Special K Part 1: Oh K, whats the problem?

Special K Part 1: Oh K, whats the problem?

There seems to be an awful lot of misinformation about the MG/Rover K engine. Probably, in the scrabble for a solution when the head gaskets started to pop, anything that appeared to work was grabbed upon and had its moment of glory as the solution everyone had been waiting for. The trouble was, those solutions didn't really get a test in the true sense, "Its now done 10,000 trouble free miles" doesn't really mean much. Add a zero and it starts to become useful. Forums are a phenominal place for sharing useful information, but they can be a disseminator of black magic and old wives tales too.

I happen to like the K Series from the design standpoint, it is a light, compact, great performing little unit. I remember its launch and how Rover went from its small engine being a pushrod Iron block (A series) to the All alloy overhead cam K in a single bound, it was like someone with a Tiger Moth replaced it with a Eurofighter.

Advocates of the K will tell you that abuse is its downfall and that poor maintenance of water and oil levels is to blame and of course, that helps, but with all due respect, other manufacturers engines suffer the same abuse without losing their head, so to speak. The head gasket failures aren't the result of one issue, but a 'perfect storm' of boring a 1.4 out to 1.8 so the liner wall is narrow,  liner movement in the block shoulder, that infamous thermostat position/type and porous areas in the head casting. Control of the quality of sub-contractors output is something Rover didn't ever seem to do well and BMW tried to fix. I remember touring one hydro-forming plant who advised that the large formings they supplied had a tolerance of 3/8" under Rover and 1mm under BMW. Fiat had a similar head gasket problem with their early FIRE engines but repaired them, gave the owners an extended warranty and fixed the issue. Rover, always starved of cash, pretended it wasn't happening.

We purchased our Rover 75 Tourer 1.8 Turbo as a 'spares or repair' with a blown head gasket. We wanted something that could act as a shop van but we didn't need the space of a full van or the insurance issues for Alfie. Mention of 'White van' and 'young driver' sends Insurance companies into meltdown.

We pulled the head and found different liner heights (they should stand equally proud of the block). You only have to look at a disassembled K to see why varying liner heights are a problem- with that narrow 'land' to each cylinder, that close to the next one, how is any gasket going to seal a cylinder with an explosion in it many times a second if they vary. The head also had some slight indentation from the liners on two cylinders. This indicated those liners were moving. There is talk online of the cylinders hammering themselves between the head and the block with each combustion, causing the block liner shoulder to distort and the gasket to blow. However, I argued, the liners have to get some movement to start that process and how could that happen? On the K the liners have a shoulder and this seats onto the block, sealed by a silicone type sealant to prevent oil and water mix. I suspected this thin film might be a place to start as it would explain the difference in liner heights and the movement in the them. We decided to pull the whole engine and 'do a proper job'. Cracking the sump off revealed a collection of stringy sealant in the oil pump pick up. So, the liners had to come out and lo and behold, just partial sealant left here and there.

To remove the liners we pulled the pistons and found the big end bearings were all nice and even and showed the little wear commensurate with the low mileage the car had completed. The pistons and rings were excellent and the liners came out easily which was encouraging as damage to the block can apparently make that difficult. They too were in good condition, the honing marks still visible. In the old days there were engine rebuild shops in every town because you'd need a rebore and decoke with some engines every few years, but these modern units and their synthetic oils are why they all closed!

Having cleaned out the block and liner shoulders, we applied the correct hylomar and refitted them together with liner shims to achieve the correct protruberence above the block. We clamped them down to set because on a K you have to retain them otherwise if you turn over the engine (as we would to refit the pistons and rods) you can pop a liner out again. We fitted the modified oil rail as recommended with the Land Rover modifications for their version of the K. This is stronger than the original item and is where the long engine bolts screw to sandwich the whole head/block/bearing cap section together. Not the sump, its an old keyboard warrior tale that the sump falls off when you undo the head bolts...

Next we had to address the head...

 

 


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