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

[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..

[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]

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]

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.

[zwill23]

One of my favorite threads for sure.

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

[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..

[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

[digger]

gonna run thr 1.75mm gasket?

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

[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

[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

[digger]

looking good.

for the bolts torque to angle changes with length so if the bolts are shorter length then you cant torque the same amount. are OE bolts from m57 too long or too short?


what crank scraper is that? ishihara johnson?

yeah makes sure you get it tuned nicely i think it will be very sensitive to knock (high CR and different dome). what ECU do you have looks like you are running a MAF?

[abit]

looking good.

for the bolts torque to angle changes with length so if the bolts are shorter length then you cant torque the same amount. are OE bolts from m57 too long or too short?


what crank scraper is that? ishihara johnson?

yeah makes sure you get it tuned nicely i think it will be very sensitive to knock (high CR and different dome). what ECU do you have looks like you are running a MAF?

thanks.

mm, yes, you are right, I actually didn't thought about that.
OE M57 is M10X86, mines M10x100, that means max torque to these bolts should be bit less, right?

really don't know, bought it used from forum.

yup, guy who tunes my car knows what to do with these bosch managements. his car has m50bxx twin turbo with the same m50 nv management(of course there is some modifications done in ecu, but still) and makes about 800hp, already few seasons driving with this setup, only now changed management to Russians Abit aka Corvet ecu.

As it was before, I use complete m50 non-vanos management.

[abit]

and some not so good news

[digger]

with the different gear and damper it looks like it needed longer bolts to get the proper thread engagement? after you fix the threads with helicoil or similar i would just torque it upto a torque value Nm appropriate for a M10 rather than a torque angle

yeah i forgot you had M50 management

[abit]

oh.. this is an head bolt, not from damper :(
dont know why this happened. seems like that was that sound I heard after second start up. this happened when engine was already turned off, just standing. all head bolts torqued to 90nm last stage, these are 12.9 hex bolts. i know many others who torque them to theese nm, so, again, problems...