These are the basic alloy plates/flanges
that need to be made up to effect the start of your conversion...You will need to cut off the front section
of your Bimmer cam cover & make these items up to fit properly to be able to make all this happen
This is the water pump idler pulley that i made up from another toyota crank pulley... I just machined it out & fitted a couple of sealed bearings in there & stuck it onto the front/upper water pump mounting bolt to keep the new toothed timing belt away from the water pump housing,,, & beside that is a pic of the mod to the oil gallery that feeds oil to the cyl head, just a threaded bung & re-drill on an angle is all that`s needed here.
This is my stainless Spagetti Exhaust system/Extractors that my good friend "Gonzo" from "Gonzo`s Racing Pipes" made up for me,,, not cheap by any means, but very strong & durable.
Bimmer Twinky Conversion text.
yeah, well,,,it`s a matter of making 2 front engine plates up,,,one for the cyl head & one for the timing gears, & i dowel those 2 to the approapriate places & machine your holes for the cams & seals etc, so that all that stuff lines up exactly with their corresponding shafts.
need to make up 2 small alloy flange plates, one to seal off the bottom of your new front cyl head plate & also , the other one after cutting off the front of the cam cover , will need to fit a mounting flange plate in there also to seal off the top of the front cyl head plate to the cam cover,,,sounds difficult but really is only a matter of making up a couple of cardboard templates & cutting a piece of alloy plate to suit,,,trim it to perfect shape by hand & glue/devcon & grub screw them both in place. easy-peasy.
make 3 pulley bosses to fit the 2 Bimmer cams & the original mini cam shaft & machine your desired choice of pulleys (ford,toyota,suzuki---> whatever you choose but must obviously be small enough in diameter to fit) machine those pulleys to suit your bosses & in the process make sure that they are all made to fit in line with eachother. (i made all my top pulleys "samdwich plate" adjustable , hee hee, tricky hey ? :-) )
also grab the corresponding bottom pulley from whatever car you chose your cam pulleys from & machine it to suit the mini crank,,,make a spacer & washer assy to space the bottom pulley correctly & also the washers either side of the bottom pulley are to help keep the timing belt in line. (my original mini front crank pulley needed a slight machin also, but i did all that as a package so if you do it make sure you do your homework there :-) )
I also machined up another toyota bottom pulley & fitted a couple of sealed bearings inside it & bolted it to the front water pump mounting bolt to act as a idler pulley to help keep the timing belt clear of fouling with the water pump & fit up a tensioner pulley as well,,,i used the Nissan EXA type, easy-peasy & mounted it down low to the timing plate that we made.
bung up all the bolt/stud holes in the block & also all the push rod holes & i also blocked up all the rear water gallery holes as well,,,i actually made my own threaded cast iron bungs to keep the expansion index of the metals as much the same as possible,,,surface grind your block nice & flat & then simply re-drill the stud pattern & water bleed holes to suit the Bimmer head.
I made a threaded bung for the Bimmer cyl head oil feed & re-drilled that on an angle to line up with the mini oil feed hole in the block & also made a groove in the front cam bearing to make it feed constant flow to the cyl head.
add a few cyl head oil drains & engine breathers, an oil filler point (either the fuel pump hole or primary case breather hole or even the original dizzy hole if you use crank ange sensor & coil pack to ignite the stuff & obviously you won`t need the dizzy in there)
Top engine steady bar brakt is easy made up & fitted onto the new cyl head front plate & also attach your new top rad braket there also, easy-peasy
anyone could do this conversion, but there are some tricky things to do properly & i did use a CNC machine to machine all my stuff up, so i have it all on program & can punch out as many items as i need to make up conversion "KITS" for people, yes i know it`s cheating but hey,,,i`m not going to go through it all again by hand & have to re-creat it all from scratch,,,way too much drama for that,,,so i thoght it was sensible to just make heaps of each item in a big batch :-)
There`s lots of options with using this cyl head, but as it`s allready got a 28cc cumbustion chamber , well, i just thought it was allready a prime candidate for forced induction, that way i didn`t have to muck with domey top pistons or any of that, i just simply used the allready tried & proven pistons we`ve been using for ever & cut off about 2mm from the tops of them for valve clearances & increase chamber size a tad more for the turbo :-)
everything else basically stays where it is,,,mini water pump, radiator,original mini cam, etc, just need to sort out a thermostat housing (i used 2 x mini ones "back to back" & a slight mod to the Bimmer water outlet & it all lines up with the 850 type top rad tank) again pretty well easy-peasy :-) i also decided to use a late model jap altinator to make room for my new cam belt idler pulley & at the same time gave me a more reliable ,higher outpout alt :-) easy-peasy :-)
inlet & exhaust is up to you, but the Bimmer head is allready set up for injection so why not :-) so mine is obviously sequential injection, fully programable, engine managment system from "Autronic" (good old OZy knowhow) :-)
I might have made it sound simple, but i can assure you that there`s lots of catches,,,too many tricky bits & pieces to go into here really,,,my fingers would get worn out typing all the crap needed to sort, but still, it`s not really that hard, especially if you wait till mine is all sorted , running , & tested with high boost for a while & i`ll start putting a few Kits together,,,i allready have some "pre-orders" but i`m afraid that i can`t even pick a price out of the hat for you yet,,,there`s a few items would need to be on exchange basis & as i said earlier, i`d really like mine tested hard core for some time before i`m happy to put my name on them for sale.
I`ve probly forgottn some stuff , but that should cover enough of the idea for you to get the gist of it all
cheers, & hope you find it fun reading...
Matt