Well Christmas has come and gone and last week the block, head and crank came back from Barum Engineering, and it looks good, but first just to catch up on the other stuff i've been doing while waiting for the engine.
All the component parts of the engine have been cleaned, sandblasted and painted. To start with the exhaust and inlet manifolds were parted mainly because the heat riser valve seemed to have been removed and welded up. As was to be expected the four bolts sheared off but with a bit of gentle persuasion the manifolds came apart. As i suspected the valve and shaft had been removed and the remaining holes in the side of the casting quite roughly welded up. I decided that this would be unrecoverable and turned my attention to the inlet manifold. The four broken bolts were well rusted in and after several attempts with stud removers i decided to drill them out, this worked but i found the reason why they wouldn't come out, they had been put in cross threaded and even after a careful clean up the threads were too far gone. I then drilled them out and inserted helicoil thread inserts, job done, the manifold was then cleaned and sprayed grey.
It occurred to me after looking online that there are two steel bushes in the exhaust manifold that support the heat riser shaft. Maybe when they welded up the holes these may still be there, some gentle cleaning up with a grinder revealed them and once i could see the full circle of the bushes I then tapped them straight through the casting and out. Manifold saved!!!! I ordered a kit and with a bit of jiggling around i managed to fit it. The valve is very simple in operation, when cold the balance weight holds the flap inside the manifold closed and diverts the hot exhaust gases up inside a cavity around the inside of the inlet manifold and then back out to the exhaust manifold, as the engine warms the bi metal spring moves the flap open and allows the gases to exit the engine straight down the front pipe.
Now, the engine. Well Lee and John at Barum checked the bores which had had liners fitted and with a a clean up with the honing tool came up lovely, the head was skimmed, and the top of the block was skimmed to remove the pitting around the valve areas. This reduction in height was matched by machining the same amount off of the top of the pistons to maintain the correct compression ratio. They also checked the valves and fitted bronze valve guide inserts and re cut the valve seats. While checking the crank John found that it had been machined out of line so i can only assume that this must have been felt in the vehicle! He waved his magic wand and re machined it. Now i've got it back, the core plugs were pulled and cleaned out, all the threads cleaned, oilway plugs taken out and the galleries cleaned. I spent quite a lot of time cleaning the very dirty and corroded exhaust and inlet ports but it was worth it you wouldn't believe how much crap came out!
The end of January means the obligatory visit Stoneleigh Military show. I went with a list of many parts and for once was well disciplined, although it was very difficult to. Walking around is like being a kid in a sweet shop.