So a couple of weeks ago somebody was advertising a BMW K bike head. I considered bidding and then thought "I reckon I might be able to get one closer and maybe cheaper". I was also thinking "Matt Read doesn't really rate those Pearce 7 port heads but loves the Twinky". So I did the usual Ebay and Gumtree searches and found a whole K1100 engine about 20 minutes drive away. It had done 90,000 km ans was a 1994 model. I don't really know why but I sort of bought it on a whim.











No sooner had I posted that I bought it than a member on here PM'd me to ask if I'd like to buy the Specialist Components conversion kit for it. Well yes I would!

http://twinkam.co.uk/epages/191f6b26-60 ... cts/SCK003

He also had some of the optional parts that should come with the kit but don't.

It seemed the world wanted me to do a Twinky!

I then got on to SC and got their build guide, the hose kit, the extractors and dip stick.



To be honest, the build guide is a poor effort for the money. About half the pages are there to sell you a kit, not tell you honestly what to do and what to look out for. There are important bits that are described differently on different pages and bits that are barely discussed at all. Searching the UK forums reveals the many traps that await. I think I will buy Matt Read's version so I can know a bit more.

So with the engine sitting in the way I needed to get the head off so I can put all these parts away until my current projects are finished.





Barely a mark on the cams or followers




The water jacket is completely clean, like new.


I had to take it to a mate's shop to get the head screws out. Big bar was needed and I didn't have a T50 Torx socket. Luckily the engine weighs less than 60kg.





Can't be seen in this shot but the bores still have all hone marks. The BMW bike boys would cry!







Once I had it apart I offered up the SC block drilling template:



Oil passage in the head doesn't line up with the block drilling template. This is one area where the book is lacking. Turns out this hole lines up with the block and the template is for re-drilling the head...


Here's how the BMW gasket lines up with the drilling template.


Here's how the BMW gasket lines up with a 12G940 head. You can see the bore spacing isn't the same but it is so close!


And finally, here is what the SC exhaust looks like when offered up. Reading the UK forums tells me this will go too close to the bulkhead. I think the primaries can be shortened where they meet the head. A little bit of cut and grind and I should get 15mm more clearance.



This is going to be my next project. I think I will go 1293cc and NA. It will get the Haltech ECU on it.

I'd like to start very soon but I have to get the dark blue car's engine back together with the thrusts fixed. I also need Matt to re-build the Moke's engine before he can have this one. Mental note, call Matt tomorrow to find out Moke engine progress.

Stay tuned.
M

Very nice!

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Looks good.

Brad

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During the day I work on English designed cars & on my own time I work on English designed cars....

Good luck have fun.

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Nick

http://www.ausmini.com/forums/viewtopic.php?f=3&t=86675

thanks for the detail on the photos, answers some questions I've had - what did the K1100 engine cost you?

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did I tell you that I won a trophy?

I paid $380. The seller has lots of K bike stuff and told me he had given away two K100 motors recently.

bloody hell!! what's his number?

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did I tell you that I won a trophy?

This guy has a heap of stuff too (that I am watching to see if anything comes up of interest, but a touch more expensive than the above ... http://www.ebay.com.au/usr/moto.genn?_t ... 1438.l2754

Complete engine seemingly minus injection (sold separately.....) - lots of kms on it though ... http://www.ebay.com.au/itm/281807843792 ... EBIDX%3AIT

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"Evil will always triumph over good - because good is dumb"

1961 Mini 850 - sold 1997
1965 Mini Deluxe - sold 2013
1977 Mini LS - in build....

Somehow I ended up on the mailing list for JustJap in Kirrawee. Last week their email showed a K1100 bike under the "arriving soon" heading.

Also see http://www.autotrader.com.au/motorcycle ... JBW3742848 ...

You could flip what you dont need pretty easily. That is the direction i'll be heading.

Sent from my SM-G900I using Tapatalk

_________________
"Evil will always triumph over good - because good is dumb"

1961 Mini 850 - sold 1997
1965 Mini Deluxe - sold 2013
1977 Mini LS - in build....

Bargin
Is it going into a Moke

He is on Gumtree if you search K1100 in Westlake (Qld) and his name is Mark. Really nice old guy, almost teared up when I told him what I was going to do to his perfect motor!

M

Nope. It will go into the light blue 850 I have been building for years. The Moke is getting its MG Metro engine back and the dark blue 850 will keep the engine it came with.

Yes, I have three empty engine bays in my shed

M

Love those graphics of the 3 minis in your footer! How did you do that?

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Zulu...

1967 mini Cooper S

Ok, a bit more playing with my Twinky today

This is the block I will be using:



Bores measure 70.55mm diameter and need to go up a size.

I threw some of the bits on the block. Can't put the cam sprocket end plate on because I haven't cut off the stud for the chain guide in the head.
UK forums say these special hoses aren't that special and need to be modified to work. I think they are right as it looks like one will rest against the exhaust if not modified.



Then I compared the BMW head gasket to the block and a BK450 gasket.



Outer cylinder alignment (yes I have greased my bores, I like them greased):



Inner cylinder alignment:



Things I noticed:

The BMW block is an open deck and the BMW head has symmetrical water passages for each cylinder. It is the holes in the head gasket that control the flow of the water from block to head. There is a pattern to the holes in the gasket that ensures that the water doesn't just short circuit around in the front of the engine. Excluding the three holes near where the cylinders meet, there is only one hole around No. 1 cylinder and 4 holes around all other cylinders. The single hole in #1 is 5mm diameter. The other holes are either 6mm or 10mm. The 10mm holes are on the exhaust side of the head and opposite from the outlet.

This is a strong difference to a mini where the water passages are no different for cylinder 1 than cylinder 4. The mini does have bigger passages on the back side opposite the pump inlet and the thermostat outlet to encourage the water around the back of the engine.

So, with BMW having obviously thought about this cooling flow issue it was surprising to see that the drilling guide from SC recommending that all water jacket holes drilled in the block be 5mm. I think some more investigation is needed on this one.

Onto the holes in the block. The SC book commits precisely 1 short paragraph in its 60 pages to this fundamental step. It helpfully suggests to "drill and tap the hole out to allow a steel insert to be thread locked in place". Not much to go on me thinks.

I see 4 different diameter holes, three if you exclude the existing stud holes that are already tapped. They are:
Use -- Approx diameter
Studs -- 9.9mm
Water -- 6.3mm <--- the build guide says that the 8 of these at the engine number side of the block can be left un-plugged but all the photos show them plugged.
Push rod -- 10.2mm
water -- 12.5mm

I guess they could have said what diameter drill, how deep to drill (the deck appears to be about 13mm thick to the water jacket) and what size tap to use but that would be too easy.

I read on the UK forums that people recommend using threaded cast iron rod so that the drill holes that overlap the existing holes don't get drill wander due to the different strength materials. I see from old pics on here that most of the holes are filled with set screws. I would like to know if it is worth the effort to get rod and get it threaded to the 4 different sizes required or are simple low strength grade screws satisfactory?

I know Matt Read will know these answers but I'd like to find out and put them in here for completeness. There is fly cutting pistons and sealing up the head to do for this conversion but I think people would agree that the block modifications are the most intimidating part of this build. They are too poorly described in the SC book for the money.

While I'm on this little rant here are the other elements not properly described in the SC book:
1) Oil passage in the head. Where to drill and where to block if you don't want the external line
2) Oil feed to the head. The 'jackshaft' that you can buy from SC is modified to allow increased oil flow to the head. Ok, but if I want to use the camshaft I have, will I get enough oil to all those cam shaft bearings? What can I do to my cam to make sure I do?
3) The alloy timing plate that goes on the front of the engine has a big hole for the mini's cam. There is another alloy piece that goes in this hole and has the shaft seal in it and an o-ring around the outside. I assume that the steel mini camshaft restraining plate (three holes for screws and one to let oil out) is used between these two. It could be left out but then there doesn't appear to be anything stopping the cam walking out of the block.
4) The crank pulley is moved out towards the radiator by this conversion. SC will know how much by and could say so we know how much we have to move the water pump pulley and the alternator by to match but no, we have to work it out ourselves.

I'm sure there are other things that will crop up but these are the ones that stand out in the first 5 minutes.

Of course none of this is rocket surgery and I will get through and over it but If this is your business to publish a how-to guide, then you want to do a better job than SC have done.

M