Ok, said i would update so here goes.
Found a really simple way of balancing rods that seems to give a more repeatable end to end weigh compared to a home build hanging rig and a lot cheaper than a £150 commercial one, should let me get down to about .5g end to end balance, which is fine considering all it needs is a screw, a plank of wood and a set of .1g scales.
FWIW stock bmw balance is 2g end mass and 4g overall so we are looking at 4x better than stock.
If people need details i might make a vid or something of this a little ghetto but really effective method, with a bit of care its accurate enough for anything a diy might need.
On the head front not a lot has changed, i have been fiddling with some bits on and off but not been in a position to do much.
Maggspower cut me some back cut valves which i intend to test asap.
I am going to build over the next couple of days a clear vacuum attachment that will fit onto a hoover. This wont yield any numbers but will allow the use of a pitot tube or a string on a stick to investigate the velocity profile and find turbulent areas without having to use a full bench.
Its a simple thing that anyone can build at home and use to get a visual idea of the flow without having to invent eyeballs that can see air flow.
See here for an explanation of what i am on about and why it could be of use.
http://www.diyporting.com/thread.html
i have had a rethink on the piston front and may be changing the chamber geometry a touch to suit, i'm still not convinced i can make it work yet so i will only post that when i'm sure it can be done. Pointless to go off down a dead end.
As some may have seen i have been looking into coil packs and alternatives to the stock manifold both of which tie into wanting to use the m50b25tu motronic 3.3.1 ecu to run this whole show.
The last week or so i decided to raid the stores and see how much of an engine i had in there, the result was this:
(no internals in these pictures, they are all in the draw atm, and excuse the mess i had to clear the front of the garage where i had been washing parts so my dad could get his BSA out.)
Just need to find and clean up an upper timing case and a few other bits and i may have enough bits to do some kind of a build.
I am thinking right now that i might build a mk1 engine as a proof of concept before going all out trying to hit the target, i am so far into uncharted territory that pretty much anything could happen.
This right now i am looking at an engine that owes me very little, i can pretty much free build it from here, i only need the loom and ecu to run the thing along with a hand full of other bits and some gaskets to have an engine that will work.
Once i have a runner and all things look good then i think a mk2 will be on the cards.
I want to get all of the key bits together in the first engine so i know the second engine will be mechanically ok and i can spend more time and money on it without the risk of an expensive paperweight.
first engine spec is looking to be:
M20 block - stock
M52 rods - balanced
M52 pistons - modified
M52tu crank - stock
885 head - chamber changed, big valves, multi angle seats, light porting
M20 cam - b25 stock
M50tu ECU
Renault coils
M52 injectors
Crank Scraper
Custom inlet manifold
Custom 6 branch likely
Now there is so much room for trouble in that list spending hundreds of pounderoos on shinny bits would be crazy at this stage.
I would love to be able to make a prediction what this combo will make but its anyone's guess due to the number of variables, lets just hope it make something north of 190hp yeah?
Edit - photos in a sec.
Edit 2 - ok thats better, serously smartphones, just like punching yourself in the face while holding a normal phone.
always fancied a go at porting! he also seems to think its the induction which makes or brakes m20 race engine. He reckons with the above mods and webers or throttle bodies i should easily see 230bhp and about 220ish ft/lbs torque!
