After the disappointing rolling road dyno session I decided to look a bit deeper into the engine state. The first step was a compresion test of all 6 cylinders. Removal of the spark plugs was straightforward and the compression showed as a bit lower than expected. about 130 on a few cylinders.
This led me to believe there was either a problem with the head or the pistons/bores. The next step is to prepare the cylinder head for removal. While at this point I decsided to check and replace the cam timing chain, tensioner and gears. This will be replaced with a duplex chain and vernier cam wheel for accurate timing.
Also the cam followers. Due to wear on the rocker tips and a bit much play on the rockers and the rocker shaft; I have also decided to replace the shaft and rockers with a new shaft. This will also have new bronze bushed rockers fitted with spacers replacing the springs between rockers.
Brief procedure for Triumph top end removal.
1: Release throttle and choke cables.
2: Disconnect Remove Air filter, carbs,
3: Disconnect radiator hoses and inlet manifold hoses
3: Remove inlet and exhaust manifolds
4: Remove radiator/ fan and water pump.
5: Remove rocker cover by releasing 2 securing bolts on the top
6: Remove the rocker arm assembly by removing the 6 bolts securing the 6 pillars. Then lift off the shaft assy.
inspect the rocker tips for wear and the push rod tips and adjusters.
7: Remove cylinder head securing nuts and lift of the cylinder head.
8: Inspect the bores and head mating surfaces for wear and distortion.
New parts used
Stainless steel valves x 12
valve guides x12
payen head gasket and others associated with job
Cam followers x 12
Vernier Duplex timing kit
Rocker shaft and bronze bushed rockers x 12
Solid rocker spacers
Oil filter and Oil
Cylinders 2, 3 and 4 were also passing gasses between each other, as could be seen by the blackened block face; under the gasket and gasket damage at the cylinder wall points
At this point I pressed in new valve guides and sent the head for a surface skim and valve seat re-cut.
While the head was away for the engineering work I cleaned up the head casting with brake cleaner and a scotch-brite scourer. as pictured above.