High Nickel Alloy Steel, 1.750" x 1.437" x .250"

Heavy Duty, High Nickel Valve Seats, set of eight

Application: Universal and some applications below:

• Caterpillar: 163 D311-D2, 212 (intake)
• Harley Davidson: 900cc and 1000cc Iron head Sportster Exhaust 1957-85
• Hercules Series QXC, QXC-3 & -5, QXD, QXD-3 & -5, QXL, QXLD, QXLD-3 & -1 Intake position
• Jeep: 230 6 cyl 1963-73 exhaust
• Opel: 1897cc 70-75 intake

Alex's Parts carries a decent valve seat selection.We carry seats from: Manley, Martin Wells & Precision Engine Parts.

Part # VS-1750-4N

High Nickel Alloyed Seats are a good choice for heavy duty applications where they're subjected to higher exhaust temperatures or longer running times such as tow or delivery trucks, or any application in need of a higher grade hard seat.

     Sizes:

• Outside Diameter: 1.750" Plus Press
  
• Inside Diameter: 1.437"
• Depth" .250"
• Radiused leading edge for ease of installation

     Material

• High Nickel Alloyed Steel
  
• Higher Hardness. Still machinable but more difficult compared to high chrome seats.
  
• Features improved resistance to high temperatures over high chrome seats.

Tech Notes-
  

1.  Intake seats do not need to be changed to run unleaded fuel, only exhaust
2.     Iron heads which came from the factory with seats usually require special size replacement seats.
3.     Aluminum heads also use special size seats. Their depth is usually much deeper then unleaded retro fit seats.
4.     Aluminum heads commonly use depths between .275"-.437"
5.     Propane applications require Hi Nickel / Tungsten Alloy seat. If you're looking for specially hard seats inquire via message.
6.     Aluminum heads require more press fit then iron.
7.     When going to oversize valves, care in selecting a seat size is important. OE iron heads are cast for smaller valves so there isn't enough wall thickness to install the typical seat size used for a oversize valve. Normally, a unique OD seat is required. Under these circumstances, a seat is selected with a .030- .040" bigger OD then the valve. This is normally done by a shop using adjustable seat cutters. (check around) Some seat manufacturers offer oversize OD seats in: +.010", .020", .030", .040" etc. In the case of a BBC w/ 1.880" exhaust, they would select a 1.875" seat +.040" which would be .035" bigger then the valve. Going bigger puts the casting at risk of breaking into the water jacket. Each head brand and model is different. Some castings are thicker then others. Consult your machinist for which heads will accept oversize seats and which ones won't.