Stage 2 Turbo Project - Crankshaft Nitriding & Journal Polishing

Most stock OEM steel crankshafts have been induction hardened, which is actually a low cost process in which the surface is heated by a high frequency alternating magnetic field that generates heat in the crank's surface quickly before being quenched.

Because of the uneven heating and cooling due to cost saving reasons, the crankshaft hardening process creates a lot of stress within the crankshaft. While it is an ideal hardening process for stock applications, but it is really less then favorable for high performance/racing applications.

Hence, we had the stock 1NZ-FE crankshaft sent overseas to be nitride coated and its now back and ready for us to assemble it along with the engine rebuild. Nitriding is a chemical hardening process in which the part is heated in a furnace, the oxygen is vacuumed out, and nitrogen is introduced which penetrates the entire surface.

The result? An extremely hard surface which will give us a peace of mind when we increase the rev cut to well over 8,000+ RPM, allowing us to stay at the redline level without any worries even under hard boost.

If you're wondering what was the material used, its titanium aluminium carbon which gives the black surface you are seeing in the pictures. Read more about it here.

The color of the crank is now different


A closer look will give you a dark bluish purple look

We also took this opportunity to have the crankshaft journals micro polished, a process where the surfaces are made clean and smooth so that it reduces the friction, allowing the rods to spin a lot more easier and faster.

The end result? A high revving friendly engine to go along with the other parts :)

Surface of the journals are now clean and smooth


Close up shot

15 comments:

achong said...

WOW!

Paul said...

Usually when a NA and Turbo frequently redline while driving, what is the component that will be damaged easily as they cannot withstand the pressure?

Chang Chew Soon said...

paul, the short answer is everything.

however, different engine will have different characteristics.

for example, SR20s are well known for their rocker arms to snap before other components let go.

as for the 1nzfe engine, the most common we've seen is rod snapping and the valve springs bouncing after 7,000 rpm.

Andrew Saw said...

Bro,

Whom will be balancing the lower end rotating assy for you?

Chang Chew Soon said...

that would be uncle toby bro....

Andrew Saw said...

OK. Pls make sure mine gets balanced too!

Nitriding said...

Very excellent technique

Anonymous said...

there is some serious under cut on that crankshaft. must make it much weaker

Chang Chew Soon said...

which pic did you see the cut?

as far as we know, there isn't any work done to the crank to reduce any mass nor anything.

plumbing said...

I know nothing about car accessories and engines but I can see that it is truly clean and well polished.

double glazing said...

Good job! Maintaining car accessories and parts should be done if you want your car to last long.

Anonymous said...

The new super crank from TBR would of been a nice add on.

It's knifed-edged, 3 pounds lighter, shot pined, polished and oil holes rechamfered for better oil flow.

Chang Chew Soon said...

it's really great to know that we have so many people developing parts for the 1nz-fe.

later, we will be able to have comparisons of various approaches to see which one yields better result! :)

Anonymous said...

how many rpm do you think it can take ???

Chang Chew Soon said...

we're looking at 9,000.....