Bill Mitchell Products BMP 084520 – Aluminum Engine Block Chevy Small Block 350 Mains, 4.115 Bore, Billet Caps

Block Specifications:

Block Applications: The BMP aluminum blocks are designed to be a replacement for the small block Chevy w/ two piece seal, driver side dipstick
applications.

Casting Number: BMP-041

Block Material: Aluminum 357T6 aluminum alloy
Block Weight: 105lbs w/ caps and sleeves
Deck Height: 9.025” (Standard Chevrolet), Sleeves are left approximately .002” above the deck for engine builder preferences. YOU MUST MAKE
SURE THAT THE SEEVES ARE COMPLETELY SEATED BEFORE DECKING. We highly recommend sleeves are pressed down with a torque plate
rather a 2×4 and sledge hammer. Sleeves can rebound.

Deck Thickness: .600 minimum.
Cam Bearings: 2.000” Cam bore, Durabond DT1T. Can be machined to accept up to a 50mm roller bearing.
Note: When installing, BE SURE the oil hole in the bearings aligns with the oil feed hole.
Main Bearings: Utilizes 350 or 400 Chevrolet style main bearings. (Depending on main size of block) All blocks regardless of main journal size utilize
a two piece 400 rear main seal such as a Fel-Pro 2909 or equivalent.

Main Caps: All five main caps are four bolt billet caps with the center three being of the splayed design. The inner row of Studs are ½” inch thread.
The outer row of bolts are 7/16 thread. Torque specs on main bolts are: 90-95 ft. lbs. inner & 75 ft. lbs. outer with oil. All BMP blocks (with either the 350
or 400 main size) will have the bolt pattern spread of a 400 block. Most windage trays fit the 350 bolt pattern. Custom fitting of the windage tray may be
required.

Lifter Bores: Standard location, Indexed. Lifter bore size is standard Chevy diameter .8437”.

Bore Center: Standard Bore Center 4.400″

Cylinder Bores: 3.990” or 4.115” standard. Cylinder bores are of a siamese design. Sleeves are a replaceable, centrifugal cast ductile steel pressed in with a .001” to -.002” fit. Sleeves do not protrude into the water and are considered to be a DRY sleeve.

Cylinder Wall Thickness: Sleeve OD on all SBC blocks are 4.280”+ approximately .200” aluminum surrounding it (except between the cylinders of
course). These blocks can be safely bored to 4.155” but engine builder must make that final call based on the application the engine is being built for.
The blocks use a smaller od sleeve which allows for more material left between the bores. This ultimately makes for a stronger block.

Freeze Plugs: All aluminum blocks include screw in freeze plugs. Torque to 35lbs with anti seize on threads and o-rings BMP part#701645
701645.
Distributors: Standard SBC

Oil System Features: Priority main oiling. As is, block is set up for OE style internal oil pump. Block has provisions to be converted to a dry sump
oiling system.

Stroke Clearance: Will accept a 4.000” stroke crank with steel rods.
Oil Restrictors: Requires 4 oil restrictors, two in the front and two in the rear. BMP part # 701804-2 (2pcs).

Filtration: Standard Integral mount for spin on filter.
Oil Pan Rails: Solid (stock width) can be clearanced for strokers. Billet splayed cap blocks may have oil pan interference with the front
and rear main caps. It may be necessary to hand fit the oil pan.

Cylinder Head Bolt Holes: Head bolt holes are blind tapped and do not extend into the water jackets. IT IS THE
BUILDER’S RESPONSIBILITY TO DETERMINE THAT THE STUDS USED HAVE THE PROPER ENGAGEMENT TO PREVENT STRIPPING THE
THREADS.

Camshaft: In long rod and stroker combinations it is recommended to use a camshaft base circle of 1.050 for flat tappet applications
and a .875 base circle for roller camshaft applications.
Fuel Pump: Uses stock style fuel pump and stock length fuel pump pushrod. When using a billet aluminum fuel pump block off plate you may need to
modify it slightly for fit due to overall size.
Starter: Starter mounting pad is drilled for both straight across and stagger bolt patterns.

Motor Mounts: Drilled and tapped for side and front mounts in OEM locations.
Bell Housing Pattern: Stock GM

Gear Drives & Belt Drives: To prevent contact between oil galley plugs and belt drive, gear drive covers, it may be necessary to either tap the block
deeper or to use shorter plugs.

Water Pump: Standard SBC