CRUSADER 60 REPAIR

This engine was sent in to us by a home builder who has done a fair job of constructing this engine but was unable to get it to run. O.K then, so let's take a look and find out why he won't run.

The engine on arrival at our workshop.

Lets get it pulled down and see what's what.

So just before we dismantled the engine we did a quick check of the compression and found that it was somewhat lacking, not a good sign but nothing that can't be easily rectified.

The back plate intake hole is also a bit large which has given a reduced intake seal area around the intake drum valve so while it looks ok at first glance with nice thick oil once fresh fuel gets involved I can see the seal disappearing rather quickly. I think this part will also need a bit of rectification work.

Having cleaned and rechecked the cylinder parts this is what we found.

Oh dear, it is now apparent that a rebore is required so we will get on and carry out this procedure first.

Once the required tooling has been produced for the rebore operation we will finish machining the replacement piston and carry out the final fitting to the cylinder.

Here we have the main case and crankshaft cleaned and reassembled ready for the refinished cylinder and piston assembly to go back onto.

Having made all the tooling for relapping the cylinder liner, here's the first pass through which shows the extent of the out of roundness of the bore and the damage caused by the gudgeon pin and piston baffle scoring the bore.

The first pass with the lap was at bore plus 28 microns up to a total clean up of 32 microns.

After removing a total of almost 0.150mm, that's 6 thou", we have a nice and round, clean bore finish that's ready to take a new piston.

Next step is to machine up the new replacement piston and required tooling to mount and final fit it to the restored cylinder liner.