Sonntag, 22. Juli 2007

Cylinder Head Preparation - Part II

This is a view through the inlet port on the open intake valve before porting an polishing the inlet port. At 1600cc engines the valve guides are not much penetrating into the port. They needn't to be shortened nor machined.
The head is milled to a total heigt of 111.2 mm. As a consequence the diameter of the in-head combustion chamber is only 77 mm. It is 1 mm smaller compared to the engine bore of 78 mm. To avoid collision with the piston a chamfer is often recommended when milling the 1600cc head to achive high compression ratios. I measured the volume of the in-head combustion chambers to 63 cm³ each.

These are the new parts of the valve spring mechanism. You can see the inlet valve (bottom), the sodium filled exhaust valve, spring seat, shim, inner and outer valve spring, spring retainer and two valve keys.
As you can see, the valve keys at the outlet valve are different from the original Alfa inlet valve. They have three "rings" instead of one. I sourced them directly from TRW Automotive GmbH, Hauptstraße 10, D-31699 Beckedorf (TRW No. K8A090M0).

In addition to that there are a set of new valve guides, valve gaskets and valve seats with a three angle valve job (15/30/60 deg). To be continued ...

Samstag, 14. Juli 2007

Air filter housing

I modified the intake system and put a new fine glossy black paint on the air box. All boreholes inside were enlarged to 14 mm diameter and a new K&N-Filter with lower air flow resistance is used.

The tube to the cylinder head cover is not mounted due to an oil catch tank on the exhaust side of the engine.

Donnerstag, 12. Juli 2007

2nd @ Oldtimerausfahrt Bietigheim

I got another cup at SG Bietigheims weekend on Sunday 8th July 2007. I finished 2nd of 13 participants in the group 1971 - 1987. A late Ford Escort XR 3i was first - damned second-hand car.

Mittwoch, 11. Juli 2007

Cylinder Head Preparation - Part I

I just started preparing my 1600 cc cylinder head. Stage one tuning consists of cleaning the head, milling -1 mm to increase compression ratio, 3-angle valve job (15/30/60 deg) and porting all air passages. New parts are
  • intake and exhaust valve guides
  • new valves, exhaust valves sodium filled
  • new higher lift performance camshaft (286 deg, 11 mm lift)
  • prologation of the intake port system
I gave the head to Theilacker machine shop. The work is done on this milling maschine. My Alfa head of course is much smaller than this Maybach head on the bench.

Theilacker has a long tradition as a maschine shop for large gasoline (Deutz) engines. In the early days they had a mobile replacement parts service for MWM engines. MWM is Motorenwerke Mannheim. They supplied for example farm tractor maufacturer like Fendt or Eicher.