Determining Crank Bolt torque

Technical Area Engine, Transmission, Exhaust etc
2

Hello all,

Did timing belt job over the past week and the car is running so seems to be all good. 

Currently i torqued the crank bolt to 137nm (mid way between the ranges for the early 90 cars, and the >91)

I did this because I am unsure which type of crank is in my car. It’s a 1990 eunos 1.6 (made Dec '90). As far as i’m aware this should have a SNC. But the pulley has 8 holes and the bolt removal was required to remove the timing belt. So i think it’s a LNC. 

Can anyone clarify a way of knowing for sure which crank it is? I know there is also the BNC which i don’t know much about. 

 

Thanks,

Simon 

3

Hi Simon

Your car has the later long nose crank which is good for this purpose.

The eight slot pulley cannot be fitted to a short nose crank engine.

You need to increase the torque for the longer nose crank setting. 

 

 

4

I [personally] use 160Nm with Loctite 242 and whizz a blind [bottom] tap inside to clean the threads if I ever need to do it again.

Ensure the three mating surfaces are perfectly clean as well

5

Agreed with Hilux,

Remove crankshaft bolt again, clean thread with tap, apply threadlock. torque to the higher value for the long nose cracnkshaft. Replace any other bits removed and go for a run.

6

I was surprised at how clean the bolt and threads were when I removed. Looked brand new. I didn’t apply loc-tite as there wasnt any before and it wasn’t in the guide I used although I had heard about using it. I’ve now torqued the bolt to 160nm though. 

7

The advise about using loctite or similar products is advised in this situation as you have a single point of failure, that is one bolt holding on a heavily stressed component.

As always it is up to the owner to use their engineering experiance to decide to take this advice or not.