M3 Engines - S14

M3 ’88-’91 - 4 Cyl DOHC Engines
Engine SeriesHorsepowerPriceCore Deposit
2400 Sport Engine210 HP$9,495Own Core
2500 Rally Engine255 HP$11,495Own Core
2500 Race Engine285 HP$13,995Own Core
2500 FI Engine 300-400 HP$12,495Own Core

Price Page Booklet
M3 Engine Booklet
M3 Engine Spec Chart

2400 Sport Engine   The factory S14 engine has a life expectancy of about 145,000 miles before they go into high oil consumption due to blow-by.This engine offer’s the M Power owner a decent performance increase, extended Engine life, no lose in fuel economy, at a reasonable price. It’s a great upgrade over a stock M engine. The following is a list of mechanical changes made to this engine;

  1. Increased displacement for more torque by;
    1. Stock 84 mm forged Chrome Moly steel crankshaft.
    2. 95 mm forged alusil 11.0:1CR pistons with vented skirts.
  2. Increased head flo with 29.5mm intake ports with surface turbulence valves to reduce detonation and increase fuel economy.
  3. Manganese bronze valve guides.
  4. Improved outer valve springs.
  5. New S50 chain tensioner, upper and lower tensioner rails, and plastic guide rail.
  6. New timing and oil pump chains.
  7. MM blueprinted oil pump.
  8. Options commonly purchased with this engine;
    1. EVO intake gasket.
    2. Ported intake manifold (customer’s manifold).
    3. 228 mm light weight flywheel and clutch assembly.
    4. MM EPROM chip.

2500 Rally Engine   One complaint I hear from M3 owners is that they wish the engine had better low-end “grunt”. Our 2500 Rally Engine delivers exactly this; more low-end torque by increasing displacement and compression! Machined larger intake ports (5m larger) make for big flow gains that transfer into higher cylinder filling. A hotter intake cam adds more excitement to the top end running. Currently, this is by far the most popular S14 engine we build. It makes 255 hp and 210 ft/lbs of torque (flywheel). It produces within 85% of its full torque from 3500rpm to 7700rpm. That a torque curve about as flat as Kansas!  We build a lot of these engines for  M3 owners who just want a hot street or track car.  If you’re a 2002 owner who wants the ultimate fast ride, this engine conversion can be your ticket. It’s very fast but also very expensive.
Here is a list of the changes made to the 2500 Rally.

  1. Increase displacement to 2414cc for more torque (94mm bore with 87mm stroke).
    1.  87 mm EVO forged Chrome Moly steel crankshaft.
    2.  95 mm forged alusil 11.5:1 CR pistons with vented skirts.
  2. Increased head flow with 31 mm intake ports with surface turbulence valves to reduce detonation and increase fuel economy.
  3. Manganese bronze valve guides.
  4. Improved outer valve springs.
  5. Hotter Rally intake cam.
  6. Premium light weight (200 gram lighter then stock) 4340 Chrome Moly forged “H” beam rods.
  7. S50 chain tensioner, upper and lower tensioner rails, and plastic guide rail.
  8. New timing and oil pump chains.
  9. MM blueprinted oil pump.
  10. Options commonly purchased with this engine:
    1. EVO intake gaskets.
    2. Ported intake manifold (customer’s manifold).
    3. 228 light weight flywheel and clutch assembly.
    4. MM EPROM chip.

2500 Race Engine   In a stock S14 engine the cam lobes run on a 33 mm shim pad located in a pocket on top of the lifter bucket. When the valve adjustment shim sits over the lifter bucket, this is referred to as a “shim over” adjustment. During runs over 8000 rpm the ” shim over” system starts to become a problem.

  1. These shim pads add a substantial amount of weight to the valve train.
  2. The diameter of the pad limits the cam lobe size both in lift and width.
  3. Under high RPM, with higher lift cams, the lobe can kick the shim out of the lifter bucket and cause serious engine damage.

The solution to this problem is to go to a “shim under” system. The stock heavy lifter bucket and shim is replaced with a light weight 37.5 mm cup lifter bucket that uses a valve lash cap for valve adjustment. This also provides a larger surface for a bigger cam lobe to run on and because the lash cap shim is captured under the bucket it can’t be kicked out. This all sounds great till you have to remove the cams and lifter buckets to adjust the lash caps. This is a real pain in the ass! When build a race engine with a “shim under” system it’s very difficult and time consuming to set up. It’s a double pain in the butt!! Due to the limited life of a 8000 + rpm race engine the valves will never need to be adjusted if done correctly. This is a great system for racer’s only. If your reading this and your intended use is street, autocross, or driver schools, sick with the stock “shim over” adjustment method. Our 2500 Race engine uses hotter race cams on both the intake and exhaust — designed to work with a “shim under” system. Race 13.0 compression pistons supported by larger piston pins and stronger “H” beam rods (then in a Rally engine). With all these “goodies” in the engine you’re probably wondering how It runs? Well, it’s pull is amazingly in the low to mid rpm range. Then the rush, at 5500rpm it comes on the cam timing hard and pulls like crazy to it’s 8400 rpm redline! Other then the above, the mechanical upgrades are the same as those found in the 2500 Rally engine.

Additional option: Steel Race oil pan with improved baffling.

2500 Forced Induction Engine   Specifically designed for boost. The internals of this engine (pistons, pins, rods, and rod bearings) are all engineered much stronger to take higher cylinder pressures. If you are a “boost junkie” who likes scary fast this is your fix!

  1. 87 mm forged Chrome Moly steel crankshaft for more torque.
  2. Stronger 144.75mm “H” Beam rods have 4 oil squirter grooves located at the big end to cool off the piston and lubricate the piston skirt.
  3. Special coated tri-metal rod bearings.
  4. Special 94mm Forced Induction Forged Pistons.
    1. Lower 8.6:1 CR with a slightly “dished design” for boosting
    2. No valve pockets to burn away.
    3. Piston Crown is 2mm thicker and it has a ceramic thermal barrier allowing it to take temperatures up to 1350 ° F continuously without failure.
    4. High Silicon Content Alloy (13%) for tighter cylinder wall clearance, greater ring and groove life, & to minimize skirt scuffing.
    5. Piston slit just under the oil ring to lower piston expansion.
    6. Lower placement of the top ring groove to protect the ring from combustion.
    7. 4mm Oil Ring for excellent oil control.
    8. Option: for higher boost levels (16 lbs. or more) we use hard anodized pistons
  5. Increased head flow with 31 mm intake ports with surface turbulence valves to reduce detonation and increase fuel economy.
  6. Manganese bronze valve guides.
  7. Improved outer valve springs.
  8. S50 chain tensioner, upper and lower tensioner rails, and plastic guide rail.
  9. New timing and oil pump chains.
  10. MM Blue Printed Oil Pump – delivers 20% more flow.
  11. Options: commonly purchased with this engine:
    1. Ported intake manifold (customer’s manifold).
    2. 240mm Lightened Flywheel and HiTorque Clutch Assembly