Delivering the seemingly impossible combination of professional racing-level strength and entry-level affordability, the LSX Bowtie Block is the next revolution in high-performance engine-building. This durable iron-block casting is based primarily on GM's production LS7 block, but designed with more material in key areas - including thicker deck and bores - to support displacements of 454 cubic inches or more, and unique six-bolts-per-cylinder-headclamping capability that enables forced-induction and nitrous combinations of greater than 2,000 horsepower.
Because the LSX Bowtie block is based on production LS blocks, all of the LS-Series Gen IV cylinder heads, crankshafts, oil pans, camshafts, and accessories bolt right up to it. There is also a tall-deck version for building even larger engines. Chevrolet Performance delivers the LSX Bowtie Block semi-finished, allowing you to finish it to your needs. Whether you’re building a “tame” 500-horse street engine for your hot rod or a 1,700 horsepower turbo engine for an Outlaw drag racer, the LSX Bowtie Block is the foundation for an unbeatable combination - at an unbeatable price!
LSX Bowtie Block - Standard Deck
- 3.880" finished siamese cylinder bores
- 9.260" semi-finished standard deck height (ready to be decked)
- 4.250" maximum stroke (professional engine builders only!)
- Capable of 364- to 482-cubic-inch displacements
- Orange powder-coated finish
- Accepts all LS and LSX Series heads, cranks, cams, etc.
- Approximate finished weight is 225 pounds
LSX Bowtie Block specs and features include:
- CNC-machined cast-iron block
- True priority main oiling
- 6-head bolts per cylinder
- Standard 4.400" bore spacing
- Extra-thick siamese cylinder bores
- Semi-finished, machined thicker decks
- LS7-style, 6-bolt dowel-located billet main bearing caps
- Wet-sump and dry-sump oiling capability
- Production-style deep-skirt head bolt holes
- Production bolt hole and thread sizes
- Maintains production exterior accessory mounting provisions
- Front motor plate mounting holes added
- Additional material cast around cam bearings for greater strength
- 8mm exterior/interior fifth- and sixth-head bolt holes
- Standard 0.842" lifter bores
- Accommodates all LS oil pumps and oil pans
- External oil pump feed (rear of block)
- Main web bay-to-bay breathing holes to support greater horsepower
- Includes unique cam retainer, rear cover and lifter retainers
For the advanced LSX competition engine builder, you will fully enjoy the following features of the new LSX Bowtie Block:
- Front oil feed holes can be plugged/restricted for mechanical flat tappet or mechanical roller lifter applications
- Can be machined safely to 9.200" deck height
- Maximum 4.200" bore at .200" minimum wall thickness (naturally aspirated applications)
- Head bolt holes can be machined for 1/2" studs
- Cam bores can be machined to accept 60mm roller bearings
- Can be machined for larger diameter lifters and/or 1.060" bronze bushings
- Front oil feed lines can be plugged and external oil pump and/or aftermarket dry sump systems can be used via oil pump feed at rear of block - may be required with certain large stroke/aluminum rod combinations
- Belt cam drive systems can be accommodated - some machining will be required
- Front motor plate can be used for racing chassis applications (sprint car, drag racing, truck pulling, etc.).
- Threaded water plugs can be used for external heaters or coolers
- Extra stock for main bearing align-honed
- 400 mPa tensile strength iron
- Engine Block Material:
- Cast iron
- Engine Block Style:
- Aftermarket
- Deck Height:
- 9.260 in.
- Cylinder Bore Diameter:
- 3.880 in.
- Maximum Bore Diameter:
- 4.250 in.
- Cylinder Bore as Shipped:
- 3.880 in.
- Finished Cylinder Bores:
- No
- Maximum Stroke:
- 4.250 in.
- Main Caps Included:
- Yes
- Main Cap Material:
- Billet steel
- Main Bolt Style:
- 6-bolt
- Main Journal Type:
- LS mains
- Rear Main Seal Style:
- 1-piece
- Main Cap Fasteners Included:
- Yes
- Main Bearings Included:
- No
- Engine Block Weight (lbs.):
- 225 lbs.
- Raised Cam Location:
- No
- Cam Bearings Included:
- No
- Freeze Plugs Included:
- No
- Finish:
- Orange
- Quantity:
- Sold individually.
- Notes:
- Semi-finished block.
- Make:
- Chevrolet
- Engine Family:
- Chevy small block Gen III/IV (LS-based engines)
