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Discussion Starter #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 (in a process to find out) my guesstimate is around 560+/-
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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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.
 

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Discussion Starter #5 (Edited)
Thanks Anri

This will be useful for everyone
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
 

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Thanks for taking the time out to both weigh all of the engines and to explain how you have cut weight.

It is great to see more data compiled that will help us improve these cars as we maintain them/modify them.
 

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Many thanks, Anri, for contributing such important information, otherwise unobtainable, to anyone else, anywhere in the world. You are a master of masters...
 

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Discussion Starter #12
Anri,,,,

small OT,, as you have mentioned gearbox weight

the Getrag 560 is 60 kg,, or 132 lbs

the size is also COLOSSAL vs G280

i can post pictures if you want

Sveinbjörn,

Thanks for your reply.

Yea I know this thing is very very heavy.
Same as weight +/- as the S65/S85 tranny.
 

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Discussion Starter #15
Very interesting.
When you say lightweight alternator. from what was it from?

Is it possible that the S70 is 165 kg?
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
 

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Discussion Starter #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
 

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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
 

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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
 

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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
Dammit Anri

Now I am hanging out for the cooling system ideas from you, while in the middle of a cooling system review and service.

Any chance of a quick bit of info with your main facts you have found??

Cheers

Dane
 
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