AFR Frequently Asked Questions

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Titon Manifold FAQ

    Titon Manifold FAQ

  1. Does sealant need to be used when installing the manifold?

      Sealant:

      You MUST use the supplied Dow-Corning 732 Multi-Purpose Sealant to ensure manifold to engine block adhesion due to its superior bonding quality. Please allow at a minimum 24 hours of dry time before firing your engine. You must ALSO use a dab of supplied Dow Corning 732 silicone in all FOUR spots where the water and port gaskets meet.

  2. What do I torque my bolts to?

      Bolt Torque:

      (12) 3/8 x 16: 25 ft/lbs. We recommend medium strength (blue) thread locker.
      (6) 6mm: 26 in/lbs. Requires medium strength (blue) thread locker.
      It is best to torque these bolts in incremental steps, tightening with multiple passes.
      Thermostat Housing recommended torque is 25 ft/lbs.
      Carburetor Nuts recommended torque is 10-12 ft/lbs.
      Distributor clamp torque MAXIMUM 15 ft/lbs.

  3. Can I install a water temp sensor in the manifold?

      Water Temp Sensor:

      Do not install any type of electric sending units (water temp related) and ground it to the engine. Electrolysis will erode the 1/2” NTP brass fitting and clip.

  4. How do I remove the manifold after install?

      Remove Manifold:

      When removing the baseplate, cut along the end wall silicone bead using a razor blade or sharp edge to ensure a clean break from the engine block.

  5. Where can I purchase a Titon Manifold?

      Purchasing Titon Manifolds:

      You may purchase your Titon Manifold directly from Air Flow Research or any one of our authorized distributors.


Small Block Chevy Cylinder Head FAQ

    SB Chevy FAQ

  1. What spark plug should I use in my AFR Chevy Cylinder Head?

      Spark Plugs:

      (14mm x 3/4" gasket) no tapered seat style! For race applications Champion C59YC, Autolite 3910 or 51, A/C R41CXLS & NGK R41 CXLS are good starting points. For street applications use AC FR3LS or RC9YC Spark Plugs or equivalent. Spark Plug selection is of course dictated by many factors including RPM level, compression ratio and type of fuel. All the above Spark Plugs are at a starting heat range; blowers or nitrous applications usually require 1 to 2 heat ranges colder. Spark Plug gap should be determined by the ignition manufacturer.

  2. What should I torque my head bolts to?

      Head bolt torque:

      All Aluminum Cylinder Heads should be torqued to 65-70ft./lbs. This should be done in the proper General Motors sequence in 10ft./lbs. Increments beginning at 40ft./lbs. All high compression, supercharged, turbocharged & nitrous motors should receive a re-torque after the first running and complete cool-down. Bolts containing a 12 point head are suggested in 3 areas on each head near the exhaust valve springs where it may be difficult to fit a standard 5/8 hex head sockets. In case of head studs use 12 point nuts. Air Flow Research stocks complete and partial Head Bolt kits, Studs and Washers for your convenience. Proper ARP #'s for Head Bolt kit, use #134-3701 and Head Stud kit, use #234-4301. We suggest not using a Torque Wrench on intake and exhaust manifold bolts, accessory bolts,or spark plugs, as inaccurate torque wrench values can easily strip the smaller threads. Just snug up hand tight with a wrench only.

  3. Do I need Offset Rocker Arms with my AFR Heads

      Rocker Stud Location:

      AFR Cylinder Heads feature two Rocker Arm Stud locations, standard GM L98 and an offset (for maximum intake port volume). The 180, 195, 210, & 220 Heads all use the standard GM Stud locations. The 227 & 235 guide plates are stamped with cylinder numbers. Install guide plates onto corresponding cylinders. Heads use the offset location which will require a matching Stud Girdle. AFR stocks both standard and offset Girdles and Adjusting Nuts for your convenience.

      Guide Plates:

      Use only the guide plates supplied by Air Flow Research! Push Rod Guideplates are supplied with each set of AFR Aluminum Cylinder Heads and installed correctly as shipped. Studs should be torqued to 60ft./lbs. Silicone sealer is recommended on aplications where the stud hole intersects the intake port. The 180, 195, 210, & 220 Heads use AFR #6110. The 227 & 235 heads use AFR # 6105. . For proper alignment of the rocker arms over the center of the valve, simply loosen the rocker studs and shift the guide plate back and forth until the proper alignment is achieved, then torque to 60ft./lbs.

  4. Does my 400ci Block require steam holes

      400 Blocks:

      Steam holes are recommended for all 400 block applications (GM blocks only). Use a 400 Gasket as a template and drill the three holes, nearest the spark plug side of the head, straight down. The other three which are very near the head bolt holes should be drilled at a 30° angle away from the bolt hole. The center hole will intersect water about 1" down and the two outboard holes to a depth of 2 1/4". Use 1/8 drill.

  5. How do I determine correct pushrod length?

      Pushrods:

      Visit the following sites for information regarding choosing the correct push rod length.
      Holley Valve Train Technical Info
      Holley Valve Train Geometry Info

  6. Where can I purchase CNC ported AFR Aluminum Cylinder Heads?

      Purchasing AFR Cylinder Heads:

      You may purchase your AFR Cylinder Heads directly from Air Flow Research or any one of our authorized distributors.

  7. Can I send my AFR heads back to AFR for additional porting services?

      Porting Services:

      AFR only manufactures new CNC ported heads and we do not offer any hand porting services. We have a list of suggested companies (CLICK LINK HERE) that specialize in hand reworking your used AFR heads. Each CNC program is unique to itself and in most cases one program will not cleanly overlay on top of the existing CNC program, creating voids and altering the critical shapes of the program (which in turn affects flow). Also many of the casting are not interchangeable to the larger ports, having different port and bolt hole locations.


Big Block Chevy Cylinder Head FAQ

    BB Chevy FAQ

  1. What spark plug should I use in my AFR BB Chevy Cylinder Head?

      Spark Plugs:

      All AFR BBC Cylinder Heads accept spark plugs with a flat gasket seat and washer (not the tapered seat style) and a .750 long reach. Projected tip plugs can only be used if you check for adequate piston dome to spark plug clearance. Some initial plug recommendations are as follows:

      Autolite #3932 Std. Tip, Race Application
      Autolite #3935 Std. Tip, Street / Strip Application
      Champion #C59C Std Tip, Race Application
      Champion #C59YC Projected Tip, Race Application
      Champion #RC12YC Projected Tip, Street Application

  2. What should I torque my fasteners to?

      Head Fasteners Torque:

      All Seventeen fasteners per cylinder head can be torqued down to 75 ft./lbs. using the standard General Motors BBC torque pattern. The best choice of fasteners being a quality kit of aftermarket studs (ARP, B&B, Milodon, etc.) Don't forget to use a non-hardening sealer on studs or bolts that enter into the engine block water jacket. Also, be aware that you need (4) one inch longer space fasteners per side along the exhaust port (bottom side) of cylinder head. The recomneded bolt kit does not work on Dart BBC as the holes are not deep enough.

  3. Will my new AFR cylinder heads accept all of my factory components?

      Factory Components:

      Yes, your AFR cylinder heads will accept all factory components with the exception to the rule being a stud. Only a stud girdle designed for a 2 degree rolled over valve andle will properly fit. We sell one under our AFR Parts and Accessories Section. Also, be aware that our exhaust port location has been raised .300 over stock height to improve flow characteristics. If you are currently running stock heads and you have a very tight header/exhaust manifold clearance, you might be forced to modify them to fit.

  4. Do I need to re-torque all my head fasteners after first start up?

      Re-Torque head fasteners after start up:

      If you are running copper head gaskets the answer is YES, with a Capitol "Y". If you are running the Felpro Permatorque style gasket, it is certainly a good idea on a normally aspirated engine and should be considered a must on any blown, turbo, or nitrous motor. any motor subject to severe usage should have the heads re-torqued for improved reliability and a longer head gasket life.

  5. How do I determine correct pushrod length?

      Pushrods:

      Visit the following sites for information regarding choosing the correct push rod length.

      Holley Valve Train Technical Info
      Holley Valve Train Geometry Info

  6. Where can I purchase CNC ported AFR Aluminum Cylinder Heads?

      Purchasing AFR Heads:

      You may purchase your AFR Aluminum Cylinder Heads directly from Air Flow Research or any one of our authorized distributors.

  7. Can I send my AFR heads back to AFR for additional porting services?

      Porting Services:

      AFR only manufactures new CNC ported heads and we do not offer any hand porting services. We have a list of suggested companies (CLICK LINK HERE) that specialize in hand reworking your used AFR heads. Each CNC program is unique to itself and in most cases one program will not cleanly overlay on top of the existing CNC program, creating voids and altering the critical shapes of the program (which in turn affects flow). Also many of the casting are not interchangeable to the larger ports, having different port and bolt hole locations.


LS1 Cylinder Head FAQ

    LS1 FAQ

  1. What spark plug should I use in my AFR LSx Cylinder Head?

      Spark Plugs:

      We recommend a NGK TR55 for most pump gas naturally aspirated motors and a NGK TR6 for most mildly boosted/nitrous applications.

  2. Can I angle mill my LSx heads?

      Milling:

      No, our heads can only be flat milled due to the fact that the intake cannot be corrected.

  3. Will my new AFR cylinder heads accept all of my factory components?

      Factory Components:

      Yes, all factory components will be accepted except for perimeter valve covers on the 97-98 year LS motors. Center bolt covers will be needed for those 2 years.

  4. What do I torque my head bolts to? Do I need to re-torque after first start up?

      Torque Specs:

      Head bolts should be torqued per the bolt manufacturer’s specs. ARP typically recommends 70 ft.lbs. on the 11mm bolts and 25ft.lbs. on the 8mm bolt. Head bolts should always be re torqued after the motor has been heat cycled once (Brought up to operating temp and allowed to cool back to ambient temp).

  5. How do I determine correct pushrod length?

      Spark Plugs:

      Visit the following sites for information regarding choosing the correct push rod length. Holley Valve Train Technical Info

  6. Can I run AFR large bore heads on a small bore block?

      AFR Large Bore:

      Yes, to run the large bore heads on the 3.898-3.905 bores you will need to run a 4.125 or larger head gasket. Options are Fel-Pro 1041 or Cometic C5318-040.

  7. What head gasket is recommended?

      Head Gasket:

      If a Block with 3.898-3.905 bores is used in conjunction with AFR p/n 1510 or 1660 AFR recommends Cometic H1294040S, all other heads and/or blocks with 4.000 bore or larger use Cometic C5318-040.

  8. Where can I purchase AFR Cylinder Heads?

      Purchasing AFR Heads:

      You may purchase your AFR Aluminum Cylinder Heads directly from Air Flow Research or any one of our authorized distributors.

  9. Can I send my AFR heads back to AFR for additional porting services?

      Porting Services:

      AFR only manufactures new CNC ported heads and we do not offer any hand porting services. We have a list of suggested companies (CLICK LINK HERE) that specialize in hand reworking your used AFR heads. Each CNC program is unique to itself and in most cases one program will not cleanly overlay on top of the existing CNC program, creating voids and altering the critical shapes of the program (which in turn affects flow). Also many of the casting are not interchangeable to the larger ports, having different port and bolt hole locations.


Small Block Ford Cylinder Head FAQ

    Ford FAQ

  1. What spark plugs should I use in my AFR Ford Cylinder Head?

      Spark Plugs:

      Use 14mm x 3/4" reach gasketed, no tapered seat plugs. Street application use Autolite 3924, for 205cc & 225cc race head use Autolite 3922, or equivalent. Plug selection is of course dictated by many factors including RPM level, compression ration and fuel type. Forced induction or nitrous applications usually require 1 to 2 heat ranges colder. Spark plug gap should be determined by the ignition manufacturer.

  2. What should I torque my head bolts to?

      Head Bolt Torque:

      Apply moly-oil mixture to washers, and area around head bolt to prevent galling and improper torque readings. Torque to 70ft/lbs. for 7/16" bolts or studs (289 or 302) or 100ft/lbs. for 1/2" bolts or studs (351W) in three or four steps following the factory tightening sequence. Then tighten the long (upper) head bolts or studs 80ft/lbs. (7/16") or 110 ft/lbs. (1/2"). A re-torque is recommended after initial start-up and cool down (allow 2-3 hours for cooling). Sealer should be applied to all head bolts or studs that enter into the blocks water-jacketing system. Permatex is a good general-purpose sealer.

      Torquing: We suggest not using a Torque Wrench on intake and exhaust manifold bolts, accessory bolts,or spark plugs, as inaccurate torque wrench values can easily strip the smaller threads. Just snug up hand tight with a wrench only.

  3. Will the 185 with 2.020 valves fit my stock pistons?

      Valve Clearance:

      Piston to valve clearance must be checked before assembly. AFR 185cc aluminum cylinder heads with 2.020 valves usually will not fit a piston without valve notches having proper reliefs. Also AFR 205cc heads with 2.080 valves might experience the same issues.

      Note: All stock pistons must be notched for clearance.


  4. Can I use my stock rocker arms?

      Rocker Arms:

      Only part #1472 & 1492 with pedestol style rocker arm boss towers will fit stock rocker arms. Stud mount style AFR heads require aftermarket rocker arms.

  5. What gaskets should I use?

      Gaskets:

      On SBF SVO blocks, Fel-Pro 1011-1 and 1011-2 cannot be used. Must use Fel-Pro 1022 (left side) and 1023 (right side).

  6. How do I determine correct pushrod length?

      Pushrods:

      Visit the following sites for information regarding choosing the correct push rod length. Holley Valve Train Technical Info
      Holley Valve Train Geometry Info

  7. Where can I purchase AFR Aluminum Cylinder Heads?

      Purchasing AFR Heads:

      You may purchase your AFR Aluminum Cylinder Heads directly from Air Flow Research or any one of our authorized distributors.

  8. Can I send my AFR heads back to AFR for additional porting services?

      Porting Services:

      AFR only manufactures new CNC ported heads and we do not offer any hand porting services. We have a list of suggested companies (CLICK LINK HERE) that specialize in hand reworking your used AFR heads. Each CNC program is unique to itself and in most cases one program will not cleanly overlay on top of the existing CNC program, creating voids and altering the critical shapes of the program (which in turn affects flow). Also many of the casting are not interchangeable to the larger ports, having different port and bolt hole locations.


Air Flow Research | 28611 W. Industry Drive | Valencia, CA 91355 | 661-257-8124

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