The Silver Buick's well Silver Buick!

[TheSilverBuick]

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. 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.


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.




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?




Got a nice "wipe" pattern on the vanes.


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.


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.


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.

[hemihauler20]

Randal I gotta say this is one awesome Buick! I'm currently on page 238 of the build so I'm still playing catch up.... My grandfather had a 455 4BBL Big Block Olds in his 1976 Oldsmobile Cutlass Supreme Brougham Coupe with a Turbo 400 trans and 3.55 gears with a Posi Trac. Now she liked to cruise but once you stepped on that skinny pedal she would just hunker down and fly haha. It was quick for a 4 wheeled Barcalounger. She was also the shittiest shade of green that I've ever laid eyes on. Had a tan vinyl top with matching interior, Bucket seats, Console shifter, Air Con, AM/FM, Power steering and brakes, crank windows and manual locks lol. I miss them both... Car went to the junkyard in 90 and my grandpa passed on 8 years later.... The Cutlass was the first car I cut my teeth on and got me interested in them. Hopefully I can find one as a tribute to him. Keep up the good work!

Bill

[hemihauler20]

Oh I forgot to add that the ol Olds was basically a drunk on four wheels hahaha... She loved gas. We were lucky to get 8-9 mpg in the city and maybe 12-14 mpg on the highway. Even though she was choked down by emissions she ran like a scalded dog. All while gulping down regular in to the secondaries

Bill

[SuperBuickGuy]

Out of curiosity, why not use a vacuum pump from a 6.5 diesel? they're belt driven and pull 13 hg at idle.

[TheSilverBuick]

Googling pictures of them, they appear to be low flow pumps. High vacuum, low flow. I actually have a vacuum pump from a Cadillac HT4100 engine, above the P/S pump. I figure I can use it on my Thunderbird if I put a turbo on it and can run all the vacuum accessories from the pump and not worry about check valves and such, but it's a low flow pump and no chance of removing crankcase gases faster than the engine can make them.

[DanStokes]

Randall - If you want it I can send you the vacuum pump from my back-up Mercedes OM617. I have no clue of the volume but they use them to run the power brakes, door locks, and other accessories on the old Benzes. The down side is that you would have to come up with some sort of a drive system as they're spun by the front gear train on the engine. I converted Mutt to manual brakes and don't run the vacuum pump at all so it's yours if you want to mess with it. BTW, I'm pretty sure it's a Pierberg pump.

Dan

[TheSilverBuick]

Thanks Dan but those are low flow pumps just designed for vacuum accessories.

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 will see about disassembling the vane and maybe trying to replace it with something else.

[TheSilverBuick]

Its not really worth starting a project thread on, but after driving my Centurion across the state last weekend and in real traffic this week, 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.

Drove across Nevada without so much as a hiccup.




Stopped for a rest break.


Why it needs paint. Just nice enough to cruise around in. Funny enough, I had the car out of storage for less than five minutes and a guy at the gas station asked me if I'd sell it, lol.


Chad and DF did a Buick engine test a few years back running the 212 cam and aluminum dual plane. The The blue line is the TA-212 cam with aluminum dual plane intake. Granted they used an electric water pump and long tube headers, but the compression ratio should be about the same with the smaller chamber heads. Nice fat torque curve for this 5,000+ lb monster with 2.93 gears.

http://www.hotrod.com/articles/ccrp-...gine-bolt-ons/

[DanStokes]

Sounds like a good combo, especially given the recycled parts. And BBBs always DID breathe. Glad to see the Centurian getting some use - and some love.


Dan

[silver_bullet]

Reminds me of the movie "Used Cars"...https://youtu.be/ZQiTRQTiMGY

[TheSilverBuick]

Reminds me of the movie "Used Cars"...https://youtu.be/ZQiTRQTiMGY

Ha! I just watched that movie in its entirety about a month ago!

[SuperBuickGuy]

but will you paint it red?

[Dan Barlow]

I had a 87 vette smog pump if you want it . Took it off a year and a half ago . Yours if you want it . If its under 10 bucks I'll even pay to ship it to you . Also have a 350 olds diesel vac pump that I've kept for such a reason as what your doing but from what you've said about all the other diesel vac pumps your not going to want it . It drops down in the distributor hole so if your running a distributor less ignition and wantbto fill the hole up with something unique you can become the owner of it too .

[TheSilverBuick]

I had a 87 vette smog pump if you want it . Took it off a year and a half ago . Yours if you want it . If its under 10 bucks I'll even pay to ship it to you .

I'll definitely take it! I'll send you a PM.

I'm hoping to go with the same blue with pinstripe. I'm going to remove the door ding protectors for now because half of them are missing the rubber inserts.

[Dan Barlow]

Just thought I'd ask before I send this off today , do you want the steel sserpentine belt pulley ?