Somebody Needs a Coat !!

[The Gorilla]

Hi,

http://www.racecarsdirect.com/listin...ill_break.html


BMW would be very proud and I am sure that
BMW MS would be first in the que for any
future Engine Development Lessons.

Under square long stroke L6 engine now making
better Torque than Short Stroke Racing V8's,
Christ I need a whole fucking wardrobe.

Regards,

The Gorilla.

[Mike R]

Originally Posted by The Gorilla

Hi,

http://www.racecarsdirect.com/listin...ill_break.html


BMW would be very proud and I am sure that
BMW MS would be first in the que for any
future Engine Development Lessons.

Under square long stroke L6 engine now making
better Torque than Short Stroke Racing V8's,
Christ I need a whole fucking wardrobe.

Regards,

The Gorilla.

It has gained a reasonable amount of capacity (which always helps with torque) and VAC do offer 13:1 c/r option (for use with race fuel) - which again does the same with the torque, but I understand your skepticism and would want to see it on a proper Superflow engine dyno before I believed the figures .

The trouble with rolling roads is that they give calculated flywheel figures and these always seem to give skewed torque figures:


The above engine was mapped on an engine dyno - guess what the REAL figures are (a cyber high-five for the closest ).

[trackm3]

Dyno Figures ! whos do you trust ?

[The Gorilla]

Hi,

Its called Resoanance and Harmonics,
and on an L6 under square stroked long rod engine
the rev limit would be well below stock
due to resonance and internal Harmonics.

Steel block would increase the frequencies.

So where all these alleged extra ponies come from
is anyboday guess, mine would be the Dyno
but then I ain't trying to sell it either.

Regards,

The Gorilla.

[Mike R]

Originally Posted by The Gorilla

Hi,

Its called Resoanance and Harmonics,
and on an L6 under square stroked long rod engine
the rev limit would be well below stock
due to resonance and internal Harmonics.

Steel block would increase the frequencies.

So where all these alleged extra ponies come from
is anyboday guess, mine would be the Dyno
but then I ain't trying to sell it either.

Regards,

The Gorilla.

As you say, without getting a base line in the first place on the exact same rolling road with the original engine format, quoting "bhp" figures of the new engine is quite misleading.

The above engine that is quoting 525bhp and 475lb ft of torque actually made 512bhp / 425lb ft on the engine dyno, so although the bhp figure isn't far off, the torque is, which would imply the 350lb ft quoted for the stroker engine is going to be optimistic what-ever rolling road the figures were produced at.

Stroker engines can work, providing you get the rod angles back to (or better than) the OE lay-out (using longer rods / raised pins). However, looking at the pistons on an S54 engine, this is going to be very hard, as there doesn't look that much room to move the pin upwards.

You may remember the 2.4 litre engines that Power Engineering produced for the Cossies that used standard length rods and a huge throw crank - they basically became a diesel engine - being very unpleasant to rev above 6000rpm. Great for towing caravans, but pretty poor as "race" engine.

You can now get taller blocks, so can stroke an engine to 2.3 litres and still have better rod angle than original - win, win .