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Design 911 Design 911 supply Porsche parts, Porsche spares and Porsche accessories, to both retail and to the trade. Our Porsche product and accessory range includes brakes, exhausts, tyres, wheels and Porsche panels and interiors. https://www.design91.uk/images/schemaLogo.png https://www.design91.uk/images/schemaLogo.png +443456003478 https://www.design91.uk Facebook Instagram

Engine Bolts / Studs

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DISPLAYING 33 to 48 (of 50 products)
1 2 3 4
Special Order item
93010117201
Product Information
Product Information
Engine Head Studs Cap Nut. 24  required per engine. 


porsche

Fits:
Porsche 911 1970-89

Click picture for large parts diagram.
Diagram Ref No 24.

99310117054/2
Product Information
Product Information
Engine Head Studs Porsche 911 / 964 / 993 1965-98
Normally 24 studs per engine.


eps

Solves the problems of loose head studs, The exhaust leak you hear in the 911 may actually be the cylinder head leaking where the studs have pulled loose. As Porsche increased displacement of the 911 engine, the different rates of thermal expansion have caused head studs to break or pull out from the engine case.

Superior Tested/Proven strength. (compared to Dilavar & Raceware)

Fits:
Porsche 911 1965-89
Porsche 964 1989-94
Porsche 993 1994-98

This product supersedes Porsche's old part numbers:
- 993 101 170 51

Click picture for large parts diagram.
Diagram Ref No 2.



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99310117054
99310117051
99310117053
99310117054

The product you are viewing cross references to these numbers
Special Order item
91110117200
Product Information
Product Information
Engine head studs upper standard. Price is for each.

Fits:
Porsche 911 1974-89 (12pcs Required)
Porsche 911 2.7L Carrera 1973 (24pcs Required)

Diagram Ref No 2




Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91110117200
91110117200

The product you are viewing cross references to these numbers
91110117200/1
Product Information
Product Information
Engine head studs upper standard.
Price is for each.

Fits:
Porsche 911 1974-89 (12pcs Required)
Porsche 911 2.7L Carrera 1973 (24pcs Required)

Diagram Ref No 2

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91110117200
91110117200

The product you are viewing cross references to these numbers
99310117054/4
Product Information
Product Information
Engine head studs. Set of 24 head studs with nuts and washers.

SET OF 24
Head stud kit for Porsche 2.0L-3.8L air-cooled engines

Fits:
Porsche 911 1965-89
Porsche 964 1989-94
Porsche 993 1994-98

Diagram Ref No 2

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99310117054
99310117051
99310117053
204-4206
90110117203
91110117200
93010117000
99310117054

The product you are viewing cross references to these numbers
99906223902T
Product Information
Product Information
Exhaust head stud, L - 45mm. Made out of Titanium (Grade 5 Ti-6Al-4V)
Sold each.

rohler

Fits:
Porsche 911 3.2L 1984-89
Porsche 930 turbo
Porsche 965 turbo

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99906223902T
99906223902
99906223903

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SR065
Product Information
Product Information
Exhaust head stud repair kit for Porsche Air-cooled 911's

stomski

Never lose sleep again over a bent or broken exhaust stud on a 911 engine. This new tool is a must for every 911 mechanic and will pay for itself the first time you use it. This is a quick and totally accurate tool to repair and replace broken studs without damaging the head, or worse, having to remove the engine. The SR065 fixture indexes off of the exhaust port (by using one of the various sized port bushings included), secures to the opposite stud, and allows you to drill out, tap, and replace the stud dead on, every time. Includes LH drill bits, tap with extension, drill jigs/guides, port bushings, and a sturdy storage case.

Now includes our SR065D drill guide.

Fits ALL of the 911 heads including the 993.
Special Order item
99906218202
Product Information
Product Information
Gearbox housing stud, M 10 X 25.

porsche

Fits:
Porsche 911 1972-73 (TYP 915)
Porsche 911 1974-89
Porsche 911 (930) Turbo 1975-89

Click 'Zoom in' for large parts diagram.
Diagram ref no 7

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99906218202
99906218202

The product you are viewing cross references to these numbers
Special Order item
99906209802
Product Information
Product Information
Gearbox housing stud, M 8 X 38.

porsche

Fits:
Porsche 911 / SC / Carrera 1977-86
Porsche 911 Turbo 1977-77
Porsche 924  1976-79 with 5-Speed Gearbox
Porsche 924 Turbo/ GT 1980-85 Manual Gearbox G31.01/02/03

Click 'Zoom in' for large parts diagram.
Diagram ref no. 2 (for 911) or no.19 (for 924)

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Related, superseded, cross reference or alternative numbers for comparison.

99906209802
99906209802

The product you are viewing cross references to these numbers
Special Order item
99903109101
Product Information
Product Information
Head nut washer. 24 per engine. Price is for each.

Fits:
Porsche 911 1978-89

Diagram Ref No 16

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99903109101
99903109101
911026

The product you are viewing cross references to these numbers
99903109101/1
Product Information
Product Information
Head nut washer. 24 per engine. Price is for each.

Fits:
Porsche 911 1978-89

Diagram ref no 16

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99903109101
99903109101
911026

The product you are viewing cross references to these numbers
Special Order item
99906103402
Product Information
Product Information
Stud bolt, M10x69. Each.

porsche

Fits:
Porsche 914/6 (1970 - 1972)
Porsche 911 F  (1965 - 1973)
Porsche 911 Carrera (1984 - 1986)
Porsche 911 Turbo (1975 - 1986)

Click 'Zoom in' for large parts diagram.
Diagram ref no 6 (and no 7 for 914 only)

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Related, superseded, cross reference or alternative numbers for comparison.

99906103402
99906103402

The product you are viewing cross references to these numbers
Special Order item
99906223903
Product Information
Product Information
Stud - M8 x 30 / 45mm - which is used to mount the heat exchanger.

Sold individually; x12 required per engine. 

Fits:
Porsche 911 Turbo (930) 1978-89
Porsche 964 Turbo 3.3L 1991-92
Porsche 964 Turbo 3.6L 1993-94

Porsche 911 Carrera 3.2L 1984-89

Diagram ref. 5A.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99906223903
99906223902
99906223903

The product you are viewing cross references to these numbers
99906223903/1
Product Information
Product Information
Stud - M8 x 30 / 45mm - which is used to mount the heat exchanger.

Sold individually; x12 required per engine. 

Fits:
Porsche 911 Turbo (930) 1978-89
Porsche 964 Turbo 3.3L 1991-92
Porsche 964 Turbo 3.6L 1993-94

Porsche 911 Carrera 3.2L 1984-89

Diagram ref. 5A.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99906223903
99906223902
99906223903

The product you are viewing cross references to these numbers
SR025
Product Information
Product Information
Through bolt o-ring installer for Porsche 911

stomski

Installing O-rings on the through bolts for a 911 engine case often slices the rings on the threads of the bolt, leading to ripped seals at best, or a leaky engine at worst. Use this cap to protect the O-ring and to insure a factory quality seal. Precisely machined from quality brass.
SR024
Product Information
Product Information
Stomski Racing SR024 Through bolt o-ring installer with sleeve for Porsche 911

stomski

Based on the factory P9511 tool, STOMSKI RACING's version of this tool incorporates a brass cap and a double-ended stainless steel sleeve to install the o-rings on the crankcase through-bolts of the 3.6 and later cases (but possibly can be used on some other 911 engines). By using the included brass cap to protect the delicate o-ring from getting cut on the threads of the bolt, you then use the "thin" end of the sleeve to slide the o-ring over the brass cap onto the shank of the through-bolt. Once the o-ring is clear of the threads, remove the SR024 brass cap and flip the SR024 stainless steel sleeve over and use the blunted end to securely and gently seat the o-ring in the recess on the 3.6 case.
DISPLAYING 33 to 48 (of 50 products)
1 2 3 4
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About Engine Bolts / Studs

Precision Engine Bolts & Studs – Strength, Accuracy, and Reliability for Porsche Engines

Engine bolts and studs are the unsung heroes of your Porsche’s powerplant — small but vital components that ensure structural integrity under extreme stress. From securing cylinder heads and connecting rods to fastening crankcases and manifolds, every fastener must deliver uncompromising strength, precision, and clamping force to maintain your engine’s performance and reliability.

At Design911, we offer a comprehensive selection of standard and high-performance bolts, studs, nuts, and fasteners designed specifically for Porsche engines. Each high performance component is precision-engineered from high-tensile steel, titanium, or ARP-grade alloy, delivering exceptional resistance to heat, vibration, and torque fatigue.

Whether you’re rebuilding a classic air-cooled 911 or tuning a modern GT model, our manufacturer-quality fasteners guarantee secure fitment, consistent torque retention, and long-term durability.

What Do Engine Bolts and Studs Do?

Engine bolts and studs hold critical components together under immense pressure. They maintain precise torque and tension, ensuring the engine block, heads, and internal assemblies remain perfectly sealed and aligned.

Core Functions:

  • Provide secure clamping force for key engine assemblies (head, crankcase, rods, etc.).
  • Maintain torque integrity under thermal expansion and vibration.
  • Prevent component movement, preserving internal clearances and sealing surfaces.
  • Support rebuild precision, allowing components to be serviced repeatedly without distortion.

Motorsport-grade fasteners are designed to handle repeated torque cycles and extreme stress, making them essential for both performance tuning and professional engine restoration.

Why Do Engine Bolts and Studs Fail?

Over time, fasteners experience stretching, fatigue, and corrosion from heat, oil exposure, and repeated torque cycles. Even the strongest bolts have a finite service life — and failing to replace them can lead to catastrophic engine damage.

Common Causes of Failure Include:

  • Metal fatigue or stretching from repeated torque applications.
  • Corrosion and oxidation, especially in humid or high-heat environments.
  • Over-tightening or under-torquing, compromising clamping force.
  • Thread wear or damage from improper installation or debris.
  • Thermal cycling, weakening material structure over time.

Replacing aged or stressed bolts and studs during every rebuild or major service ensures your Porsche’s engine remains structurally sound and leak-free.

Why Replace with Precision-Engineered Bolts and Studs?

Upgrading to high-performance fasteners delivers the security and strength demanded by Porsche engines. Precision-engineered bolts and studs ensure consistent torque retention, improved reliability, and extended component life — especially in high-load or high-temperature conditions.

Key Benefits:
Superior clamping strength and torque retention for critical assemblies.
High fatigue resistance, preventing loosening or failure under pressure.
Improved corrosion protection with zinc, nickel, or black oxide coatings.
Ideal for rebuilds, upgrades, and performance tuning applications.
Precision-thread machining ensures repeatable installation and alignment.
Available in titanium and high-tensile steel for maximum strength-to-weight ratio.

These bolts and studs provide the perfect balance of motorsport-level performance and road-going durability, keeping your Porsche engine secure mile after mile.

Highlights:

  • Comprehensive range of bolts, studs, and fasteners for Porsche engines.
  • Manufactured from ARP-grade steel, titanium, or high-tensile alloy.
  • Precision-machined threads for perfect alignment and consistent torque.
  • Improved resistance to heat, corrosion, and vibration.
  • Essential for rebuilds, tuning, and restoration projects.
  • Designed for air-cooled and water-cooled Porsche engines.

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