- Thread Starter
- #61
To continue on - installation of the new cams. This work needs a clear head and, perhaps dare I say so, a little bit of 'knowing what you're doing' and how it is best and safely done. The main considerations are twofold, namely:
1. To have the cams in the correct valve timing position as one must not move the cams once the cam towers are bolted down - remember, one needs to avoid valves touching pistons, and when the chain wheels are disconnected from the chain, the pistons don't move, but the camshafts would. Result: Bent valves.
2. One of course needs to turn the shafts at some time - therefore the towers are left quite loose even though all bolts have been fitted. You need to leave enough clearance to turn the shafts without any pressure on the valves.
What I had done was to make a drawing of both camshafts, and depicting the position of each of the sixteen lobes. It's quite easy, because on the right hand cam only one lobe points downwards, whilst on the left cam it is numbers three and six. Observing the lobes, you are assured of correct valve timing because, remember, the crank is at TDC and has not been moved at any time. Care needs to be exercised when tightening the cam towers - always, but always start with the one closest to the lobe pointing downwards. Start tightening that to just a smidgeon, then have the others (bolts for cam towers) catch up with just small pressure, and then back to the first one. If you don't do it that way, there is every chance that you could snap a camshaft or put uneven loads on the camshaft towers.
Well, I guess that's about it for the time being. There will possibly be more to follow. Regards Styria
1. To have the cams in the correct valve timing position as one must not move the cams once the cam towers are bolted down - remember, one needs to avoid valves touching pistons, and when the chain wheels are disconnected from the chain, the pistons don't move, but the camshafts would. Result: Bent valves.
2. One of course needs to turn the shafts at some time - therefore the towers are left quite loose even though all bolts have been fitted. You need to leave enough clearance to turn the shafts without any pressure on the valves.
What I had done was to make a drawing of both camshafts, and depicting the position of each of the sixteen lobes. It's quite easy, because on the right hand cam only one lobe points downwards, whilst on the left cam it is numbers three and six. Observing the lobes, you are assured of correct valve timing because, remember, the crank is at TDC and has not been moved at any time. Care needs to be exercised when tightening the cam towers - always, but always start with the one closest to the lobe pointing downwards. Start tightening that to just a smidgeon, then have the others (bolts for cam towers) catch up with just small pressure, and then back to the first one. If you don't do it that way, there is every chance that you could snap a camshaft or put uneven loads on the camshaft towers.
Well, I guess that's about it for the time being. There will possibly be more to follow. Regards Styria
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