We have just done our first Merc MB100D head and think that our experience will help the next shop.
Engine 6619 111
This head design is a 4 cyl indirect injection diesel SOHC. The head will normally arrive less camshaft. The problem area is the pre combustion chambers removal and fitting that has to be done as the chamber extends 12mm proud of the head face.
The pre comb chamber is of two part construction and fitted dry without any seals. We were able to reuse these ones.
First step is to buy the splined 1/2″ drive socket tool that is needed to remove the splined tube that secures the second part, the pre comb, into the head. Tool item number 8220 80 037 available from HSY phone 03 8416 8416 for $156.00 plus gst.
Second step is to make a tool to use with a slide hammer to extract the pre comb. from the head. It is a 22mm by 1.5mm pitch female thread into the pre comb.
Caution when using the slide hammer as the thread is on a different centre line to the centre line of the pre comb. It wont pull out straight or easily. Carbon will have anchored the pre comb into the head. It’s a two man job.
Ensure each is numbered to go back into the same cyl to assist in sealing. Each one is keyed for orientation. Use a good quality, fine, rotary wire brush for cleaning. Rest of job is straight forward 4 cyl alloy head.
Parts from HSY and Precision. Six hour job with eight guides done. Plus make tooling time of three hrs. (learner)
Regards
Hedley James
Ph 03 9372 3111
www.engineaction.com
