Head gaskets. True? or bull?

F

FlyingApe

New member
Location
Loch Lomond, Scotland
1)  I have heard it said that when new head gaskets are stored, the copper head sealing ring hardens with time ( in the same way copper work hardens).

So, if I have an immaculate unused head gasket that's about 25 years old, should I scrap it, or use it? ( and yes it is the rounded end version)


2)  The workshop manuals state you can re-use a head gasket. I am very reluctant to do this, but what do you think?

3) RGS Torque settings. Laverda's workshop manual states 32ft lb for CH and 28 ft lb for outer camshaft nuts.  The green book states 27ft lb and 20 ft lb respectively.

What should I be using?

If it makes a difference, I am running 1200cc and high comp pistons with Mikuni flat slides. Hoping for 100bhp+ once set up.

Thank you

 
IMHO (not any one else's)
don't re-use a composite head gasket,
new old stock gasket should be fine, don't forget the O rings in the butchered flame rings for the outer four studs.
torque settings I use are 25ft/lbs for the 12 off 9mm studs and 15 ft/lbs for the  six off 8mm studs. They all have the same 13mm spanner size.

100 BHP can be achieved on dynamometers with high lift gauges.
CLEM
 
But what about the copper related question?? And speaking of copper...I have one of your gaskets, its art! Only not used as dont want to mill or deck my head...
 
I don't think the copper flame rings are solid copper as they are designed to crush down. I don't think there will be any issue with NOS head gaskets due to this.
I think to achieve 100+bhp with a high comp 1200 is stretching it a bit.
In my experience the RS36 Mikunis are not a performance aid, just a better design carb giving better fuelling and economy.
Maybe if the inlet ports are opened up to 36mm from 32mm to match the carb size, degreed cams, big valves, ported head and so on, then 100 is feasible.
Red in Australia is achieving over 130bhp with his full race engine, but who knows (other than him) what is inside that engine.
Gijs Van Dijk is offering a 4 valve head along with fuel injection and Nikasil bores and uprated crank, but I heard it makes big power and revs to 11,000rpm.

Dave, is that you?
 
and........................its no use at all using a torque wrench that in any way is "dubious" finest quality only, eg Snap On,  Stahwille etc and one calibrated to 200ft/lbs wont even show you where the marks are for 25 and 15, my low end torque wrench only goes to 40ft/lbs. I have another that does 200 odd and another which is 1/4" drive and is measured in inch/lbs on a dial guage. I also have several 1/4" drive ones that are pr-eset single value.
CLEM
 
I have a pile of NOS 750 head gaskets that I have been slowly using up over the past years, no issues whatsoever.

Composite gaskets are not to be re-used, factory manual advises against re-use.  Used gaskets cannot fulfill their purpose.

You'll need a bit more than hi-comp 80mm bores to achieve a real 100+hp.  After many grabs to the bottom of the box of tricks, my 78mm bore triple is making around 105, which I regard as just about the end of the pole for a road motor.  Even with the clapped out 75.6mm motor, it made a respectable 98.  Without serious porting and meticulous valve seat work, you're going nowhere...

Our experiments with FI back in the 90's yielded a good 112hp with a 80mm bore 120? triple.  Same engine barely made 90hp on carbs!

piet
 
FlyingApe said:
1)  I have heard it said that when new head gaskets are stored, the copper head sealing ring hardens with time ( in the same way copper work hardens).
Click to expand...

If you work harden the copper in your stored head gaskets ....... then they will become work hardened.

If you store them in a static state then they will not become work hardened.

Jim
 
Could an old, unused copper gasket be annealed? Really don't know so posing the question to those who do.
The  navy taught us to use a torque wrench where the settings you require fall in the middle of the wrench's range.
 
I've reused many copper washers after having annealed them. As long as they haven't changed shape too much or been squashed to death they have worked fine.
 
Copper doesn't age harden (some copper alloys do, but not pure copper). I could launch into a technical treatise on the crystallography of age (aka precipitation) hardening, but I doubt anyone wants to be bored to death.

Suffice to say that old copper gaskets should be perfectly OK to use.
 
Dellortoman said:
Copper doesn't age harden (some copper alloys do, but not pure copper). I could launch into a technical treatise on the crystallography of age (aka precipitation) hardening, but I doubt anyone wants to be bored to death.

Suffice to say that old copper gaskets should be perfectly OK to use.
Click to expand...
Some of us aren?t afraid of dying, time to spew forth
 
SOLID copper gaskets can be re-used, and I have done so many times, on many types of engine, the requirement is to freshly re-anneal them and bolt it all up the same day.

The standard Laverda head gasket is composite and the copper or alloy (maybe even steel) flame rings are a "wrap" and have a thickness either side of the composite, just look at the cut outs for the O rings and you can see that inside the flame rings it is composite. The liners are set about 8 thou below the alloy castings and when you bolt everything up the gasket "settles" into this very small indent, that gives the gasket the effect of a "dam" the pressure is pushing the gasket against the tiny backstop if it ever let anything past the flat to flat surfaces, this doesn't always work however and I once blew a lump of gasket out of the right side of the motor (a triple) in between the two outer studs, the lost bit hit me in the leg and hurt a lot, oil then pissed everywhere and it was game over. I have never used ( on a Laverda triple) a composite gasket since,
CLEM
 
You must log in or register to reply here.
Back
Top