New M3 Owner - Engine specs, details....

[m3f_rlearp]

I just purchased a 1998 (US Spec) M3 Coupe. First impressions are a fantastic car - well balanced. Not an incredible amount of power, but pretty decent, with good brakes and very nice handling. I like it, look forward to using it on the track.



I was wondering if anyone could point me somewhere with detailed engine specs on the 3.2L six. I'm looking for specific info such as:



-Internal make up, that is, forged pistons or not? Forged crank?

-Cam specs, lift and duration

-Combustion chamber size

-Flow numbers on the stock head, intake and exhaust

-Flow numbers on ported heads, or what might be possible



Thanks,

[m3f_Cleveland]

GO here:



http://www.eurospeed.org/e36m3faq.pdf





It will answer most of your questions.





More detailed engine questions are available, I'm not sure if it is all in one spot. Are you going to try to mod your engine with "natually aspirated" upgrades. Gains will not be anywhere near what you can expect from a supercharger or turbo. And also, will cost you more money per hp gained. A LOT more.

[m3f_rlearp]

Checked the FAQ, but not much detail that I am interetsed in.

[m3f_Cleveland]

Maybe this can help you.



http://www.parts4sale.com/bmw/E36/Engine/

[m3f_rlearp]

A little better info, but I'm still looking for more. My intentions are to be NA since SCCA doesn't allow any forced induction. In fact, you can do little beyond cleanup and blueprinting of the engine.

[m3f_Ty Vil_fe6451789c]

i smell euro motor.

[m3f_SG_M3_d1201712b5]

cast pistons. 3.0 had a cast crank, 3.2 has a forged crank.

Intake: 10.2mm lift, 252 duration

Exhaust: 10.2mm lift, 244 duration



I don't know any cfm numbers for the head. Head work really isn't worth it on a street driven car.

[m3f_Cleveland]

Valuable info compiled over the years on BMW's:



http://www.bmw-m.net/techdata/98m3.htm



1996-99 BMW E36 M3

Crank is Forged

Rods are Forged

Pistons are Cast

Block is Cast Iron

Head is Aluminum

Intake is Molded Plastic

Exhaust Manifold is Stainless Steel

Valves for S52us e36M3 are Intake (30mm) and exhaust (27mm).

Cats - (dual)

Resonators - (dual)









Schrick Intake Flowbench Results



http://www.turnermotorsport.com/image/Intake_Exhaust/intake_schrick_manifold_lg.jpg





Today I flowtested a Schrick intake that belongs to Garrick Louie. Just like the M50 and M52 intakes that I tested, the unused runners were blocked off, and the measurements were taken at 28" of water on the 300cfm scale of the flowbench.



cyl.........%.........cfm



..1.........81.........243



..2.........80.........240



..3.........83.........249



..4.........82.........246



..5.........81.........243



..6.........81.........243





Observations:



A) The runner to runner balance is excellent. B) The outlets of the runners (where they mate to the cylinder head) have been CNC'd to the same dimensions as the M50 intake (55mm x 25mm). The actual runners are slightly larger than these dimensions though. C) The surface texture inside the runners is VERY rough (the factory plastic intakes are worlds better). D) The plenum is about the same size as the M52 intake (ie, smaller than an M50 intake). E) The Schrick intake flows between the M50 and M52, yet its port cross-sectional area is about the same as an M50 intake.



Comparison to M52 intake:



The Schrick has larger runners than the M52 intake, and more flow. I calculate the M52's port velocity to be roughly (and this is a VERY rough calculation, just for comparison's sake) 288 ft/sec, whereas the Schrick's port velocity is less than 273 ft/sec. The lower port velocity of the Schrick would explain the loss of low-mid range torque versus the M52 intake, and the higher port volume and flow would explain the slight horsepower gains with it. If the plenum where larger, maybe it would pick up more power up top.



Comparison to M50 intake:



The Schrick's runners have the same outlet size as the M50's intake, but the M50 intake has about 40cfm more flow per runner. The M50's port velocity would be at about 315 ft/sec, much higher than the Schrick's. So the Schrick has less flow, less port velocity, a smaller plenum, and *slightly* larger runners than an M50 intake. (Gee, I wonder why it's said that the Schrick is worthless on an M50 engine?)









M50 vs. M52 Intake Manifold



http://www.bmw-m.net/TechData/images/Intake_Plenum_Comparo.jpg

M52 left and M50 right plenum size

comparison. Notice how much larger the M50 is.







http://www.bmw-m.net/TechData/images/Intake_Port_Comparo.jpg

M52 left and M50 right port opening size comparison. The max. dimensions for the M52 is

45mm x 23mm. The M50 is

55mm x 25mm.



I put the M52 intake manifold on the flowbench today. Below are the results and the previous numbers I got from an M50 intake. All measurements were made on the 300cfm scale and at 28" of water. The unused runners were blocked off, so the numbers represent the flow from the throttle body opening to the port face.

..............M50..........M52

cyl 1.....284cfm.....188cfm

cyl 2.....276cfm.....191cfm

cyl 3.....288cfm.....201cfm

cyl 4.....288cfm.....195cfm

cyl 5.....276cfm.....194cfm

cyl 6.....284cfm.....191cfm













Schrick Camshafts - E36 M3





http://www.turnermotorsport.com/image/engine/engine_cams_lg.jpg



High performance Schrick camshafts for E36 M3



Specifications:



Intake - 284° Duration, 11.9mm lift



Exhaust - 284° Duration, 11.9mm lift







As stated the stock E36 M3 camshaft specs are:



Specifications:



Intake - 252° Duration, 10.2mm lift



Exhaust - 244° Duration, 10.2mm lift



One of the easiest and most cost effective ways to get more horsepower and instant throttle response from a M3 is aftermarket cams. Schrick is hands down, the best performance camshaft manufacturer for BMW. These fit both 95 and 96-2000 M engines. Additional parts may be required.



Power gains are subject to speculation when you add more than one at a time. :hmm:

[m3f_Sirius_880bd69485]

Nice write up. Never knew there was such a difference between the M50 and M52 intakes.

[m3f_rlearp]

Good info and especially with the cam specs. Stock cams are definitely short of duration for what I'd typically see or for that matter, what I build, into some of the engines I've done in the past.



That is some nice info on the intakes too as I'm new to BMW. Therefore, this tutorial makes a lot of sense and helps me with what the different numbered intakes are. The Schrick piece wouldn't seem to make a lot of sense as the M50 intake is quite strong and balance in quite good too.



Anyone mess around with re-working the heads? That is, larger valves if you can go up and port work as well. Interesting use of cast pistons where forged rods and crank are used, I imagine the folks who run blowers or turbos will swap them out for forged slugs and a lower compression ratio though, so maybe no big deal of the cast bits hold up for NA use.