Final Assembly

When torquing down the cam covers I managed to sheer one of the cap head bolts, on closer inspection it seems that most of the bolts have stretched. Swapped them out for new after market items. A worthwhile upgrade for £15 per set.

Re checked the cam timing, the inlet was 104 and exhaust set to 106. The timing settings did not change when the chain snapped.  

Dismantled the cam chain tensioner and checked that the rubber head was in place and that the pivot pin was in good working order.

While the engine was out I decided to fit the high output stator to give it a try before fitting it to the turbo engine later on in the year. 

Fitted all casings and oil lines, the engine is ready to be refitted. 

Cleaning And Re Assembly

Removed the dry sump and cleaned out the pieces of broken chain and plastic chain guide.

Fitted a new head gasket and an uprated APE cam chain. Torqued the head down to 30NM and then to 52NM, starting in the centre and then out to the sides. Used assembly lube on the cam buckets and  cam and then re assembled.

 Fitted my Extreme Engines cams and re shimmed to 8 thou on the inlet and 10 thou on the exhaust. Fitted a replacement chain guide and the chain tensioner. 

Preparing Replacement Head

New head has arrived, removed cams, springs, valves etc. cleaned the valves and head with brake cleaner and scotchbrite. 

Fitted new valve stem seals and re ground all of the valves. 

Damage From Broken Timing Chain

Removed the engine to check for further damage, the head has bent valves and some cracked valve guides. I have removed the valves and stem seals to see the damage. To repair the head it will need a complete overhall with news guides and valves which is uneconomical to repair.

I have bought a replacement head from eBay in the US and paid £219 plus shipping. The head comes complete with standard cams, cam cover and throttle body rubbers. I can refit my uprated cams and replace the stem seals when the head arrives in a week or so.

Just need to order a new timing chain, stem seals and head gasket.

Broken Timing Chain

Went on a track day today, during the first session, while breaking and changing down I lost all power and the engine cut out and then wouldn't start.

In the pits I removed the cam cover to see a broken cam chain and damaged buckets. Once home I removed the head to see the extent of the damage. 

I found that I had 10 bent valves and the pistons look ok. Will remove the engine at the weekend to see if there is any more damage.