Crank question ??????

[8thsin]

In the process of rebuiding my engine and have been asked if I wish to nitrite the crank and cryogen it (exuse the spelling)

Does anyone know if nitriteing it will make it to brittle.

Cheers

[Chris Wilson]

It already has an induction hardened heat treat, leave it alone.

[8thsin]

Thank you for taking the time to answer this enquiry
Its a new crank that has been cryo'd and balanaced and is going into an engine to hopefully produce approx 1100-1200hp.
You wouldn't do anythink else to it??:search:



It already has an induction hardened heat treat, leave it alone.

[suprafan72]

1200hp!! why do u need that much?

[RobSheffield]

Drag car iirc ;)

[suprafan72]

Drag car iirc ;)

Expensive hobby!

[SUPRASUZUKI]

Thank you for taking the time to answer this enquiry
Its a new crank that has been cryo'd and balanaced and is going into an engine to hopefully produce approx 1100-1200hp.
You wouldn't do anythink else to it??:search:

1200bhp? Is that all? :blink:

[8thsin]

Ive been racing the car for approx 4 years and the best i got was 10.4 @138MPH with a T88 34D
Spun a bearing and the engine came out only to realise the crank was bent. So I bought a new one.
My T88 34D was damaged so insted of fixing it, i spent an extra $500au in replacing it with a T88 38 GK.

Now I am in the process of having it put back together.

and yes a very expensive hobby:( though a rewarding one:D
1200hp!! why do u need that much?

[Chris Wilson]

So it's a none stock steel crank? Every crank manufacturer over here sells aftermarket race cranks ready heat treated and balanced.

You aren't trying to build such an engine on a stock crank, surely??? :(

You should be looking at something in S312 at least, and I'd probably spec oversize rod journals with custom rods, and bigger diameter tool steel piston pins.

[RobSheffield]

replacing it with a T88 38 GK

:blink:
:blink:
:blink:

lol nice one :D

[8thsin]

Ive got JUN rods and Arias pistons. Excuse my ignorence but what is s312.

So it's a none stock steel crank? Every crank manufacturer over here sells aftermarket race cranks ready heat treated and balanced.

You aren't trying to build such an engine on a stock crank, surely??? :(

You should be looking at something in S312 at least, and I'd probably spec oversize rod journals with custom rods, and bigger diameter tool steel piston pins.

[Digsy]

You should be looking at something in S312 at least, and I'd probably spec oversize rod journals with custom rods, and bigger diameter tool steel piston pins.

Is that an SAE spec? That's in the numeric range for stainless, although there's no direct BS equivalent in my Macready's book.

What standard is that to?

[Chris Wilson]

It is, as far as I recall, a none maraging, vacuum melted aerospace grade of EN40B, now popular for long cranks with either poor pin overlap, or being given a very hard time, and things don't get much harder than an in line 6 crank, turning 1200 BHP, in a drag car :)

[AndyT]

It is, as far as I recall, a none maraging, vacuum melted aerospace grade of EN40B

Reasonable quality then? :d

[8thsin]

Just searched EN40B and it is a chromium-molybdenum nitriding steel usually supplied in the hardened and tempered condition.
Would you know the composition of the standard crank (OEM) and if hardening would make it too brittle.:search:



It is, as far as I recall, a none maraging, vacuum melted aerospace grade of EN40B, now popular for long cranks with either poor pin overlap, or being given a very hard time, and things don't get much harder than an in line 6 crank, turning 1200 BHP, in a drag car :)

[Chris Wilson]

Just searched EN40B and it is a chromium-molybdenum nitriding steel usually supplied in the hardened and tempered condition.
Would you know the composition of the standard crank (OEM) and if hardening would make it too brittle.:search:

I don't know, the stock material spec is something that I tried to research and got no conclusive answers. I wouldn't even consider a stock crank for your application though.

[8thsin]

I know it sounds crazy but Ive seen in excess of 1500 hp out of a stock crank in a local drag supra engined tube car. I won't be going that far..... From what I've seen (which probably isn't that much) the weakest part of the supra internals - if you're chasing power- is the rods and pistons. So I supose my confidence comes from this, not any particular science. I dont mind if you call me crazy coz there is a bit of madness in wanting that kind of power....[/GRIN][/GRIN]
I don't know, the stock material spec is something that I tried to research and got no conclusive answers. I wouldn't even consider a stock crank for your application though.

[Alex]

Is your car the 8thsin on Mario's site???

[Chris Wilson]

It is, as far as I recall, a none maraging, vacuum melted aerospace grade of EN40B

Reasonable quality then? :d

£2200, in S312 you can choose the stroke and big end journal diameters.

£1700 in EN40B, again, choose your stroke or keep it stock

Both fully machined, heat treated and balanced. 8 to 10 weeks delivery.

Pics of my Skyline one at ftp://ftp.chriswilson.tv/Skyline_Stuff/crank

[RobSheffield]

Is your car the 8thsin on Mario's site???

Yeah, iirc marios site is Ex Vi Termini isnt it?

[8thsin]

Yep thats it.
Its been down for a while.(mario can be a bit lazy:) )
Yeah, iirc marios site is Ex Vi Termini isnt it?