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Timing Gears

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Skip & Lynne

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I am wondering if I need to replace the cam and crank gears on my engine I am rebuilding. They look good and I am replacing the chain but do any of you regularly replace the gears. I have some really great cam numbers I am having mine reground to. It should outperform the BJ8 cam by a good margin. Skip
 
S&L
I can not think of a better time to do it.-Keoke
 
The crankshaft sprocket wears faster than the cam sprocket (2:1). If the crank sprocket looks good, surely the cam sprocket is okay (unless the crank piece was previously replaced...).

Definitely replace the timing chain, as it stretches noticeably and will retard the cam timing with a loss of acceleration rush. A simple test to check for chain stretch is to hold it up to a straight edge (horizontally) and see how much it sags. Compare to a new chain for reference.

Did you ever give the thermal barrier/dry film lubricant polymer coatings any consideration?
 
Hey Randy thanks I was going to replace the chain for sure but I didn`t know about the gears. I usually replace them as a matter of fact but I wasn`t sure about the British cars. The gears look pretty good and I can`t see any visible wear but since I am already here I might as well replace them. I had the piston domes thermal barrier coated and the skirts dry filmed. I didn`t do anything with the head except a valve job and gentle port cleanup. Ground the crank 10/10 and had the journals dry filmed. I had some really good cam numbers from my circle track days and had the cam reground to them. A good deal more duration and different lobe centerlines but with a good idle and excellent mid range and more torque. It should be a good driver but with a little cam chop at idle. I just finished the carbs and ran them and the manifolds on the flow bench and they are much improved. I`ll let you know how it comes out. By the way do you pre oil your engines through the oil pressure port or where. You can`t spin the pump once the engine is togther. thanks Skip
 
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