S65 engine weight - and some surprises!

[catpat8000]

BMW claimed the S65 weighed 450 lbs when they introduced it. That seemed pretty light to me but then I started looking at some other normally aspirated V8s:


(0) BMW S65, 4.0 liter, 414hp, 295 lb-ft, 450 lbs
(1) Coyote, 5.0 liter, 412hp, 390 lb-ft, 444 lbs
(2) GM LS3, 6.2 liter, 436hp, 430 lb-ft, 415 lbs
(3) GM LS7, 7.0 liter, 505hp, 470 lb-ft, 440 lbs


I was shocked to find a 7 liter LS7 weighs less than the S65.

[rev9k]

not surprising at all and a good reason why LS swaps are so popular and keep (at least BMW cars) 50/50

[rev9k]

Almost sad to read the torque ratings for each though

[catpat8000]

Originally Posted by rev9k

Almost sad to read the torque ratings for each though

Torque is proportional to displacement in non-FI engines and the S65 actually does better than the LS engines in torque per liter. The engine is just too small to have more torque.

[Ezio]

Originally Posted by rev9k

Almost sad to read the torque ratings for each though

but they dont rev like a S65 though. trade offs

i swear people are clueless about the S65 and what makes its so different.

[wheatpaste]

Keep in mind that the architecture of the S65 and the small block Chevys are completely different. S65 is DOHC, while the Chevy engines are just single cam OHV.

The additional cams and valvetrain of the S65 adds a lot of weight.

The 5.0L coyote engine is more similar to the S65 in this regard, which is probably a good reason why it weighs similarly.

[DLSJ5]

Originally Posted by catpat8000

BMW claimed the S65 weighed 450 lbs when they introduced it. That seemed pretty light to me but then I started looking at some other normally aspirated V8s:


(0) BMW S65, 4.0 liter, 414hp, 295 lb-ft, 450 lbs
(1) Coyote, 5.0 liter, 412hp, 390 lb-ft, 444 lbs
(2) GM LS3, 6.2 liter, 436hp, 430 lb-ft, 415 lbs
(3) GM LS7, 7.0 liter, 505hp, 470 lb-ft, 440 lbs


I was shocked to find a 7 liter LS7 weighs less than the S65.

Wow, very surprising! Interesting info, thanks for posting up.

[L4ces]

Good to know!

[bigjae1976]

Even more surprising, the S54B32 is heavier than the S65B40 by about 30 lbs IIRC.

Still mystifies me how an E9X M3 is 300lbs heavier than an E46.

[Billj747]

Originally Posted by catpat8000

Torque is proportional to displacement in non-FI engines and the S65 actually does better than the LS engines in torque per liter. The engine is just too small to have more torque.

The Porsche GT3 RS 4.0 has 339lb-ft (44lb-ft more than the S65).

Originally Posted by Ezio

but they dont rev like a S65 though. trade offs

The BOSS 302 has a 7,500rpm stock redline and has no problem at 8K (S65s seem to be fine at 8,750) -pretty close IMO.

[catpat8000]

Originally Posted by Billj747

The Porsche GT3 RS 4.0 has 339lb-ft (44lb-ft more than the S65).

Yes, there is some variation. The F 458, for example, has 398 lb-ft from 4.5 L. The Porsche 991 GT3 generates 324 lb-ft from 4 liters.

But ultimately, with non-FI, it is quite hard to get much over 100% volumetric efficiency. With lots of R&D, some engines get slightly better but not much. The two highest rated engines using torque per displacement that I know of are the Porsche GT3 and the 458 and those cost major dough, in part because of large investments in the drivetrains.

That's why non-FI need either displacement or rpm to make big power.

[Billj747]

Originally Posted by catpat8000

Yes, there is some variation. The F 458, for example, has 398 lb-ft from 4.5 L. The Porsche 991 GT3 generates 324 lb-ft from 4 liters.

But ultimately, with non-FI, it is quite hard to get much over 100% volumetric efficiency. With lots of R&D, some engines get slightly better but not much. The two highest rated engines using torque per displacement that I know of are the Porsche GT3 and the 458 and those cost major dough, in part because of large investments in the drivetrains.

That's why non-FI need either displacement or rpm to make big power.

991 GT3 is a 3.8L -So 29lb ft more torque and 200cc less.

The E46 has 269lb-ft out of a 3.2L

[the_road_less_traveled]

Originally Posted by Billj747

991 GT3 is a 3.8L -So 29lb ft more torque and 200cc less.

The E46 has 269lb-ft out of a 3.2L

Its a trade off. Longer stroke = more torque => lower revs. It comes down to mean piston speed. It all conforms to that thing called physics and metallurgical limits.

I expect you to come back with some S54 specs next, but 7900 redline is not an 8750 redline. The S65 revs over 10% higher than the S54.

[speedaddictM3]

Originally Posted by bigjae1976

Still mystifies me how an E9X M3 is 300lbs heavier than an E46.

Size. Park an E92 beside an E46, step back and take a look, and you will have your answer.

[dparm]

Originally Posted by speedaddictM3

Size. Park an E92 beside an E46, step back and take a look, and you will have your answer.

It's also got more "stuff", like more sound deadening, better chassis rigidty, more safety items, etc. That stuff is heavy.

[W Cole]

The GM engines are very light and compact. Single CAM.

[bigjae1976]

Originally Posted by dparm

It's also got more "stuff", like more sound deadening, better chassis rigidty, more safety items, etc. That stuff is heavy.

I'm sure there is a little more chassis rigidity but the E9X used more aluminum, the fenders are plastic, more FRP aka CF...we're not even talking about the DCT. Oh and lighter suspension components.

Just an observation rather than a complaint...more lightweight materials but heavier curb weight. The fact is the M3 is just about the lightest 4 seat sports sedan that you can ACTUALLY fit 4 adults in.

[Someone?]

Originally Posted by Ezio

but they dont rev like a S65 though. trade offs

i swear people are clueless about the S65 and what makes its so different.

Word, i go to the drag track and beat the hell outta most any 6.2/5.0's

The extra weight comes from our dual cam head vanos set up and that awesome oil pan/8 throttle intake set up.

[catpat8000]

Originally Posted by Billj747

991 GT3 is a 3.8L -So 29lb ft more torque and 200cc less.

The E46 has 269lb-ft out of a 3.2L

I'm kinda losing your point. All I am saying is that torque is proportional to displacement with non-FI. Like everything in life, there will be slight variation because there is variation in engine design. But it's not much.

Here is an exercise: divide the torque in ft-lb by the displacement in liters for your favorite engines.

Most likely they all fall between 70 and 80. Some may get into the high 80s. It won't matter what engine you choose, as long as it is normally aspirated, you'll see between 70 and 88 or so. More efficient designs get higher numbers. But you won't find any engine over 90 lb-ft per liter no matter what you look at.

Even NASCAR, F1, they all need to obey physical laws. The 2.4 liter Formula 1 V8s, for example, only produced something like 215 lb-ft of torque.

Pat

[FogCityM3]

Also safety has been enhanced significantly from E46 days, especially in the side impact, where the E46 was weakest. Safety was improved significantly in the E9x models, judging by crash test results. As you stated, E90 especially has more load carrying capability.

Originally Posted by bigjae1976

I'm sure there is a little more chassis rigidity but the E9X used more aluminum, the fenders are plastic, more FRP aka CF...we're not even talking about the DCT. Oh and lighter suspension components.

Just an observation rather than a complaint...more lightweight materials but heavier curb weight. The fact is the M3 is just about the lightest 4 seat sports sedan that you can ACTUALLY fit 4 adults in.

[Richbot]

Originally Posted by catpat8000

BMW claimed the S65 weighed 450 lbs when they introduced it. That seemed pretty light to me but then I started looking at some other normally aspirated V8s:


(0) BMW S65, 4.0 liter, 414hp, 295 lb-ft, 450 lbs
(1) Coyote, 5.0 liter, 412hp, 390 lb-ft, 444 lbs
(2) GM LS3, 6.2 liter, 436hp, 430 lb-ft, 415 lbs
(3) GM LS7, 7.0 liter, 505hp, 470 lb-ft, 440 lbs


I was shocked to find a 7 liter LS7 weighs less than the S65.

Welcome to 1997 glad you could join us

[Ezio]

Originally Posted by ibmike

Word, i go to the drag track and beat the hell outta most any 6.2/5.0's

The extra weight comes from our dual cam head vanos set up and that awesome oil pan/8 throttle intake set up.

yup thats what i am saying. high low end torque only helps with daily driving in the most part. if you launch the M3 propertly and or keep in its power band the car will keep up or beat V8 muscle cars