Angle-Tightening: gradually?

[VanDiesel99]

Hi, with thanks for previous help here with my 'mysterious spring'

My XUD9A (Peugeot 405) Head is now rebuilt and ready to go, but I'm a little concerned that the Angle-Tightening required as part of the Torque-ing up of the Head Bolts might actually warp my shiny rebuilt, skimmed Head

(I'll do the ten Bolts Up in the correct sequence of course)

Its a 120degree Angle Tighten...

...would it be prudent of me to 'split' this and do it 'progressively', eg as

3 x 40degrees
or
2 x 60 degrees

Rather than the whole 120 degrees at once

Or would this be 'wrong'?

Making tightening my Head Bolts a 'Five or Six Stage' process, rather than the three suggested
Stage 1: 30Nm
Stage 2: 70Nm
Stage 3: Angle Tighten 120degrees

As you might guess, this is my first time rebuilding a Head

Thanks everyone !

[E-bmw]

While I stress that I haven't done this particular engine myself I have always just done sequences like that as per the instructions.

My understanding of it is that the 2 earlier stages basically torque everything down & then the last one pre-tensions the bolts to keep the head under the correct torque for the gasket/engine combination.

I am assuming that it says use new bolts/studs & that you have done so?

[paintman]

Unless the manufacturer of the hg advises differently I've always followed the vehicle manufacturer's instructions.

ETA I suppose there would be a third way if you have substituted the vehicle manufacturer's fasteners for something else e.g an engine that normally uses bolts being changed to studs.

Edited by paintman on Wednesday 15th April 16:05

[DuraAce]

Just do it in one go. As per manufacturer instructions.

If they wanted it doing in stages then they'd say so.

[Penelope Stopit]

Have you applied sealant under the cam end caps?

Don't know where you're getting the information from

This is from the LDV XUD9A manual



Manual Here

Edited by Penelope Stopit on Wednesday 15th April 16:48

[VanDiesel99]

Thanks everyone for clarifying that, partic fair point made by DuraAce there, “if they wanted it done in stages they’d say so”.

I was terrified that I was going to warp the Head in the course of the 120 / 180 degree tightening, which will be with new Stretch Bolts, as per manufacturers instructions.

A lot of hours have gone into every facet of this rebuild, as is always the case with something when you’re doing it for the first time; some of which have been pretty tedious, such as cleaning the mating face of the Thermostat Housing

Yes Penelope, there’s Sealant under the Cam Caps, I might’ve been a bit generous on this one actually. Do you notice that I have no Garage; only two sheds and a short driveway.

Talking of Cams by the way, most impressed with Plus-Gas: my Cam Pulley didn’t want to budge from the Camshaft when I removed it (but it came out as one unit anyway). However, a few applications of Plus-Gas (I usually favour Diesel, which I figure is thin enough to get into the tightest space) and it eased off with just the gentlest pry; a whole lot of hassle avoided.

Thanks also Penelope regarding the excerpt from the LDV Manual, which are closer to those in my ‘405 Diesel (Haynes 3198)’ than those in my ‘Peugeot Talbot Diesel Engine (Haynes 950); I was a bit torn which set to use and was previously leaning towards the latter coz of the lesser degree of angle-tightening suggested.

[Penelope Stopit]

http://site-90526.mozfiles.com/files/90526/LDV_XUD...

Critical not to put sealant on all the bearing cap face

Suggest you take a look at this topic https://www.pistonheads.com/gassing/topic.asp?h=0&... that shows information posted by PH in the know engine people

Information is also in the manual linked above, see page 40 of the manual

Edited by Penelope Stopit on Wednesday 15th April 20:27

[VanDiesel99]

Oops! Thanks Penelope, thinking about it now, I can't imagine why I was so generous with it in the first place. That'll be redone shortly

[Penelope Stopit]

VanDiesel99 said:

Oops! Thanks Penelope, thinking about it now, I can't imagine why I was so generous with it in the first place. That'll be redone shortly

Glad that you visited back here

Keep well