TheSilverBuick's 1977 Skylark

Discussion in 'The "X" bodies' started by TheSilverBuick, Jul 5, 2010.

  1. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    It wasn't even on my radar until yesterday afternoon when a friend mentioned he was going on the Car Craft Anti-Tour this year. They are finally doing something different after five or so years of the same drive. I'm not sure if I'll be able to make it, but I have the wife warming up to letting me make the drive to southern California, do the cruise up to Redding, CA and her and my son will just make the 4 hour drive from our house to Redding on Thursday night. I'd drive down Wednesday night, drive back up Thursday with the cruise.

    https://www.facebook.com/events/1414314585308860/

    April 27-30.
    Looks like there is a drag strip runs at 5:30pm on both Friday and Saturday!
    https://koolaprilnites.com/Koolpage.asp?ID=7
     
  2. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Been doing some tinkering in the background. I've wanted to experiment with converting a smog pump to a vacuum pump but have been finding it quite difficult to find smog pumps for cheap and to get them sent to me. So far after several months of looking I got one in my hands last month from Hector (CARHEX). A seized up unit from an early 70's Buick.

    Some background, it's fairly well documented that the carbon seals in these things don't like oil. For some reason it causes the units to lock up, sometimes catastrophically enough to shear the pulley off. After opening one up, I think I know how the catastrophic failure happens, the carbon seals not only seal up against the vanes but also keep it fairly centered through the rotation, and if oil cooks itself to the vane and chips the carbon seals, eventually breaking them into pieces then the support for the vanes go away and it jams, hard. GZ Motorsports I think is the only company that uses the smog pump design and their solution is a custom seal that can take the heat and not be significantly damaged by debris/cooked oil. Taking a page from them I went to the hardware store and bought some large 3/16th O-rings to make new seals out of. My thought is, if the seals keep somewhat oiled they may be happy, and if they get slightly damaged, they aren't at risk of completely shattering like the hard carbon seals. Google'ing indicates the hardware store seals are Nitrile and tolerate temps up to 250ºF which is pretty low for the working environment, but it's what was available.

    The pump came apart reasonably easy. I cracked the external fan, but I have no plan on re-using it anyways. Seems just a bit of rust build up from sitting caused it to be stuck as all the needle bearings and bearing surfaces were in good shape. Heck, even the carbon seals were in good shape.
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    First order of business was sealing up the intake hole so I can make a new one that a hose can slip on to. The hole was behind the external fan, so with some crappy welding (aluminum casing, generic MIG welding) to make some support structure that RTV could be smeared over to seal it up.
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    It seems that one carbon seal is fixed in place and the other seal has a small bent piece of metal to spring the seal against the vane to maintain the seal. The small bent piece of metal wasn't going to work with the flexible rubber. I found that zip ties were the right width so clipping some of them I shimmed the seals into place. It actually seemed to be a decent fit with minimal resistance on the vane when I turned it. I used hi-temperature wheel bearing grease on all the bearings and coated the rubber seals and vanes with it as well. Hi-temp right?
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    Got a nice "wipe" pattern on the vanes.
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    I cleaned out most the gunk that was built up in the housing and back plate. I tapped the stock outlet on the backing plate with 1/2" NPT and drilled and tapped a corresponding hole on the inlet side (seen on the top left) and put it back together.
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    Seems I didn't take a picture of it assembled and on the engine, but the result of test #1 is yet to be determined, but I've removed the pump for disassembly and inspection. I ran it for about 10 minutes with the outlet not connected to anything and it pulled just under 5inHg at 2,000rpm, which is on par with how I had the intake pulling vacuum through two oil separators. However the outlet gas smelled of burning rubber, which I took as a bad sign and removed the pump for disassembly and inspection. I expect to find partially melted rubber, but who knows? I haven't looked yet, but I'm going to start looking for teflon o-rings or small plates to cut in the 3/16th thickness range to try next.
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    Fun fun, and if you know where some GM smog pumps are you want to send me for cheap, let me know! I figure I'll eventually break this one in testing.
     
  3. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I finally got around to disassembling the pump and it seems one of the vanes started de-laminating and formed a bubble and that lack of smoothness started cooking the seal. I'm not sure if it's a defect of the vane and it was delaminating before I installed it or if the heat started it's failure. The other side looks mint. Its still flat and the seals still look like when I put them in. So I'm not on a holding pattern until I can source another pump. Since I have a bad vane now, I'll see about disassembling it and trying a different material.

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    Last edited: May 16, 2017
  4. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Its not really worth starting a project thread on, but after driving my Centurion across the state and in real traffic, not idling around a podunk town, it's safe to say the engine seems to be feeling tired. I rebuilt the engine in 2000 or 2001 when I first got the car and other than a head gasket in 2006 or so it's been a good reliable engine, but I think the valve springs are starting to get weak as it doesn't seem to want to rev much over 4,000-4,500rpm anymore and it used to pull easily to just over 5,000rpm and chirp the tires hitting second gear.

    So thinking about parts left over from use on the Skylark, I have a TA-212 camshaft I used for a year or so, aluminum edelbrock performer intake manifold and set of smaller chamber 1970 Buick 455 heads with big valves, gently used springs and mild porting I did sitting in storage, all that can easily go on this engine. Though it's approaching 100,000 miles, it doesn't seem to burn any oil and still has great oil pressure, so I'm thinking of a simple head, cam and intake swap could really wake it back up. The 212 cam should pull better than the single pattern smaller isky cam in it now with a slight bump in compression ratio, fresher valve springs and aluminum intake it should wake up nicely. Of course I'm not sure when I'll have to time to do this, but I'm technically a gasket kit away from doing it......

    I also see that Maaco has a $299 summer paint special going. With some quick and dirty bondo rust repairs I think I can get some new paint on the car that'll last a couple years for under a $1000. Going to stop by there later this week.

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  5. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Well Photobucket knocked $300 off their ransom demands and for $99/yr (>$9/mo) I paid them off to restore my photos across the web. Not a homerun win but at least not completely ridculous.
     
  6. newmexguy

    newmexguy Well-Known Member

    I should have at least two smog pumps I could send for shipping. Know one is off a '87 chev truck (first year TBI)
    Dave S. dona Ana NM 88032
     
  7. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I would very much like to have them! The last couple I got are pretty rough, to put it lightly. I'll PM you.

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  8. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    As for the Skylark, just out driving it from time to time. Going to Cars and Coffee's and such when the weather is decent enough.

    Just about defrosted.
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  9. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    They arrived yesterday, thanks!!
     

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