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!!! Built to Order !!!
Each S52 head is assembled only after purchase, with options for porting and valve train configuration. Typical lead times apply.
Overview
S52 engines remain a popular choice for street, track, and drift builds, but their heads are more prone to cracking compared to the later S54 design. Because of this, thorough inspection and preparation are essential to ensuring reliability under high-performance use.
We highly recommend replacing the exhaust valves during service, as they are generally the most wear-prone components besides the guides. Valve guides—especially on the exhaust side—tend to wear out more often than not, making them frequent candidates for replacement.
Process
Each S52 head we build is fully disassembled, cleaned, and inspected. Components such as valve springs, valves, and spring seat retainers are removed and washed in our high-temperature jet wash.
NEW VALVE SPRING RETAINERS ARE REQUIRED FOR ALL S52 HEADS.
Inspection & Machining
All components visually inspected for wear or damage
Valve spring pressures sampled to ensure a 5–8% consistency range
Guides checked for clearance; replacements determined based on valve condition
Valves individually inspected for wear
Seats cut with 4 angles on intake and a radius cut on exhaust
Head surface measured and refinished minimally (typically .003”–.010”). In rare cases, S52s can require up to .020", more common on IMC repo heads.
Valve stem seals replaced
Reassembly & Testing
The head is reassembled with the buyer’s choice of valve train. If wear permits, old valve train may be reused. Final assembly is vacuum-tested to confirm proper valve-to-seat sealing. New Elring valve stem seals are provided with final assembly
!!! Built to Order !!!
Each S52 head is assembled only after purchase, with options for porting and valve train configuration. Typical lead times apply.
Overview
S52 engines remain a popular choice for street, track, and drift builds, but their heads are more prone to cracking compared to the later S54 design. Because of this, thorough inspection and preparation are essential to ensuring reliability under high-performance use.
We highly recommend replacing the exhaust valves during service, as they are generally the most wear-prone components besides the guides. Valve guides—especially on the exhaust side—tend to wear out more often than not, making them frequent candidates for replacement.
Process
Each S52 head we build is fully disassembled, cleaned, and inspected. Components such as valve springs, valves, and spring seat retainers are removed and washed in our high-temperature jet wash.
NEW VALVE SPRING RETAINERS ARE REQUIRED FOR ALL S52 HEADS.
Inspection & Machining
All components visually inspected for wear or damage
Valve spring pressures sampled to ensure a 5–8% consistency range
Guides checked for clearance; replacements determined based on valve condition
Valves individually inspected for wear
Seats cut with 4 angles on intake and a radius cut on exhaust
Head surface measured and refinished minimally (typically .003”–.010”). In rare cases, S52s can require up to .020", more common on IMC repo heads.
Valve stem seals replaced
Reassembly & Testing
The head is reassembled with the buyer’s choice of valve train. If wear permits, old valve train may be reused. Final assembly is vacuum-tested to confirm proper valve-to-seat sealing. New Elring valve stem seals are provided with final assembly