Connecting rod nut torque

[mwredit]

I'm rebuilding the engine in my 77 HPE 1800 and have gotten conflicting information in regards to connecting rod nut torque.  The manuals say 54 ft lbs and the Guy Croft book says 34 ft lbs for a 1600-1800.  When I go to 34 ft lbs, the nuts torque down as they should.  However, when I go to 54 ft lbs, the feel is not right and I quit torquing.  Fortunately, I've only done 4 nuts so far.  I'm thinking either the nuts are on the verge of stripping or the bolts are stretching.  Thoughts?

Mike Rivers

[Neil-yaj396]

Can't see Guy Croft getting it wrong.

[mwredit]

Yeah, that's exactly what I thought.  34 ft lbs seems more logical to me.

[rossocorsa]

Just had a look on my phone and on later cars it's 75nm don't know if they differ in any way from 1800 ( that's about 55 lb ft). I can have a better look when at home

[rossocorsa]

Ok on earlier cars all models except 2000 and USA 1800 51nm for 2000 and USA 1800 74nm.

[peteracs]

So both Guy and the manual are correct sort of, depends on the model.......

Odd that the USA 1800 varies from the standard 1800....

Peter

[rossocorsa]

Out of interest I had a look at the parts book for early US cars and they use the same bolt as the European 1.3/1.6 so the higher torque setting doesn't make sense.