Quote:
Originally Posted by Jake Raby
Whats holding the IMS sideways in the bore is the timing chain for bank 1. That chain has load because at least one pair of cam lobes on that bank are opening valves. If you force the IMS sideways, you are stretching a chain thats already known to stretch and break. I have the only matter linked chains in the world, but they are far from cheap, if you ever need one. Also, never force anything within an engine, if it doesn't want to budge, you must find whats necessary and relieve the tension. If not, you'll be sorry.
Because rotating the engine ANY from the point you are at now will make the cam timing even worse, and you can crash valves into pistons. You can't get the flange back on to support the IMS, because its no longer centered in the bore, so rotating an unsupported IMS is a recipe for bigger disaster.
I invented and developed that tool, this was never its intended purpose. That said, you do not know how far out the cams are at the present, and you won't know if things will crash until you move the engine. Not saying this won't work, but I am saying that its not a smart approach.
The entire valve drive system has shifted when the flange was removed without the engine being at TDC and having the CAMS locked. Something had to move when the flange was removed, and its likely retarding bank 1. This means that the exhaust valves on that bank can crash into the pistons fairly easily, and you don't want to risk that.
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Thanks a lot for the explanations. I don't have a very mechanical background so I hope you'll excuse my perplexity.
In terms of forces acting on engine components, I'm not clear on why forcing the bearing back to center with the pull-out tool differs from the typical operation of the flange. Why would the forces from moving the bearing back to center stress the chain more than the usual?
I'm also pretty fuzzy on the shift you describe above when the flange was removed. How exactly would the timing get thrown off? During this shift, are you suggesting a sprocket has skipped a link in one of the camshaft-IMS chains? I'm not sure how the timing could be off otherwise.
Quote:
Originally Posted by Jake Raby
No, it can be done in the chassis, engine assembled. Pull both cam covers, and have fun.
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What steps are you recommending to re-time the camshafts, and where would replacing the IMS bearing fit into that procedure?
Before removing the cam covers, the
Pelican Parts article on setting the camshaft timing says to put the engine at TDC and install the camshaft timing tool. This makes sense because the shaft is normally held in place by bearings built into the cover. I'm not currently at TDC, and you don't recommend rotating the crankshaft while the IMS isn't support. The timing tool only fits onto the camshaft heads at TDC, so I'm not sure how to proceed with safely removing either camshaft cover.