Tag Archives: porting

Engine, Gearbox

Cylinder head removal, refurbishment and re-build

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Evidence of valves not sealing as they should in the cylinder head
Evidence of valves not sealing as they should in the cylinder head. Also slight chamber work seems to have been carried out on this head. Abnormalities seem to be the plug recess has been blended and the shrouding around the valves also blended slightly. Almost akin to the Vizard tuning manual for Triumphs

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
Anti freeze

Vernier cam gear for for a GT6, TR6, Triumph 2000
Duplex vernier cam gear for the for a GT6, TR6, Triumph 2000
Rocker arms for for a GT6, TR6, Triumph 2000
New Rocker shaft and bronze bushed rockers for a GT6, TR6, Triumph 2000
Can followers for a GT6, TR6, Triumph 2000
New cam followers x 12 for the for a GT6, TR6, Triumph 2000
Combustion Chamber for for a GT6, TR6, Triumph 2000
New valves fitted after ne guides , skim and seat cut for for a GT6, TR6, Triumph 2000
Cylinder head for for a GT6, TR6, Triumph 2000
Triumph 6 cylinder head after a fresh skim
New valves installed
New valves installed

 

 

Head removed and prep work for the top end rebuild of a Triumph 6 cylinder engine
Head removed and prep work for the top end rebuild of a Triumph 6 cylinder engineAt this point I removed the valves and pressed out the valve guides.     After removing the 12 valves I found evidence of gas passing past most exhaust valves.  This can be seen by the blackening and pitting on the valves and valve seat face.
Sandblasted water pump and housing for triumph GT6, 2000, 2500 and TR6
Sandblasted water pump and housing for triumph GT6, 2000, 2500 and TR6
Triumph GT6, 2000, 2500 and TR6 inlet manifold opened up (ported) slightly for better breathing to cylinder 5
Triumph GT6, 2000, 2500 and TR6 inlet manifold opened up (ported) slightly for better breathing to cylinder 5
Triumph GT6, 2000, 2500 and TR6 inlet manifold opened up (ported) slightly for better breathing to cylinder 2
Triumph GT6, 2000, 2500 and TR6 inlet manifold opened up (ported) slightly for better breathing to cylinder 2
Triumph GT6, 2000 TR6, or 2500 Valve clearances set. 0.25mm or 0.010"
Triumph GT6, 2000 TR6, or 2500 Valve clearances set. 0.25mm or 0.010″
new rocker shaft with bushed rockers and solid spacer kit
new rocker shaft with bushed rockers and solid spacer kit
triumph sandblasted and painted GT6, TR6, 2000 or even 2500 exhaust manifold
triumph sandblasted and painted GT6, TR6, 2000 or even 2500 exhaust manifold
triumph 6 cylinder GT6, 2000 or TG6 duplex vernier can timing using the overlap method on cylinder 6, hence cylinder 1 on compression stroke
triumph 6 cylinder GT6, 2000 or TG6 duplex vernier can timing using the overlap method on cylinder 6, hence cylinder 1 on compression stroke

 

 

 

 

 

 

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.