Tuesday 2 March 2010

Back to Work

It seems strange to be updating the blog after such a long interval, but my work commitments have now slowed, and I am able to work on the estate again.

I took a trip to the machine shop today and collected the engine parts.

Unfortunately while pressure testing the heads and block various porous areas were found. This necessitated liners being fitted to some of the bores. You can just see the lip of the bottom of one liner in the following picture

 

The heads needed welding where corrosion had damaged the faces. The best head is here, you can see where the welding was done near to number 2 chamber from the slightly closed water way



The other head was much worse, and you can see far more evidence of welding, particularly near the chambers - the rough edges.

 

Both the heads now need work, to reshape the chambers back to standard, radius the chamber edges (to help prevent detonation) and to equalise the chamber volumes.
Because I had the welding done, only 10 thou was taken off the faces, so it won't need thick gaskets (or stainless steel head shim, and it shouldn't cause any alignment problems in the V with the inlet manifold.

I decided to recover these heads rather than try and find other good ones, as the low mileage means that the cam bearing faces are all good, the cam bucket bores too, and many secondhand heads have damage in this area which is even worse to recover.

New valve guides were fitted, the crank was crack tested, tuftrided and balanced as an assembly, with front pulley and flywheel and dummy pistons. (weights are attached to replicate piston and rod weights). Con rods were weighed and matched end to end.

The balancing is worth it for a smooth running engine, and pressure testing and crack testing should help with reliability, when this goes back in, I don't want to be fetching it out again in a few thousand miles due to unforseen problems.

The next step is to build the bottom of the engine, and assuming it rotates correctly, measure all the piston heights and then machine block and front cover to zero deck the pistons.

I need to buy another burette (mine is broken) before I work on the heads, as I intend to equalise the combustion chambers, and smooth out the ports.

I hope to get some roof work done later this week, so the engine will wait.


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