FAQ

What is the difference between the Black Nitride valves and the Inconel valves? Can the inconel valves be used on the intake side?

The black nitride valves are stainless steel valves, with a black treatment that hardens the valves. The Inconel valves are made from a Nimonic 751 alloy which has better resistance to heat then the stainless steel. The Inconel valves are only used on the exhaust side, it is the only side that it is needed to use a higher temperature alloy.

When should Inconel valves be used, over Black Nitride valves?

Inconel valves should be used, when an engine yield more than 250Hp if the engine yields more than 800hp Supertech suggest using our Sodium filled/Inconel valves.

Can custom valves be manufactured?

Yes, Supertech custom make any make or model of valve, however a minimum run of 50 of each valve would be required for custom manufacturing, in stainless steel material or Inconel, for Titanium valves, Supertech require 100 valves per szie.

What is the hardness of the Nitride layer on the valves?

The Nitrided Valve hardness is about 800 Vickers = equivalent to 52 Rc (equivalent because is just a thin layer.

What are the operating temperatures of the valves?

Supertech stainless valve has a 1,460 F. (approx 1900 F EGT) The INCONEL valves have 1,600 F (approx 2200 F EGT)

What is the durability of our Titanium valves?

Depends on many factors like operating temp., seat hardness, rpms, etc. but a reasonable number are 1000 miles in racing applications.

What is the piston to Cylinder wall clearance?

All pistons come with a specification sheet, please read that sheet carefully. Piston diameter must be measured at the gauge point indicated on the sheet. Required clearence depends on the diameter, alloy, type or forging (full Skirt or Slipper design) application, operation conditions.

What is the clearence between the Connecting Rod and the Wrist pin?

The clearence between Rod and Writs pin is 0.010-0.012mm (0.0004"-0.0005")

What is the difference between 4032 alloy and 2618 alloy?

A) 4032 High Silicon (aprox. 11% of Silicon but enhanced with additional Copper, Nickel & Magnesium) Low expansion alloy.

B) 2618 Low Silicon High Expansion alloy. Because most use the 2618 they say it is better, but that is not always like that. In fact they are pretty similar and the difference is not that big.

What is the Expansion rate of 4032 alloy?

4032 expands 18% less than 2618

What should the clearence be between the Piston dome and Cylinder head?

For Steel rods: 0.040” (1mm). For Aluminum rods: 0.060” (1.5mm).

Do Pistons come with Pins, locks and Rings?

Supertech pistons come with Pins and Locks, however the Rings are sold separately.

Do the cam followers come with Shim, and what size are recommended?

The 8mm shims are sold separately, and one should alway measure the clearence between cam and valve tip to know what size shims are needed.