BMW K100 8 valve flow figures
Turbo Mini Forums

Well the results are in - I don't have the graphs at the moment just the peak flows. Firstly the cylinder head, head tested was from a 55K miles 1986 K100 8v twin cam engine (980ishcc lump) The head was not prepared in any way, it was taken from the bike and plonked on the flow bench, no cleaning up the backs of the valves, no cutting the seats, no de-coking exh ports/chambers, nothing - exactly as come of a used and abused bike.

inlet valve 34mm dia, exh valve 30mm dia

peak inlet flow 132cfm
peak exh flow 92cfm


From Viz's yellow bible the just of the matter is a REALLY good full on 5 port head n/a with big offset valves etc will flow around

135cfm inlet
100-110 exh

So I think we can safely say the 8V twink has enough flow in std form to give most 5 port heads a good spanking! - These flow figs could be improved drastically with a de-coke and the throats blended in as they are quite coarse in std form. For this engine its all going together bog standard (de-coked!), I may have a 8V fully ported to see what it'll do with big valves etc.

So with this head and the 284 deg cams on a 1293 bottom end 110bhp should be well within reach for a nice smooth torquey engine road.

When I have the graphs I'll post them up with the K1100 16v flow figs.

JK

If Carling made Mini engines
it would probably be like this one!

Top Man!!!!!!!!!!!

Thing I particually liked (like) about the 8v one is the ability to log TONS out of the chamber (usefull for boosted applications) - and of course to build it up with weld where it's needed aswell.... Basically allowing the outer chambers to be 'shifted' back such that they were central about the bore.

Round of applause from JohnK for sharing this methinks :)

bloody right dave .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

what were the flow figs for the 16v for comparison?

bloody good effort doign all this fella.....

Pete

And on the 7th day........... God created turbochargers!

Ok the 16v head in std "clean!" form gave:-

150cfm inlet
116cfm exh

these heads have 2 x 26mm inlets and 2 x 23.5 exhausts. The flow figures liven up dramatically when the throats are worked mildly and 3 angle seats used etc. Again a very good effort straight out of the box for the valve sizes. These heads in 8v and 16v form have long short turn radius lengths to them which appears to keep the air attached to the port longer before departing for the rear of the valve - giving good airflow figs for smallish valve sizes.

John

If Carling made Mini engines
it would probably be like this one!

John, your a star thanks mate!

Team Racing

No problem

cheers

If Carling made Mini engines
it would probably be like this one!

Thats cool information :) Sounds like a plan :)

Manchester Minis

does anyone have an idea of what a bog standard 12g940 flows like? I've not got my vizard book to hand

Edited by Jimster on 19th Sep, 2006.

Team Racing

from memory its about 90cfm inlet, 70cfm exh

If Carling made Mini engines
it would probably be like this one!

What where your CFM figures given with pressure drop wise . Vizard gives his figures with 25" pressure drop
The figures i've got for KAD are at 10" H2O [ not being up on the physics ] I guess this equates to 10" pressure drop?

at what max lift where these figures taken John,
i have some for the small valve KAD, i'll dig them out,
carl A

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

from my extremely poor memory it was 25" - I'll confirm when I dig the graph out - Carl lift was 10.5mm

If Carling made Mini engines
it would probably be like this one!

john , did you get some graphs in the end ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

somone has been bored 2day

Drives
-Ford S-max Mk2 Ecoboost
-Rover 100 VVC #2 - track project

Searching is all you need on TurboMinis

On 13th Mar, 2009 Paul R said:
somone has been bored 2day

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

cor that was a while back!! I'll have some flowed 8v head figures soon as well

JK

If Carling made Mini engines
it would probably be like this one!

John,,, would you have some std 2nd hand K1200 head flow figures?

we`re shoving ours onto the flow bench thingy shortly,,, it would be good to compare std 2nd hand K1200 cyl heads from across the globe,,, if not but also to compare different flow benches

www.miniman.com.au

"""LazyGoodForNothingSmartArseKnowItAllBackYardMiniMechanic"""

blooody good idea matt.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I'll get some miglia head flow details for you

Team Racing

thats great jim good idea ,,, i feel a fit of graphing coming on .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I think I'll start a new thread in the technical Section. I have the miglia figures, I'll copy these too, if you can all help fill in the blanks.

Team Racing

It is quite interesting tho, that altho flow figures at full lift & at certain low pressures (high vacuum) are all well & good,,, it really makes little impact on the overall torque "throughout" the rev range when in the real life situation, comming out of a corner at the track... full lift & high vacuum flow bench work is just not real life... especially when the entire inlet & exhaust system, valve train & combustion process isn`t able to be factored into the equation properly as in a real life situation... it is only a guide & works well enough for the average comparison

However,,, for all those who continue to harp on about full lift flow figures, it`s a good starting point to gag them & their lack of confidence in the performance dept of these cyl heads.

Looking forward to seeing some more results of these tests tho,,, should be good because we did a 16v head, (std 2nd hand, un-touched, straight off the bike) & it came up at 135cfm,,, a far cry from John Ks result of 150 wasn`t it John>>>???

Interestesticulating

www.miniman.com.au

"""LazyGoodForNothingSmartArseKnowItAllBackYardMiniMechanic"""

Matt - I'm not sure of the point you are trying to make but those of us which go to the trouble and expense of getting a head flow tested know that full lift flow is not everything. I also benchamarked other high performance 16v heads at the time of the first K1100 work back at the start of 06 and know how the K heads compare to other 16v heads out there. The stg 1 port was developed on the flow bench and the Sprint cams to suit - do you have any race grinds?

So other real world data we are willing to share - dyno curves? - our website shows plenty of interesting info - lets be seeing some Oz comparisons - you do dyno your motors don't you?

JK

If Carling made Mini engines
it would probably be like this one!