

hunt4cleanair

Simple but rather ingenious. The O2 burns the excessive unburned hydrocarbons (gas) thus maximizing combustion. The argument against is the horspower to drive the pulley and A.I.R. motor but its reported to be negligible.

The perception built up over the years is that anything to control smog...undermines performance. The rationale is not really understood and therefore the myrth plays on.

JB

Not to be argumentative (OK, I like to be argumentative :D ), but how could air injected into the exhaust stream after it's left the combustion chamber do anything for horsepower? Or am I missing something (entirely possible)?

JB


[Modified by JB, 5:20 PM 5/9/2004]

hunt4cleanair

Well we could believe what the GM marketeers told us in the late 60's but that would be suspect. Here's my take. A.I.R. allows the vehicle to run with a richer mixture such as we find with big blocks and LT1s in contrast to the leaners mixtures of base and latter 454 big blocks. The richer mixtures produce more hp on "quick" acceleration, uphill and cold starts while simultaneously neutralizing the unburned hydrocarbons...making you a very good eco contributing citizen.

But I guess one could argue "I can run those richer mixtures anyway without the squirt of O2 and the neglible power robbing of the pulley!" Ok but L88s still produced over 500 hp with A.I.R.!