Mi16 Head Bolt Tightening.

[ORB 227 1 Cars]

Well, I guess the title has told us what I am asking.

 

And I know there is a search function, but I am not looking for info on how to do it, I am more looking to look at the differednt methods people use and stick to?

 

There are a few different sequences that I have seen over the years and even Puma racing say that the standard method is over kill.

 

So I am trying to work out what is the most popular sequence, what method did you use? and have you ever had bother?

[James_R 3]

25lbs, 50lbs then 75lbs middle outwards in a sprial each time.

[Anthony 1,003]

As per James's post above

[DamirGTI 342]

1. stage - 30Nm

2. stage - 55Nm

3. stage - loosen each bolt one at a time 1/8th turn and retighten to 55Nm

4. stage - 80Nm

5. stage - 95Nm (70lbf ft)

 

Damir

[woodsy 0]

I did mine the puma racing method and aint had any trouble at all.At least theres less chance of stripping a thread in block

as original stages is stupid.

[yorkshirekowboy 19 1 Cars]

1. stage - 30Nm

2. stage - 55Nm

3. stage - loosen each bolt one at a time 1/8th turn and retighten to 55Nm

4. stage - 80Nm

5. stage - 95Nm (70lbf ft)

 

Damir

 

 

this above is what ill use when i do my spare engine

[Miles 331 1 Cars]

As per the OE spec on std head bolts, xx lb ft then 300 degress on the later type of bolts.

[Cameron 16]

Slight variation on the original, 60Nm, then 20Nm, then 270 degrees in 3 stages of 90 degrees. Dead easy.

[Tom Fenton 1,542]

I must admit I always do the angle tightening part in three lots of +90 deg.

[brumster 135 1 Cars]

Up to first torque in the spiral order specified, then just straight up to the final torque on the 2nd pass. How AB told me to do it, and also was echoed by Longman when I chatted to them. No problems for me

[Stu 18]

Ive tried both ways, the angular method and the torque method, and either way its held together! I did prefer the torque method tbh, simply because im not a fan of using the angular gauge, especially on the top left headbolt..

 

Although i must admit, ive never put 300degrees on in one hit; ive always halved it and left 24hrs between tightening. You'd be suprised how much an alloy head/block moves under compression...

[Cameron 16]

Nah, you don't need to leave it any amount of time between stages. The tightening angle is specified to consider any shrinkage or movement.