Recently purchased a 69 eldorado and am planning on removing smog pump if i can find some free time.I have read about the ways people have done it on this forum.What i was wondering is if the lower pulley on the crankshaft is made in 2 pieces?It kind of looks like the double inner pulley for a/c and p/s is one piece and the outer for smog pump is either bolted to it or possibly spot welded to it.What i am thinking is simply spacing the outer lower pulley forward to line up with the alternator pulley,putting on a longer belt and being done with it.It appears you only need to come forward with that pulley a 1/2 to 3/4 of an inch though i havent measured it yet.If its 2 seperate pieces this makes life easier and i can add either 4 thick walled tubing spacers or have a solid doughnut spacer made by a friend either out of aluminum or steel.Which do any of you think would be best.If pulley is spot welded i can just drill out the welds and add my spacer.Any thoughts and opinions would be greatly appreciated.Also i am looking for a GOOD vacuum routing diagram.It seems most stuff like this has only 1/2 of what you need to see.I have just a couple lines that were plugged when i got the car and need to find out there proper routing.Im pretty sure they are affecting my climate control.The car has 70,000 original miles and is pretty well unmolested except for those vacuum lines.Also im looking for a set of reasonably priced and decent set of 67-68 hubcaps.
There was a post in the for sale section recently where someone saw a 67 in a junkyard and was willing to go get parts for members.
There were some vintages of this engine family that had a separate balancer and pulley but I dont recall ever hearing about a version where the pulleys are not one piece. There were a few variants of the pulleys and as you were thinking the difference in the smog and non smog engines was the spacing of that front groove. The smogs all the grooves are fairly close. The non smogs that outer groove is about 3/4 apart from the rear grove. The -74's had a dual power steering / AC belt. 74- had a single belt. The belt change was when they went to the HEI distributor. Both versions came in smog and non smog. THere was a matching water pump pulley. The smogs were dual and the non smogs were a single groove. There was a slight change in the water pump to clear the dual belt but it seems like 90% of the pumps out there will clear either style. There was a period in the early years that was a lighter pulley and then 77+ that was a stamped pulley but most of them had the heavy cast one. I would be concerned about balance and other unforscene forces being introduced if you spaced the whole thing out. Its usually not too hard to find a set of the non smog pulleys. 70, 75, and 78 were the most common years to not have the smog pumps but there were other years that has some too. You also want to get the timing marker with the pulleys because those varied slightly also. Most of the 500 enthusiasts on the CadillacPower forum have a stash of non smog pulleys. When someone asks for a set they usually seem to get a set. MTS also will sell used ones if they have em. They make a new set of aluminum pulleys if you wanted to to that way also.
Another thing that has been done if you are not running the AC is to space the power steering forward to use the smog groove and that then drives the alternator.
Why are you removing the pump? They usually dont really seem to hurt things. There is certanly not any sort of performance gain by removing it. Biggest issue with them is the check valve on the engine goes out. Easy to replace because they were used well into the 90's. This lets exhaust work its way down to the diverter valve and kills that and eventually works its way to the pump and kills that which takes out the belt which leaves you with no alternator or water pump. I have been told that the diverter valves are difficult to find. When the diverter valve is no longer working and the pump still works it keeps pumping air into the exhaust during deceleration which causes a popping backfire sort of a thing.
I think 68 is the first year for the 472, and it has an AIR pump, so no help there. The 67, I think, would be a 429?
Just my 2 cents. I thought about removing mine too, however as I looked into it it's not worth the expense or trouble to me. The horsepower loss is only about 1 hp and the air it pumps into the exhaust helps clean up any unburned fuel. So mine is staying. Getting rid of it won't provide any real benefit that I can see.
I removed the AIR Pump on my '72 Eldo, and realigned the Alternator by modifying the Alternator Bracket, and it really tidies up the engine bay.
My Pump was noisy, and as a replacement was out of the question, plus I installed an HEI Distributor, and the AIR Delivery Tubing was in the way, it was a no-brainer to get rid of it.
Funny thing is that now the engine is a lot quieter.
I have better photos of the brackets if anyone wants them.
Bruce. >:D
I have a 68 CDV and I absolutely HATE that @#$%^* A.I.R. pump!
Its on its second a.i.r pump since I've owned it and it is NOISY! POP POP POP POP. The first one did the same thing.
It just makes this great quality car sound like a popcorn machine!
I looked at a few "remedies"...MTS, etc...but too expensive for my limited budget...so I live with it! But I really hate it!
Bruce...can something like that work for my '68?
G'day Steve,
The thing that has to be done is to reposition the Alternator to the rear, so it is in the alignment with the AIR Pump Belt.
Then once the Alternator is in place, bearing in mind that the power terminals must be clear of hitting the head, and you have sufficient movement to tighten the new belt, it is all go from there.
The pictures I have attached are one I did on a '69 SDV, but hung the Alternator down low. It was smaller than the Original and suited that location.
As you will see, I modified the rear bracket by cutting off the excess material, and trimmed the front mount, and fabricated a piece to extend out to mount the front part of the Alternator.
The adjuster piece is one of the parts I had laying in my stash for future use, and not sure what it was from, but it isn't difficult to make one yourself.
The biggest thing is to ensure that there is sufficient clearance where the arm is close to the fan on the Alternator.
Bruce. >:D
Steve, I have never experienced the pop pop you describe with my 68 ELDO. Is it possible you are missing the silencer?
Thanks Glen, but yes, I DO have the silencer....
I have never noticed a noise from the pump over the rest of the engine and fan noise. The pop must be through the exhaust? If thats it would be because the diverter valve is not working and its still pumping air on the 'overrun' when its too rich.
No TJ...it isnt thru the exhaust. Its a sort of muffled pop sound coming from the pump itself...but it is louder than the fan belt or fan noise...and easily as loud as the engine noise itself. I didn't mean to suggest its like a backfire pop its more like the sound of a popcorn machine....a little louder of course. Maybe I just got another bad pump that replaced the other bad pump? The old one froze up. I don't even know how to tell if this thing is even working correctly or not...I'm just using it because I HAVE to for the pulley!