M5/M6 Engines

S38 B35 (3453cc) E24 and E28 M5/M6 U.S. and Euro Models, M88

S38 B36 (3535cc) E34 M5

Stock Rebuilds

The high quality parts and rebuilding techniques we offer in our performance engines are applied in our stock rebuilds. All parts are meticulously cleaned and inspected, the block is bored and precision honed with a torque plate for complete cylinder roundness, and pistons, bearings, oil pump, seals, etc. are replaced with OE parts. A careful hand assembly and blueprinting gives you an engine we expect to outlast the original, and at a substantial savings over a factory exchange engine. Since valve guides on the S38 engines can not be replaced, valves with oversized stems must be used in cases where wear exceeds factory specifications. These are not included in our rebuild pricing since we must inspect the old valves at teardown. 

Stock Rebuild P/N 1100M560

Korman Stage 1 Rebuild

In addition to the parts included in our Stock Rebuild, our Stage 1 Rebuild adds our offset exhaust cam gear and a performance computer chip. The cylinder head is ported to Stage 1 specifications, including unshrouding of the intake and exhaust valves. Connecting rods are precisely balanced. This combination yields the following results: P/N 1101M560

Suggested Options:

• Exhaust header thermal barrier coating

Korman Stage 2 Rebuild

This engine pulls hard to redline, yet is well behaved for daily driving. Special parts include a Schrick 272º cam, offset exhaust cam gear, BMW Motorsport performance valve springs, titanium valve spring retainers, and BIG intake and exhaust valves. The cylinder head is ported to Stage 2 specifications and valve bowls are enlarged to take full advantage of the larger valves. The valves are also unshrouded, further improving flow. Connecting rods are both lightened and balanced, and we apply our oiling system modifications for additional high RPM durability. 

P/N 1102M560

Suggested Options

• Exhaust header thermal barrier coating

• Light Weight Competition Connecting Rods

• Light Weight Piston Pins

• Big Bore Throttle Bodies

Stroker Engines

These special engines are based on a BMW Motorsport crankshaft yielding a displacement of 3.8 liters. This conversion can be applied to any of our S38 rebuilds. All necessary hardware is supplied including our competition connecting rods.

S38 Stroker Kit (add to engine rebuild) P/N 1100M538

example: S38 B36 Stage 2 Rebuild, 3.8 liter 385hp, 343lb/ft torque

Korman "Engine Plus" Program-M Engines

From our many years of experience building BMW engines we offer our "Engine Plus" program. Our quoted engine prices represent much more than just the essential internal parts that other businesses quote. We also include the external parts which are usually in need of replacement.  Typically, these tune-up and maintenance parts represent over $700.00 of our package prices. All of our rebuilds include these NEW parts where applicable.

 In the event that you have just replaced one or more of the above items which are included in your rebuild and prefer to re-use the part, it will be deducted from your invoice.

In engines subject to extreme wear it may be necessary to replace some of the following additional parts. The cost of these parts is not included in our engine quotations unless specifically noted.

• Valves, valve springs, locks, eccentrics

• Camshaft and crankshaft gears

• Fuel injection components

• Piston pin bushings

•  Flywheel pulley

• Distributor (included on many high performance rebuilds)

• Throttle linkage

• Water Hoses, heater hoses, fuel lines, vacuum lines

Our goal is to provide you with an engine that will offer many miles of driving pleasure with no unexpected surprises.

S38  Valve Cover and Plenum Set

BMW initially offered the Evolution M3's with a valve cover and plenum painted white with Motorsport stripes.  These were manufactured by various vendors for BMW, all with one recurring flaw, they turned yellow with heat and age.  They were also sold separately for a short time by BMW but at a high price, since you were purchasing both a new valve cover and plenum PLUS the special paint job.

Modeled after the M3 S14 valve cover and plenum sets, we are now able to offer our own special paint service to M5 and M6 customers without requiring the purchase of new parts. Your valve cover and plenum are chemically stripped, cleaned, and glass peened to remove all traces of old paint.  A special high temperature, self-etching, self-leveling epoxy primer is applied, followed by high temperature epoxy color coats.  As a final step, a  high temp non-yellowing clear coat is applied.   Please note that each casting is unique and some have more pitting and flaws than others.  These casting flaws may not be completely hidden by the painting process, just like the originals.  These are special order parts, full payment is required at time of order, no refunds or exchanges.  If you are sending your valve cover to us, ask your salesperson for an estimated time of completion.  We have had these in service for over 7 years with no yellowing, fading, cracking or peeling.

P/N  99MSPTVCS38, core P/N 99MS38VCORE

Korman Stage 1 Performance Kit

These kits offer the best horsepower per dollar increase available for your M5 or M6. Kits include performance computer chip, offset exhaust cam gear and camshaft lock plate.

Performance Computer Chips

As used in our Stage 1 Performance Kit above.

Offset Exhaust Cam Gear

Retards cam timing for a noticeable increase in torque from 2000-4000 RPM. Can be used alone but is most effective when combined with our performance computer chip.

B35 (>88 M5, M6) P/N 11311312M28

B36 (E34 M5 '91>) P/N 11311312S38

Lock Plate for exhaust cam gear P/N 11311305070

Schrick Camshafts

Unsurpassed power for your big M engine.  Euro engine requires machining of cam carrier for lobe clearance.  All engines may require adjustments to valve stem length or lash caps to achieve proper adjusting range.  May be installed singly or in pairs.  When installed singly, use the 272 as an intake on the M88 and S38 B35 engines, 280 as an intake on the B36.  

P/N 1131M056272-272º duration, 11.0 mm lift

P/N 1131M056280-280º duration, 11.0mm lift

BMW Motorsport Valve Springs

Increased pressure for high performance applications. Enables the engine to rev higher without the fear of valve float. Springs are sold in pairs and include 1 inner and 1 outer spring.

P/N 11341312702

Titanium Valve Spring Retainers

Half the weight and twice as strong as stock steel retainers. Allows quicker revs, higher RPM's. Weight is 12.5 grams each.

P/N 11342016

Lightweight Piston Pins

Similar to those used in our racing pistons. Nice addition to any engine job. Ten to twenty percent lighter than stock pins, suitable for full race or street applications.

All M5 and M6 P/N 1125K712103

Korman Modified Connecting Rods

Lightened, balanced, peened, sized, rebushed, and alignment checked. About 8% lighter than stock rods. Shipped complete with new rod bolts and nuts. Sold on an exchange basis.

S38 All (each) P/N LAB11241205

Korman Lightweight Competition Connecting Rods

Designed for full race use, equally suitable for the street. Super strong and light alloy composition reduces the rotating mass of your engine, reduces stress forces at high RPM. Can be ordered in stock sizes or custom lengths for special applications.

M30 6 Cyl. (550 grams) P/N 11241500

Engine Oiling System Modifications

Increases oil pressure to the engine's bottom end, provides more even flow and pressure to rod bearings. Controls oil flow to cylinder head, reducing oil pooling during high rpm operation. Kit includes special main bearings and charges for modifying your crankshaft.

P/N 114115M6

Ignition Wires

OEM style wire set complete with loom and coil cap.

E24, E28 M5/M6 P/N 12121307171

Bosch Ignition Components       

• Distributor Cap12111725070                 
• Rotor P/N 12111734110
• Street Spark Plug P/N X5DC (all except E34 M5),  P/N Y6DC (E34 M5) 
• Track Spark Plug XR4CS (all except E34 M5)

Heavy Duty Alternator Bushings

These heavy duty polyurethane bushings replace your stock rubber units. The stock rubber bushings collapse over time causing misalignment of the alternator, resulting in a thrown belt. Look and see if your alternator is crooked, then use these improved bushings for a long term solution.

Long Bushings (4 required) P/N 12311268433

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