JHM - Cylinder Heads, Rebuilt (JHM) w HD Valves, HD Springs, Ti Retainers for B6 - B7 S4, C6 A6 and C5 allroad w chain 4.2L 40v (NLA)
Introducing Rebuilt Heads for the B6-B7 S4 4.2L V8 from JHMotorsports! This is a pair of FULLY REBUILT heads for your B6-B7 S4. Not only are these heads fully rebuilt and resurfaced but they also feature our brand new, JHM Heavy Duty Coated Valves and a Heavy Duty High-Rate Valve Spring and Performance Titanium Retainer set.
Our Rebuilt Heads also include: full resurfacing of the sealing surface to factory Roughness Average specifications (RA), replacing all of the valve guides in the heads, replacing all the valve stem seals, a thorough cleaning and inspection, and a three angle valve job. You may notice that we replace a lot more parts than are normally replaced with your standard "head job". An industry standard "head job" would reuse valve springs and as many valve guides as possible but we go above and beyond that with our Rebuilt Heads. For one reason running stock, USED valve springs that have tested within specifications have been known to fail at any given time with these heads. With all the money it takes to work on these motors and the possibility of destroying the entire motor, we replace ALL of the components. However, if you are on a budget, we'd be happy to sell our Valves and/or our Springs and Retainers separately (go back one section). We stand behind our quality products and the work that we do. If we were to sell used springs or guides in these motors, we run the risk of damaging your investment and our reputation.
JHM HD VALVES FEATURES AND SPECIFICATIONS
Our JHM Heavy Duty performance valves are upgraded in nearly every way over the stock Intake and Exhaust Valves in the B6-B7 S4 4.2L V8. Our JHM HD Performance Valves feature our proprietary valve coating. This coating is a multistage, nitrocarburizing treatment with superior lubricity that also increases corrosion and wear resistance. This makes the JHM HD Performance Valves exactly what you want the surface of your valves to be: slippery, hard, and tough.
Additionally, the stock valves have almost ZERO margin which makes them nearly impossible to service unless you were regrinding super low mileage valves. However, there's really no reason to ever do that. Our JHM HD Performance Valves feature more margin for longer serviceability and longer life. This allows for a greater possibility of being able to regrind your JHM Valves during a future rebuild (depending on mileage). The larger margin also gives the valves more durability to withstand the heat of high performance or boosted applications.
We also beefed up the Intake Valve Stem in response to the high rate of Intake Valve failure we have seen. Stock, these intake valves break very easily at the stem and cause catastrophic damage to the cylinder wall and piston, rendering the motor un-repairable. Our JHM HD Intake and Exhaust Valves are 21-4N stainless steel and single piece. Stock, the Exhaust Valves are two-piece. With a very small increase in stem diameter at the base of the valve, the strength of the valves is dramatically increased. Additionally, we had these valves tested on a cylinder head flow bench and the increased valve stem diameter resulted in a negligible amount of flow loss. In our testing, the resulting power numbers were the same as stock. Any negligible weight increase in the valves due to our improvements in the design, has been counteracted by increasing the dish in the head of the valve, making them still compatible with stock valve springs. Additionally, with our Fully Rebuilt Heads, the massive weight loss from the Titanium Retainers makes the resulting combination dramatically lighter than stock. Click to enlarge picture
Click to enlarge picture
HEAVY DUTY HIGH RATE VALVE SPRINGS AND TI RETAINERS FEATURES AND SPECIFICATIONS
In the valvetrain, we replace all of the springs standard for several reasons. We have seen many heads and engines damaged as a result of the weak and failure-prone Intake Valve Springs on these motors. The Springs are replaced with a Heavy Duty High-Rate Valve Spring set featuring a single spring setup for the Intake Valve Springs, a dual-spring setup for the Exhaust Valve Springs, and Titanium Spring Retainers. The Heavy Duty, High-Rate Springs and Titanium Spring Retainers allow for high-RPM operation of this motor by reducing the weight of the Valve, Spring, and Retainer combo. Reducing the weight of the combo reduces the amount of inertia required to propel the valves and this allows for a more stable and longer lasting valvetrain. Just the long list of advantages above was enough to convince us to run these parts in all of our JHM Rebuilt Heads. Since these upgraded spring kits cost about the same as OEM springs ONLY, upgrading to these Heavy Duty, lightweight, and more durable components was a no-brainer.
Click to enlarge picture
Click to enlarge picture
Click to enlarge picture
Our JHM Rebuilt Heads come pre-assembled and will include the following:
- 1x Pair of OEM B6-B7 S4 4.2L V8 Heads, Resurfaced and Reconditioned
- 1x Full Set of OEM, Matching Cam Caps/Towers (Not pictured)
- 44x OEM Cam Cap/Tower Bolts (Torque to Yield, Must be replaced)
- 24x JHM HD Performance Intake Valves w/ Coating
- 16x JHM HD Performance Exhaust Valves w/ Coating
- 24x High-Rate Intake Valve Springs
- 16x High-Rate Exhaust Valve Dual Spring Pairs
- 16x Dual Spring Spacers
- 40x Titanium Retainers
- 40x Valve Keeper Pairs (80x total), Holds the retainer to the Valve
NOT INCLUDED, Replace as Needed or Use Original:
- 1x Pair of Intake Camshafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 1x Pair of Exhaust Camshafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 1x Pair of Intake Rocker Shafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 1x Pair of Exhaust Rocker Shafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 8x Pair of Intake Rocker Arms/Lifter Assemblies (OEM rarely fail. We have used ones available for sale.)
- 8x Pair of Exhaust Rocker Arms/Lifter Assemblies (OEM rarely fail. We have used ones available for sale.)
- All associated mounting hardware, gaskets, bolts, etc. Please go back one section to add these items to your cart!
Core Options:
- Yes, I will send my stock heads in after. +$1500.
- No, I will send in my heads to JHM to get rebuilt. Expect a 2 - 4 week turnaround time based on current backlog.
Note for Core Returns: The core return fee will be deducted based on our costs to repair or replace cracked heads or damaged heads. This can be due to broken valves or any other major damage that is not already replaced by our full rebuild. For example: If one head is cracked or heavily damaged due to a broken valve (and since we replace just about everything else) you will only have the possibility of receiving 1/2 of the core charge back.
For shipping quotes, please sign in or create an account then put the items you want in your shopping cart and proceed to checkout.
Our Rebuilt Heads also include: full resurfacing of the sealing surface to factory Roughness Average specifications (RA), replacing all of the valve guides in the heads, replacing all the valve stem seals, a thorough cleaning and inspection, and a three angle valve job. You may notice that we replace a lot more parts than are normally replaced with your standard "head job". An industry standard "head job" would reuse valve springs and as many valve guides as possible but we go above and beyond that with our Rebuilt Heads. For one reason running stock, USED valve springs that have tested within specifications have been known to fail at any given time with these heads. With all the money it takes to work on these motors and the possibility of destroying the entire motor, we replace ALL of the components. However, if you are on a budget, we'd be happy to sell our Valves and/or our Springs and Retainers separately (go back one section). We stand behind our quality products and the work that we do. If we were to sell used springs or guides in these motors, we run the risk of damaging your investment and our reputation.
JHM HD VALVES FEATURES AND SPECIFICATIONS
Our JHM Heavy Duty performance valves are upgraded in nearly every way over the stock Intake and Exhaust Valves in the B6-B7 S4 4.2L V8. Our JHM HD Performance Valves feature our proprietary valve coating. This coating is a multistage, nitrocarburizing treatment with superior lubricity that also increases corrosion and wear resistance. This makes the JHM HD Performance Valves exactly what you want the surface of your valves to be: slippery, hard, and tough.
Additionally, the stock valves have almost ZERO margin which makes them nearly impossible to service unless you were regrinding super low mileage valves. However, there's really no reason to ever do that. Our JHM HD Performance Valves feature more margin for longer serviceability and longer life. This allows for a greater possibility of being able to regrind your JHM Valves during a future rebuild (depending on mileage). The larger margin also gives the valves more durability to withstand the heat of high performance or boosted applications.
We also beefed up the Intake Valve Stem in response to the high rate of Intake Valve failure we have seen. Stock, these intake valves break very easily at the stem and cause catastrophic damage to the cylinder wall and piston, rendering the motor un-repairable. Our JHM HD Intake and Exhaust Valves are 21-4N stainless steel and single piece. Stock, the Exhaust Valves are two-piece. With a very small increase in stem diameter at the base of the valve, the strength of the valves is dramatically increased. Additionally, we had these valves tested on a cylinder head flow bench and the increased valve stem diameter resulted in a negligible amount of flow loss. In our testing, the resulting power numbers were the same as stock. Any negligible weight increase in the valves due to our improvements in the design, has been counteracted by increasing the dish in the head of the valve, making them still compatible with stock valve springs. Additionally, with our Fully Rebuilt Heads, the massive weight loss from the Titanium Retainers makes the resulting combination dramatically lighter than stock. Click to enlarge picture
Click to enlarge picture
HEAVY DUTY HIGH RATE VALVE SPRINGS AND TI RETAINERS FEATURES AND SPECIFICATIONS
In the valvetrain, we replace all of the springs standard for several reasons. We have seen many heads and engines damaged as a result of the weak and failure-prone Intake Valve Springs on these motors. The Springs are replaced with a Heavy Duty High-Rate Valve Spring set featuring a single spring setup for the Intake Valve Springs, a dual-spring setup for the Exhaust Valve Springs, and Titanium Spring Retainers. The Heavy Duty, High-Rate Springs and Titanium Spring Retainers allow for high-RPM operation of this motor by reducing the weight of the Valve, Spring, and Retainer combo. Reducing the weight of the combo reduces the amount of inertia required to propel the valves and this allows for a more stable and longer lasting valvetrain. Just the long list of advantages above was enough to convince us to run these parts in all of our JHM Rebuilt Heads. Since these upgraded spring kits cost about the same as OEM springs ONLY, upgrading to these Heavy Duty, lightweight, and more durable components was a no-brainer.
Click to enlarge picture
Click to enlarge picture
Click to enlarge picture
Our JHM Rebuilt Heads come pre-assembled and will include the following:
- 1x Pair of OEM B6-B7 S4 4.2L V8 Heads, Resurfaced and Reconditioned
- 1x Full Set of OEM, Matching Cam Caps/Towers (Not pictured)
- 44x OEM Cam Cap/Tower Bolts (Torque to Yield, Must be replaced)
- 24x JHM HD Performance Intake Valves w/ Coating
- 16x JHM HD Performance Exhaust Valves w/ Coating
- 24x High-Rate Intake Valve Springs
- 16x High-Rate Exhaust Valve Dual Spring Pairs
- 16x Dual Spring Spacers
- 40x Titanium Retainers
- 40x Valve Keeper Pairs (80x total), Holds the retainer to the Valve
NOT INCLUDED, Replace as Needed or Use Original:
- 1x Pair of Intake Camshafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 1x Pair of Exhaust Camshafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 1x Pair of Intake Rocker Shafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 1x Pair of Exhaust Rocker Shafts (OEM are steel and rarely fail. We have used ones available for sale.)
- 8x Pair of Intake Rocker Arms/Lifter Assemblies (OEM rarely fail. We have used ones available for sale.)
- 8x Pair of Exhaust Rocker Arms/Lifter Assemblies (OEM rarely fail. We have used ones available for sale.)
- All associated mounting hardware, gaskets, bolts, etc. Please go back one section to add these items to your cart!
Core Options:
- Yes, I will send my stock heads in after. +$1500.
- No, I will send in my heads to JHM to get rebuilt. Expect a 2 - 4 week turnaround time based on current backlog.
Note for Core Returns: The core return fee will be deducted based on our costs to repair or replace cracked heads or damaged heads. This can be due to broken valves or any other major damage that is not already replaced by our full rebuild. For example: If one head is cracked or heavily damaged due to a broken valve (and since we replace just about everything else) you will only have the possibility of receiving 1/2 of the core charge back.
For shipping quotes, please sign in or create an account then put the items you want in your shopping cart and proceed to checkout.
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 w HD Valves, HD Springs, Ti Retainers for B6 - B7 S4, C6 A6 and C5 allroad w chain 4.2L 40v (NLA))
