Grogee's spannering (Puma, Maestro , Corsa & Avensis). MAESTRO MALAISE

[Mr Pastry]

50 minutes ago, grogee said:

I get this, but it's nearly impossible to get my eyes level with the block to see if there's daylight under a straight edge. 

Also, if the block isn't flat, I won't like that answer. 

A couple of things.

Use a feeler gauge or even a bit of paper or thin card under the straight edge.  Which of course works on the head also.     

When you have the head off - before you take the valves out, check with paraffin in the ports that they are actually sealing.  They should be if you have ground them in, but you need to know definitely.

Was the misfire evident when you first started it up, or has it developed since?

 

 

[Cluffy]

Use feeler gauges? Sure you have some in stores or borrow mine?

Likely you've already done. If so, as you were....

[grogee]

I've checked block and there is no apparent banana-ing that I can detect. However there is pitting on areas of the block around the coolant channels, but not near the rings which seal the combustion chambers. There is no way of getting rid of this without a mill and a fly cutter so I'm going to live with it. 

I have been On A Journey as far as O-Series family tree is concerned. I was blithely assuming that all blocks and heads were basically the same, and I've successfully ordered parts for other cars (eg Rover 2000 and Freight Rover manifold gaskets) that fit just fine. 

Delving a little deeper I have found that head gaskets differ, at least between FWD and RWD cars and possibly even between FWD car derivatives. 

Part of my previous HG woes may well have been because I've been trying to fit the wrong gasket. 

The gasket in the plastic film is for a Sherpa/LDV and you can see the oil way and coolant channels don't match up. 

Fortunately I have a gasket listed for MG Maestro and Rover 800 (bASe models of which used O-series) coming. 

Whisper it, but I've also smeared a bit of sealant around the block where the pitting is apparent. This is a big Haynes no-no and must not ever be done under any circumstances. 

I wonder if it'll work? 

[Jenson Velcro]

I’ve used JB Weld to fill some slight pitting in the block mating surface before. Worked well