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S14B23B25+S38B35/M88/3+S38B36/B38+S50/B30B32+S54+S62+S85+S65. Engine Weight !

22K views 24 replies 14 participants last post by  genius 
#1 · (Edited)
Hi Gents,

For those who are interested in Engine Weight

For many years I have listen to people giving their opinion about how heavy the S38 is.
Does it look heavy ? Absolutely,
Does it rev heavy absolutely.
Does BMW used heavy parts absolutely.

No one was able to bring the Exact information of the numbers all these years.
All the info was brought from the silly sites or other guesstimate numbers.

Lots of wrong information is floating.

I decided to find out the truth about all NA BMW Motorsport engines measured with full accessories attached.

Before I started building my E24M6 race car I wanted to find what options do I have in therms of weight.
I like all BMW NA MS engines. 4cyl-6cyl-8cyl-10cyl,each one has its own character.

But I have been always an S38 guy. I do like to improve this engine as much as possible, I don't mind to mess around with other MS engines but for now I am happy with the S38 engine.

So lets get to the point. I did measurements with full accessories.
All the engines will be +/- few pounds but the main weight is there.

S14-B23/B25- 415pounds/188kgs
S38-B36- 587pounds/266kgs
S38-B38 -602pounds/278kgs(due to heavier dual mass flywheel vs 3.6)
M88/S38- 530pounds/240kgs
S54-B32- 522pounds/236kgs
S50-B32 -(Euro engine) 560pounds/254kgs
S62-B50 -602pounds/271kgs
S65-B40- 530pounds/240.4kgs
S85-B50- 625pounds/278kgs

Out of the box the S38-B36/B38 engine is damn Heavy !!!

When I build last year S38-B36 for a customer inside E30M3.
I wanted to drop as much weight as possible.

I was able to drop the weight of the S38-B36 to ~476pounds !!!
I am pleased from my outcome result. I was able to drop 100pounds and still retain AC compressor.
So basically the same as M88/S38-B35 is the lightest engine from the S38family.
Basically, M88/S38 inside the S38-B36 skin.

Hear is the weight savings for S38-B36-B38 engine.
  • Deleted air pump system down to the last nut and bolt.
  • Removed the S38 Bracket and installed M30 AC bracket.
  • M88/S38 complete cooling system.
  • Lighter, internals, crank, rods, pistons.
  • Light weight flywheel.
  • Light weight alternator.
  • Removed Engine Hook.
  • Removed some other studs, bolts (not much saving but adds to the gross weight)
  • Light weight engine drive pulleys. Water, Power steering, Alternator, Crank V belt pulleys will give another ~2pounds

I studied how BMW put an effort inside the S54-B32 to make it more modern using still cast iron block and used lighter parts.

Gents, 100pounds is not a joke removed from the E34M5 nose !!!
I helped my friend Ed with his Dytona Violet station wagon M5/touring to drop all that weight and you can feel the difference right away!

Very interesting fact I found.
The S54 bottom end is the same weight as the M30/S38.(+/- few kgs in a favor of the S54)
How is that possible ?
Due to the Undesirable 91mm stroke BMW MS reinforced the bottom of the block and added weight. Regardless, the S38 has longer parts.
S54 crank is lighter and also rods and pistons and still about the same weight.

The S54 Engine has already a plastic Intake that weights +/-9pounds.
The S38 Intake weight +/- 20pounds!
(waiting on Greg to make the light weight one.)
I can install Plastic/Carbon Fibre intake and Save 18pounds !
But I am not ready to lose the Intake flapper option on the 3.6/3.8.
(So, Greg I am waiting on the list for 3-4 qt)

Also I am going to investigate were can I use 7075 Aluminum grade bolts and nuts just hold parts Not in a critical areas.

Also the S38-B36 Wire harness is very heavy vs S54 harness.
I think 5pounds easy can be saved using a complete standalone.

Basically when I use all the best light parts and light weight hardware
I will be able to drop the engine weight at around ~460/pounds=213kgs
This will be very light weight S38 engine in reliable daily driving condition.

AC system is option for any engine so you keep it or remove it.

The other engines such as S62-S65-S85 BMW already used light weight internal parts.
Aluminum block, Light weight pulleys, no smog pump attached.
The only think can be saved is the Super Heavy Dual Mass flywheel+header cats.

Another factor I measured are Transmissions:

The S38 G280 weights 89pounds
The S38/S54/S62 6spd G420 weights 102pounds
The S65/S85 weights 135pounds!

Gents a further discussion and questions are welcomed.

Enjoy the facts.

Best Regards
Anri
 

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#5 · (Edited)
Tony,

It took me years to find out the truth!
In ordered to have all the engines handy.

Tony, remember nothing comes perfect out of the box.
That is the reason I always think how to improve Dated design.
On the new engines you can not improve much down to none.
Because they already have good parts.

I have another post for 3.6/3.8 cooling system coming soon!
This will be very helpful for guys in hot weather including you.
Stay tuned!
No more blowing and leaky engines!

Regards
Anri
 
#3 ·
Such a cool post, thanks! I was thinking, how did he know the weights, then realized you actually weighed them yourself, wow. Other posts like these would usually get weights from different sources, and you couldn't tell whether they counted the same accessories or not.

How much lighter is an M88 cooling system, and why is it lighter?

What alternator did you go with, and is it 90 amps? I hear Subaru STI amps are pretty light.
 
#22 ·
*digging up an old topic*

Can anybody help me with the information about a lightweight alternator for the S38? Is it just the 90 amps from a M30 or is it something else.

Would love to have this info, as this is kind of a missing link for my project :)

Thanx in advance and keep up the good work!
 
#10 ·
Many thanks, Anri, for contributing such important information, otherwise unobtainable, to anyone else, anywhere in the world. You are a master of masters...
 
#12 ·
Sveinbjörn,

Thanks for your reply.

Yea I know this thing is very very heavy.
Same as weight +/- as the S65/S85 tranny.
 
#15 ·
FatAndre,

This is exactly how people are very well confused about the engine weight.

Indeed everybody visits BMWfans.info and see its called short block
weight, very wrong.

BMW sells you the short block only but not the rest......

Interesting how BMW advertise S65 short block is lighter than S54,
by 33pounds but the remember a short block/no accesorries does not make the car start....

Always look at the whole package Engine+gear box.
Many say its located down low and in the middle of the car...
But its still connected to engine, right.
Plus on hard braking the weight is pushing forward, right...

Not worth to lighten Alternator on your E31....You are going to save
7pounds wich you will never notice.
I do own E31 840Ci '97 and I know it very well inside outside.

The M70/S70 with all accessories will be in the mid 55Xpounds range.
That is my guess.(i have not measure it)
It has no Motorsport Parts such as TBS, Large Intake, Throttle Linkages,
extra hardware, wider cyl heads in order to fit 4 Valves, Short manifolds etc..etc...

Enjoy your E31 as it is.

Regards
Anri
 
#16 ·
Gents,

Basically the S38 3.6/3.8 is the heaviest engine on the planet earth.

I was thinking about what other manufacture or BMW Motorsport Engine you can remove 100pounds? The answer is None.
Very few pounds yes but that does not help much...

Regards
Anri
 
#17 ·
Gents,

Basically the S38 3.6/3.8 is the heaviest engine on the planet earth.



Regards
Anri
Well,,,,,,,, another OT,,

my E30 cabrio,,, was 1450 kg /// 3200 lbs with S38B38 + Getrag 280

believe it or not,,, the V12 with Getrag 560,,, is the same weight
3200 lbs,,,

the M70 is a full alu engine,,, the G560 is 35 lbs more in weight vs G280 and in my case a lot of extra stuff is in the engine bay,,vs S38,, so IMO this is stunning how the real weight of V12 is vs S38

it is fantastic to see these ACTUAL facts about how heavy this and that is,, compared to that and this,,,

well done Anri,,, really well done
 
#18 ·
Hi Anri

A late thank you for this excellent info thread, I have been staring at my S38B36 a bit lately working through some matters and was wondering what the damn thing weighed, did a search today and Lo and Behold, this thread of yours, a brilliant bit of fact checked info from you, as always.

Cheers and please keep up your curiosity and factual approach, it is invaluable.

Regards

Dane
 
#23 ·
Reviving an old thread...
swapping a s85 into e30 m3. Your weight of s14 I’d right on @415Lbs, I pulled it out of the car and the whole swap with trans fully dressed(no ac compressor) Is 480Lbs dry. With ac compressor would be right at 500Lbs.
I do not have the s85 yet so in still trying to figure out the weight, it’s listed here at 625lbs but the pic shows 261kg which is about 575lbs( although it’s missing intake plenum...I’d say 15 lbs max) which would put it at 590lbs or so.
i looks like the ac compressor is still attached as well. Where did you get the 625lbs figure from?
if anyone has weighed an s85 lately please chime in.
Motor vehicle Automotive fuel system Automotive tire Automotive design Vehicle
 
#24 · (Edited)
Reviving an old thread...
swapping a s85 into e30 m3. Your weight of s14 I’d right on @415Lbs, I pulled it out of the car and the whole swap with trans fully dressed(no ac compressor) Is 480Lbs dry. With ac compressor would be right at 500Lbs.
I do not have the s85 yet so in still trying to figure out the weight, it’s listed here at 625lbs but the pic shows 261kg which is about 575lbs( although it’s missing intake plenum...I’d say 15 lbs max) which would put it at 590lbs or so.
i looks like the ac compressor is still attached as well. Where did you get the 625lbs figure from?
if anyone has weighed an s85 lately please chime in.


Hi Genius,

S85 is one large pig. S85 was scaled by the UK chap and appears to be
around ~620pounds fully dressed. If you add the dual Intake and other small
bits it will show you right in that range +/- but call it 600pounds.

The transmission either SMG 7spd or 6 spd whichever is another large pig.
So you will end up with about 750 pounds axle weight and if you think that the
transmission is located toward the back that is not even close to the center
of the wheel base.

I know V10 is love and sounds like F1 car but not really clever to put into E30.

You will add about ~200pounds over the std S14+5spd box.

My suggestion: Put S54 in the E30M3 with cams CSL box, easy 350RWHP.
and I promise you will destroy the V10 in E30M3 because front will not turn.

S54 complete engine is 525pounds I have scaled it with the dual mass flywheel.
Put 10pounds flywheel, put CSL box that alone will drop you down to ~480pounds.

So the difference between the S54 and S14 will be around ~60pounds which is
not really that bad and if you retain 5spd box which is slightly lighter than the
5spd Getrag-265 will get you in the ~55pounds range. So those 2cyl are ~55pounds.

With the V10 up the front you will have very hard time to dial your suspension due
to its massive weight up the front with very light rear....

I have completed 3) E30M3s 1) S54 and 2) S38 and I would not go anything over
6cyl its balance between power and handling.

Regards,
Anri
 
#25 · (Edited)
S85 is set in stone and I plan to shave plenty of weight from the pig...billet crank, forged internals, lightweight flywheel&clutch, no plenum or airboxes, evolve headers no cats etc. I’m also planing to use an e36 m3 trans with an adapter plate or cut and weld bellhousing (75lbs). I think this combo will be around 100lbs heavier then full s14 swap Give or take a few. I will be modifying the firewall so the engine can sit 4-5 Inches further back ( mount points right over Cross member). I’m using all carbon front end body panels...bumper, hood, fenders, door skins and roof which will further reduce nose weight. For suspension I have the dtm aluminum control arms, lightweight manual rack. I’m confident that I can keep front to rear weight ratio near stock levels. When I bought the car it was a pig with full sound system and 80lbs of dynamat. Now it’s on a rotisserie getting all under coating, sound deadening stripped. Interior will be carbon dash ,heater or ac and I have recaro pole position seats which weigh 15lbs with brackets. It was 2900lbs and hoping to get it to 2400lbs with s85. The only other option I’d consider is a Honda k-series Stroked to 2.7 can make well over 300whp and is much lighter then s14.(purists hate me anyway)
 

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