Thread: 1.8t hgf
View Single Post
Old 29th April 2015, 07:29   #29
RodgerD
Rodger & Out
 
Rover 75 Saloon

Join Date: Nov 2014
Location: London
Posts: 712
Thanks: 10
Thanked 159 Times in 141 Posts
Default

Quote:
Originally Posted by barry View Post
Kaiser
Just a thought regarding your HGF problem. I once had a Singer Vogue which twice ended up with HGF. In addition the original head and one replacement cracked between the two centre cylinders after several attempts to rectify the failure. In the end it was neccessary to replace the engine due to the water ingress into the cylinders.
The third cylinder head after surface grinding was fitted to the replacement short block. The block itself had been resurfaced on its top face. This engine and cylinder head never gave any more trouble which led me to believe that the original block top surface was not true, possibly distorting the cylinder head under torque.
Sorry to be long winded but thought it may be worthwhile if the head is removed again for the block to be checked for trueness although the visual signs in your case are indicating something quite different at this stage.
Barry
It's an aluminum block with spun cast steel cylinder liners with the two metals expand at different rates. The liners should be around 0.004" higher than the block when cold, which results in them being flush at operating temperature.

A lot is going on, thermal expansion of dissimilar metals, possibly electrolytic corrosion or cavitation. The original HG was a single sheet gasket with perimeter elastomer seals and a flame ring with a multi-layered gasket being an improvement. Its fitment only recommended if liner heights are within specification. Just checking that a block face for 'trueness' isn't sufficient.
RodgerD is offline   Reply With Quote