~400bhp CSLs?

[The Gorilla]

Hi Lawsy,

On the S54 Heads, its very hard to
make real world gains.

But I did Lightly port the exhaust ports,
de-burr, and Glass polish them.

At the same time I roughed up the Intake
upper and smoothed up the lower intakes a
little and again some small de-burring.

Triple cut the valves and made sure all
valve seats were flush.

Gains, maybe more than likely not.

I had the head skimmed 0.4 thou to make
true, but kept with std H/G as there
not exactly 'thick' to start with.

Regarding the posts of 400 BHP S54's on std CR or the even more
ludicrous 450 BHP 'Stroked' S54's just go
do the Maths, either all calaculators have
been incorrect for years or ''stroking'' the
S54 defies the rules of how an engine
makes Torque/Power.

Regards,

The Gorilla.

[cantfind1]

I can honestly say that 445BHP from an NA S54 is completely possible!

However the only thing that is standard on the engine is the block, the crank and the volume!

The Head in the S54 is pretty well flowed already but there are some improvements to make, but its a lot of money for not much gain....The exhaust valves in the CSL are a big improvement over the standard M3 ones....

Its all about getting more flow through the engine, the more air you can get into and out of it in a given time the more power you will create....to an extent.

Hence the Carbon airbox and exhaust cams from BMW in the CSL...

[The Gorilla]

Hi.

Quote- ''I can honestly say that 445BHP from an NA S54 is completely possible!

Please can you explain how ?

If you do the numbers of a ''stroked''
3.4 S54 assuming it makes 90lb ft Torque
per ltr, and remember at 8000 rpm
its already shaking itself to bits.
The Vac 3.4 stroked Crank is made by
Arrow precision and its rev limit
is 7900 rpm so as follows
I have also assumed that peak Torque
is made at 85% of max engine power
nearly every S54 Torque cure I have
ever seen is falling off before that so
not trying to manliputate the figures -

3.4 [S54] 90lb per Ltr x 3.4 = 306

306 @ 85%/100 = 260.1

260.1 @ 8000 rpm/5252 = 396 BHP

The fact is that to make 445 BHP then
the S54 engine needs to be making well
past 90lb Torque per ltr.

F1 engines while not Torque monsters struggle to
make 95lb Torque per ltr.
I think its well accepeted that F1 engine
designers know what there doing.

While Stroking improves Torque its at the
cost of revs.

Increase the stroke, but even compensating with
lighter Rods, 2 ring pistons, Ti wrist pins,,
block girdle, opening up the bearing clearances
and so on, will not enable increased revs.

I know of at least 3 stroked S54' s [3.4's]
2 built by well known Race Engineers and
when they hit 8200 rpm, they were no more.

Regards,

The Gorilla.

[cantfind1]

Hi.

Quote- ''I can honestly say that 445BHP from an NA S54 is completely possible!

Please can you explain how ?

If you do the numbers of a ''stroked''
3.4 S54 assuming it makes 90lb ft Torque
per ltr, and remember at 8000 rpm
its already shaking itself to bits.
The Vac 3.4 stroked Crank is made by
Arrow precision and its rev limit
is 7900 rpm so as follows
I have also assumed that peak Torque
is made at 85% of max engine power
nearly every S54 Torque cure I have
ever seen is falling off before that so
not trying to manliputate the figures -

3.4 [S54] 90lb per Ltr x 3.4 = 306

306 @ 85%/100 = 260.1

260.1 @ 8000 rpm/5252 = 396 BHP

The fact is that to make 445 BHP then
the S54 engine needs to be making well
past 90lb Torque per ltr.

F1 engines while not Torque monsters struggle to
make 95lb Torque per ltr.
I think its well accepeted that F1 engine
designers know what there doing.

While Stroking improves Torque its at the
cost of revs.

Increase the stroke, but even compensating with
lighter Rods, 2 ring pistons, Ti wrist pins,,
block girdle, opening up the bearing clearances
and so on, will not enable increased revs.

I know of at least 3 stroked S54' s [3.4's]
2 built by well known Race Engineers and
when they hit 8200 rpm, they were no more.

Regards,

The Gorilla.

Well seeing is believing....and I know the guy that built it and races it!

http://www.youtube.com/watch?v=qgD6K_4kslc

By the way this engine was mapped by an F1 engine builder.....

[0-60motorsports]

Well seeing is believing....and I know the guy that built it and races it!

http://www.youtube.com/watch?v=qgD6K_4kslc

By the way this engine was mapped by an F1 engine builder.....

Wow, more details on this please.

[NZ_M3]

This is all starting to remind me of the days of B18C Honda vtec, when people claimed that 260bhp at the crank was the peak for that motor, then someone in the States went and stroked it to 2.1 litres (physically impossible until you added a decking plate to the block), upped the compression and various porting and intake tricks, block work and rev'd the thing to 9500rpm and it cracked 300bhp, nobody believed him until he showed all the engine work and posted up a detailed build on the net, stuck the motor into his daily driven EF CRX and started building these motors for race teams (well known shop in the Honda community by the way, if not the authority on everything NA Honda).

450bhp does sound a little unbelievable I have to admit for an s54 (I'd like to know the full spec for that above motor posted by cantfind1) but 420 is definitely plausible, and unless the guys that race in open class here are all lying about their horsepower figures but yet still somehow miraculously beating the occasional 5.0 V8 powered E46s .... I have no other explanation.

[cantfind1]

Spec of that engine is know by only 2 people in the world....and I am not one of them I am afraid...

Sometimes you just have to believe....

[NZ_M3]

Spec of that engine is know by only 2 people in the world....and I am not one of them I am afraid...

Sometimes you just have to believe....

Oh don't get me wrong, 450+hp is possible (see the ALMS team description below), I just don't know how reliable or how many actual 'race' hours you can get out of that motor before a big rebuild. I know that 380 ~ 400 can be done reliably, 420hp pushing it, and stroked at 450+ .. probably 30 hours before a rebuild?

But yes, from the horses mouth (and I believe it when these guys say that their motor is 450hp+ they are afterall the official ALMS team for BMW Motorsport) - and they rev these to 8600rpm .... clearly stroking these motors gave it a better rod/stroke ratio vs stock allowing them to rev a bit happier.

http://www.racecarsdirect.com/listing/44208/factory_bmw_m3_gt_alms_gtr_race_car_003.html

[The Gorilla]

Hi,

Not looking to argue, but for the
S54 to produce 95lb Torque per
liter then it would a first for
a volume prodcution based engine,
even if the block is the only
original part retained.

C63 AMG, BMW E60 V10, BMW S65,
the list goes on and none of these
engines produce anywhere near 95lb Torque
per liter.

So not a believer here.

Regards,

The Gorilla.