6a13tt broken crankshaft

[Radko]

my 6a13tt broken crankshaft. Does it change or does not get 6a13 crakshaft V6 120kW

[Nick Mann]

I'm not sure I understand the question.
I have heard that the crank is the same between the 6A13 and the 6A13TT but I don't honestly know.

[hbkuk1]

I have heard the fto crank is also the same and it's the bore increased too 2.5lt I don't know how true that is

[Louis]

I'm pretty sure the vr4 crank is heavier built, there is info on comparison on here somewhere.
(I'm mot a full ember at mo so can't check )

[Adam.Findlay]

I have heard the fto crank is also the same and it's the bore increased too 2.5lt I don't know how true that is

Its not true. 6a12 has a much shorter stroke and smaller big end and main bearing journals.

[hbkuk1]

Fair enough Stand corrected :)

[Davezj]

What about the original question 6a13tt and 6a13 crank shaft?
I don't know but an sure Adam will know.

[Nick Mann]

http://www.clubvr4.com/forum/showthread.php?71435-help-engine-problems

[apiqeva]

Yes same the crankshaft. 6a13 with 6a13tt support.

[Davezj]

I know swinks has always said the 6a13 crankshaft is not forged and the 6a13tt is forged (stronger) I have no reason to doubt him as a seem to remember seeing pictures of the differences in one of the threads on hear.

So on that rational you could use a 6a13tt crank in a 6a13 engine but not the other way round.

[adaxo]

IIRC pictures was off 3000GT or GTO crank explaining difference in between forged/non forged, ASA states clearly the same part number for both 6A13 and 6A13TT so I have no reason to believe they got it wrong.



73323

[Davezj]

you would think that, if it is the same parts number then has to be the same part.

but has it always been the same part number, does a very early date code 6A13 crank have the same part number as a late date code 6A13tt crank?

if so then any 6A13 crank should be the same as 6A13tt crank.

[Adam.Findlay]

cranks are the same between N/A and TT

[adaxo]

you would think that, if it is the same parts number then has to be the same part.

but has it always been the same part number, does a very early date code 6A13 crank have the same part number as a late date code 6A13tt crank?

if so then any 6A13 crank should be the same as 6A13tt crank.

Again asa say 'all' and not specify any dates which I understand as it has not been revised throughout production period, which means it must be the same.

[Davezj]

well it blows this comment out of the water

http://www.clubvr4.com/forum/showthread.php?71435-help-engine-problems&p=781093&viewfull=1#post781093

[adaxo]

well it blows this comment out of the water

http://www.clubvr4.com/forum/showthread.php?71435-help-engine-problems&p=781093&viewfull=1#post781093

Which part?

[Davezj]

Swinks says the following in the post I have linked to,

"Had seen pictures of both crankshafts taken off 6a13 sohc and 6a13tt dohc. Yes, they do look similar, but different numbers casts."

[adaxo]

'Different numbers casts' not necessary means they forged or not, various cranks can have different numbers on them which means they require different bearings than others, iirc there is about 3 different sizes of bearings to chose and marks on crank help to pick right size.

[Davezj]

so the question has been answered they are the same crank.

but this does raise the question, is the VR4 crank forged as standard or is this just an assumption.

[adaxo]

so the question has been answered they are the same crank.

but this does raise the question, is the VR4 crank forged as standard or is this just an assumption.

Im afraid it will be a mistery unless you know someone who's good in metals or someone who is close to mitsi technicians. Anyway Im not sure if thats matter, as few push them to 500hp and find out that crank its not the weakest link.

[Adam.Findlay]

I beleive they are cast steel like almost evey other japanese cranksahft. Anyone who says they are forged is just speculating as no-one on any of the VR4 forums has taken a stock crank to a metallurgist and had the grain structure analyzed to prove they are in fact a forged steel not just a cast steel
The numbers cast into them is just the batch or mould number not a part number. Even two turbo cranks can have different cast in numbers.

[Louis]

Hi page below is lifted from another website, the discussion was related to mivec heads n a 6A13TT.

There is a quote "All Mitsubishi factory turbo engines are nitrided".
Which would mean that only the turbo engines are nitrided.

This is not from Mitsubishi, but someone's gathered info which would need verified.

[Louis]

Lol!,
Also found info that says the above is not true!.
Mitsubishi aren't really great at engine specification info.
I have a collection of brochures and info sheets and magazines from Mitsubishi dealers re vr4, I will have a dig through for sales spec info.

[adaxo]

LOL

Thing is with internet that you never know who is on the other side of the screen, it could be a metallurgist specialist (very doubt in that) or could be someone who thinks know everything and its a guru on some kind, I personally not believe in everything what I read until I check that by myself as it happens many times in the past (not only here) that some one talk completely bull**** without even knowing what's he's/she's talking about.

[Adam.Findlay]

At the end of the day It doesnt matter how its made. A stock crank will fail when its going to fail regardless. If you want a stronger crank you need to spend big bucks at the likes of Auscrank or other crankshaft manufacturer to get a new one made from a forged billet. But if your spending that much money (5knzd+) you may as well redesign it to run wider bearings for improved reliability and possibly change the stroke to gain capacity or stability at revs

[Badger_01]

At the end of the day It doesnt matter how its made. A stock crank will fail when its going to fail regardless. If you want a stronger crank you need to spend big bucks at the likes of Auscrank or other crankshaft manufacturer to get a new one made from a forged billet. But if your spending that much money (5knzd+) you may as well redesign it to run wider bearings for improved reliability and possibly change the stroke to gain capacity or stability at revs

Sounds like a plan for when someone wins lotto, go the whole hog and get billet block and heads hahaha