no not yet bean ....the poor facing of the valve seat up to the combustion chamber is inherant in the actuall casting-assembly process i guess ....and i dont want to changing anything in there . (seat height versus valve and guide length )
im sure that it could be machined out by the right folks and reinstalled down flush .

this excersize is going to be just in cleaning up the airpaths and working with "what we all got" and hopefully getting a measureable outcome . 

but a good point you have and worthy of noticing .  
its good to see whats in there huh ?


addition : there is still some grubby coke hanging round the exhaust port valve seat ....as some of the work I have been doing is very late at night ...I haven't revved up the dremmel tool with suitable brush and cleaning agents
 but will do ....after I stop travelling around on the weekends.

Charlie, 

I admire the work you have done to your RS!   One word of caution, of which I'm sure you are aware;

About the only way to gain improvement on the dyno is with a flowbench.   I went through this with  460 C.I. ford heads for my boat.  Spent lots of time on them, and thought I did everything right in regard to porting and polishing.  After obtaining (what I felt) were inadequate  results and uneven flow, I took them to a head Guru who allowed me to attend the "head rubbing" session at his flow bench. As was mentioned, I learned that what I didn't know far outweighed what I did!  lol.   I later took a set of aluminum Super Cobra jet heads & intake to him and what he was able to achieve was phenomenal!  (42 more HP on the dyno over stock condition)


If you do a google on a home made flowbench they are not really that complicated or expensive and really the only way to achieve acurate flow.


Ken

thanks for the advice ken

yes a home made device is in the plans already

have been reading very similar across a few websites 

still trying to find out more on the valve guide and the best way to open that area up ....as there seems to be a pronounced reduction in the cross sectional area of the port just there .
the mold process will help confirm that.

some of this info might come in handy for our sidecar mates especially

in any case   without going to extensive expense im hoping for a small but noticeable difference on this project path

pulled the valves out of the other head     an 86 model

the overall finish and attention to detail seems apparent

possibly the sand casting is a lot better


simarly the porting


the valves show a little more wear ...with some pitting marks still evident

 



ps  thanks alby couldn't have done this without the valve spring compression tool

made a latex mould of the inlet port ....to try and better understand some of the internal dimensioning
besides the small defects ( created in trying to remove the mould from the port )
it does give a good measurement of whats going on in there

 

Charlie.....so that is what latex is used for.

Don't make any more Charlie or they'll start breeding.

doing up some throttle bodies

some bad looking gunk in tb number 1 ...took some time to get that out ....which would have made this set a bugga to work with.. .the bypass and vacume lines were almost completely blocked
and the rails are bent ....good grief .....another pull down to get it all straight I guess



mean while  the kilometres mount up ....after the last little trip



2,168k .this last bit

modifying the path through the throttle bodies




last bit for tonight

a bit of sunshine to see the effect of the tb mods

 

this is to be compared with the standard setup ...once the flow bench is setup and calibrated
it will be a standard inlet path and a modified one ....I believe it isn't just ports of the inlet- output flow rates on the head that makes a difference ....hopefully I can see some differences in the long term

a bit more work today


found a few more casting marks  ....to be expected I guess





now have a good idea about the ports ...how they are a little too narrow at the back of the long curve ...and a little too sharp an edge on the inside of the short radius  on the inlet

the porting on the exhaust is a botch job  with a few layers of size boring down past the seat , particularly on the short turn radius of the port ....leaving a very sharp edge ...I can see I will need to make a mould of the outlet port as well

tried a little clean up of the inlet valve area

 


coming along well ...with some previous changes in angle and finish achieved ...also got a bit deeper in the long radius depths - width behind that valve stem

the deformities- casting marks on the inlet just near the external side have been reduced also  

before 

more still

will try this with flow bench before advancing further



and a little work on the exhaust



still a little concerned at the seat to port match up .....but hey! ...thats whats there...  at least I can see now after I have dug out the deep scars off the port walls just below the seat ...and opened up the sharp edge on the short radius

Charlie, what TB mods did you do?

Charlie you need a busted or broken warped head to cut up, I can see work to be done on those ports but as I have no refference to say how much, if you can chew out the anomalies in the port flow that will be huge move forward, but how to ensure you do not get too close to the water jacket, best to put up an add for one you can cut through and see what meat you have to work with. i know it should taper, but not regrow in volume as it seems to going past the injector. the exhaust seems to be a place for better improvements in gas flow so show us the plastic foem for it and we can speculate mate

got a few pics  from a "mini" site keith

ill post up a pic as an example

yes, I will be making a taper from the inlet port to the seat

I haven't done a proper drawing yet that will explain what I see ...except on paper by freehand with all the little bits of notice .
but the diameter of the port just below the seat around the bend  has been opened up to at least the inlet seat diameter (before, it  lost a couple of mm on the long radius ...and the sharp turn short radius (maybe less than 4mm radius - now about 8-10 mm)   ...just about the valve stem the height of the port closes up a little with the  stem shroud ...(which is in for a little cutting up ...maybe even disappearing ....grin )




I just wanna see what difference it makes... so far

and you can see from this cutaway that his radius is much better than what I saw ...so have made mine similar ...at least
im thinking that the early model castings appear to be formed better than what im working with ...you can tell by the before shot that they resorted to just machining down the bore to make minimum specs ...but not the best that it could be , and the outlet is really crap  on the one I have .....but opened up now

I guess many are like this

but im just trying to optimise what is there at first ...
yes I could pull the valve guide and machine that whole shield away  and just leave a taper on the valve guide as the only restriction in the path ( as seen on many performance improvement sites )


 cheers you guys watching and offering some feedback ...I really appreciate it ...and giving me new ideas ..

that's what its all about hey ?!!

hi robin

I just smoothed out the tb extrusion ...you can see the before pic ...below


the best mod is to do the k1100 tbs replacement ...you get an extra mm or so on the butterflys and the whole path through ...but have issues with the axil = pivot "connect up" to the tps switch between the models ....unless you modify that area ...(SOMEONE HAS DONE THIS SUCCESFULLY )

but for me at the moment ...im working with what I got

I figure that any abrupt change in diameter adds some kind of drag to the flow ...so just made the change in diameters  smoother as it approaches and leaves the butterfly's ..

my test with the flow bench  will contain the apparent differences between the 2 ...standard and modified ....I seem to recall that great lengths were taken by "old time " performance folks to make that path  as smooth as possible ....we just have inherited superior and reliable electrics ...besides the carburettors of the day ...and no longer have to worry about measuring flows to compensate mixture settings whilst on the run ... I guess

rick and I have talked about transplanting some newer electrics (motronic 2 ) into the system ....along with different injectors and stuff ...but that's for later .

well you sure are safe with the water jackets, blending in those machining marks and a tidy up for the guide will allow a better look at how the airflow is slowed before entering the seat, it might all happen in a micro sec but it sure does hinder performance if not at its best, Thats a good pic of the sectioned head.

with the 100 TB's it would be great to know what a taper to the crack point (when you crack the throttle open from fully closed) from that shoulder would do to the stoicometric values on the go with an unmodified mapflap as against stock one

charlie99hi robin

I just smoothed out the tb extrusion ...you can see the before pic ...below


Now I see

keith we have an additional issue ....

the rubber adaptors to the inlet port ...reduce from 34 mm to 31.5 mm in their length of just about 12mm

now this might be to compensate for the tb pivot pin restriction to flow though the throttle bodies and the flow into the port ... it may add to increase the velocity at that point and promote torque at certain revs through the whole induction process

to me that issue is kinda a problem

I recon that the rubbers could be made to match the port if opened to the size of the tb diameter and the inlet port to match ...

I do have another set of rubbers that will go into that measuring process ...there is an issue with static versus working loads though during the flow bench process

so that's why I want to test with standard port diameters and standard rubbers ....once you pull the metal out ...its pretty difficult to replace huh ?!!!

but those ideas are in the mix mate ...

let me know what works best before I start ...

The flow rates at those points 34mm and 31.5MM are quite different, so the mod to the TB's will be drowned out by the changes made trialing the mods to the rubbers. I'd consider stock TB's till the rubber mods are trialed on the flow bench. what sort of flow bench are you building?? One for all four Tb's on the head or one that runs on one cylinder

doing it the hard way keith ...about 1 at a time is all I can afford to do right now

hoping to get an afm off a Hyundai that has a good flow to output voltage reading ,,,for cheep mate ..and a couple of broken vacume cleaners for the suck

have to get a "measured flow " reference hole made and a vacuum gauge for the references

bit of trial and error to get the flow ranges right for the head

oops should have mentioned I have unmodified and modified throttle bodies ...so can test all the variations

Good progress charlie. Crosssection pic is interesting.

Will

Charlie, I have an AFM if you want to borrow. Keep it as long as you want.

thanks blakey

all good mate ...I have one also

im hoping the either the daiwoo or the gm type "wire" afms are already documented for output voltages and flow volumes

else ill have to resort to some experimentation with the old barn door of our machines

which might not be an bad thought ...

but honestly with the spring tension issue and age ...may not be replicate able very easily

but I guess I could get percentage differences ??? 

whatcha recon ?

I would think that there may be more info on the Daewoo and the GM systems rather than the BMW.

"else ill have to resort to some experimentation with the old barn door of our machines

which might not be an bad thought ..."   I'm no expert, but if the AFM came off a releively low mileage bike, I'd start there.

well did some test regardless of lack of calibration

the setup ...applied to both heads , throttle bodies etc ...and vacume cleaner applied to inlet port

all ports blocked ...5 volts applied to the afm then reading the wiper for feedback on flow

all just comparative testing

first an unmodified head afm  reads              0.72 volts with no flow

with standard throttle bodies and all          got a reading of 3.38 volts

next ported head  with standard throttle bodies   reading of 4.38 volts

next ported head with moded throttle bodies        reading of 4.44 volts

 
its no where near a good test in relation to vacuum reference points  and full flow of the system with standardised tests of 100 thou lift and 2 bar vacuum
then all the other flow parameters

But ...it is showing signs for encouragement to continue further

so some quick maths are

base reference voltage with no flow         = .72 volts ...steady =no flow
base head  with standard tbs                  = (2.67 volts as unity - with the static reading subtracted)
ported head over base head  with standard tbs  = 36.7 percent increase
ported head over base head with moded tbs      = 40.9 percent increase

this will probably mean something once the actual flows can be referenced and standardised with vacuum readings

 woohoo

I love this backyard engineering. keep it up Charlie, makes good reading.

does anybody have a link to the bmw k 2 valve afm mapping data

the data from a borrowed amemometer  thingy ...was just over the top  for trying to measure volumes mass flow etc ....
appreciate any help I can find

cheers !

milling out some more aluminium





 
clean up to happen soon

did a little test and put a full 12 volts on the afm for range sweep voltages (I was scared that the higher currents would do some damage before )

still looking for data on the afm sweep

but inge might be able to help with a post I saw on flying brick de   that I cant seem to access
so will post the afm tests that I did before ...with the full voltages of the tests I did instead of the 5 volt reference voltage

but still no reference data of flow (cfm) versus afm output voltages ...yet !

in other news ...my odometer has finally stopped working ....bloomin gears I expect ...giggles

final bit for today

got all the intakes back to looking clean ...maybe a bit of polishing to accomplish  but all looking very similar ...

the flow bench will confirm the work I guess



 likewise the exhaust ports

bit of port to tb rubber matching today

did a bit of adjustment to the afm tonight

I think I may have found a good cause of some systems being over rich ...

I think that I have read that there is an cheat on the fuel mix ratios regarding spring tension of the vane ...which in fact maybe correct ...but more work needs to be done on this before I can reliably get some gainfull knowledge of the effects

but I did find in "berts" comparison tables that there is a relation ship of vane potentiometer reading to working afm s and non working ones 

I found some data on the flying brick site and did some investigation (thanks inge )

whilst berts data reads the actual resistance measurements  , I think a better way of testing is to apply voltage to the afm and read off what its putting out .

with this knowledge now I think  can solve some issues ...or at least consider them in the mix of what im trying to do and what im seeing on other machines .

Eindringtiefe (mm) distance from entry to afm to flap?	Spannung (V) voltage out
geschlossen, relaxed? 42	1,1
45	1,7
50	3,2
55	4,3
60	5,2
65	5,6
70	6,2
75	6,65
80	7
85	7,2
90	7,35
95	7,45
100	7,55
voll offen	7,6

which ties up nicely with some readings I made

the previous measurements I took were wrong so I have done a conversion

previously the wiring I used  was

With afm connections  of 5 = earth
                                     7 = output
                                     8 = 5volts

 new wiring is                  5 = earth
                                      9 = +12
                                      7 = output



the conversion worked out as
base reference = 0 flap ====1.72 volts  ???  (1.1 as specified on the  fb data )
      3.38 becomes  5.35       = 62 mm of afm flap (old head)                = 20mm deflection
      4.38 becomes  6.93       = 78 mm                  (moded hd)              = 36mm deflection
      4.44 becomes  7.02       = 80 mm of afm flap  (moded + mod tbs)  = 38mm deflection  

(wouldn't that be grand if these measurements translate to more horsepower directly but don't hold your breath )

so I have adjusted my afm potentiometer down slightly to get the best I can ..reliably so this will mean a change of about 3mm in each case

I got 1.162 with adjustment (close enough )

from a reading of 1.72 from before starting the adjustment

(which indicates from the table above as 3mm of flap )



this is interesting as it looked to me as if the setting hadn't changed much since I did the fix on the wiper and anvil pin connection ( it hadn't changed much on the multi meter from what I could see )

so im guessing that the flap potentiometer is actually showing 3mm of movement of open when in fact it was at home position .

this to me sounds like a likely cause of over fueling ...or rich running machine which I suspect is why some folks get better fuel economies  than others 

perhaps vibration wearing carbon track etc could make this error apparent over time ?

I will do some tests on my running machine (when i can) to confirm this    

(ps ...found another mod regarding the pin and anvil repair involving a piece of flexible cable across that junction.... which I will do )                                              

just doing a valve grind to start putting things back togetherish ....for testing

 

plotted out the afm readings according to the tables

there might be a issue with the collected data

my map from a hand generated graph shows possibly an error in measurement

sorry about the pic ...but converting excel data looses the scale that I was hoping to see


just adding a corrected and labelled graph



at about 65 mm of vane deflection,  there seems to be a odd deviation in the readings
now having read that a lot of research and precission went into making the system I cant imagine that such a odd value would be let out on a production release  so I guess the author had a (minor ) slip of the finger

( given that 42 mm is closed , I started from that point as it would be the reference for bottom of the afm voltage readings )

no biggie ....but will amend my readings once I have measured with accuracy myself




but on the whole not a bad curve

im thinking of taking the afm to a tuneup workshop and getting the readings calibrated for cubic flow  along the same scale so we can get an absolute ...and reliable flow assessment

?? does that sound like something worth doing ??

I would not discard a reading like that Charlie it could well be turbulance that sorts out after that air speed. That sort of thing can cause a flat spot or similar.
When I was running the injected big block we had one port on a head that was coming up like that on the flow bench untill we got one of the porting experts to have a look and there was a flat area on the inside of the turn of that port which was nor present on the others so we had to leave it alone and accept it or discard a very expensive head.

more cleanup





plus added tittled graph above

Good work Chas, keep it up.

3rd attempt at getting better mirror finishes happening ...
thanks to blakey some months ago I got something with real plastic ...that hadn't been busted ,,,,,erm yet

shiney



bloody dropped one of the shells ...and will have to strip it completely and repaint the whole deal on that one .
just have to remember in getting fumbly ....sometimes

have a great christmas season fellows ... cheers from down under

charlie99 wrote:bloody dropped one of the shells ...and will have to strip it completely and repaint the whole deal on that one .

Been there, done that mate. I repainted many panels on the blue bike, it was acrylic paint.

The whole tail section fell off the table here the other night while sanding something else.
The 2 pack primer cracked where it hit. I was able to sand the cracks out. Truly weird stuff.

return to tank line fuel cooler installed
a few stainless fittings

should test it tomorrow ...to dang hot to continue this afternoon

I suppose that you will now have to have a new radiator cover.....getting too posh for us Charlie.....well done.

I guess not stan ...well so far .

I put 10 mm u section to mount the cooler off the radiator ...I guess theres no reason that I cant put another section at each end ...and fill with some mesh between  with 10mm standoff.
 would really like to get a subframe made up out of alloy for the front ...with just a few mating screws to the radiator ...to hold the whole sub assembly ...one can dream ...eh ?  or better I go learn how to do it ?

just redoing the insulation under tank before it goes back on


 

just back from test ride on a very humid high 30s day out there ...up Mount Cootha and back (about 20 ks off ...after a local streets tour round here of about 30 ks ...total up maybe 80 ks )just to get it heat soaked

subjectively ...the whole tank feels a lot cooler ,,,mind you some of the heat I felt was due to direct sunlight ....below the fuel level line a notable temperature difference...especially from what I am used to

did you experience the same rick ?

Yep the first time I used mine after fitting it was a freezing cold day and I sure noticed the difference

just doing a little meter modifications (to the temp guage ,,,swings and sways when up near top end deflection (92 c ))
added tantalum cap to the shunt to slow down - dampen the movement

and some additional lamps

so I can see them at night properly



turned out ok  I think



update ...the tantalum cap needs to be a bigger value (it certainly has steadied the swing down a lot ) ...say 100 uf instead of the 4.7 uf that I installed (had on hand ) ...I have a feeling that the current through the meter (after adding resistance to the sensor line to recalibrate it to read higher on the scale ) is insufficient to drive the coil properly with all the vibrations etc and at speed and above 90 odd degrees c ...I guess I could modify the shunt a little instead to achieve a similar result with a little more current going through the coil ????

well see

btw can read the instruments with the dark visor down and at night ...a great result

great day out with some of the guys round here

the fuel cooler mod is fantastic ...a very noticeable temperature difference between the rs of blakey  and old gerty

stirred up some rubber around the twistys on the way home

those chicken strips took a beating from this old fella ...

and a big smile on my face after the trip with friends towards a verry warm Kingaroy in the hills  not far from here