Sounds like one of those "it wasn't me honest" but I would like to know on behalf of a friend who is almost too sick to talk........ With the timing out by two cogs on a 355 engine, is it possible to bend valves when turning the engine over by hand (36mm socket on the crankshaft bolt, ratchet handle about a foot long; engine seemed to turn over without excessive force; did not notice that the belt had gone slack and jumped a couple of teeth). Thanks in advance.
Yea, I seen an engine turn over with the cams out a tooth or two and be OK. I would definitely pull the cams and do a leak down test, then start over again.
Depends on how many valves are damaged and to what degree. If only one cylinder or two cylinders affected and the timing belts were still in place then surely the engine would run. However, a belt breaking with the engine running would surely be pretty horribly dramatic!
I agree, "probably" ok, but wondering why belt would go slack. You should check the tensioner mechanism to be sure the hydraulic damper is operating correctly.
He was installing the belts (together with Hill tensioners and new hydraulic tighteners) and while turning the engine over by hand using a socket on the crankshaft pulley bolt to achieve the "working" 2.5mm clearance on the tighteners, failed to notice that the belt had gone slack up top (over the camshaft sprockets). Obviously this would not have happened if the tensioner pulleys had been kept tight during this adjsutment but it's easy to be wise after the event. As I said, a leak down test will reveal all very soon. I had no idea how many degees the camshaft has to be out before the piston meets the valves. Still don't have a figure but Plugsit (who knows a lot more than most) helped to allay fears. Thanks for your interest and to those who replied.
I doubt you would have ben vlves cranking by hand and I also think you will get away with the 2 teeth out. When you get it reset, I would put the tensioner pins in and set the gap so that the tensioner just touchers the bearing bracket. Release the pins then crank it over by hand again. you should find it releases to almost exactly 2.5mm... Hope that makes sense?
