Why wont my oil cooler work?
 

Hi, I've fitted an oil cooler to my R80 G/S 1982. To do this i've changed the inner pipe to one of 162mm, fitted the longer filter, have the correct shim and white ring washer and rectangular black washer fitted, changed the outer cover (BMW part) to accomadate the cooler pipes and clamped the cooler onto the cross bar just below the horn. The cooler stayed cold, I mean cold. Have taken it apart a number of time but everything seems OK. Change the oil relief spring at the base of the filter cannister (for bypassing the filter it it gets blocked) as the old one when examined was half the lenght it should have been and the cooler now get warm on long trips. Have a thermometer in the dip stick hole that reads 120C and the cooler maybe warm to touch say 25c. Any suggestions? Where is the oil going if not through the cooler?

Also how much should you retard the ignition when you have twin plugged?

Thanks David

Do you need that shim? You may find your oil pressure is on the low side with that in. They don't all us it... it just depends... Have you got a pressure gauge you can attach?

Mines an R100 but does not use the shim or gasket but then my oil cooler take-off is thermostatic (HPN).

John

If your cooler is -not- heating up, there is no oil passing through it.
Is it BMW original with thermostat or a pattern?

Dual plugging...
I've tested what is written on the net (see my strings and replies elsewhere on Horizons Unlimited) - and it took me from 1994:ish untill the summer of 2008 before I finally got the dual-plugging working.

Here is -my- theory:
What you find and read on the net is based on tests done in the 1970:ties, i.e. braker-point system. You are riding a semi-electronic "bean-can" modernity...
When you look at "up-dates" of the old original texts they claim that just retaring to OT or slightly above will do. I do strongly disagree!

Friend of mine tune R75-90 - i.e. braker-point system. These -all- work nicely with the ignition just retarded by about 4-6 degrees, and really well with Boyer Bransden fully electronic ignition system.

My R80 had a topspeed of about 155-160km/h (inspite of 1000cc conversion...) with engine oil temps going through the roof (I have recorded over 180'C).
When I at last tested Daniel Derdickes suggestion by blocking the full advance to about 26'(?) - then oil temps dropped to 90-95'C and top-speed (fully RT converted) was -over- 200km/h(!). Timing is set as stock - not retarded though I opted to use 2' retarded anyway thus dropping full advance down to about 24'.
Daniel Dicke: Doppelzündung
Get these and install them:
http://www.derdicke.de/mot/img/doppelzdg.jpg

I've got a tool made for me about a week ago to facilitate opening the ITU. I can send you pics of it if you want. Contact me directly with you e-mail if so.

Now - what does the old recommendation cause in the new engines?
Overheating the mixture
What does this cause?
Overheating the exhaust valve!
What may this result in?
Separation of valvestem and disc...
Do you want to see how that looks?
That happened to me with my 800cc 10.3:1 system... ( I loved the smoothness of 800cc, but my walled prefered the less pricy 1000cc replacement parts from Wunderlich to the BMW original part cost for 800cc...)

If your engine oil temp is over 120'C at 90km/h 70-80% relative humidity, 20'C... then your timing is set way too early! Disconnect one of the plugs per cylinder untill you have a propper restriction of full advance. I would say that 90-100'C should be the correct engine oil temp under these conditions...

Another option is:
Omega Ignition Willkommen bei Omega-Oldtimer
or
Silent Hektic Ignition SILENT HEKTIK Automotive Hard- & Software - Home
BMW repair modification restoration
These two can adjust the ignition curve to dual-plugging. I can't use them since I have a belt pulley where the stock generator is situated...

Think about physical facts:
- a second plug placed at the corresponding site on the opposite side of the bowl will reduce the time it takes for the explosion/burning to be completed.
- the reduction of time is not wholly corresponding with the stretch so an exact reduction is hard to give less tested in a lab.
- a fair estimate of burn-rate reduction time is about 40%; i.e. in about 60% of the original time it takes to complet the burn, the burn will have been completed...
* at idle timing is set at 6' since the stock burn-time is about 6'.
* 40% less of 6 is 2', hence about 2' retared ignition at timing should be just about right.
* 40% less at 32' (full advance) is about 12'; hence optimum full advance should be at about 19-20'... however this is a figure that I have never seen nor come across. It seem as if 24-28' is where the optimul full advance appears to set in...
# ... at idle 2' and at full advance at least 6'... It is a shear impossibility to fix this by turning the ITU!

Now for other set-back.
I never get the idle to work well at less than 4'. At OT is simply will not work, less start.
I did get over 200km/h with fulladvance at about 26', and that is far better than I ever got it with just turning the ITU...

Now - do you still want to just turn the ITU?...

Further reading on this:
* 4-stroke performance Tuning by Graham Bell (no referenses in that book!)
* Internal Combustion Engine Fundamentals by Prof Heywood, MIT. (plenty, serious reference at the back of the book; all formulas that you may need; and very easy to read a quite enjoyable book).
* DualPlugging by Oak Oshlen (Air Head Beemer Club) Airheads Beemer Club - Home (note: I stronly disagree with Oak on timing for the 1981-on models; and I base my experience on three /7 800-1000cc engines and 15 years of hassle/headache).

Happy Reading!

Have you inserted it to the correct depth? It should be inserted so it sticks X mm out of the engine case. Can’t remember how much but you should find it on the net somewhere… If it’s too far in the oil (or parts of it) will not reach the cooler but it will circulate behind the cover, engine will still get oil.

You should be able to blow through the cooler via the cooler pipes, have you tested it? Use your mouth; be careful if you use compressed air.

There are multiple covers, if you use a simple cover (like 11 42 1 338 511) you should be able to blow through it.
The cover has to be compatible with the banjo-bolts.


Retarding the ignition alone is not an optimal solution.
To get a good solution you need to alter both the ignition-point and the advance-curve. It’s possible to achieve this with the bean-can but IMHO a system from Silent Hektik (as Lindberg suggests) or Q-tech is the way to go.

I’m not at home right now so I’m not sure if I’m able to follow this.

Hi, thanks for the information. Too much to reply to the timing question at present without really studying the links. My german doesn't exist so it will take a while.
With regards the cooler: - there is an article on the web called the $2000 O ring which gives all the diamensions and I have set it up to that. Did remove the gasket after reading it. Have done an oil pressure test and it's fine (7 bar at startup droping to 2 bar at tick over when hot) Oil pressure light never comes on. The cover is non thermastat with a 4mm bypass hole. The older one I believe had a 2mm hole but this I think put too much pressure on the cooler. Have blown through the cooler and although there is resistance it is clear. It would seem there is equal pressure in the flow and return pipe to the cooler which is stopping any oil movement. Why and how could this be?
Back to studying German. Thanks for your input. David