Head bolt torquing procedure

[Neal R19]

OK so the F7P specs go 30Nm, 50Nm, slacken off, 25Nm, 108degrees

But the F7R specs do the same, but then afterwards an extra stage of running the engine to temperature, cooling, then slackening off and retorquing to 25Nm, 107degrees.

Question is, why the difference? It's essentially the same engine.

 

[Chet T16]

I suppose the F7P ones could be from '88 and they refined them when the F7R came out?

 

[Chris H]

there is no reason, its stupid don't do it.

Retensioning headbolts was relevant with iron blocks and heads or even old ally headed guff from the 80's like GTT's, not with ally heads when using tty bolts. Won't do any harm unless the bolts are dodgy right enough unless you loosen them all off at once then you'll have a right mess :lol: