The timing cover should be milled at the same time as the block should it be re surfaced? In this case it was forgotton and stood proud by about 0.008" or so?
When this is the case, the cylinder head gasket will not tighten level and the excess alloy must be removed.
Having done much smaller areas the day before, I knew this was going to work, the process was now understood and went very quickly. Do not over tighten the bolts, you may introduce distortion?
The Makita 3612 router, this model has an auto brake and stops very quickly, recomended!
The 13mm milling cutter, a tungsten tipped type will also work but the finish will not be as smooth?
Click on the pictures, they should enlarge.
Next I will show you how I fitted the 998cc steel liners into the alloy sockets which had distorted some 0.003" ?
Roy
When this is the case, the cylinder head gasket will not tighten level and the excess alloy must be removed.
The jig or template I made for the removal of alloy on the block edges has been re cut to expose the area over the timing chain cover. Even with bolts some distance away, the 32mm thick MDF (supawood) stays perfectly flat, note the plastic safety glasses, a must have when milling metal is concerned. Thinner MDF should also work, say down to 18mm thick but thicker is better.
Having done much smaller areas the day before, I knew this was going to work, the process was now understood and went very quickly. Do not over tighten the bolts, you may introduce distortion?
The Makita 3612 router, this model has an auto brake and stops very quickly, recomended!
The 13mm milling cutter, a tungsten tipped type will also work but the finish will not be as smooth?
The template will be stored away for other work on alloy Hillman Imp blocks.
The finished job, I took around three cuts to make the load on the milling cutter less, this way you can slowly move down to the required depth.
Click on the pictures, they should enlarge.
The milled Hillman Imp alloy block and timing cover. This fix cost me nothing, all the tools were to hand, scrap MDF was the template material and I did not have the expense of a machine shop or the traveling time there and back.
Next I will show you how I fitted the 998cc steel liners into the alloy sockets which had distorted some 0.003" ?
Works for me!
Roy
