the perfect m10 build

[joecrotch]

ok guys describe your idea of the perfect power build for the m10 9no swaps) be specific what parts,fi system,pistons head work whatever///lets see who has the best ideas for power!!!!!!

me je pistons .50 over bore motor built to withstand a nuclear blast and turbo the hell out of it maybe a 7.1 litre ford diesel turbo with megasquirt running rc 50 lbs injectors and voodoo custom cam grind to match turbo needs with methenol/water injection to coolturbo charge air and a six speed custom built tranny. and a 50 shot of nos for some icing on the cake.

something like that

[OldGray320i]

How about the mild overbore, 9.5/1 (? we'll see...) 284 cammed motor I'm about to pick up from the machine shop this week?

Some of these other fellas have already done the cool stuff....

[BoomerDJ]

S14 crank
overbore
high comp pistons(maybe 10:1)
ported and poilished head
288-302 cam
dual DCOE 45mm carbs or ITBs
big header
abd prob MSD ignition

haha basicly turn an m10 into s14

mmmmmmm

[kdanielson]

The "perfect" engine build is different for each person and application-it still requires compromises. Having said that I will post my personal "recipe". Though I have done it in the past it continues to evolve.

Short block:
84mm stroke (s14 crank) counter weights coated with oil shedding coating
92mm bore forged flat top pistons set at .000" deck height, skirts coated with dry film lubricant (DFL) and tops with ceramic heat reflective coating.
Bearings coated with DFL
Reworked stock connecting rods coated with oil shedding coating (I would love a set of 5.7" custom H beam rods but the cost outweighs the benefits)
A light weight dampener/pulley with 36-1 tooth wheel attached
Lightened stock flywheel
All reciprocating parts static balanced to within .5 gram and rotating parts dynamically balanced.

Cylinder head:
Milled for combustion chamber volume of 50cc (a compressed head gasket thickness of .035 and zero deck height will give 11-1 compression)
Mildly ported head with DFL on intake valve stems, ceramic on valve heads and combustion chamber
Elgin 284 X 10.47mm valve lift cam coated with DFL (this cam should perform in a 2.2L engine much like my current Elgin 278 does in my 2.0L)
rocker locks
rockers with shaft and bushings coated with DFL
Titanium valve retainers
Valve springs with "just enough" pressure to control the valves with that cam.
Single row timing gears/chain
Distributor hole plugged

Exhaust:
4-2-1 header, 1 5/8" primaries 18" long into 1 3/4" secondaries 20" long, merged collectors used throughout and a venturi on the last one to a 2.5" exhaust using mandrel bends, one Edelbrock RPM oval muffler and exiting through the body behind the passenger seat.

Oil system:
External crank driven single stage oil pump-no stuck relief valves to worry about.
Remote filter
oil thermostat
oil cooler

Intake system:
Fabricated intake with 15" intake runners (plenum to valve head length) not sure on the plenum volume yet
65mm throttle body

Fuel system:
MS efi with EDIS ignition
29lb injectors at 48psi rail pressure
aftermarket external fuel pump
1/2" steel supply lines
3/8" return lines

As you can see there is much more than most people think, an engine is a system and EVERY part must be considered when modifying it.

Compromises with this configuration:
single stage oil pump with wet sump vs. 3 stage oil pump with dry sump
5.315" rods instead of 5.7" rods
Crank is heavier than I would like
Lightened steel flywheel vs aluminum flywheel
These compromises save about $2000 in parts and labor cost but don't reduce power much.

This engine should easily push 200hp and nearly equal torque in the mid range. In a 2200lb e21 it would have 11lb per hp. The e46 M3 6 cyl (333hp) has about 10.5lb per hp and the 3.2L e36 m3 has about 10lb per hp so it would be pretty easy to startle those drivers. A properly set up e21 would be more fun anyway...

These are just my opinions and educated guesses.

ken

[sbcrockett]

Nice Ken!

So the question now is: How much would it cost for you to build it for me?!

You mention the compromises would save a couple grand, but seriously, how expensive are we talking to build something like this?

[myersport]

Could you be more specific??

My engine (currently under construction) is 1.2 overbore w/9.5 CR piano tops, 2.0 Crank, e12 casting head, 288 cam, mild port/polish, +1mm intake and exhaust stainless valves, dual springs, e21 parts.net (RIP) ignition system, ceramic coated header, 2 1/4" stainless exhaust with magnaflow resonator and silencer. All is done except for the head work, I had to source another head, the first ended up being junk.
--dennis

[kdanielson]

Well, for me it would be much less because I can do it all other than the machine work on the block, milling the head and balancing the crank.

I have the ported head, s14 crank, EDIS, MS and can build the header/exhaust and intake.

I haven't really thought about what the total cost would be but I'm sure it would be less than a MM 2.2L

If I get it done and sorted I MAY be persuaded to sell it but I would likely sell the whole car to make way for the next project.

Oh yeah, more specific... I forgot to specify an e21 head casting.

My current engine is similar. Ported head, 278 Elgin cam, Euro domed 2.0L pistons and I've had a couple different headers on it. It ran well with CIS but MUCH better with MS EFI.

BTW, the oil system with the external pump is a REALLY nice to have but not necessary so that would save some $$ too but I REALLY like good oil systems.

ken

[Layne]

Ken, are we talking flat top pistons or some replica of the "D" dome? Have to be custom either way due to the s14 crank. How do you suppose the cost/benefit ratio stacks up against using euro M30 pistons with the e12 head? Those aren't forged of course.

[sully32]

I simply cannot resist. This is the "ultimate" M10 build:

I remember having a distorted sense of pride when Nelson Piquet (Sr.) won the world title in '83 with this thing thinking "gee, I have the same block in my car". HAH. I don't know if this is factual but I either heard or read that BMW obtained the blocks for their racing program from junked cars, attributed to the fact that the blocks were "seasoned".

We now return you to people who have real contributions to this thread

[kdanielson]

Layne,

Aircooled VW type 1 92mm "A" pistons (stock stroke) have the correct compression height to work with the s14 crank and stock m10 rods. The block needs decked slightly to get to zero deck height but not much. They are available as forged flat tops for pretty reasonable $$.

An adjustable cam sprocket will be necessary to correct the cam timing due to the shaved deck and milled head.

ken

[mrbobian]

Seriously though, what would something like that cost... very roughly. I desperatly need a new motor and I am just kinda feeling out prices at the moment.

[Cid]

Seriously though, what would something like that cost... very roughly. I desperatly need a new motor and I am just kinda feeling out prices at the moment.

If ya have to ask... ya probably can't afford it

[good & tight]

2.0 crank
lightened stock rods
91mm flat tops
Stock 1.8 head from a 318i
318i intake manifold, M30 TB
SS valves,double valve springs, 294 regrind cam
ARP head studs, MLS gasket
MS/EDIS 750cc injectors, big bosch FP
Equal length turbo manifold, big intercooler, LARGE Turbo in the T4 range
Solid hub 3 puck disk w/heavy duty PP
Turn the boost up around 25psi shift around 8k and hold on!!!!!!!!!!!!!!!!!!!!!!!!

[mrbobian]

2.0 crank
lightened stock rods
91mm flat tops
Stock 1.8 head from a 318i
318i intake manifold, M30 TB
SS valves,double valve springs, 294 regrind cam
ARP head studs, MLS gasket
MS/EDIS 750cc injectors, big bosch FP
Equal length turbo manifold, big intercooler, LARGE Turbo in the T4 range
Solid hub 3 puck disk w/heavy duty PP
Turn the boost up around 25psi shift around 8k and hold on!!!!!!!!!!!!!!!!!!!!!!!!

Isn't that what you pretty much had in your e30? Then it blew to billions of bits?

[Layne]

Isn't that what you pretty much had in your e30? Then it blew to billions of bits?

If I may idly speculate...With that engine he did everything to make more power, and nothing to create a stronger longer lasting engine. We all know you must have both, or replace them frequently. Forged pistons and H-beam rods should be a necessity in an engine like that. But considering either of those things cost as much as 2 used replacement engines, maybe changing them all the time isn't such a bad idea...

[Jmabarone]

Ken, that engine build sounds similar to what I want to do...cheap, but potent. The build that I am going for is built around engine rules for an SCCA class and to make BMWCCA club racing classing:
Stock crankshaft balanced, blue-printed, and coated...and yes, maybe even knife-edged
Stock rods lightened and balanced
Stock head (e21, 1.8, or 318i, preferably the latter) ported and polished
Pistons may not change initially, only if I can't get the CR I want (10:1), and then bored to 89.2mm (I think).
Top End Performance reground cam, probably close to the 300s, as well as an adjustable sprocket.
Upgraded valvetrain including dual-springs, rocker locks, and new stock rockers (required for my class)
2002 intake manifold mounting a 32/36 Weber (40 DCNF if I'm down on power), and possibly a custom intake if needed.
Top End Performance 1.5" header, coated and taped.
Crank-trigger custom ignition based on Ford EDIS-4.
I won't go into the other stuff in detail, but the water pump would be upgraded, as would the oil pump. I'd add an oil cooler, and a crank scrapper, and probably a set of underdrive pulleys.

Maybe not as thorough as Ken's build, but as I wrote it, it made me think about how much there will be...
Jake

[good & tight]

Isn't that what you pretty much had in your e30? Then it blew to billions of bits?

The Nitrous killed the rods not the boost.

[Layne]

You had ~25 psi boost and felt the need to throw nitrous on top of that!? At least it proves the whopping strength of the good 'ol M10's.

[mrbobian]

Yeah, that is pretty damn amazing accutally. Was that stock internals?