Technical Cam locking tool advice...

[Bushboy]

Hi

The waterpump on my 4 day old mk1 Sporting gave up this morning (annoyingly less than 12 hours after I finished changing the thermostat and coolant :bang. Pissed my fresh new coolant all down the road as I set off for work.

Luckily I was in time for the bus and made it to work in time...

So I've just ordered a timing belt kit and new waterpump. Not in any major hurry to fit as Ive just purchased a new weekly bus pass anyway :devil:...

Reason for this tread is that Ive replaced the belt on the 8v fire a number of times. Simple job. Done in an hour or 2. Never done a 16v though, and whilst Im assuming its just as easy, any kind of guide I've seen says you need to use a cam locking tool... Why?

I understand the purpose of the tool but surely I can just put a mark on each pulley in line with a mark on the engine, then before fitting the new belt, check they all line up? The pulleys are hardley going to spin round in circles, are they?

Am I missing the point or is the locking tool really that essential that I will destroy some internals if I don't use it?

 

[blu73]

Can't help you there, i would be of the opinion that if you made sure you didn't move them they would be fine as well but perhaps i'm wrong..

 

[Bushboy]

Thats what I'm thinking. The pulley isn't going to spin freely on its own.

Just reading through a guide it says about having to remove the pulley... not sure why. Maybe more will be obvious once Ive stripped it down. Going to do that tonight just to make sure it is definately the water pump. Seems to be though as coolant is pouring from the belt cover :bang:

Did the 8v belt with nothing but a few sockets, spanners and my hands. Not sure why this would need to be any different? Someone thats done it before, please enlighten me

 

[Bushboy]

Ok I've enlightened myself

Seems it can be done but risky and likely to knock the timing out and not be tentioned properly.

What I need to know now is that if I buy the cam locking tools, do I really need the piston level thingies?

Reason being as the timing is fine now. I'm taking the old belt off and everything will be in the right position. If I lock the cams into place, surely the pistons will be level and I dont need to buy silly tools to check them?

EDIT : No, I lie. Now reading again and looking at a guide, I'm still unsure why I need to lock the cams. Makes no sence as there is only 1 pulley for the 2 cams so why do I need to slacken the pulley and lock the cams? 2 pulleys I would understand as tentioning the belt would turn the pulleys towards each other which would knock the timing out slightly. 1 pulley makes f-all diffference?... just like an 8v...

But again, please enlighten me if I am wrong.

 

[Vento]

Another way of belt replacement without cam locking tools, not sure if it works, cut the belt in longitudenal direction, lengthwise over the heart of the belt and remove the part closest to you, this wil leave the gear wheels in the desired position and creates the needed space to slide on the new belt. After the new belt is on for 50%, one can remove the last part of the old. I am curious how you proceed.
Regards
Vento

 

[dave]

belt wont tension right if cams not locked and top pulley loose :bang:

 

[Bushboy]

Another way of belt replacement without cam locking tools, not sure if it works, cut the belt in longitudenal direction, lengthwise over the heart of the belt and remove the part closest to you, this wil leave the gear wheels in the desired position and creates the needed space to slide on the new belt. After the new belt is on for 50%, one can remove the last part of the old. I am curious how you proceed.
Regards
Vento

Has potential but no good if you want to replace the tentioner and waterpump too.

Dave, surely the top pulley doesnt need to be loose if you dont lock the cam?

I understand there is a reason for these tools (wouldnt exist if there wasnt) but im failing to see how they relate to what I plan to do.

Im not removing the head and the engine is already timed, so, unless I am clumsy and move the cam, I dont need to lock it. But even then, if I put markers on, I can just set it back the few CM i move it anyway.

As far as not tentioning right, When I did the 8v engine, I pulled the belt over the crank, water pump and cam. Made sure this was as tight as I could get without moving the cam. Then tightened the tentioner. I then rotated the engine slightly one way which moved the slack and allowed me to tention some more. I then turned the engine back the other way slightly which moved the slack again. I tentioned some more which was perfect.

Can't see why this wouldnt work on the 16v seeing as it only has the 1 cam pulley, not a twin cam with a pulley per cam, which would be a different kettle of fish.

You be at Stanford Dave? The forum keeps telling me it wants me there. I'm tempted but likely to be working

 

[dave]

if you dont lock the cam then when you tension it the cam will move and timing will be out.
with cam locked an pully loose pully will move slightly as you move tensioner and take up slack on water pump side of belt.

forget what you have done on 8v that has a fixed tensioner 16v has a sprung tensioner.

i'm not going to stanford. if i go anywhere that weekend it will be modded nats

 

[Bushboy]

What difference does a fixed or sprung tentioner make?

Besides the tentioner as you mention, I cant really see any difference between the 8v and 16v belt setup. Both have one crank, one cam pulley, one tentioner and one water pump. When you tention the belt on the 8v, the cam pulley will move too, so why such an issue on the 16v but not on the 8v?

Not trying to catch you out dave, or take the ****. Genuine "i have no ****ing clue" moment

 

[fingers99]

I'd use the tools, every time. Get it wrong on an 8v and you lve to try another day. Get it wrong on a 16v and valves hit pistons whch hit heads.

 

[dave]

with cam locked an pully loose pully will move slightly as you move tensioner and take up slack on water pump side of belt.
if you dont do that belt wont be tensioned properly before the mark is lined up

 

[DaveMcT]

The pistons can be aligned with four equal lengths of wood dowel down the spark plug holes. The cams MUST be locked as Dave says. Its enough to make sure the crank isnt moving while tensioning the belt never mend two more shafts at the top of the engine.

When done ALWAYS turn the engine CAREFULLY BY HAND to make sure nothing touches. Valves bend VERY easily.

 

[Bushboy]

Ok, so did the cam belt, tensioner and waterpump today.

Thank **** I didn't waste my money on those stupid tools Absolutely no need for them replacing the belt on an already timed engine.

Exactly the same as doing an 8v engine except that the tensioner is sprung, which was a bit fiddly but I managed and its tensioned perfectly with no excess slack on any part of the belt. Buying the tensioner tool would have saved me approx 10 mins thinking how to tension the belt without 3 arms. A tiny little allen key keeping the spring mech in position using a breaker bar to apply the tension and a spanner to tighter as I did it, did the job perfectly.

Timing is spot on as before.

 

[Bushboy]

Thought I would pop these in here too ...