Special K Part 3: Reassembly

Special K Part 3: Reassembly

If ever there was an indicator of how far things have come, try lifting a B series and then a K! One would make a ship anchor and the other would only be suitable for a dinghy!

A notorious coolant leak point on the K is the inlet manifold gasket so make sure you use the later version and be careful it doesn't get crimped as you fit the manifold to the head. That's easy with the engine out of the car but slightly more of a challenge when its in. The original thermostat is deleted on our K as it has the external housing modification thats been retrofitted to most MG/Rover installations of the engine and called the 'PRT' or 'Pressure Release Thermostat'. The gasket for the old housing still needs something in it to provide the thickness to support it and seal the old chamber. The usual choice is a thermostat with the centre cut out but this restricts flow as the aperture is quite small. We have created some stainless steel inserts that have an aperture that doubles the area through which the coolant flows. These are available by clicking the link below.

The sump on the Turbo 75 has the addition of a stainless steel gasket between sump and block and this was coated both sides with Hylomar. Some factory versions were prescoated with a soft gasket material.

With the core engine completed we turned our attention to the turbocharger. When the oil and water of an engine have mixed and it is turbocharged, you can almost guarantee the turbo bearing is Kaput. Rotating at many times engine speed, lack of lubricant is quickly fatal to the turbo shaft bearing and this was the case with ours. Fortunately, good quality replacement cartridges for the Garret turbo on these angines are relativaly cheap. Make sure you get a good one as many of the Far East copies have been coming over with smaller oil feed ports. We assumed these were the version for the MG6 but have confirmed they are not, so something of a mystery.

Clean out or replace the turbo oil feed and drain pipes otherwise you'll be pumping old oil/water creamy froth into your sparkling new turbo.

As a bit of a homage to Rover Groups ancestry and because we had it laying around after a B Series build, we painted the block in Austin engine green and very pretty it looks too.

After installing it is imperative to bleed the cooling system well. Here is the MG Rover official method for refilling and bleeding:

  1. Disconnect hose from bleed valve. Attach suitable tube and blow through to ensure that valve pin is not sticking. Reconnect hose to bleed valve.
  2. Remove bleed screw and fill cooling system keeping level at neck of expansion tank.
  3. When a steady stream of coolant is emitted from the bleed orifice, refit bleed screw. Continue filling until level remains static at expansion tank neck.
  4. Turn off air conditioning by selecting 'Econ' mode [this is only to prevent the radiator fan running constantly].
  5. With expansion tank cap off, run engine at 1500 - 2500 rpm whilst keeping coolant level at expansion tank neck. When level rises, fit cap.
  6. Continue to run the engine at the same speed until the radiator fan starts running. [In practice the engine may not get hot enough for this.]
  7. Reduce engine speed to idle until fan stops. Switch off engine.
  8. When system is cold, check level in expansion tank and top-up to the 'Max' marker not the expansion tank neck. [In practice you may have to do this a few times after a journey before the level stabilises.]

Good luck with your project.


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