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frenchyd
frenchyd UltimaDork
9/8/21 7:47 a.m.
jr02518 said:

Find a shop to acid dip the body. The under coating alone is many pounds the poor car doesn't need to drag along on a race track.

I put the chassis on a rotisserie and just use a propane torch to melt it off.   But you are absolutely correct,  undercoating is dead weight. Same with sound deadening etc. 

   The rotisserie saves a lot of struggle and pain. Once the bottom is cleaned paint can go on. Fuel lines run, brake lines, run, maybe even exhaust can be put in place.  If the doors are off  it's even easier to paint the interior, trunk, and engine compartment. Sitting on a chair on wheels easy. 

wspohn
wspohn SuperDork
9/8/21 10:58 a.m.

Exercise in wishful thinking to use an overweight underpowered car as the basis for any sort of race car just because the initial cost was zero.  Especially a marque that is going to cost a premium for parts like a Mercedes. And depending on what rules you race under, good luck getting  14" tires for it.

A friend owns one. When in good shape they are great looking, heavy, ill handling pigs. And that is fine, there is a market for those and IIRC they all predate when Mercedes went for unreliability somewhere around the turn of the century.

Besides, given your involvement, I'd expect you to be wanting something more like a later M120 engined V12 car.....wink

Tom1200
Tom1200 SuperDork
9/8/21 11:14 a.m.

The weight reduction solution is easy; sell the Mercedes and use the cash to buy a vintage Formula Vee.................problem solved.

The SL shop in the UK has prepped cars for track work and you can should be able to find some articles on the basics.

If it were me and I had my heart set on running the 450SL I'd simply pull all of the weight out of the car and swap it to manual transmission and be done with it. Read leave the motor alone for now; after he's decided he likes the car then you could do a carb swap (it's been done) and install a mild cam.................I seem to recall another Mercedes cam fits in these motors (560SL maybe).

parker
parker Reader
9/8/21 1:32 p.m.

I've got one.  It's the wife's nice day, top down cruiser.  I don't know where you're going to find 1000+ lbs. weight reduction.

Tom1200
Tom1200 SuperDork
9/8/21 1:56 p.m.
parker said:

I've got one.  It's the wife's nice day, top down cruiser.  I don't know where you're going to find 1000+ lbs. weight reduction.

The seats.....................

Realistically I'd expect 400-600lbs; bumpers, seats, AC compressor, cast iron exhaust manifolds, aforementioned sound deadening, the dash etc. 

AnthonyGS (Forum Supporter)
AnthonyGS (Forum Supporter) SuperDork
9/8/21 2:04 p.m.

You CAN race anything.  The real question is SHOULD you.  And being human if you WANT to, you can.  People race lawnmowers, so yeah you probably can race an old complex, heavy Mercedes convertible.

frenchyd
frenchyd UltimaDork
9/8/21 2:23 p.m.
wspohn said:

Exercise in wishful thinking to use an overweight underpowered car as the basis for any sort of race car just because the initial cost was zero.  Especially a marque that is going to cost a premium for parts like a Mercedes. And depending on what rules you race under, good luck getting  14" tires for it.

A friend owns one. When in good shape they are great looking, heavy, ill handling pigs. And that is fine, there is a market for those and IIRC they all predate when Mercedes went for unreliability somewhere around the turn of the century.

Besides, given your involvement, I'd expect you to be wanting something more like a later M120 engined V12 car.....wink

Since I'm not going to do it,  it won't be a V12 ( besides that would put it up in group 10 against 5 year old cars). 
  But 3600 pounds doesn't sound all that heavy to me. ( I've gotten  a 4600 pound car down to 3000 ).   
   The rules say tires and wheels of the era, not that they need to be original. Choices are 15x10 or 15x8.5.  Treaded Goodyear Blue streaks , Dunlop treaded, or Hoosier treaded. 

frenchyd
frenchyd UltimaDork
9/8/21 2:31 p.m.
Tom1200 said:
parker said:

I've got one.  It's the wife's nice day, top down cruiser.  I don't know where you're going to find 1000+ lbs. weight reduction.

The seats.....................

Realistically I'd expect 400-600lbs; bumpers, seats, AC compressor, cast iron exhaust manifolds, aforementioned sound deadening, the dash etc. 

 

Now remove windshield, windshield  frame, windows, electric motors to move them up and down.  Gut the doors,  or just replace them with fiberglass skins.  What do you think a door weighs?  With hinges, latch mechanism  etc?  
Same with hood and trunk lid. Can't  use Dzues  fasteners but hood pins are allowed.  
  The rule of weight is cu.in. Times 9.3  That's 2557 pounds.    If it's heavier than that the engine can be bigger. 

buzzboy
buzzboy Dork
9/8/21 2:47 p.m.

In my 1979 Benz we lost ~800lbs in bumpers, seats and interior. Although that's a Sonderklasse so you probably won't get as much out of an SL.

frenchyd
frenchyd UltimaDork
9/8/21 3:05 p.m.
Tom1200 said:

The weight reduction solution is easy; sell the Mercedes and use the cash to buy a vintage Formula Vee.................problem solved.

The SL shop in the UK has prepped cars for track work and you can should be able to find some articles on the basics.

If it were me and I had my heart set on running the 450SL I'd simply pull all of the weight out of the car and swap it to manual transmission and be done with it. Read leave the motor alone for now; after he's decided he likes the car then you could do a carb swap (it's been done) and install a mild cam.................I seem to recall another Mercedes cam fits in these motors (560SL maybe).

It's not my choice. But I understand wanting to do something different.  
As far as leaving the motor alone.  That's really his call. Me, I know there is power hiding in that motor. I could run the computer and find out how much is easy to pull out and the point it starts to get too expensive to go after more. Non Mercedes Pistons that fit and reground cams should be less than a $1000 ( assuming the engine isn't hurt ).  Hopefully someone like Rock Auto sells gaskets etc.  

     I raced a Corvette using other people's cast off junk.  Keep the revs reasonable and you don't have to spend a lot on block prep or other machine shop expenses.   High mileage with fresh rings usually winds up with clearances on the loose side.   He  should be able to pick up a used Holley reasonable.  Then it's figuring how to weld up a manifold. 
   I don't know how much room there is for headers but with a V8 that gets pretty important. Super glue and plastic plumbing is my choice to make patterns. 
  

frenchyd
frenchyd UltimaDork
9/8/21 3:15 p.m.

In reply to buzzboy :

You could be right.  The car only weighs 3600 pounds and it has an aluminum V8  that's only 275 cu. in.  I'll bet it has a brass radiator since it's a 1972 before aluminum radiators became common.   No 5 mph bumpers,  so not much weight there. But A/C in that era was heavy. Transmission should be close although might be a few pounds.  


 

A 401 CJ
A 401 CJ SuperDork
9/8/21 3:45 p.m.

A '72 with pre battering-ram bumpers?  For Pete sake, don't cut that up.  Get an '82 or such.  You're fixing to hack up a beautiful machine that likely will never be competitive.

parker
parker Reader
9/8/21 3:47 p.m.
buzzboy said:

In my 1979 Benz we lost ~800lbs in bumpers, seats and interior. Although that's a Sonderklasse so you probably won't get as much out of an SL.

What?  Do the seats weigh 200lbs each? I'm looking at the SL and I don't see those seats being over 50lbs and the bumpers are probably not over 100.  There's not much else in the interior.  I can see dropping 400lbs.

frenchyd
frenchyd UltimaDork
9/8/21 3:54 p.m.
A 401 CJ said:

A '72 with pre battering-ram bumpers?  For Pete sake, don't cut that up.  Get an '82 or such.  You're fixing to hack up a beautiful machine that likely will never be competitive.

I'm not going to do anything to a Benz. 
   But his grandfathers's been trying to sell it ( probably always asking too much). 
    Decided to give it to his grandson.  But how much does it cost to restore a 450SL  and how much do they sell for?   
I'll pass those numbers along. 

parker
parker Reader
9/8/21 4:42 p.m.

A good driver is probably worth about $15,000.   How much does it cost to restore?  How long is a piece of string.

 

CrustyRedXpress
CrustyRedXpress HalfDork
9/8/21 5:45 p.m.

I'm 99% sure that Mercedes used a 450slc as a rally car sometime in the 70's. 

Some aluminum panels (trunk and hood?), some sort of 5.0 engine (also aluminum?) and I think they kept the 3 speed auto. 

Most of what they did for the SLC should translate to the SL. Should be good for inspriation anyhow.

EDIT: Here is an overview: https://www.supercars.net/blog/1978-mercedes-benz-450-slc-rallye/

EDIT^2: That article is talking about the 450SLC 5.0, but two of the pictures show some sort of SL that is ralley prepped as well. So dunno?

californiamilleghia
californiamilleghia SuperDork
9/8/21 5:55 p.m.

Do you need to put a cage in it ?

pretty hard to put it back to a street  car if you cage it !

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/8/21 6:21 p.m.
Tom1200 said:
parker said:

I've got one.  It's the wife's nice day, top down cruiser.  I don't know where you're going to find 1000+ lbs. weight reduction.

The seats.....................

Realistically I'd expect 400-600lbs; bumpers, seats, AC compressor, cast iron exhaust manifolds, aforementioned sound deadening, the dash etc. 

I am pretty sure that the seats are just vinyl over a few slabs of 3/4" plywood suspended by springs.  wink I dunno what Mercedes was thinking in the 70s.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/8/21 6:24 p.m.
CrustyRedXpress said:

I'm 99% sure that Mercedes used a 450slc as a rally car sometime in the 70's. 

Some aluminum panels (trunk and hood?), some sort of 5.0 engine (also aluminum?) and I think they kept the 3 speed auto. 

Most of what they did for the SLC should translate to the SL. Should be good for inspriation anyhow.

EDIT: Here is an overview: https://www.supercars.net/blog/1978-mercedes-benz-450-slc-rallye/

EDIT^2: That article is talking about the 450SLC 5.0, but two of the pictures show some sort of SL that is ralley prepped as well. So dunno?

Everybody rallied something in the late 70s/early 80s.  Mercedes chose the SEC, I assume because it was the only fixed roof car they sold of the proper dimensions.

Triumph rallied the TR8 and Rover rallied the Vitesse amongst other things and BMW rallied, I believe, the M1...

yupididit
yupididit PowerDork
9/8/21 8:16 p.m.

In reply to Pete. (l33t FS) :

Nah those seat frames are heavy lol

Keith Tanner
Keith Tanner MegaDork
9/8/21 8:24 p.m.

What we have learned:

  • most of us don't think it would be a good race car. 
  • everyone is pulling weight and power numbers out of their butts other than the factory numbers which are awkward for a race car
  • mercedes made an SLC rally car 40+ years ago that looked awesome but did not set the rally world on fire
  • frenchy is gonna do what he wants anyhow :)

 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/8/21 8:34 p.m.

In reply to Keith Tanner :

Well, to be fair, the question was "can it be raced", not "should it be raced".

 

Lots of people have had good times with bad ideas.  More bad times than good, but it is all in the spirit.

yupididit
yupididit PowerDork
9/8/21 8:40 p.m.

If I had a SLC that I didn't care about, I'd turn it into a race car. I wouldn't expect it to be competitive. Weight removal, m113 + manual swap. Do something about the rearend and suspension (probably look in Sweden somewhere) then have some fun. 

Fueled by Caffeine
Fueled by Caffeine MegaDork
9/8/21 8:44 p.m.

Whelp... I wanna see this done now.

 

parker
parker Reader
9/8/21 9:03 p.m.
Fueled by Caffeine said:

 

Whelp... I wanna see this done now.

 

What does birthing a puppy have to do with anything?

 

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