htr
Well-Known Member
- Posts
- 1,602
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- Central Otago, Southern New Zealand
Okay, after getting it all back together I found I had a persistent coolant leak when hot and cold. Coolant was coming out of the Head joint right above the block serial number and I could see beads of coolant along the joint face behind the exhaust manifold. Hmmmm. I was tempted to take the cam cover off and give the head bolts a 'tweek up; to see if that would fix it but I was to frightened that I might snap a head bolt.
After much reading and correspondence with those much more experience than I, I realised that the only option was to take the head off. Now this project of mine hadn't had a coolant loss issue that I knew of, and there was no evidence of one either, no coolant stains seen while I was taking it to bits.
What I found. The fire ring on cylinder #1 closest to the distributor was unevenly crushed and there was a deformed and slightly raised lip at about the 4 o'clock position. The shim above it showed that it wasn't centred accurately over the cylinder as you can see in the photos below. This would match up with where the coolant was coming out of the head joint.
I've carefully checked the liner height and yes there is an issue with all liners. I checked with a steel ruler diagonally across each cylinder, both ways, and can't get my thinest feeler gauge 0.0015 beneath the ruler except at three places and they are toward the cam belt end - cylinders 3 & 4. My guess is that they may protrude by 0.001mm or possibly less
I'm thinking of ordering a Payen BW750 HG which has the later fluro blue polymer on it. I read on the MG Rover forum that the blue handles chemicals [oil, fuel. coolant ...] better. To go with that I fit a Head saver shim that I've seen on eBay see here
Advice please: I had the valves enshrouded on my head. That possibly increased each cylinder's capacity by about 2 to 3 cc so possibly as much as 8 to 12 cc in total. The head skim would have worked toward correcting this. I should fit a head saver shim what thickness would be best?
The shim that came with the MLS HG is in good condition. If I remove the grey / black coating I guess that would be about 0.003mm, could that be usable?
After much reading and correspondence with those much more experience than I, I realised that the only option was to take the head off. Now this project of mine hadn't had a coolant loss issue that I knew of, and there was no evidence of one either, no coolant stains seen while I was taking it to bits.
What I found. The fire ring on cylinder #1 closest to the distributor was unevenly crushed and there was a deformed and slightly raised lip at about the 4 o'clock position. The shim above it showed that it wasn't centred accurately over the cylinder as you can see in the photos below. This would match up with where the coolant was coming out of the head joint.
I've carefully checked the liner height and yes there is an issue with all liners. I checked with a steel ruler diagonally across each cylinder, both ways, and can't get my thinest feeler gauge 0.0015 beneath the ruler except at three places and they are toward the cam belt end - cylinders 3 & 4. My guess is that they may protrude by 0.001mm or possibly less
I'm thinking of ordering a Payen BW750 HG which has the later fluro blue polymer on it. I read on the MG Rover forum that the blue handles chemicals [oil, fuel. coolant ...] better. To go with that I fit a Head saver shim that I've seen on eBay see here
Advice please: I had the valves enshrouded on my head. That possibly increased each cylinder's capacity by about 2 to 3 cc so possibly as much as 8 to 12 cc in total. The head skim would have worked toward correcting this. I should fit a head saver shim what thickness would be best?
The shim that came with the MLS HG is in good condition. If I remove the grey / black coating I guess that would be about 0.003mm, could that be usable?
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