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E: Engine Half Time Pinion Sizes

greg brillus

Well Known and Active Website User
VOC Member
Definitely a clearance problem, but also every owner tends to start and run their engines differently........Being a mechanic, I have never revved an engine straight away from a cold start........but I have watched many who happily do, including folk at the race track, fire their engines and rev the guts out straight away. The outer cam bush definitely shrinks in size when the cam pinion gear is pressed on....... I get them honed to size at the engine shop.......folk might say this is incorrect, well you can do far more damage with a reamer if your not careful. Very easy to press a cam pinion on crooked as well, it will happily broach its way home.......... Any press fit item, linish/polish a slight taper on the end of the cam, start the assembly a small amount, slide the cam assembly onto another spindle mounted in the lathe, then spin the cam and see how true the pinion is.......realign as necessary, and then press it on further.........Remember to measure twice and cut once.


Well Known and Active Website User
VOC Member
There is a bit of debate about the best way to size Oilite bushings. This is from Oilite's site.

There are a few basic machining practices required to optimize retaining surface micro-porosity and the self lubricating properties of Oilite® bearing materials.

Cutting tools must be sharp. For this reason, PCD-Diamond inserts are very highly recommended since they hold a cutting edge much longer. This preserves the open-pore structure from which oil can flow freely. A dull tool will smear the pores, greatly reducing the self-lubricating qualities of the material.

Turning: Cutting Feed Rate: 0.002-0.006 IPM
Speed: Oilite® Bronze 375-500 SFM
Speed: Super-Oilite® 250-500 SFM

Roller Burnishing is an excellent choice to modify an ID slightly. Ball sizing can also be used on the ID effectively for final sizing.

Honing and grinding are never recommended on Oilite® bearing materials. Using these methods on any surface which will become the bearing surface will introduce grinding media and could easily smear the bronze pores sealing the micro-porosity.

After extensive machining, bearings should be re-impregnated with appropriate / specified oils. Vacuumed impregnation is recommended. If bearings were not lubricated prior to machining and if cutting fluids were used, that medium must be removed prior to any impregnation of the oil selected for the application. Your authorized distributor can provide oils for re-impregnation after machining.
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