BMW M88/3 3.5-Liter Inline-Six Engine Long Block & Parts Collection

Euro BMW M635CSi | Assembled Long Block + Extensive Spares

This collection of BMW M88/3 3.5-liter inline-six engine components originates from two mid-1980s Euro-spec BMW M635CSi donor cars acquired by the seller between 2001 and 2003. Included is an assembled long block mounted on an engine stand along with a substantial assortment of original and spare components from both engines.

The M88/3 is the high-performance European variant of BMW’s legendary M88/S38 family, featuring individual throttle bodies and motorsport-derived engineering.

Assembled Long Block Details

The assembled long block was completed in September 2003 by Carlquist Competition Engines of Watertown, Connecticut.

Block & Rotating Assembly

• Engine type: BMW M88/3 inline-six

• Displacement: 3.5 liters

• Cast-iron engine block

• Factory bore and stroke retained

• Original BMW crankshaft

• Original connecting rods and pistons

• Replacement piston rings installed

• Frank Fahey Motorsports front crank hub fitted

Cylinder Head & Valvetrain

• Factory BMW camshafts

• Replacement dual valve springs

• Replacement bucket lifters

The seller notes that the rotating assembly was periodically turned during storage.

Donor Engine Background

Engine 1 – Connecticut M635CSi

• Vehicle was wrecked; engine sustained damage

• Damage noted to crank snout, block, and tubular headers

• Pistons, rods, and pins from this engine were used in the assembled long block

• Included components from this engine:

  • Single tubular header

  • Airbox with damaged intake

Engine 2 – Arizona M635CSi

• Vehicle crash reportedly did not impact the engine

• Engine purchased disassembled circa 2002

• Crankshaft shipped installed in the block

• Pistons, rods, and pins shipped separately

• Supplied numerous new and spare components

The assembled long block combines:

• Block, crankshaft, and oil pan from the Arizona engine

• Cylinder head, pistons, and rods from the Connecticut engine

Carlquist Competition Engines selected compatible components from both donor engines during assembly.

Included Spare Parts & Components

• Two-piece Euro “bundle of snakes” tubular headers

  • Cuts and welds present after the collector

• Additional header section

• Airbox with damaged intake

• Oil pan

• Gaskets

• Dual valve springs

• Various ancillary engine components

• Miscellaneous original and new parts accumulated with both engines

Condition Notes

• Long block assembled in 2003 and stored since

• Rotating assembly periodically turned during storage

• Headers show prior modifications

• Airbox intake damage present

• Parts offered as a collection

Highlights

• Genuine Euro M88/3 engine components

• Professionally assembled long block

• Combination of two M635CSi donor engines

• Frank Fahey Motorsports crank hub

• Extensive spare parts inventory

• Ideal for restoration or motorsport projects

Ideal Applications

• Euro BMW M635CSi restoration

• BMW M88/3 / S38-based performance builds

• Period-correct BMW M powertrain projects

• Engine rebuild core with extensive spares

This BMW M88/3 engine long block and parts collection offers a rare opportunity to acquire a professionally assembled core alongside a deep inventory of original and spare components from two period-correct Euro M635CSi donor cars.