Why are 3.6s so light?

[dd74]

I was just looking at some engine weights that Bill Verburg posted a while ago. Here's the link:

Weight of the 911 2.0 6cyl.

By all that is said, it seems one can whittle down the weight of a 3.6 to something close to a 3.0. Amazing!

I have a 3.0 with no A/C or heating and '74 H/Es. I figure the engine is about 410-420 pounds. I won't say the 3.6 can be that light, because it seems it can. But how? Is CIS that heavy? Was a different material used inside the 3.6 engine other than what the 3.0 or 3.2 uses? Is one version of the 3.6 engine lighter than another?

Hmmm...just wondering.

[project911]

One thing I can think of is the valve covers are plastic. Not sure how much that accounts for though, if any.

[Randy Webb]

They used CAD/CAE to redesign the crank. That saved some. Also, the recip. parts are a bit lighter. I bet the oil pump is heavier tho. And they probably saved some wt. on the induction (dunno, but a lot of more modern cars have done that).

[Chuck Moreland]

The holes are bigger.

[Adam]

Isn't the intake manifold on a 3.6 plastic or resin, compared to the 2.7/3.0 cast manifold?

Also - no engine-mounted oil cooler, unlike an oldie.

[nostatic]

ok David...when's the 3.6 going in? Hmmm?!?!?

Wife will never even notice that

[dd74]

Originally posted by nostatic
ok David...when's the 3.6 going in? Hmmm?!?!?

Wife will never even notice that

Hilarious!

Nah...I'm just fact finding. I figure I should learn how to drive a 3.0 before wondering about a 3.6.

But I better hurry. I've got dibs on Jack's motor if he goes 3.8. Right Jack?

[dd74]

Originally posted by nostatic
ok David...when's the 3.6 going in? Hmmm?!?!?

Wife will never even notice that

Hilarious!

Nah...I'm just fact finding. I figure I should learn how to drive a 3.0 before wondering about a 3.6.

But I better hurry. I've got dibs on Jack's motor if he goes 3.8. Right Jack?

[dd74]

Wow...a double post. Never did that before.

[nostatic]

it just means you want the 3.6.

Or maybe the double post signifies a twin turbo...

[BB911SC]

When I installed my 3.6 (along with a kevlar rear bumper, 2kg), my rear suspension raised about 2 1/2 to 3 inches from the original 3.0 (stock bumper) height. Car looked like a 4x4...

[Tyson Schmidt]

The chain boxes and covers are magnesium, and the early ones had mag cam covers. Then they went to aluminum cam covers, then plastic on the 993. They also have a simplified chain tensioning scheme that is smore reliable and weighs less.

And the stuff mentioned in the above posts, of course.

[Randy Webb]

OK, here are some tidbits from my collection of light wt. trivia:

964 engine has 30.2 lb crank (4.84 lb lighter) than previous crank from CAD work; same stiffness and balance - Aichele 1999, p. 69
996 engine has no vibration damper, stiffer crank (bending and torsion), thicker crank cheeks, lower axial movement of fan pulley
996 also has 55g lighter pistons (602g), and 112 g lighter connecting rods - Aichele 1999, p. 75

36.6 crankshaft in 3.2L engine (Frere, p. 86, 93)
31.75 964 crankshaft (Frere, p. 93)
34 993 crankshaft (Frere, p. 93), but has no vibration dampers, saving 732 g. (p. 96)
964 crankshaft (M64 engine) was 2.2 kg lighter than in its predecessor (the 3.2?) - Frere, p. 86
reinforcement of the crankshaft for the 993 engine (M64/05-06) raised weight from 14.4 to 15.4 kg (Frere, p. 96)
993 conn. rod wt.s were reduced from 632 g. (in 964) to 520 g. (Frere, p. 96)
993 piston wt.s were reduced by 55 g. (from 964?) to 602 g. (Frere, p. 96)
993 hydraulic rockers are 15 g. (intake) and 21 g. (exhaust) lighter than the previous (964?) manually adjustable rockers (Frere, p. 96)

It's from an Excel spreadsheet, so sorry about formatting issues.

[KobaltBlau]

Originally posted by Chuck Moreland
The holes are bigger.