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lightweight aluminum bumper swap

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1981 malibu
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lightweight aluminum bumper swap

Postby 1981 malibu on Fri Oct 22, 2010 7:29 pm

I was in the junkyard yesterday thinking about how to reduce the weight of my malibu (1981 4 door) it's already got the aluminum rad support, aluminum drums, etc. + i swapped out my dented rear doors for a set of '78 rear doors to eliminate the awkward looking vent windows. (i've run across a diesel cutlass wagon which will donate its aluminum hood and hydroboost).

Specifically, though, i was thinking about the bumpers. I've gutted out the innards of both front and rear bumpers, which were equipped with aluminum supports, but the remaining chromed steel shells feel like they weigh a ton. It's a street car, so i've ruled out those fiberglass drag racing bumpers.I was looking at Ford Fairmont aluminum bumpers, which are super-light, but they're too wide and their shape doesn't work well with the Malibu's lines. Quite by accident i stumbled across a GM X-car Buick Skylark (fwd), which apparently (i never knew this before), was factory-equipped with aluminum bumpers, front and back. They're a really similar design to the Malibu units, but shorter by a couple inches and narrower by about 3-4 inches. :idea: With a little more hunting, i found an Olds Omega, also with aluminum bumpers, and a Chevy Citation, with steel ones. IIRC the fourth X-car, the Pontiac Phoenix, had urethane bumpers, so it seems only the Buick and Olds versions got the aluminum ones..

I pulled both bumpers and they weigh next to nothing. Once I got them home, some quick measurements showed that the 3-4 inch narrower width will put these bumpers just slightly wider than the Malibu's body lines, so hopefully, besides being much lighter, they will also give that "tucked" look that would normally require cutting, rewelding and rechroming the stock ones. ($$$$)

Naturally, the mounting points don't line up, but they're only a few inches out from the Malibu's bumper shocks, wider front, narrower rear. Fabbing up some small adapter plates should be all that's necessary.

My schedule being what it is, I probably won't actually get around to doing it for a while, but I'd like to know if anyone out there has done this swap before, and if so, how did it look?

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kornball426
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Re: lightweight aluminum bumper swap

Postby kornball426 on Sat Oct 23, 2010 2:13 am

If you already stripped the so called "innards" I'm guessing by that you mean the 1974 federally mandated 5mph safety bumper pieces. Aluminum is weak... It will crumple like tin foil in an accident. Ever seen an old Jag or Shelby, or a drag race car from the 60's with aluminum fenders... And they have stickers that say "do not lean on". :lol: That's because you'd dent it.

There's no more safety in aluminum than fiberglass in my opinion... If that's why you ruled them out.
Now I don't know, but I been told it's hard to run with the weight of gold,
Other hand I have heard it said, it's just as hard with the weight of lead.

1981 malibu
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Re: lightweight aluminum bumper swap

Postby 1981 malibu on Sat Oct 23, 2010 3:27 am

That doesn't make sense. Whereas it's true that I weakened my stock steel bumpers by removing their aluminum supports, the bumpers i'm considering switching to are bone-stock X-body pieces, which i'm assuming passed the same federally (U.S.) mandated tests in order to be fitted as standard equipment in that chassis. These bumpers are without internal reinforcements of any kind, so I would just be mounting them to the G body chassis without any modification. I'll admit they won't perform as well on my car because its weight (right now 3050#) will probably always be more than an X-body's, which I figure falls somewhere between 2500-2800#. In any case, I see no reason they should be as flimsy as you suggest. These are not thin-gauge body panels like those race-car pieces you compared, but a thick-gauge stock bumper similar to many others fitted by various manufacturers over the years (the Ford I mentioned, many BMWs, etc.). These do not crumple like tin foil. If they had, they wouldn't exist at all. If they're maybe slightly less safe than what's on the car already, I'll take that trade off to save the weight. I've already sacrificed a ton of safety(airbags, stability control, abs, crumple zones, etc.) to drive a G-body in the first place, and the car keeps me happy enough I won't lose sleep over a little more.

79elky454ss
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Re: lightweight aluminum bumper swap

Postby 79elky454ss on Sat Oct 23, 2010 6:26 am

I seem to remember the mid-70's camaro/vega maybe others that had an extruded, clear anodized aluminum bumper,that was tough as hell. They were maybe 1/4" thick or more.
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buickestate
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Re: lightweight aluminum bumper swap

Postby buickestate on Sat Oct 23, 2010 7:19 am

If you keep looking you might luck into finding a set of factory malibu aluminium bumpers. They are not common and were a one year only and only one of the production plants used them. I did not believe they existed until a buddy of mine showed me them on his 81, no rub strips or bumperettes just plain. they were chromed right over the aluminium so if you didn't know GM made them you would over look em. GM in those days were all about increasing the fuel efficiency of their fleet cars, so weight reduction was one of their concerns.

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kornball426
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Re: lightweight aluminum bumper swap

Postby kornball426 on Sat Oct 23, 2010 1:28 pm

I can't say as I've ever seen a thick aluminum bumper... The ones I've seen have all been thin little flimsy things on there basically just for look. These were on some old 60's Mopars and Fords and stuff... Factory drag cars stuff like that. So you have a point... I'm sure it would be fine.

Not going to hold up like a steel one of course, but it'll do the job. Good luck in your search. 8)
Now I don't know, but I been told it's hard to run with the weight of gold,
Other hand I have heard it said, it's just as hard with the weight of lead.

1981 malibu
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Re: lightweight aluminum bumper swap

Postby 1981 malibu on Sat Oct 23, 2010 4:08 pm

buickestate wrote:If you keep looking you might luck into finding a set of factory malibu aluminium bumpers. They are not common and were a one year only and only one of the production plants used them. I did not believe they existed until a buddy of mine showed me them on his 81, no rub strips or bumperettes just plain. they were chromed right over the aluminium so if you didn't know GM made them you would over look em. GM in those days were all about increasing the fuel efficiency of their fleet cars, so weight reduction was one of their concerns.


That's very interesting. I had no idea those were available. So they're 1981 only? Do you know which plant they came out of? Naturally most of what we have here are Canadian-built cars, so if Canadian plants used those bumpers my chances are better.

Learn something new every day on this forum..

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billyjack
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Re: lightweight aluminum bumper swap

Postby billyjack on Sat Oct 23, 2010 5:17 pm

There were also aluminum bumpers on the 78-80 Buick Century models with the "Sport Coupe" package, painted in body color. They're extremely rare also, primarily because the "fastback" coupes were never popular, but you never know what you might stumble across in your search.

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buickestate
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Re: lightweight aluminum bumper swap

Postby buickestate on Fri Oct 29, 2010 1:03 am

1981 malibu wrote:
buickestate wrote:If you keep looking you might luck into finding a set of factory malibu aluminium bumpers. They are not common and were a one year only and only one of the production plants used them. I did not believe they existed until a buddy of mine showed me them on his 81, no rub strips or bumperettes just plain. they were chromed right over the aluminium so if you didn't know GM made them you would over look em. GM in those days were all about increasing the fuel efficiency of their fleet cars, so weight reduction was one of their concerns.


That's very interesting. I had no idea those were available. So they're 1981 only? Do you know which plant they came out of? Naturally most of what we have here are Canadian-built cars, so if Canadian plants used those bumpers my chances are better.

Learn something new every day on this forum..


They were not original to my buddy's 81 he found them at a salvage yard and never tols me what year they came off of, I don't think they came out of the Oshawa plant.


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