My m10b engine thread

[Jean]

Couple more things to remove and then off to a machine shop for inspection/cleaning and a head / valve job.

coolant temp. sender housing


fuel rail, fpr, injectors


manifold with icv, tb and tps


Can I safely remove this cold start valve and run without it ?


why does this manifold have to be so damn ugly


can't get this 17mm nut on the pulley off


stock bottom end


every bolt/washer is in it's own bag


Doesn't look to bad, once I know for sure it's straight and good I'll start ordering all new gaskets/lines/bearings. Thinking about maybe painting the block once it's clean and doing something with all those aluminum parts, powder coating maybe ?

[2002maniac]

if you are ordering new pistons you might as well have the block bored for more displacement. Boring shouldnt add any more than $200 to your machining bill. Call TEP and tell them you are using a 2.0 Crank and rods with a 318i head (you have them, might as well use them). They can provide you with JE pistons any size or CR.

Should be a fun motor.

[Jean]

Am I not better off leaving the bore alone to not make the block weaker when boosting ?

[peete]

I'm pretty sure the nut on the oil pump gear is reverse thread. But not 100%

[Good & Tight]

Am I not better off leaving the bore alone to not make the block weaker when boosting ?

Hell no, hog that bitch out to 91mm.

[Jean]

Any suggestions on 91mm pistons and matching set of rods ? Is the wall thickness on a 318i block the same as on the 2002 block, I thought someone was cracking a couple of blocks by going wider...i might be wrong though, you are the man when it comes to the m10s :)

[Rocla]

Any suggestions on 91mm pistons and matching set of rods ? Is the wall thickness on a 318i block the same as on the 2002 block, I thought someone was cracking a couple of blocks by going wider...i might be wrong though, you are the man when it comes to the m10s :)

2002 block weights more than e30 block... so most likely wall thickness is bigger, most hardcore m10 builders use early blocks and claim that they are better.

[new2bmw]

early block

ok, I have an 84 318i, its manufacture date is nov, 1983, will it have what would be considered an early m10 block?

[Rocla]

ok, I have an 84 318i, its manufacture date is nov, 1983, will it have what would be considered an early m10 block?

No. E30's never had "early" blocks from factory. And I'm not sure if all e21's had the "heavy" version, all e21's DID have the old pattern motormount, some the latest had even dual pattern for right mount.

[iNetMANN]

ok, I have an 84 318i, its manufacture date is nov, 1983, will it have what would be considered an early m10 block?

No, use 2002 block. I used a late 70's block w/2002 crank and 92mm flat top wiseco pistons. Plenty thick on the old blocks to even go with 93mm...
Rockers/springs are the week point on the M10 at high RPM's so use either aftermarket rockers/springs or arm locks. I can regularly peg my car at 7000+ RPM with stock rocker/springs and the arm locks keep them from falling off the valve stem.

RODD

[Jean]

Just picked it up today, only needed new valve seals, rest was in good condition, total cost $290.




This coolant hose connector is not perfect but looks like this part can be replaced with new.






Cleaned oil pan and manifold.



Next I need to get the TB and injectors cleaned and get the gaskets / head bolts / and injector o-rings. Should I even bother with the bottom end rebuild ?

[Jean]

No updates yet as this was an autocross weekend for me, but a friend and some air tools got the stupid crank bolt pulley out . I was going to drop the bottom end off but was told it would be a good idea to have custom pistons/rods on hand so that the shop can machine the block to the right pistons. I was originally going to drop the block off for cleaning/testing and then would get the rods and pistons (h-beam, je). Once I figure out what compression ratio to shoot for and what pistons / rods I would want to order..


I need to re-think this, and figure out if it's not going to be much more to shoot for about 300-400hp instead of my original goal of 200-250. The custom forged pistons and h-beam rods should be good for more than 200-250 hp safely, and if I spend that much money on them I wouldn't mind getting the most out of it.

Doable or is the head not going to like it ?

[Jean]

Got the oil pump, crank pulley out. Have two options now:

1) take the whole thing to a machine shop to inspect / clean , put new seals, drain plugs, bearings and re-use stock rods and pistons

2) take the bare block only, have it cleaned , new drain plugs, install crank with new bearings and front/back seals, machine / hone block for new pistons (have yet to order), maybe 1 over ?


Here is another question, I was discussing this with my co-worker who is big in drag racing....

the idea of "high bore vs. longer or shorter stroke" , and when one should be picked over another. to my understanding, longer stroke = bigger bang = more torque, also = lower revs with longer stroke compared to short stroke. With FI, I was told I am better off leaving the stroke alone and just going with the next oem size up in bore to keep everything as strong as possible ? Also, to stroke I wouldn't be able to use stock crank, and would need to go with custom crank + pistons and/or rods, basically crank works together with the longer/shorter rods or pistons and is part of the equation. Since I am going FI, I don't see a benefit to going the route of stroking the engine. I am thinking about going maybe 1mm over in bore to gain just a little more CCs.

Does this make sense, any suggestions ?

[HST]

I think that the 2002 crank would give you a longer stroke, and it is forged.

[Jean]

Right, but would it be worth the hassle and is there any benefit to longer stroke with FI ? or am I fine with forged pistons/rods , stock crank, and basically stock bore but maybe 0.5-1mm over ?