Jmac, The thought had crossed my mind to have stud kit installed.

You're right about the need to back off the bolts before retensioning. The torque needed to get them moving will exceed the torque needed to keep them moving and thus give potentially a false correct reading.

When I checked them I simply put the torque wrench on to see how tight they were and they moved as described ,no backing off first.

I doubt if there would be much oil getting past the threads on the oil feed head bolt to cause an hydraulic lock.The point is well made though.If you removed and then reinstalled the bolt then I agree that it would become an issue then as any oil around the bolt will go to the bottom of the stud hole.

Fandatstik, Interesting you should mention that. I am aware of that problem however have no experience of that with the the Dato engine. I wonder what temps would be needed to cause that on a Dato head? The temperature recorded is viewed by others as not as bad as it sounds.

If the head has softened I query if it can be re-heat treated or is it then just a fancy looking block of silver swiss cheese ?

Last night we checked the tension on the head bolts and that was quite surprising. All of them torqued down quite a lot. They all went down around 45-60 degrees to reach the manufactures spec of 45ft lb which is what I originally set them at when the motor was assembled. So much for monotorque!

We are going to pull the head off and fit a new gasket. We will also be checking the tension of the head bolts after every meeting from now on.

I have to confess that the idea of a single tensioning of the head bolts after fitting a cylinder head is something I have never been comfortable with generally. Even moreso on a race engine.

Thanks to all who responded. All useful stuff.

Jmac, I like your thinking about the use of stock type gaskets and the "relief valve" approach to them.

The motor we are running now has flat tops and .060 over bore so we are getting quite good compression now compared with our old motor which only had those standard dished jobbies. That motor was more a set and forget type setup that was reliable meeting after meeting. Now it is making more power so everything is a bit more stressed including the head gasket.Once Ive checked the valve lash we'll decide what to do but I'm about 95% convinced at this stage we will pull the head to make sure all is well.

I realise this is resurrecting and old thread however it is still a relevant topic today.

Has anyone had recent experience with the Monotorque head gaskets?

We are using one on our Junior Sedan and suspect a failure after only 3 meetings. We experienced some overheating due to mud on the radiator core and reached about 225 deg.F ('ken hot!)

Now, we can't get it to idle properly. Changed carbs and no difference so that is eliminated from the range of possibilities. No vacuum leaks. On raising the RPM it runs smooth.Still investigating at this stage and need to eliminate valve lash as a possible problem. I am now inclined to the view that the head gasket is the source of the problem.

Any suggestions or comments?

Disco-bob,
Thanks for your input .

Do you have a part no. for these bungs?

I have access to a lathe so I might just turn up some new ones in brass.

Don't worry about the beer , there is a carton already organised!

bttt.

Anybody have a view on this?

I am in the process of building up a fresh 1200 . I am curious to know if the oil gallery in the block can be adequately cleaned without removing the two gallery plugs?

If not, it appears they need to be drilled out. Anyone done this before?

I note the concern about the accelarator pump leather softening up. The simplest way to check that is to take off the air cleaner and manually activate the throttle and look at the accelarator pump discharge nozzle and see how strong the discharge is. Should give a nice strong continuous squirt.

If that is all good then you should consider the jetting particularly on the secondary side.

Do you know what size are the jets for this carb? The secondaries can be anything from 135 to 150. The secondary jet might need fattening up a bit if it hesitates in the manner as you describe.

It does sound like it is sticking.

Have a look at the pic attached, you can see the the PVC joiner wedged in the relevant port.

The one on the side is just a breather to allow the piston to move up and down freely don't worry about that one.

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