3.1L, 85.5mm Bore, 9.0:1 Compression, Short Block (S52)

3.1L, 85.5mm Bore, 9.0:1 Compression, Short Block (S52)


Thayer Motorsports is proud to announce the start of our BMW performance short block program.

No longer will it be necessary to wait 6-12 weeks for your bottom end build!  Buy on Monday, drive on Friday!

With a no-compromise mentality, we are bringing the best to the market.



Effective Displacement 3.1L (.514L x 6)
Compression Ratio 9.0:1
Bore 85.5mm
Stroke 89.6mm



Block M52, Tanked, Decked, Bored, Honed
Crank S52, 89.6mm Stroke
Main Bearings BMW OEM
Main Fasteners ARP
Pistons Thayer Motorsports by Wiseco, 85.5mm Bore, 9:0:1 Compression
Wrist Pins Wiseco Upgraded
Connecting Rods K1 135mm BMW
Rod Bearings BMW OEM
Rod Bolts ARP



In order to keep our short block program flourishing, it's important for us to collect cores.  While we do have an option below for a no-core return, it should be only used in cases where an appropriate core cannot be found.

We have three core options to serve each need:

Option #1 - Provide Core Before Purchasing

Provide a core M52 short block assembly before purchasing.  Purchase price does not include any core charge but will not be delivered until a suitable core is received.

Option #2 - Provide Core After Purchasing

Provide a core M52 short block assembly and S52 crankshaft after purchasing.  This option includes a $1,000.00 refundable core charge.

Option #3 - No Core Provided

No M52 short block assembly and S52 crankshaft provided as a core.  This option will incur a $1,500.00 additional charge.  Finding cores is not only expensive but time consuming.  Please consider providing a core instead.

All cores subject to inspection for suitability.  Please contact us if additional detail is necessary.


Shipping / Pickup

Prices listed are not inclusive of shipping charges.  Customers will be contacted after placing an order with shipping charges.  Pickup is also available in the Richmond, VA area.  Please contact us with any questions or detail requests.

$ 4,199.99