Topic: Head Gasket Selection Help?

[BenelliSEI]

Gentlemen….. Thsnks for all the great advice! Much appreciated. John D.

[PeWe]

I test first if nuts will move when continue with same tourqe when I want to know how much gasket has compressed.
Nut by nut from inner to outer.

Next is to loosen 1/2 turn followed by tighten again.

The thin M6 as last ones. 4 under rubber coins + 2 on each side of cam tunnel.
The earliest have only 1.

If the nuts sat loose, I'll redo the day after again. No hurry when working at home for myself

Thanks Per. Will give this a try. J.

Loosen 1/4 turn is enough just before retighten the last again

Since I have wrenches in Nm, I tighten, 5, 10, 15, 20, 25 ... (MLS need 29Nm. It will collapse a little just before when it feels easier)

I have 2 wrenches.  German made Hazet.
1/4" 2.5-25Nm (usually max 15Nm with it)
1/2" 10-60Nm

All M6 max 9 Nm. I tightened 10Nm before.
But why tighten just above max for grade 8.8 bolts in steel when aluminium is not that durable?
Too many thread inserts used.
https://www.unitconverters.net/energy/ft-lb-to-nm.htm

[BenelliSEI]

Curious why you all pull the head nuts so tight? All my early (and later) copies of the Honda workshop manuals say 15.9 ft.lbs.

[Phoenix]

I have a Cruzin Image 836 head gasket and Mark said they should be ok.  It's 1.55mm thick.  When I put it on my shaved jugs, I get a dimension of 2.66 so I would need an o ring larger than 2.66.  Does that make sense.  Can I use two o rings to fill it in?  DON'T WANT A LEAKER.

[Don R]

 Which dimension is 2.66?

[Terry in Australia]

I think he’s talking about the fire ring Don? 67.5mm.

[PeWe]

Oil feed o-rings for thicker gaskets, 1-1.2mm thick.  10.78x 2.62mm
(Stock 11x2.5mm)

I'll measure mine CI 836 gaskets.
Rather sure they are 1.2mm thick measured on the fiber area, not metal rings around bores.

[BenelliSEI]

I have a Cruzin Image 836 head gasket and Mark said they should be ok.  It's 1.55mm thick.  When I put it on my shaved jugs, I get a dimension of 2.66 so I would need an o ring larger than 2.66.  Does that make sense.  Can I use two o rings to fill it in?  DON'T WANT A LEAKER.

Ed.... is the 2.66= 2.660”? Is that the I.D. of the bore (piston holes)? Why do you need “0”rings that diameter? As PeWe suggested, measure your head gasket thickness at the fibre edge.

[PeWe]

I measured mine. I'm rather sure it is a CruzinImage gasket
1.25 mm thick. It will compress for sure.
Tighten nuts by 20 ft lbs. Not less when using 836 and higher compression.

Retighten after 24 hours or longer.

O-ring comoression calculation:
Gasket + o-ring groove max 2.2mm.
O-ring thickness 2.62mm makes 0.42/2.2 mm compression of 0.1909-->19.1% wich is just under minimum recommended compression.
20-30% as I found at an o-ring resellers specification.

O-rings can not be too thick. They can collapse inwards.

Lets say that gasket compress 0.1 mm further, total 0.15mm. 1.1mm thick, o-ring groove in cylinder 1mm. It can be 0.9 too or less if milled without adjusting the o-ring grooves.
# Total depth 2.1mm,
#  o-ring 2.62mm
Compression:
# o-ring- total depth= 0.52.
0.52/2.1=0.2476-->24.7%
This will be fine.

If o-ring groove is 0.9mm
Gasket compress to 1.1mm
Total 2.0mm
Compression  0.62/2.0=0.31 -->31% which is at max.

In last case with stock o-ring 2.5mm thick
Compression 0.5/2.0=0.25 -->25%

 O-rings Hondaman has recommended on several forum threads. 10.78x2.62mm. This is a std size possible to order from several sellers.
I have ordered viton from UK.

Gasket below 1.25mm thick, photo might not show exact due to  where camera lens is located, parallax error.