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E24 and E28 U.S. M5/M6 (S38B35), Euro  M5 (M88), E34 M5 (S38B36 and B38)

 

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

Engine

Stock HP

Stock Torque (LB/FT)

Stage 1 HP

Stage 1 Torque

S38 3.5

254

239

295

301

S38 3.6

310

260

340

306

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 272 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. 

Engine

Stock HP

Stock Torque (LB/FT)

Stage 2 HP

Stage 2 Torque

S38 3.5

254

239

365

322

S38 3.6

310

260

373

331

Standard Valve Size-All S38

Intake

Exhaust

37mm

32mm

BIG Valve Size-All S38

38.5mm

32.5mm

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

 

Standard 84/86mm crankshaft left, radiused and hollowed counterweights of the 3.8L 90 mm stroke crank, right

 

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.

  •  Pistons, rings, pins and clips   

  • Rocker Shafts Oil pump

  • Oil pump chain

  • Water pump

  • Thermostat

  • Freeze Plugs

  • Ignition wire set

  • Oil Filter

  • Fuel Filter

  • Distributor cap and rotor

  •  Points, condenser

  • Alternator V-Belt

  • Main Bearings

  • Rod Bearings

  •  Timing Chain or Belt

  • Slide Rail

  • Tension Rail

  • Upper and lower gasket sets

  •  Spark plugs

 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.

Engine

Stock HP

Stock Torque (LB/FT)

Stage 1 HP

Stage 1 Torque

P/N

S38 3.5

254

239

295

301

11124755

S38 3.6

310

260

340

306

11124756

 

Performance Computer Chips

As used in our Stage 1 Performance Kit above.

 

 

Application

ECU#

P/N

M5/M6 Euro 84-88

0.261.200.055

124M88150

M5/M6 US 87-88

0.261.200.079

124M88100

M5 91> US

0.261.200.350

124M88200

 

 

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 1131M056272-272 duration, 11.0 mm lift

P/N 1131M056280-280 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

 

Roadsport Suspension Systems

Our Roadsport Suspension Systems are available for cars which came equipped with the load leveling rear suspension. These kits offer improved handling through the use of shorter, stronger springs and larger, adjustable anti-sway bars. Ride is firm and controlled, but still suitable for daily use. These kits come complete with the necessary hardware kit for keeping your load leveling connected.

Korman Roadsport Suspension Systems

BMW

Type

Shocks F&R

Front Anti-Sway Bar

Rear Anti-Sway Bar

Lowering Front/Rear

Kit P/N

E34 M5

Maintain Load Leveling

N/A

26mm

19mm

1.0"/1.0"

3110M51

 

 

Clubsport Suspension Systems

Our Clubsport Suspension Systems offer greatly improved handling with a very firm, controlled ride. Bilstein Sport Shocks, more aggressive spring rates and stronger anti-sway bars give you complete control in any situation. For cars equipped with load leveling, we include the necessary components which allow you to use conventional rear shocks. Additional weight savings can be realized by removing the oil pump, reservoir and other unneeded load leveling components.

Korman Clubsport Suspension Systems

BMW

Type

Shocks F&R

Front Anti-Sway Bar

Rear Anti-Sway Bar

Lowering Front/Rear

Kit P/N

E28 M5

without load leveling

Bilstein Sport

25mm

18mm 

1.25"/1.25"

3110M561

E28 M5 with load leveling

Delete Load Leveling

Bilstein Sport

25mm 

18mm 

1.25"/1.25"

3110M563

E24 M6

without load leveling

Bilstein Sport

25mm 

18mm

1.25"/1.25"

3110M561

E24 M6 with load leveling

Delete Load Leveling

Bilstein Sport

25mm 

18mm

1.25"/1.25"

3110M563

E34 M5

Delete Load Leveling

Bilstein Sport

26mm

19mm

1.3"/.75"

3110M52

Stock Sway Bar Sizes

BMW

front

rear

E24 M6

21mm

16mm

E28 M5

25mm

18mm

E34 M5

25mm

18mm

 

Competition Adjustable Anti-Sway Bar End Links

Allows for custom tuning of anti-sway bar pre-load to suit specific track layouts and to facilitate corner weight adjustments. Light weight aluminum threaded centers connect right and left hand threaded joints for quick adjustments. Front links may be used singly or in pairs.

Front Adjustable Link-P/N 3102847

 

Heavy-Duty Thrust Rod Bushings

Front end shimmy and vibration which mimic warped rotors are a common problem with the E28, E24 and E34 chassis cars. The addition of larger wheel and tire packages often accentuates the problem. The most frequent cause we see in our shop are the worn factory thrust rod bushings. These bushings are mounted at the rear of the strut rod, a diagonal link which helps prevent fore and aft wheel movement. Our hard rubber bushings address this problem as well as improving steering feel and turn in. Sold in pairs.

All E24, E28 M5 and M6 P/N 3111567

E34 M5 3112567

Remember to check the condition of the entire front suspension as well as wheel balance/tire roundness and rotor run out/thickness when trying to diagnose a shimmy.

 

Fixed Upper Decamber Plates

A pair of hardened aluminum plates with studs and bolts for easy installation. Increases front negative camber by about 1. Sold in pairs.

E28, E24 M5/M6 P/N 31062056

E34 M5 P/N 31062059

 

Polyurethane Adjustable Camber Plates

Allows easy adjustment from the top of the car.  For use with stock springs.  Harder material improves handling and responsiveness.

P/N 31330030

 

Strut Braces

Strengthens chassis, minimizes strut tower deflection. Polished aluminum finish.

E24, E28 M5/M6 FRONT P/N 3131055

E34 M5 FRONT P/N 3131056

 

Front Upper Support Bearings

Always replace when installing new front springs or shocks. Sold each.

E24, E28 M5/M6 P/N 31331124508

E34 M5 P/N 31331139437

 

Offset Upper Support Bearings

Increases negative camber for improved handling and tire wear. Sold each.

E24, E28 M5/M6 3131143

E34 M5 P/N 31331139481

 

Offset Rear Trailing Arm Bushings

Used to make very small corrections in rear wheel camber or toe. Sold in pairs.

E24, E28 M5/M6 P/N 332202203

 

Adjustable Rear Polyurethane/Eccentric Bushings

Replaces your rubber bushings with locking eccentric type.  Kit includes a set of (4) bushings allowing adjustment of both camber and toe. 

P/N  332202205

 

Rear Subframe Camber/Toe Assembly

Our eccentrics allow adjustment of rear wheel camber and toe in just a matter of minutes. Enables the restoration of factory specified alignment settings, and are adjustable for racing settings. Sold on an exchange basis.

E24/E28 M5/M6 P/N 33203567L (camber or toe only, x 2 for both)

 

Big Brake Kits

Korman Kit

Front Rotor Diameter

Front Rotor Thickness

Caliper Type

Notes

P/N

324mm Brake Conversion

324mm

30mm

4 piston Brembo

16" Wheels required

34180112

332mm Brake Conversion

332mm

34mm

4 piston Brembo Aluminum (As used on Ferrari F40)

17" Wheels required, crossdrilled rotors

34180111

345mm Brake Conversion

345mm

32mm

Ate 4 Piston

17" Wheels required, rotors are directionally vented 2-piece with aluminum hats

34180113

Original Rotor Sizes (for reference)

BMW

OE Front Rotor Diameter/Thickness

OE Rear Rotor Diameter/Thickness

E24 M6

300mm/30mm

284mm/10mm

E28 M5

300mm/30mm

284mm/10mm

E34 M5

315mm/283mm

300mm/20mm

 

Korman High Performance Brake Rotors

Available in either a computer controlled crossdrilled version with the holes chamfered to the wear limit, or in a computer controlled gas slotted version with the gas ports milled to the wear limit. Our rotors are then finish plated with cadmium. While nothing beats the appearance of crossdrilled rotors, we suggest using the gas slotted versions for true high performance and track use due to superior wear rates and brake cooling. Please specify crossdrilled or gas slotted when ordering.

BMW

Front Rotor

Rear Rotor

E24 M6

3411D225007

3421D121387

E28 M5

3411D225007

3421D121387

E34 M5

3411D226385

3421D159659

 

Ferodo Performance Brake Pads

Developed as a non-asbestos street alternative. Formulated with metallic fibers and other inorganic substances that yield a high friction level with good resistance to fade and wear. This competition grade compound is completely suitable for normal street use as the friction level is affected very little by temperature.

 

hawk.jpg (2811 bytes)

Hawk High Performance Disc Brake Pads

  • Superior Pad Life

  • High friction coefficient

  • Extremely rotor-friendly

  • Pre-bedded at factory

  • Ferro-Carbon™ friction material evaluated up to and beyond 1800 F.

  • BLUE compound for full race applications*

  • BLACK compound for street and track

*Next best to our Endurance Pads.  Excellent for short races, good brake air ducts required.

 

Korman High Performance Brake Pads

Developed for use in our IMSA E30 M3's. Good enough to win both the drivers and the manufacturers IMSA Sport Class Endurance Championships. This pad material is a non-asbestos graphite/metallic formulation. Unlike some racing materials that work well only when hot, the broad coefficient of friction of these pads also enable them to work well under cool, light braking conditions. They are therefore ideal dual purpose pads for both street and club events.  Not recommended for full race use.

 

Korman Endurance Racing Brake Pads

Developed by BMW Motorsports specifically for endurance racing. Tested and proven on our IMSA Endurance Series M3 CSL and 328's. Nothing else comes close.

BMW

Ferodo

Hawk Blue

Hawk Black

Korman Endurance

Korman Racing

Front

Rear

Front

Rear

Front

Rear

Front

Rear

Front

Rear

E24 M6 & E28 M5

FDB163

FDB296

N/A

N/A

N/A

N/A

KDB056F

KDB056R

N/A

N/A

E34 M5

FDB577

FDB578

HB135BLUE

HB140BLUE

HB135BLK

HB140BLK

KDB007F

KDB003R

KDR028F

KDR028R

Don't forget new brake pad wear sensors!

Stainless Steel/Teflon Brake Lines

Essential for driving schools and highly recommended for all high performance driving. Provides stronger pedal, improved modulation under hard brake usage. Eliminates expansion associated with rubber lines. Kit includes a full set of 6 lines.

E24, E28 M5/M6 P/N 34321056

E34 M5 34321056

 

Super Blue Racing Brake Fluid

A non-silicone high performance dot 4 brake fluid designed for the extreme demands of motor racing, yet perfectly suited for street applications. Sold in 1 liter cans.

P/N SUPERBLUE

 

Super Blue

Dot 4

Dry Boiling Point

536F

414F

Wet Boiling Point

392F

279F

 

 

 

K&N Filterchargers

The K & N Filtercharger is unsurpassed in filtration protection, while maintaining an air flow greater that the OEM paper filter. Constructed of a pleated special cotton fabric with aluminum screen mesh and wide rubber seals, it comes pre-oiled with a one million mile warranty. When dirty, simply clean, re-oil and reinstall. Fits stock air box with no modifications required.

E24, E28 M5/M6 P/N 1372332559

E34 M5 1372332617

 

K&N Accessories

K&N Oil, 8 oz. P/N 13720008

K&N Cleaner, 32 oz. P/N 13720032

 

Big Bore Throttle Bodies

Enlarging the throttle butterflies alone does little to improve intake flow or performance. After installing 48mm butterflies (+2mm), our big bore throttle bodies are enlarged through their entire length. We then port and match the air horn assemblies and intake gaskets for best flow. Most effective when combined with other engine modifications. Sold on an exchange basis.

All M5/M6 P/N 1161048016

 

European Exhaust Headers

For E28 M5/E24 M6. Equal length headers designed and manufactured by BMW Motorsport GmbH. Improved flow offers power increases on any engine, especially effective when combined with other performance modifications.  Factory catalytic converter requires modification for use with this header.  Shown with ceramic coating

P/N 11621307250 (cyl. 1-3), P/N 11621307251 (cyl 4-6)

 

 

Ceramic Thermal Barrier Coating

From Aerospace technology comes this oven baked metallic/ceramic finish that is far superior to ordinary header paints. In salt spray testing where high temperature paints lasted 40-50 hours, the ceramic coating lasted over 5,000 hours. The ceramic thermal barrier finish also coats the inside of the pipe. The thermal barrier will reduce underhood temperatures and testing has shown horsepower gains due to combustion chamber stabilization and increased gas velocity.

All M5 and M6 P/N 182110016

Supersprint Stainless Steel Performance Exhaust-E34 M5

Reduced back pressure offers improved sound and performance. Mounts using existing hardware and mounting points. Low, aggressive tone, dyno tuned for best power.

Front Resonator P/N 18837114634

Rear Muffler P/N 18837196695

Stainless Steel Performance Exhaust-E24, E28 M5/M6

Twin 3" tips, 100% stainless steel construction. Very strong sound, suggested primarily for autocrossing or club events. Somewhat loud for everyday use, but extra power when you need it on the track.

P/N 18840285

 

Korman Adjustable Short Shift Kit

Let's you select the shifter throw that suits your needs

  • Adjusts in minutes from inside your car

  • Accepts original or aftermarket gearshift knobs

  • Assembled unit saves on installation time

  • Adjustment locking mechanism

  • Replaceable, self-lubricating bushings

  • Includes shifter cup bushings and complete instructions

  • Easily installs in less than an hour

E28 M5/M6 >9/85 P/N 25250004

E28 M5/M6 9/85>P/N 25250003

E34 M5 P/N 25250001 

 

Sachs High Performance Clutch Components

We sell only quality SACHS clutch components. Heavy duty pressure plates feature increased clamping force for better performance with high horsepower engines, bigger tires, etc. The heavy duty light weight pressure plates feature the same increase in clamping force but the center plate, normally cast iron, is replaced with lightweight aluminum for even better performance. Heavy Duty Sport Discs feature a performance grade friction surface which is both riveted and bonded for greater strength.

BMW

Heavy Duty Pressure Plate

Heavy Duty Light Weight Pressure Plate

Heavy Duty Disc

Release Bearing

E24, E28 M5/M6

2121147006

2121999510

2121561002

21511208423

 

Sachs OEM Type Clutch Kits

Kits include pressure plate, clutch disc and release bearing.

E24, E28 M5/M6 P/N 21210000007

E34 M5 P/N 21210000008

 

Lightweight Steel Flywheels-E24 and E28 M5/M6

Precision machined and balanced steel flywheel. 35% lighter for reduced inertia and more rapid acceleration. Sold on an exchange basis.

E24, E28 M5/M6 P/N 11220056

Flywheel Bolts-Always replace torque to yield bolts when removing or replacing the flywheel. E24, E28 M5/M6 P/N 11220616142 (ea.)

 

Clutch_Line_2.jpg (42547 bytes)Stainless Steel Braided/Teflon Clutch Hose

Replace your cracked rubber hose with our more durable stainless steel braided unit. Improved clutch feel and modulation when compared to OE rubber line.

P/N 2152115667S

 

Korman Manual Gearbox Rebuild

2 year/24,000 mile warranty

We rebuild your gearbox using only BMW original parts. Includes new bearings, synchronizers, seals, gaskets and labor. Please supply your transmission model number when requesting rebuild information. 

P/N 23231900 Getrag 280 6/86>

P/N 23231901 >6/86

 

Korman Standard Differential Rebuild

2 year/24,000 mile warranty

Differentials with normal wear don't usually require the replacement of the ring and pinion gears. Our standard rebuild includes complete disassembly, through cleaning, close inspection of all parts, replacement of all bearings, seals gaskets, crush sleeve and lock ring. Includes meticulous attention to correct gear lash, gear contact, precise pre-load of bearings and exact torque specifications. We expect our rebuilds to last well over 100,000 miles. Note: UPS can pick up and deliver your differential at your door!

E24, E28 and E34 M5, M6 P/N 33126082

 

 

Optional Ratio Differential Gear Sets

"My first BMW, a 1964 1800 TISA four door sedan regularly beat the performance sport cars of its day in autocrosses: E-Jaguars, Lotus Elans, Corvettes, MG Twin Cams, Porsche Super 90's, and more than a few 911's! Along with very minor engine changes, a good suspension package, wider wheels and tires, and a close ratio gearbox, my most effective "speed secret" was the change to a 4.75 gear set!"

Ray Korman

 

Korman Suggested Differential Gearing

BMW

original gear ratio

suggested ratio

P/N

Euro M5/M6 (early)

3.73

3.91

33125391

E24 M6, U.S.

3.91

n/a

n/a

E28 M5, U.S. 

3.91

n/a

n/a

E34 M5 U.S.

>7/91 3.91

n/a

n/a

7/91> 3.73

3.91

33125391

Call us for recommendations, pricing and more information on upgrading your differential.

 

We recommend Redline Synthetic Lubricants for your BMW's Driveline

 

Items in this category can be found in the respective chassis catalog sections, E24, E28 or E34

 

Korman Autoworks, Inc. 2629 Randleman Rd. Greensboro, NC USA 27406