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Thanks guys, I am now comfortable with the 1/4 inch of slack I have, thanks. As for it tightening up after installing the valve train, it did not reduce the amount of slack on the passenger side of the chain. It did make the driver side tight but that is only because there was tension put on the cam. The same 1/4 amount of slack was measured on the passenger side.
Good info Rockin. I saw that same website you found that on.
This would mean that nine inches of material in an aluminum block expands .0186 in between cool and hot.
As the distance between the crank saddles and cam bore is just under three inches, the cam bore would migrate just less than .0062 inches away from the crank when hot.
My opinion is I doubt this is enough to tighten up chain slop.
Additionally, if you were "lucky" enough to have a timing chain set without any slop (nice and tight as installed) and the block expanded enough to tighten up a loose chain, this tight chain set would be too tight at operating temps. This would cause excessive wear on at least the number one cam bearing.
The bottom material on the front cam bearing is often very worn on many H/C build threads and IMO .006"-.007" closer (since the deck is 9.24" height) would easily tighten the chain right up. Think about how it's also dry when you're installing it. Once oil gets on it...or if someone wanted to try a messy experiment and soak their chain in oil and then install it I'd be willing to bet it's noticeably better.
When GEN I blocks are line honed or if splayed caps are installed and the mains are bored and then honed; the distance to the cam bore only gets closer by a few thousandths (at most) if the machinist is any good and yet even a quality aftermarket T-chain with billet gears will have 1/4 in. slop. So the fix is a chain that they make in incrementally shorter lengths by .002". Even the most disastrous main bore job I've ever seen didn't need a .010" shorter chain....FWIW
This thread is of particular interest to me as I've torn down my motor (that I had recently built) to upgrade to these sexy pinned forged Katech caps (from the fine folks at WS6store). Too bad they can't be seen after the engine's buttoned up!
After the align-bore, will my Roll Master IWIS chain set become to loose?
It may be a while so don't hold your breath waiting for the results.
05-09-2015, 09:27 AM
