Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: VX1 on 04 September 2010, 22:10:51
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Just a brief discription to let you know whats happened.
Engine out of car
stripped down to cambelt
turned engine over by hand to get camshafts and crankshaft to alignment marks. Inserted cam locking tools into cam sprockets, locked cranshaft with crankshaft locking tool, released tension from tensioners then removed belt.
Now I have come to put all new rollers and tensioners on and refit with new cambelt. Camshafts and crankshaft still in alignment, fitted rollers and tensioners then fitted cambelt as per instructions, then it was time to turn engine over manually to see if any further adjustments are needed, got to about 15 degrees of turning over and it stopped solid. I did not proceed any further but turned the engine anticlockwise back to the original position.
What has happened?
Why did it happen?
Nothing was moved or touched before new cambelt kit was fitted.
What happens now?
Any ideas? Can anyone help with this confusion? I am baffled as to what has/went wrong. Was hoping to get the engine back into the car this weekend.
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Just a brief discription to let you know whats happened.
Engine out of car
stripped down to cambelt
turned engine over by hand to get camshafts and crankshaft to alignment marks. Inserted cam locking tools into cam sprockets, locked cranshaft with crankshaft locking tool, released tension from tensioners then removed belt.
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Was that with No 1 cylinder at TDC ?
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Yep. everything checked.
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sorry. what work has been done to remove the engine?
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Are the spark plugs still in? Could it just be the compression that you are fighting?
How is the engine supported? Is the clutch cover fouling on the engine stand?
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The engine is from another mig. Engine was perfectly sound except the cambelt needed replacement due to not knowing when it was last changed. Engine turned over manually before cambelt was removed.
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Are the spark plugs still in? Could it just be the compression that you are fighting?
How is the engine supported? Is the clutch cover fouling on the engine stand?
Plugs still in, Engine on a 205ltr barrel and it's an auto and the torque converter is clear of any obstructions
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inlet manifolds still attached?
turned over fine before old belt was removed?
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inlet manifolds still attached?
Nope, inlet manifolds removed.
turned over fine before old belt was removed?
Engine turned over manually before cambelt was removed.
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Would be very easy if I had the car here.
When you say you turned the crank and it stopped daed, I presume you didn't try to force it all? On that assumption, it sounds as if you have got the belt on wrong somehow. If you haven't forced teh crank,. it is probably no harm done, but now the fun starts.
You will have to effectively strip the belt off and line evert thing up correctly. BUT you will have to be very careful to get the pistons to neuatral, ie all away from TDC (cannot remember the crank position for this, so best checked with a straw through teh plug holes until you gat all about the same hieght). Then relining the cams - dangerous bit, followed by correct alignment of the whole lot again.
IF this is what you need to do, then procedure would be to backwind the crank as above to neutral without forcing anything, Then releasing the timing belt by undoing the tensioner. This is VEY dangerous and you MUST keep all fingers away from the cam sprockets as they will or may suddenly spring around and nothing will stop them. They will very easily remove a finger, so be warned! Just because they haven't moved doesn't mean they wont!
then having removed the belt you will need to rotate each cam via the sproket nut clockwise until lined up with the timing marks on the back cover plate, before moving its pair carefully to match. then inserting the locking took. This is agin VERY dangerous and where you are most likely to take a finger clean off. UNDER NO CIRCUMSTANCES get you fingers between the pair of cam sprokets. I cannot emphasise this enough!!!
One one pair is lined up, repeat for the other bank. Once all 4 cams are correct, refind TDC (doesn't matter which stroke as there is only one TDC until cams join in!) and lock crank. Now you can start with the belt again. The belt is fitted from crank, ANTI clockwise so crank, cam 4, cam 3, pulley, cam 2, cam 1, tensioner and finally crank./ The slack should only be on the tensioner side. So, so slack at all on right side of engine as you look from the front.
Once tensioner is on, check the alignment with the spec tool. It should be more or less right with a few thou. If so, remove the locks and rotate twice clockwise, relock crank and check with spec tool again. Any adjustments are done with either the tensioner or top guide depending on what needs moving in which direction.
Once done, remove locks and repeat until spot on.
ANY resistance at all and stop.
If you have any worries about tjhis at all, do NOT go any further until Marks DTM is back tomorrow. he will excpalin it better than I have.
Bottom line is getting all 6 pistons to a position where the valves cannot contact them. Once there you can effectively cut the timing belt off and not harm the engine. BUT I must say again, the cams may or may not decide to spring around. they give no warning and absolutely will not stop for a finger! ASUME THEY WILL MOVE!
the difficult part is getting the cams to their correct position. You get one, and whilst getting its pair, the first one springs around. Persevere. I have done it and it certainly works.
HTH
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I agree with Mr. McB. Belt off and wind the crank anti-clockwise to 60° left of TDC (roughly, it doesn't have to be precise, it's just the safe position). Turn each cam to line up with the marks and refit the locking blocks until you are happy each bank matches/lines up perfectly. Once all 4 cams are lined up and locked, turn the crank clockwise to TDC and refit the belt. Then try to turn it over by hand. :y
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Yep, but remove the cam and crank locks first! ;D
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Yep, but remove the cam and crank locks first! ;D
Surely that's obvious ;D
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inlet manifolds still attached?
Nope, inlet manifolds removed.turned over fine before old belt was removed?
Engine turned over manually before cambelt was removed.
if the timing did not move between removing and refitting the belt.. i would check for a foreign object in the chambers.
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Would be very easy if I had the car here.
When you say you turned the crank and it stopped daed, I presume you didn't try to force it all? On that assumption, it sounds as if you have got the belt on wrong somehow. If you haven't forced teh crank,. it is probably no harm done, but now the fun starts.
You will have to effectively strip the belt off and line evert thing up correctly. BUT you will have to be very careful to get the pistons to neuatral, ie all away from TDC (cannot remember the crank position for this, so best checked with a straw through teh plug holes until you gat all about the same hieght). Then relining the cams - dangerous bit, followed by correct alignment of the whole lot again.
IF this is what you need to do, then procedure would be to backwind the crank as above to neutral without forcing anything, Then releasing the timing belt by undoing the tensioner. This is VEY dangerous and you MUST keep all fingers away from the cam sprockets as they will or may suddenly spring around and nothing will stop them. They will very easily remove a finger, so be warned! Just because they haven't moved doesn't mean they wont!
then having removed the belt you will need to rotate each cam via the sproket nut clockwise until lined up with the timing marks on the back cover plate, before moving its pair carefully to match. then inserting the locking took. This is agin VERY dangerous and where you are most likely to take a finger clean off. UNDER NO CIRCUMSTANCES get you fingers between the pair of cam sprokets. I cannot emphasise this enough!!!
One one pair is lined up, repeat for the other bank. Once all 4 cams are correct, refind TDC (doesn't matter which stroke as there is only one TDC until cams join in!) and lock crank. Now you can start with the belt again. The belt is fitted from crank, ANTI clockwise so crank, cam 4, cam 3, pulley, cam 2, cam 1, tensioner and finally crank./ The slack should only be on the tensioner side. So, so slack at all on right side of engine as you look from the front.
Once tensioner is on, check the alignment with the spec tool. It should be more or less right with a few thou. If so, remove the locks and rotate twice clockwise, relock crank and check with spec tool again. Any adjustments are done with either the tensioner or top guide depending on what needs moving in which direction.
Once done, remove locks and repeat until spot on.
ANY resistance at all and stop.
If you have any worries about tjhis at all, do NOT go any further until Marks DTM is back tomorrow. he will excpalin it better than I have.
Bottom line is getting all 6 pistons to a position where the valves cannot contact them. Once there you can effectively cut the timing belt off and not harm the engine. BUT I must say again, the cams may or may not decide to spring around. they give no warning and absolutely will not stop for a finger! ASUME THEY WILL MOVE!
the difficult part is getting the cams to their correct position. You get one, and whilst getting its pair, the first one springs around. Persevere. I have done it and it certainly works.
HTH
Thanks Mr Mcb, sounds like that could be the problem, put the belt on clockwise not anticlockwise plus didn't move the crank back 60 degrees so this is very likely. Just to add, when the crank stopped I didn't force it any further I just stopped and moved it back. Lets hope this works.
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inlet manifolds still attached?
Nope, inlet manifolds removed.turned over fine before old belt was removed?
Engine turned over manually before cambelt was removed.
if the timing did not move between removing and refitting the belt.. i would check for a foreign object in the chambers.
Engine has been covered for the entire time so no foriegn objects plus the inlets have been covered as well.
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OK. Just to clarify, you don't move the timning back 60 degrees to fit the belt. Only because of the situation you are currently in. Once the timing is -60 you can then safely let the cams move. That is where you remove the belt having slackened it off. BUT WATCH YOUR FINGERS.
then line up all 4 cams THEN turn crank back to TDC.
Now refit the belt starting from the crank and going anticlockwise. You will be left with slack on the left side as you look from the front, that is when you finally fit the tensioner to take that up.
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inlet manifolds still attached?
Nope, inlet manifolds removed.turned over fine before old belt was removed?
Engine turned over manually before cambelt was removed.
if the timing did not move between removing and refitting the belt.. i would check for a foreign object in the chambers.
Those bloody illegal immigrants will try ANYTHING to get into the UK! ;D ;D ;)
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OK. Just to clarify, you don't move the timning back 60 degrees to fit the belt. Only because of the situation you are currently in. Once the timing is -60 you can then safely let the cams move. That is where you remove the belt having slackened it off. BUT WATCH YOUR FINGERS.
then line up all 4 cams THEN turn crank back to TDC.
Now refit the belt starting from the crank and going anticlockwise. You will be left with slack on the left side as you look from the front, that is when you finally fit the tensioner to take that up.
Must confess I didn't do that Oooppss!! Now the belt is off is it best to put the belt back on then start again?
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I am getting a little confused. Let me just check some facts.
1. When you originally fitted the new belt, you lined up the crank at TDC, locked the crack then locked the cams before removing the old tensioner and belt.
2. You then fitted the new built (we now know incorrectly) before turning the crank and finding it stopped by something (piston touching valves).
3. You then wound the crank back and removed the belt? Did you remove the belt with the crank at TDC and the cams not locked? If so you will now have bent valves most likely.
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Just to clairfy what I just wrote.
If you let the cams turn under their own spring pressure with the crank NOT at neutral, ie you do this with the crank incorrectly at TDC the strength of the valve springs is such that the cam will spin around with great force and is certainly enough to bend the valve that hits the piston. This is the exact reason why you need the pistons NOT at TDC if you do this.
Now, it doesn't mean that a valve IS bent, but it is highly likely that you may have bent a valve, chipped the piston, or damaged a valve guide if you did this with the crank at TDC.
I suggest NOT doing anything more until we clarify what you have done.
If you locked the cams, then no harm will be done. But if you removed the belt without locking the cams and they spun with the crank at TDc you will have damaged it.
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I am getting a little confused. Let me just check some facts.
1. When you originally fitted the new belt, you lined up the crank at TDC, locked the crack then locked the cams before removing the old tensioner and belt. Correct
2. You then fitted the new belt (we now know incorrectly) before turning the crank and finding it stopped by something (piston touching valves). Correct
3. You then wound the crank back and removed the belt? Did you remove the belt with the crank at TDC and the cams not locked? If so you will now have bent valves most likely.
[/highlight]
Cams were Locked Crank back to TDC. Moved crank back by hand NOT turning over by key (as engine is out of car)
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Ok, so if the crank and cams were locked and you have removed the belt, you now need to get everything lined up.
1. Turn crank by hand genttly back 60degrees. Check with a plastic straw through each plug hole that teh pistons are all NOT at TDC.
2. Then remove the cam locks - dangerous bit healthwise. Fingers!
3. Then line each cam up with the backplate. This can be very frustrating because the cams will often jump around to the next lobe just as you were about to get it. AGain, I cannot emphasise enough FINGERS. Be particularly careful of doing the seond cam in a pair ie 3&4 or 1&2, because whilst you do teh second, the first can sudeenly spring around. Fingers again!
4. Once a pair is lined up, lock them with teh cam lock and do the other pair.
5. Once all 4 cams are lined up and locked, turn the crank gently CLOCKWISE toi TDC and lock it also.
6. Belt on. under tha crank and wedge left side of it then up to 1st guide, onto cam 4, onto cam 3, under 2nd guide, onto cam 2, onto cam 1 and job almost done. Then keeping the belt pushed towards the right, fit the tensioner. Finally check and adjust guides/tensioner as usual.
Before you do anything else, make 100% certain that the belt is tight on the right side. The crank pulls on cam 4. The rest follows. The tension is all on the right side as the engine turns clockwise.
Once all lined up and you are happy, remove all locks and turn it gently 2 x clockwise. Then lock everything up again and checko markings. Go by the markings on the SPECTACLE not the backplate. The cam tool is very acurate.
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Ok thanks thats great. What if the cams are already lined up with the cutouts on the back plate, do I still need to refit the belt and move back 60 degrees then lock it all up and follow your procedure?
Just to clarify so I get it right.
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Oh no. Not at all.
What you need before fitting the belt is for the cams to all be lined up with the markings ideally on the spectacle tool, if not on the back plate AND the crank to be at TDC. If that is already the case, then no problem. That is the hardest bit done.
ps... if you want to PM me your landline, I will gladly clarify any concerns.
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Ok thanks McB, I will give it a go. Wish me luck. ::)
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Yes, good luck VX :y What a fascinating thread this has been. 8-) 8-) :y
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Just to let you all know, I re-done the crankshaft back to it's timing mark then moved it a further 15 degress to a neutral position. Moved the camshafts round by 1 revolution, in turn, to there rective marks on the camcover backing plate, then checked with the camshaft timing gauge and all back to spot on and locked with cam locks, must point out that I did lock the crankshaft with the locking tool, moved the crankshaft back to TDC then re-fitted the belt clockwise not anticlockwise.
Once I had done this and tensioned the belt I then turned the engine over, by hand, for 2 revolutions until the cams were back in alignment, which happened first time :). Engine did not lock once so a nice pat on the back for me plus first time I had fitted and timed a V6 cambelt by myself and I did not use the V6 dvd.
So three cheers for me,
Hip, Hip Horay!
Hip, Hip Horay!
Hip, Hip Horay!
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Nice one :y :y :y :y
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So three cheers for me,
Hip, Hip Horay!
Hip, Hip Horay!
Hip, Hip Horay!
Well done VX1, I think a few cheers for RonaldMcBurger2 are also in order.
:y