Abit's 318iA m20b30 + pssycat cam and more...

[abit]

:D


so after got all parts modified it was time to put it all together :D


assembled block


bought oil scraper
but it needed some machining done to fit :D
at start, already some bits cut off


and my version for 90mm crank :D


I always thought that I have ''light'' one of m20 flywheels, but seems like i was wrong :D
so, took this one of my mates e28 m20b20


so next...let's put it in


we put block in, everything looks ok, rotated etc, torqued down gearbox with engine, tested clutch...its ok, gone back to engine...aaand it wont rotate :D
just liiitle bit unscrewed gearbox bolts and it started to rotate, dayumn..block out :D

gearbox primary shaft was pressing crank forward, so it stopped in axial shafts
no big deal, cut 5mm's off gearbox primary shaft, and everything is fine :D


beauty of m20


and all in one piece


the view of front pulley
used 12.9 bolts from market, torqued as m57 spec 40nm +60 +60degrees, but seems like they are stretching, so I will replace them with shortened old head bolts


and of course...first start video
coils was not fully plugged on, so engine was not working as it should,
later fixed that problem


done some test drive, feels pretty nice :D
only it needs new tuneup, seems like it wants to detonate on more load, so driving pretty safely now.

HG collection + 2 out of photo

[abit]

gonna run thr 1.75mm gasket?

did you check the rod to shaft clearance after machining it?

no, I will use 2,05mm HG

yes, abooout 3mm. sticked clay round the shaft :D

[digger]

gonna run thr 1.75mm gasket?

did you check the rod to shaft clearance after machining it?

[abit]

sooo, cut some material from pistons
1 x 5 mm off from piston edge
now it looks more promising :D
so now it should be about 1,+ mm distance piston to head




also shaved oil pump shaft :D


so with distances between parts everything looks promising, but
CR is pretty high, 11,4:1 but I hope e98 + management tuneup will help to run without detonation :D

stay tuund

[abit]

One of my favorite threads for sure.

Also, for the record... I use this gif all the time:

[IMG]https://i.makeagif.com/media/1-11-2016/V2mi_U.gif[IMG]

oh, nice to hear :)
dayumn, that was so long ago :D

also, while I was waiting for engine parts, finally changed o rings for heater


..what you do when your work light breaks?
you improvise..

[zwill23]

One of my favorite threads for sure.

Also, for the record... I use this gif all the time:

[digger]

You should machine them. It's only going to be close near the edge. If you add the coorect chamfer style around the circumference you might even get some squish to.

[abit]

depends on rods but D18mm near where the rod should goes by works with m52 style rods and many aftermarket. you only need a local scallop

ok, I will check it. and Im using m52 rods, yes.

but Digger, what you think about that small piston to head distance and machining piston edge off lil bit?

[digger]

depends on rods but D18mm near where the rod should goes by works with m52 style rods and many aftermarket. you only need a local scallop

[abit]

ok


fiiiinally got parts from machine shop, dayumn 3 months to make crank complete to fit in..

ok, assembled 1 piston again, now with timing belt etc
piston 2 valve distance looks veery promising, I'm happy
intake about 5+mm, exhaust ~4.5, so very good..


but, not so good about piston to head clearance :D

mathematically
206.2+2.05=208.25
45+135+27.8=207.80
208.25-207.8=0.45mm and as we know head gasket will be thinner when head will be torqued

this is how piston looks @ TDC with used 1.75 HG


something like this with clay




I will use 2.05 thickness HG, but that's pretty minimal more than this
so what should I do? thinking of, machining liittle bit off piston edge, what you think?


and how much is normal to shave off oil pump shaft?
1..2 mm ?


that's all for this moment..

[abit]

Of course, first test assembly, then measuring :D

bolted in one piston, aand it's not below deck, but above, fail...
later done some measurements and that actually should be like that :D
45 + 135 + 27.8 = 207.8 (if we believe that m20 block deck height is 206.7 or 206.2?)
means about 1.1 or 1.6mm over deck, in reality something closer to 2mm's, of course that's not precise measuring, but for test fitting, it's ok :D


so there is two alternatives:
1. shave off material from piston
2. 130mm rods

as we know these are one of thinnest 84mm pistons, so there in not much material from top compression ring to piston head..
what could be the smallest distance piston to top? so it won't overheat top rings and piston won't crack details out :/
i believe 1mm off, could be enough for me
if now its something about 5mm, what I think already is really low


I don't tried second (130mm rods) thought but i believe that its not actually possible because of crank counterweights could hit piston skirts and m20 rods maybe won't rotate in block

aaand so big stroke and short rod on 84mm bore could be not best idea, right?


some comparison
m54b25 m52b28 late m20b25

[abit]

dayumn, almost forgot, every years acceleration video :D
this time pretty crappy quality..
compare to last year, just lil bit different exhaust, adjusted cam(in both thank's for advices goes to Digger ), and different differential ratio

[abit]

So before the end of the year? ;) I want to see burnouts with all the extra torque! Any plans outside of the motor?

that's impossibruu :D I believe first start could be about @ february.

many things should be fabricated, made to fit etc.

also thinking about 240mm clutch, using m30 disc and m57 pressure plate, but that assembly is thicker than m20 assembly, needs ''longer'' throw bearing, don't know, maybe from e21 or smthng?

also some while ago I thought about m3 fenders and bumpers (fiberglass), but then there is problems with MOT, will see..will see :)

[mila325]

Yes Sir!
for sure, errm, now block is disassembled, I hope tomorrow I get crankshaft and then some measuring, machining, aand putting together, as fast as possible, as always :D

So before the end of the year? ;) I want to see burnouts with all the extra torque! Any plans outside of the motor?

[abit]

So going for a cheap 3 litre stroker? Let me know how it goes! Any idea on how long until done? :D

Yes Sir!
for sure, errm, now block is disassembled, I hope tomorrow I get crankshaft and then some measuring, machining, aand putting together, as fast as possible, as always :D