Keith
Keith SuperDork
1/31/10 1:27 p.m.

I needed to move the LS-powered MG in order to do some work in the garage. Since it was coming off the jackstands anyhow, I figured I'd find out what the current weight is. The engine, transmission and rear end are in the car. There's no cooling or exhaust system or spare tire. The fuel tank is in, but empty. The front bumper's off. The interior consists of one Miata seat but no steering column, and there's a 26 lb box of Camaro wiring sitting on the roof.

My weight estimate for the car, complete, is around 2500-2600 lbs. That's based on a published curb weight of 2401 lbs and the fact that Miatas gain around 200 lbs with a similar conversion.

So imagine my surprise.

Filling the fuel tank - I always weigh with a full tank - and installing the battery will add around 86 lbs over the rear axle. Granted, there are some parts missing from the car right now but I'm not sure it's going to gain more than 500 lbs. I've probably saved a bunch of weight on the front suspension and definitely on the wheels.

At 2400 lbs, it'll be at least 100 lbs lighter than the mighty Elvis. I'm starting to look at the car differently, this brought to my attention just how fast this car will be.

Fittingly, "Black Devil Car" by Jamiroquai came on the iPod about the time I came to this realization.

Spinout007
Spinout007 HalfDork
1/31/10 2:18 p.m.

ummmm, Holy SHEEP #$%$% BATMAN!

That's all I have to say, that and can I have a ride? PLEASE? that sounds like fun, lots and lots of fun.

4cylndrfury
4cylndrfury Dork
1/31/10 2:22 p.m.

teh sek-c

maroon92
maroon92 SuperDork
1/31/10 2:48 p.m.

wow, that is infinitely better power to weight ratio than any car I have ever driven...well done.

Jensenman
Jensenman SuperDork
1/31/10 2:58 p.m.

I bet you accidentally filled the tires with helium. One of the sites out there shows a 1977 MGB GT (big black bumpers) as weighing 2448 pounds.

mtn
mtn SuperDork
1/31/10 3:27 p.m.
Jensenman wrote: I bet you accidentally filled the tires with helium. One of the sites out there shows a 1977 MGB GT (big black bumpers) as weighing 2448 pounds.

Must not have been in the states--IIRC, the GT's were only imported until 1974.

Jensenman
Jensenman SuperDork
1/31/10 4:23 p.m.

Yeah, 74 1/2 was the last of the GT's here in the Colonies. In the last half of 1974, a few (~250) snuck over with the big bumpers so they are not totally unheard of here but yes they are pretty rare. IIRC it stayed in production overseas right to the bitter end.

Treb
Treb Reader
1/31/10 5:21 p.m.
Keith wrote: My weight estimate for the car, complete, is around 2500-2600 lbs. That's based on a published curb weight of 2401 lbs and the fact that Miatas gain around 200 lbs with a similar conversion.

WOW. That's awesome news.

I've never lifted a Miata motor, but I can't imagine they weigh what a B-series weighs. That's a HEAVY motor you took out.

I've seen comparisons that say swapping a B-series and its 4-speed for a 302 and a t-5 comes out pretty close to even, with aluminum heads and headers. I sure wouldn't expect the LSx to have 200lbs on that setup.

Always love updates on this car, Keith.

Gimp
Gimp Dork
1/31/10 5:23 p.m.

I love you.

mad_machine
mad_machine SuperDork
1/31/10 6:03 p.m.

that is my goal for my Fiat... 2000 pounds and 200hp... I expect it to be fast.. your car... is going to be frightening

aussiesmg
aussiesmg SuperDork
1/31/10 6:16 p.m.
Gimp wrote: I love you.

nuttin else to add

Slyp_Dawg
Slyp_Dawg New Reader
1/31/10 6:56 p.m.

that is going to be monstrous. claps well done sir, well done. given this, estimates on what the final curb weight might end up being? I'd say around 2,100-2,200, but then again I've got no idea how much more needs to be done to it and how much weight those remaining items might add

modernbeat
modernbeat HalfDork
1/31/10 7:21 p.m.

The cast iron lumps known as BMC engines weigh an incredible amount for the displacement they give.

neon4891
neon4891 SuperDork
1/31/10 11:36 p.m.
iadr wrote: cool. Link to the build thread? I've said before, the LS alum block as made the "Rover" engine obsolete- massively more potential for a fraction of the $'s...at effectively the same weight. Perfect example!

What about packaging size?

jgp1843
jgp1843 HalfDork
2/1/10 12:09 a.m.

Yikes! I have got to see this thing when it's done. Elvis is impressive, but this is even better!

Autolex
Autolex HalfDork
2/1/10 9:08 a.m.
iadr wrote: Link to the build thread?

http://www.slowcarfast.com/MG/

Keith
Keith SuperDork
2/1/10 10:20 a.m.

Yup, that's the build diary: http://www.slowcarfast.com/MG/ It's also a reader's ride on the GRM site.

I know there's a lot of weight still to go back in the car. 60 lbs of fuel, 26 lbs of battery, at least 75 for the interior, probably 50 lbs worth of exhaust, then sway bars, cooling, etc. I'm going to be conservative and say it's going to come in at around 2400 lbs, 2300 at the lightest. If I'm happily surprised - like I was this weekend! - great. Light weight has never been an overall goal on this swap.

But still, thinking that it will be able to outrun Elvis in a straight line (assuming I can get the car to hook up) - wow.

mad_machine
mad_machine SuperDork
2/1/10 11:39 a.m.

I would definatly look into a odyessy battery for it. Weight is the enemy!

Keith
Keith SuperDork
2/1/10 11:47 a.m.

It's getting an Optima D51, lots of cranking power for the big engine. I run Odysseys (Odyseeies?) in two other cars that are more weight sensitive.

DukeOfUndersteer
DukeOfUndersteer SuperDork
2/1/10 12:10 p.m.
Gimp wrote: I love you.

i second this motion...

Nashco
Nashco SuperDork
2/1/10 12:11 p.m.

Old cars are shockingly light; that whole lack of attention to crash safety, chassis rigidity, and generally keeping cars cheap through using fewer materials makes a huge difference.

Bryce

Spinout007
Spinout007 HalfDork
2/1/10 2:13 p.m.
Nashco wrote: Old cars are shockingly light; that whole lack of attention to crash safety, chassis rigidity, and generally keeping cars cheap through using fewer materials makes a huge difference. Bryce

yeah had this argument with a co-worker the other day, funny enough it was over the fact of which one weighs less? Del Sol or Crx, I kept telling him the Crx is lighter, but he argued that there's "NO WAY, because of all that glass. LOL is it bad that one of the managers overheard us and mentioned he wouldn't argue too much with me due to how much time I spend on break reading car related material. Quick google search ended the argument. He's now hunting for a CRX.

Chris_V
Chris_V SuperDork
2/1/10 3:18 p.m.
neon4891 wrote:
iadr wrote: cool. Link to the build thread? I've said before, the LS alum block as made the "Rover" engine obsolete- massively more potential for a fraction of the $'s...at effectively the same weight. Perfect example!
What about packaging size?

The LS is suprisingly similar in size to the Buick/Rover V8, though the Buick is abut 100 lbs lighter (318 lbs). But the power potential for the LS is frighteningly huge compared to the Buick mill.

I was supposed to be installing a modded Buick mill into my buddy's '73 MGB GT that's in my garag right now, but he decided he wanted to stick with the "stock" engine it has (a breathed on B mill). I was thinking of putting the Buick into my B convertible, but I've been thinking about looking up an L33 truck version of the LS engine (as they are considerably cheaper to buy, but have th esame power potential)

kreb
kreb Dork
2/1/10 3:54 p.m.

As LS motors creep down in price, the question is starting to be: "If you're doing a transplant, does it make any sense NOT to put a LS in it?". If Keith put a Miata mill in the GT it would likely go down in value. A decently sorted LS makes it go up. A friend had two almost identical Dax roadsters (a british-made Sevenesque), One with a V6, the other with a SBC (This was before LS motors were common or cheap). A guy showed up to look at the V6 one, and drove out with the V8 one - for $10K more!

The Buick/Rover is a charming old engine. It's also pretty good-looking. But from a performance perspective it makes no sense compared to a LS.

Now if one could get an old Toyota V series pushrod V8, that would be worth it on coolness.

Keith
Keith SuperDork
2/1/10 4:13 p.m.

I've actually got a Buick engine in my garage, although it's buried deep under Land Rover parts so I can't do a side-by-side comparison of the two. I've often described that engine to people as "the small-block Chevy of the UK". However, it seemed appropriate to use the small-block Chevy of the US for my build

What makes the LS so compelling to me is not the size of the fundamental block, but how well everything else is packaged. The intake manifold is low. The coils are attached to the valve covers so there's no goofy distributor sticking out and getting in the way. Everything's just tucked into a dense 2'x2'x2' cube of horsepower. The fact that it (can be) all-aluminum is an extra bonus. It was my first look at the bare engine that convinced me to abandon my previous plans with this car. Power? Yeah, it makes a bit.

I doubt I'm paving the way for a legion of B enthusiasts to follow in my footsteps, as I'm going far beyond the minimum necessary.

As for older cars being lighter - the original car was about on par with the weight of a later Miata. But apparently much of that weight came from the engine and suspension (leaf springs are heavy!), not the chassis.

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