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Engine Specific Info and Questions => IDI Engine => Topic started by: Blocksmith on September 12, 2011, 07:37:44 am
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First the history: 1.6td with a leaky IP; took the pump out, resealed it, started to put everything back in. Everything's going well until I start to re-time, when I discover this:
(http://i1180.photobucket.com/albums/x402/blocksmithwiggin/VW%20cracked%20cam/IMG_1721smaller.jpg)
Just wanted to verify before I go tearing the head down: this isn't like the cracks between valve seats, is it? This is a legitimate need-to-replace issue, right?
Never torn a head down before and didn't want to get half way through it and learn that it wasn't necessary.... ::)
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most of the cam notch is still there.. is there enough of it left to time it back up?
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Most likely that's a result of someone tightening the cam bolt with the cam lock tool in place.
It's definitely annoying, but cosmetic really. As long as you can still get a cam lock in the slot and ensure the cam is positioned properly you can continue on with this cam.
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You may want to drop your oil pan. I have found pieces of the cam end stuck on the oil pump uptake mesh before when people (not me) broke their notch and it fell down an oil return.
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Most likely that's a result of someone tightening the cam bolt with the cam lock tool in place.
It's definitely annoying, but cosmetic really. As long as you can still get a cam lock in the slot and ensure the cam is positioned properly you can continue on with this cam.
look at the way its broken, its from LOOSENING the cam..
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Thanks for the quick replies! Glad to know that it's not going to require a new cam--that would've been a royal pain with all the other stuff I've got on my plate at the moment.
Though, the IP wasn't as difficult as I had anticipated (provided I got it back together correctly :-\), so maybe tearing down a head is similar???
And yeah, I had thought about dropping the oil pan and fishing around to make sure that piece of metal isn't still down there, so I'll be sure to go ahead and do that while I've got it in the garage.
I love this forum ;D Thanks again for the input.
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Well either way this is a perfect example to you in the future of why to not use the cam lock when your tightening or loosening the cam sprocket bolt. Instead use a large adjustable wrench on one of the cam lobes.
I would also shine a light or poke a wire down the drains of the motor to see if there isn't any chunks stuck up in there.
Definitely pull the pan for sure.
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If that was in my head, I would replace it. I would think it would eventually wear down the flat side surface of the bearing cap and allow the cam to slide toward the passenger side... until bad things happened.
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get a performance cam from giles ;D
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If that was in my head, I would replace it. I would think it would eventually wear down the flat side surface of the bearing cap and allow the cam to slide toward the passenger side... until bad things happened.
the bearing cap is still in good shape tho, and its been running this way for quite some time it seems..
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I noticed that. I jsut wouldnt want to take the chance. In theory, one would think that it would start machining the cap at some point. Especially if it developed an irregularity..
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I noticed that. I jsut wouldnt want to take the chance. In theory, one would think that it would start machining the cap at some point. Especially if it developed an irregularity..
its not like the cam really goes thru much lateral thrust tho.. the timing belt isnt trying to pull the cam out of the head..
and for the cam to machine the cap and head, there would need to be a burr, or something..
im just one of the kinda people that go by the old saying " if it aint broke, dont fix it"..
and clearly, its not broke to where its damaging anything. the op would have been none the wiser had he not opened up the top end.. could have ran another million miles..
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I'd just run it. Check sump for any bits, perhaps.
Peer at the nearest oil drain in case it's wedged, but chances are the plonker fished it out... if it ever went in; as it would be resting on the timing bar.
Clearly if this engine has run, and not scratched the bearing so far, then it wont tomorrow either....
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Well either way this is a perfect example to you in the future of why to not use the cam lock when your tightening or loosening the cam sprocket bolt. Instead use a large adjustable wrench on one of the cam lobes.
I would also shine a light or poke a wire down the drains of the motor to see if there isn't any chunks stuck up in there.
Definitely pull the pan for sure.
I think it would be better to use vice grips on the raw casting of the cam instead of on the lobes.
You dont use a vice on crank journals to remove the timing gear do you?
(extreme example, but you get my point, hardened metals should not fight)
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I noticed that. I jsut wouldnt want to take the chance. In theory, one would think that it would start machining the cap at some point. Especially if it developed an irregularity..
its not like the cam really goes thru much lateral thrust tho.. the timing belt isnt trying to pull the cam out of the head..
and for the cam to machine the cap and head, there would need to be a burr, or something..
im just one of the kinda people that go by the old saying " if it aint broke, dont fix it"..
and clearly, its not broke to where its damaging anything. the op would have been none the wiser had he not opened up the top end.. could have ran another million miles..
not arguing lateral thrust. I totally agree. Sometimes things move around a bit and the edge of the damage cam is part of what was engineered to keep the cam from sliding.
Agreed on the burr. Should something cause a burr, anything, then things would go downhill very fast. If the end of the cam was intact, then it would be less likely that a burr could happen. Think of the potential for joe backyard billybob overtightening the belt and it causing just a little bit of extra pull...
I understand you view of 'if it aint broke dont fix it', but in this scenario, we have pics of it being 'broke'.
either way, choose your own adventure (flip to page 42). Not my engine, not my problem (potentially) :)
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(http://vincewaldon.com/images/stories/how_to/timing/cam_hold_wrench.jpg)
Unless you have a badly marred crescent wrench, then i see no reason why two perfectly flat surfaces should have issue together?
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Although that may be true, I am saying that it is an avoidable, unnecessary risk.
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Well either way this is a perfect example to you in the future of why to not use the cam lock when your tightening or loosening the cam sprocket bolt. Instead use a large adjustable wrench on one of the cam lobes.
I would also shine a light or poke a wire down the drains of the motor to see if there isn't any chunks stuck up in there.
Definitely pull the pan for sure.
I think it would be better to use vice grips on the raw casting of the cam instead of on the lobes.
You dont use a vice on crank journals to remove the timing gear do you?
(extreme example, but you get my point, hardened metals should not fight)
Absolutely.
With my engine; I undo with a wrench on the bolt, and then a sharp tap with a 2lb hammer always works.Tightening with same procedure.
Mind you though I never overgraunch this bolt in the first place, because I always clean to a 'matt finish' both sides of the taper.
When the fitting is good even finger tight has some grip.
'CAD'-man's tap on the bolt head before final tightening is a good policy too.
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Vice grip on the cam casting to tighten the cam sprocket nut? I'be be worried of it slipping and gouging the head. Make or buy a sprocket lock tool. Long piece of angle iron and 2 big bolts. The scissor type is the best design since it self adjusts to the holes in the sprocket.
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Vice grip on the cam casting to tighten the cam sprocket nut? I'be be worried of it slipping and gouging the head. Make or buy a sprocket lock tool. Long piece of angle iron and 2 big bolts. The scissor type is the best design since it self adjusts to the holes in the sprocket.
Not to tighten/loosen the nut, just for fine movement of the cam. Always use a pulley counterhold. Gripping the cam risks snapping it.
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Wouldn't that throw off the balance of the shaft and cause vibration and premature wear/failure?
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if bending pulleys were an issue, they wouldnt have you knock it loose with a drift.
Also, They seem to be cast? (maybe wrong) but they seem like they would fracture long before they would bend.
plus they are just tough and over engineered.
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Someone gave me a complete (hydro) engine and the cam looks like this one. I was afraid to use it ( hydro cams are in short supply south of the border), but looks like it's a pretty even split of opinions.