Headgasket woes

[ekranoplan]

No sealant was used - just engine oil as per Lancia workshop manual. Cheers,

L

[lancialulu]

Hi

For what it is worth here is the advice which I have heeded from Paul LeClerque on head bolts.

"Unbrako 12.9 grade standard cap screws. My procedure with a new gasket, is to tighten them to 15 lbsf/ft, then to 20 and after half an hour, to 25. In 23 years of Fulvia ownership I have never had a gasket failure. Where possible I always use second hand head gaskets."

Dont know if this would have made any difference but I have also yet to have a gasket failure after several top end rebuilds.

The cam cover gasket is another issue however and on one occassion it just did not seal. Offending object(s) the 2 new spectacle gaskets from Spesso!!! they were 2mm too thick

Tim

[Andrea Nistri]

Just a few general comments on head gasket problems which luckily I never had in >25 y of Fulvia ownership.

Spesso is a reputable company and I never had any problems with their gaskets.

Skimming the cylinder head can cause problems and it is worth checking that the head surface is indeed very flat after machining. The engine block surface is often (and surprisingly) not flat at all: when this happens, it makes the head problem worse.

I assume the head bolts were torqued up in the correct sequence and that the gasket (always dry in my experience despite the Lancia manual) did not move sideways during this operation. Harry Manning had simple tools to ensure this did not happen.

I cannot say anything about modern hexagonal head recessed bolts and their torque. I usually torque up all bolts in three stages after having cleaned their corresponding holes (in the block) with a tap. It is interesting to see how much junk comes up with a tap from each hole and how this can distort the efficiency of the fastener.

Bolt torque is re-checked after about 500 km of careful running-in avoiding over-revving the engine.

Use of a high quality torque wrench fine-calibrated for low values is recommended.
Good luck
Andrea

[ekranoplan]

Thanks for the replys,

I will endeavour to have the head and block checked before attempting to reinstall the gasket.

On another subject the amount of carbon on the valves probably means she has been running very rich so the webers will need adjustment later.

[Andrea Nistri]

I don't know what sort of Webers you are using and what set up they have. I myself have no experience with them as I use only Dell'Ortos or Solexes. Extensive carbon build up in the combustion chamber may come from a fuel mixture that is too rich, and also from inefficient sparks (that, among other things, include faulty plugs). If there are also oil deposits, the piston rings are faulty. I would suggest to do a simple cylinder compression test once the engine is reassembled. Regards, Andrea