Reply To: Re: 62 Jetfire engine, trans, & turbo rebuild

[62oldsf85]

I’ve actually seen cam bearings done (cam bearings machined), but not the cam itself. It’s not as uncommon as it might sound, and from my machining coursework, depending on what amount of material they’ve removed, it can be “just fine.” Most of the time (and when I was building my engine, there were at least 8 others being built around me in the classes), it seemed pretty common to me that when the cam bearings were torqued down sometimes the cam wouldn’t spin freely. Sometimes it just meant that a very light sanding (I think with an emery cloth)and others it meant very precise measuring (with a bore dial gauge, if I remember it right) and then a very slight boring of the cam bearings to get everything perfect. Bearings oftentimes aren’t perfectly matched, one can differ slightly in bore size from another – there’s usually a tolerance to it within very tight specifications. I think what we did on mine was some very exact premeasuring to ensure consistency among the bearings, and if I remember right (been about 3 years now) I had to purchase another set of bearings to get the pre-installed set to match the tolerances we wanted. We did not machine the cam, however. I’ll have to ask about that.

I understand the desire to “get it together,” but your instinct is dead on to get it right no matter how long it takes. A slight delay now might mean years more of it running right. As somebody who’s had a post-build glitch or two that made me consider what I’d have done differently if I’d have rethought it during the rebuild (and mine runs pretty damn great now), take your time and think every little thing through, and seek advice.