View Full Version : ditching the smog pump?
frankenstang57
10-20-2005, 06:14 PM
:evil: Since I'm swapping a '69 472 into an earlier model Caddy, I see no point in running the smog pump. I plugged off the holes in the heads with 11/16" expansion plugs. I haven't gotten to the point of hanging all the accessories on the front of the motor just yet, but I did notice the our boys at GM try to force you to run the pump with their belt placement.(ie, running the alt off of the water pump and the what not) Have any of you guys dealt with this? Way I see it, one of 3 things can happen. I can gut the pump and run it like an idler, or, grab a v-belt idler pulley off a Lincoln or some other Ford, or build a custom alt. bracket. Any thoughts? :evil:
how about finding a shorter belt and take it totally out of the loop. Thats what i would try.
frankenstang57
10-20-2005, 09:47 PM
:evil: That won't work. They have 2 belts going from the crank to the ac and ps pump. They have another going from the crank, to the water pump and the smog pump. There is one more running from the water pump to the alt. No smog pump, no water pump, = no alt. I was kinda thinking about backspaceing the alt. to eliminate the sp, that is if there is room. :evil:
STDog
10-21-2005, 07:23 AM
If you can find the pulleys (crank and water pump) from a non-smopg car, the PS, A/C, and alt will line up. 1970 engines (472 and 500) didn't have it, nor di 7x-8x 425s and 368.
Alternative is figure out an idler system.
fleetwood472
10-21-2005, 07:23 AM
Plug the air ports in the heads with cup plugs then swap a 425 pulley setup on which doesnt use the pump. - Justin
frankenstang57
10-21-2005, 08:52 AM
:evil: Thanx guys! Now I just need to find one... :evil:
I've run into this alot, and I found it faster to build my own idler. If you can't fabricate, then I would look for replacement pulleys.
DOC
STDog
10-21-2005, 10:45 AM
I've run into this alot, and I found it faster to build my own idler.
perhaps you could fab a few for those in need? Add it to the CSOB Ind. timing tab?
frankenstang57
10-21-2005, 05:56 PM
:evil: DOC, that's probably what I'll do. I've got a pretty well equiped shop and fabbing something up shouldn't be a problem. I was just wondering if there was a factory "cheat" out there. The only Caddy I know about locally is a '78 Eldo with a 425. It had a SP. It would probably be faster to carve an idler out of a block of steal than the hours of looking for pulleys at the pick-n-pulls... :lol: See, now if you were manufacturing idlers, you'd have your first customer! Then again, to keep it legal with the EPA, you'd have to mark them, "not intended for highway use!" :lol: :evil:
Next time it comes up I'll make a batch and see what happens. Don't count on it to soon, it's huntin' season around here!
DOC
Andy V
10-22-2005, 07:15 AM
I chose the easy route and gutted the AIR pump and used it for a belt tensioner / idler. Works good.
If you can find the 425 pulleys though they are a nice option.
Careful on the 425 pulley deal....
Contrary to what everyone says, there WERE some 425's with smog pumps. (or at least one - I always find the freak!)
I was as surprised as anyone; thought I had a 368 for parts, but when I tore it down, low & behold it was a 425.
Food for thought anyways....
CadillacPat
10-28-2005, 01:24 AM
I too first thought 425 pulleys were hard to find (because of my small town small junkyard, although I have bought two 472's from it in the last five years)....until I bought a '77 Cad from my next door neighbor for $75 and stripped it's rusty body of it's new fuel tank, radiator, TH400, two newer tires, wiring and 425. I disassembled the 425 and the car for scrap, but also kept the smogless pulley system. Then, while looking in a large junkyard in the Detroit area, I found not one, but three 425 Caddy's without smog pumps. I bought the pulley's off of one for $15 and am going back for the other two the next time I am in the city.
Also, I thought only 425's were smogpumpless...not so. I met a guy who has an original '76 Sedan with a smogpumpless cast iron crank pulley (425's are stamped steel).
Terrible One
10-28-2005, 04:46 AM
Yeah, my '76 came without a smog pump! :D
linearone
08-24-2006, 04:01 AM
Hello, Sorry to drag this thread back up but I have a 368 engine, injected, my air tube in the front has rusted through and a replacement is looking to be nonexistant. I read that you guys pulled it out and plugged it up with 11/16" plugs? what kind of plugs? the neoprene ones or like a small oil galley/freeze plug? will it hold up to exhaust pressure? heat? did you also use loctite?
Andy V
08-24-2006, 05:21 AM
yep 11/16 cup plugs like you would use on an oil galley hole. I don't think you will find the neoprene type in that small a size.
Pound the plugs in, then stake in a few places with a chisel, it won't come out. I've also seen them pounded in backwards (cup facing in) and they didn't come out either.
there's not a lot of exhaust pressure cause it takes the path of least resistance, which is out the manifolds.
There IS another option - space the Power steering pump out about an inch or so, and run a belt from crank/waterpump/Power steering, and another belt from waterpump/alternator.
Cleans everything up and if you are creative enough with the spacers nobody can even tell.
Chris
Ted in Olympia WA
09-04-2006, 07:07 AM
Could you just make a new mount for the alternator and move it back about an inch. Then you can run a belt in the back pulley of the water pump to the alternator, water pump and crank?
TED
Ted in Olympia WA
09-04-2006, 01:54 PM
Just as a side note, I have 12 Eldos here and I think they just about all have differnent pulleys. The 425 I have, one does not have the pump and the other two do. One the 500 there are double belts, single belts, air pump no air pumps, cast pulleys, tin pulleys etc.
TED
jayss109
09-04-2006, 04:38 PM
I spaced out my power steering pump using longer bolts and placing nuts against the block, both sides of the brackets. (i'll get pictures later). The best thing about doing it this way is it allows TOTAL adjustment for getting the belt perfect. The problem is that there is not alot of belt wrap from the alternator to the crank. That belt is damn tight, and depending on the weather, it will still slip a little when the enigne is cold.
Jason
STDog
09-05-2006, 07:17 AM
Could you just make a new mount for the alternator and move it back about an inch. Then you can run a belt in the back pulley of the water pump to the alternator, water pump and crank?
Not sure there's enouigh room to move the alt back that far.
On mine, the alt barely clears the bracket at the head, and it's close to the head.
Does it look like there's room to you?
I'm thinking maybe a 1/4", 3/8" is the most you could gain.
Ted in Olympia WA
09-05-2006, 11:33 PM
You have to move the alternator up and out of the way but this is what I did with mine. Look at page three of my pictures and you will see four there. Takes some welding but it can be done.
http://www.msnusers.com/CadTBird/shoebox.msnw?Page=3
On the water pump pulley I removed the outer pulley to clean it up. This was not as easy as it sounds, it was spot welded to the to the inner one on the edge not the face, you can just see a spot weld in the picture.
The weird thing that when I got done I could use the same belt for the power steering pump and alternator.
TED
burnrubber
09-18-2006, 06:44 AM
Neither my '76 500 nor my '70something 425 had smog pumps, but my '73 472 did. What's up with that?
STDog
09-18-2006, 07:12 AM
Neither my '76 500 nor my '70something 425 had smog pumps, but my '73 472 did. What's up with that?
California cars were more likely to have it.
'68 and '69 engines all have the A.I.R. pump. Then in '70 they tried something different. I guess it wasn't enough, since A.I.R. was back in '71. I think it was there untill '74 (the switch to 120cc heads) and then became a California thing mostly.
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