M20 Super Sport 2.5L Engine

The BimmerHeads Super Sport M20 2.5L Long Block is our Stage 2 build — a significant step up from stock, built for enthusiasts who want real performance from their M20 without going the stroker route.

Every Super Sport engine comes standard with a hand-ported cylinder head, BimmerHeads performance dual valve springs, and KM Cams forged steel rocker arms — upgrades that set this build apart from our Touring Engine and any standard rebuild.

Every Super Sport engine is run-in and tested on our custom-built engine run stand before it ships — we break in the camshaft, check for oil leaks, and verify quality control using Motul Break-In oil and Mahle oil filters. We never slap something together just to send it out the door.

Choose your camshaft, piston, and timing belt kit configuration above — not sure which combination is right for your build? Contact us and we’re happy to help.

Every Super Sport engine includes a fully rebuilt Super Sport spec 885 cylinder head receiving:

• Cleaning & pressure testing
• Resurfacing
• Porting & polishing by hand
• New Supertech stainless steel black nitride valves
• New Supertech valve guides
• New performance valve seals
• New camshaft o-ring & seal
• New BimmerHeads performance dual valve springs — engineered for high-lift camshaft applications
• New KM Cams forged steel rocker arms with a wider pad for improved camshaft contact — eliminates the failure risk of cast aluminum rockers under performance use
• New rocker arm hardware & eccentrics
• New intake manifold studs
• New thermostat housing studs
• New exhaust manifold studs
• New valve cover studs

Every Super Sport engine bottom end receives:

• Cleaning
• Magnaflux block to check for cracks
• Deck resurfacing
• Cylinder boring & honing
• New Mahle pistons
• New wrist pins & piston rings
• New wrist pin bushings
• New ARP connecting rod bolts
• New ACL Race crankshaft main bearing set
• New ACL Race connecting rod bearing set
• Reconditioned OE BMW crankshaft
• New engine oil pump
• New engine oil pan
• New magnetic oil drain plug
• New oil pressure switch
• New Gates Racing timing belt
• New timing belt tensioner
• New timing belt tensioner spring
• New timing belt tensioner stud
• New intermediate shaft gear
• New water pump
• New freeze plugs
• New engine block coolant drain plug
• Satin black engine block paint
• Ultimate head gasket set
• Bottom end gasket set
• New NGK spark plug set

Camshaft options:

• Regrind 274 — increased lift and duration over stock, ground on a used OE BMW core. Excellent street manners with a noticeable mid-range improvement. Best for stock to mild builds.
• New 274 — same 274 grind on a brand new core. For those who want the performance upgrade without a reground cam.
• Regrind 280/274 — dual pattern — ground on a used OE BMW core with different intake/exhaust duration for stronger pull under boost. The go-to grind for forced induction builds.
• New 280/274 — same dual pattern 280/274 grind on a brand new core. For those who want the 280/274 grind without a reground cam.

Piston & head fastener options:

• Mahle OEM Pistons — OE BMW Head Bolts — Mahle OEM 84.5mm, 8.8:1 compression pistons with factory-spec BMW head bolts. Factory compression, factory fitment — the right call for a strong street build.
• Mahle OEM Pistons — ARP Head Stud Kit — same Mahle OEM 84.5mm, 8.8:1 pistons upgraded with an ARP head stud kit for improved clamping force. The right choice when you want added security on a performance build.
• Mahle Motorsport Pistons — OE BMW Head Bolts — Mahle Motorsport 85mm, 10:1 compression forged pistons with factory-spec BMW head bolts. Built for higher compression, naturally aspirated performance builds.
• Mahle Motorsport Pistons — ARP Head Stud Kit — Mahle Motorsport 85mm, 10:1 forged pistons paired with ARP head studs. The full performance combination for a high-compression, naturally aspirated build.

Timing belt kit options:

• Gates Racing belt (standard) — HNBR elastomeric composite construction, up to 300% stronger than stock. The performance belt we reach for on our own M20 builds — included on every Super Sport engine.
• INA tensioner — OEM-spec INA timing belt tensioner. The reliable, correct choice when you want a proven OEM-spec tensioner.
• PPF billet tensioner — precision-machined from heavy-duty billet aluminum for lasting reliability. The upgrade we recommend for performance builds.
• Early pump (84–87) / Late pump (88+) — select the water pump fitment that matches your engine’s year.

Each engine is built specifically for your order — no cancellations are accepted once placed. Allow a minimum of 14–15 weeks production time.

Price includes a refundable $700 cylinder head core charge and a refundable $300 engine short block core charge ($1,000 total). Once your BimmerHeads engine arrives, use the original crate to return your core engine. Cores that pass our inspection and testing receive a full $1,000 refund. If the camshaft is unusable, the crankshaft is scored, or repairable damage is found, we will contact you before any deductions are made. Return freight is the customer’s responsibility.

Freight is billed separately. Due to the variables in engine freight cost, shipping will be invoiced once your engine is complete and ready to ship.

Our Spec Sheet has the installation references you’ll need — valve clearances, torque specifications, oil recommendations, and break-in instructions.

Every Super Sport engine is assembled with the same care we’d want if it were going in our own car. If it doesn’t meet our standard before it ships, it doesn’t leave.