General K4 Cam Timing Marks and Belt Tensioning - (simplified thread) - MG-Rover.org Forums
 
 
 
Go Back   MG-Rover.org Forums > Ask The Gurus! - Help and Advice Forums > How Do I - Answers To Common Problems.

Reply
 
Thread Tools Rating: Thread Rating: 4 votes, 5.00 average. Display Modes
Old 24-12-2010, 11:25   #1
1955diesel
Never forgotten
 

Join Date: Jan 2005
Location: Birmingham
Car: Other Manufacturer. Previously - more Rovers than I care to remember.
Posts: 16,734
K4 Cam Timing Marks and Belt Tensioning - (simplified thread)

Dr Dave's original cam timing thread was getting a bit long in the tooth and confusing so here is the same information again, but condensed and simplified plus some additions of my own. Some of the images are taken from the original thread, but I have replaced or updated others. Thanks to all who provided them originally!



Timing Marks Plus Some Hints and Tips.


K16 Cam Timing Position.



K8 Cam Timing Position.



Crank Pulley in Timing (Safe) Position.


Timing Dots on Crank Sprocket Behind Crank Pulley.



Inlet Cam Pulley Drive Pin Position.



Exhaust Cam Pulley Drive Pin Position.



VVC Front Cam Pulleys with Locking Tool in Position.



VVC Rear Cam Pulleys. (This position is used for setting timing. Before cam carrier removal, pulleys should be positioned with marks facing outwards)



Cam Pulley Holding Tool for Bolt Removal / Tightening



Cam Pulley Tool for Fixing Position during Belt Fitting






Tips when working on cam timing related parts:

* Before removing the belt, make sure that the engine is set to its timing marks. In this position, the crankshaft is at 90 degrees before TDC and all the pistons are half way down their bores. This means that the cams can be turned at will without damaging the valves. Cam pulley marks can be seen after removing upper belt cover.

* Only turn the engine over using the crank pulley bolt or by rocking the car with it in gear. Do not turn it using the cam pulley bolts. Removing the spark plugs will make things easier.

* If you need to undo the crank pulley bolt, do it before removing the belt and make sure that the cam locking tool is NOT in position between the pulleys or you risk damaging the belt or even bending the valves if the crank should turn a bit.

* Never turn the crank with the head removed unless the liners are first clamped in position. If the timing position has been disturbed, an alternative would be to refit the head with no cams installed so that the valves are shut and can not be damaged.

* The cam timing tool is only required to assist in final fitting of the cam belt. It is not required at any other time - if the cams move, this is not a problem with the crank in its Safe (Timing) position and they can easily be turned back when required.

* Do not use the cam timing tool between the pulleys to hold them while undoing the bolts. The tool to use is either one that picks up on the pulley spokes or you can use some types of oil filter strap wrench (not the chain type) wrapped around the cam pully.

* Cam belts can fail internally and still look new on the outside. If a belt has been contaminated with any fluid (including water!) or pinched it should be replaced.

* Final belt tension should only be set after rotating the engine a couple of turns by hand, stopping at the timing position.

* Cam timing notch is on the front flange of the crank pulley as shown and positions the crank at 90 Degrees BTDC (Safe or Timing position). Painting the marks white will help you to see them.

* A mark may also be found on the rear flange of the crank pulley. This was used with the timing degree scale on the cover to show ignition timing.

* The most reliable crank timing mark is that indicated by the two dots on the crank sprocket. The rim of the crank pulley has been known to slip round on the hub giving a false indication. Also, the pulley location feature is very small and it is possible to damage it when refitting, again resulting in an incorrect timing mark position. However, the dots on the sprocket can still give a false reading if the pulley location feature has become damaged for some reason, so if in any doubt check that all the pistons are at exactly the same position in their bores.

Last edited by 1955diesel; 20-05-2011 at 15:05.
1955diesel is offline   Reply With Quote

Sponsored Links
Advertisement
 
Old 28-12-2010, 09:14   #2
1955diesel
Never forgotten
 

Join Date: Jan 2005
Location: Birmingham
Car: Other Manufacturer. Previously - more Rovers than I care to remember.
Posts: 16,734
Cam Belt Tensioning.

The original K series engine had a manually adjusted cam belt tensioner which is set using an external spring. This is then discarded after use to stop it jumping off into the cam belt! Later ones (and I think VVC) had a rubber sleeve fitted to prevent this from happening. The tensioner on the standard engine was changed at 97.5 MY to a spring loaded automatic tensioner that self adjusts to compensate for wear after initial setting, but the VVC and 8 Valve engines retained the manual tensioner. The cylinder head casting was changed to accommodate the different fixings of the new tensioner so they are not directly interchangeable.



The two different tensioners look like this:

Auto Tensioner.



Manual Tensioner.


Belt change intervals are 60,000 miles / 6 years (4 years on some models) for manual tensioners and 90,000 miles / 6 years for automatic. However, I think that most people accept 60,000 miles / 6 years as being safe for most engines.


There are three different cam belts available to suit the various engine / tensioner combinations plus the one used on the 8 valve engine -

143 teeth 23mm wide manual tensioner standard.
143 teeth 26mm wide manual tensioner VVC.
145 teeth 26mm wide auto tensioner.


Tensioning Procedure.


After fitting the cam belt, the tension should be roughly set and then the engine is turned by hand for two revolutions clockwise. This both settles the belt and also gives the chance to check that nothing is going to lock up. Stop turning when the timing marks are lined up again and recheck that they are correct, then finally set the tension.

With the manual tensioner this is done by slackening off the fixings a little so that the spring tension can set the tensioner position then retightening the fixings. If the spring does not have a rubber sleeve fitted around it, it should then be removed.

The auto tensioner is set by slackening the fixing and then turning the tensioner with an allen key anticlockwise until the wire pointer lines up with the indicator notch. The fixing is then retightened. The action of the auto tensioner while setting up is shown in this video. (he gets his clockwise/anti-clockwise mixed up! Turning anti-clockwise as shown is correct)
It is normal for the auto tensioner position to change as the engine is rotated, but it should return to the set position when the engine is stopped at the timing marks.

Last edited by 1955diesel; 31-05-2011 at 18:12. Reason: auto tensioner intro date changed- thanks Dave :)
1955diesel is offline   Reply With Quote

Old 28-12-2010, 09:19   #3
Dr Dave
Administrator
 
Dr Dave's Avatar
 

Join Date: Dec 2001
Car: 2006 330d M Sport
Posts: 79,059
Blog Entries: 5
Garages
The auto tensioner was introduced in 97.5MY on the K Series engine John.
__________________
Dr Dave is offline   Reply With Quote

Old 10-02-2011, 16:15   #4
adam renshaw
Registered User
 

Join Date: Feb 2011
Car: Rover 200 (95-99) 'Bubble Shape'
Posts: 24
valve posistions

hi guys i am rebulding a engine that threw a belt i have just recd replacement head and just have a question

when both cam wheels are lined should all valves be closed
adam renshaw is offline   Reply With Quote

Old 10-02-2011, 16:47   #5
1955diesel
Never forgotten
 

Join Date: Jan 2005
Location: Birmingham
Car: Other Manufacturer. Previously - more Rovers than I care to remember.
Posts: 16,734
No, there is no position where all the valves are closed.
1955diesel is offline   Reply With Quote

Old 11-04-2011, 13:25   #6
david_steam
Registered User
 

Join Date: Dec 2009
Location: SE London
Car: Rover 45
Posts: 76
Timing thread....however....

If the timing is lost, the timing thread shows how to get it back, a great guide.
However it depends on being able to see the the top 12 o'clock position.
This is hidden behind the various covers and engine mount.
I tried to approximate the position by using a knitting needle mounted on the pulley, lining up the notch and the centre of the pulley bolt. The knitting needle then set to a best guess 90 degrees, to the sump / bottom of engine joint.

Is there an easy way of getting the timing right, or do I have to remove all belts and crank pulley, to get the 2 dots? or Remove the covers and engine mount?

Any thoughts?
david_steam is offline   Reply With Quote

Old 11-04-2011, 14:40   #7
Phil.
Registered User
 

Join Date: Aug 2010
Location: Olney, Bucks
Car: MG ZT-T
Posts: 377
Remove the left hand engine mount and cam belt cover, support the engine with a jack and block of wood on the sump.

Lower the engine until you can see the pulley and marks through the wheel arch, you may have to remove a panel but cant remember exactly.
Phil. is offline   Reply With Quote

Old 11-04-2011, 16:03   #8
1955diesel
Never forgotten
 

Join Date: Jan 2005
Location: Birmingham
Car: Other Manufacturer. Previously - more Rovers than I care to remember.
Posts: 16,734
The above method is about the only way of seeing the marks directly, but most people manage with a mirror on a stick and a torch.
1955diesel is offline   Reply With Quote

Old 11-04-2011, 18:00   #9
david_steam
Registered User
 

Join Date: Dec 2009
Location: SE London
Car: Rover 45
Posts: 76
Ive just checked, I am spot on with my timing marks. Many thanks.

This was very useful, maybe the moderator could add it to the timing thread for sake of completeness?



David
david_steam is offline   Reply With Quote

Old 17-04-2011, 17:42   #10
1955diesel
Never forgotten
 

Join Date: Jan 2005
Location: Birmingham
Car: Other Manufacturer. Previously - more Rovers than I care to remember.
Posts: 16,734
Timing Position Lost?

If the cylinder head has been removed without first setting the crankshaft to its timing marks there is a risk of bending valves when the head is replaced. Note that you can not turn the crank while the head is removed or you risk moving the liners and disturbing their seal with the block casting.

To get around this, you can either clamp the liners into position and then turn the crank to its marks or you can remove the camshafts and then refit the head. Removing the cams will close all the valves so that they come to no harm and the crank can then be turned.

Liner clamps look like these or you can make some using lengths of 22mm copper tube, big washers and head bolts.

1955diesel is offline   Reply With Quote

Old 30-04-2011, 18:36   #11
hawickjohn
Registered User
 

Join Date: Apr 2011
Car: Rover 25
Posts: 1
timming belt

please follow my guide on how to fit a timing belt to a k series , i posted a video on you tube hope this helps any of you guys

http://youtu.be/CM5oA2X03z8
hawickjohn is offline   Reply With Quote

Old 18-05-2011, 00:00   #12
jblack3
Registered User
 

Join Date: May 2011
Car: Classic Rover
Posts: 5
Confused about the timing marks

Hi

great information above, thanks. however i'm confused about a couple of things.

My timing marks are as shown above. however, if for example i turned the crank shaft 360 degrees, it would still be in the correct position (timing marks aligned) yet the pistons while all the same height, are now travelling in the opposite direction -the pistons that were going up are now going down and vice versa. The cycle is then out of sync.

So the question arises -how do i know if the pistons are going in the right direction regardless of the timing marks.

This then raises the question of the sprockets -if I turned one sprocket 360, and the timing is lined up correctly -is it still going to work?

Is it just a case of no matter what random number of turns the crankshaft and camshaft have made, if the timing marks are lined up it will work??

Am I confusing this or are these valid questions?

many thanks
jblack3 is offline   Reply With Quote

Old 19-05-2011, 15:19   #13
1955diesel
Never forgotten
 

Join Date: Jan 2005
Location: Birmingham
Car: Other Manufacturer. Previously - more Rovers than I care to remember.
Posts: 16,734
You can turn any of the pulleys through 360 degrees and everything will still be fine. The cams can also be turned through 180 degrees (if both are turned) and this will make no difference either, other than the markings being upside down. The next time the crank is turned 360 all the markings will appear correctly once again.

There are no hidden traps waiting for you when setting the timing, just line the marks up as shown and all will be well!

Last edited by 1955diesel; 31-05-2011 at 18:15.
1955diesel is offline   Reply With Quote

Old 14-11-2011, 13:39   #14
AStockley
Registered User
 

Join Date: Feb 2006
Location: South West London
Car: 214Si 16v '94 M
Posts: 45
Sorry to revive this old thread, firstly this is great - exactly the straght forward info I was after.

But......linking in with this thread I started here: http://forums.mg-rover.org/showthrea...94#post4713694
and thinking from what Ive read I do have a timing issue, I have a couple of queries:

1. If the cam sprokets are removed - it looks like it is possible for them to be refitted in the wrong angle to the camshaft it's self, so that even if you then set the timing marks all correctly as per the photos, you could still have the valve timing out and hence also the distributor positions look wrong?

So how can/do you ensure the sprokets are in exactly the right orientation to the camshaft? I see about the peg going in the indicated inlet or exhaust position, but it looks like there is more than one recieving hole in the cam from the photos so how do you know which one it is?

2. If, as I suspect might have happened, the timing has been set to TDC and not the 90 deg BTDC marker, does anyone know if this will result in damage to the engine/ valves or do you get away with it? If this has happened in my case (not sure yet) i'll mention the engine does actually run and seems incredible that it would do at all!

3. in checking the above, so far I have looked at back of flywheel where crank pos sensor is (cover is not fitted yet) and am I right in thinking the two dimples on back of flywheel, and the missing teeth here, indicates TDC when aligned / passing the sensor?

If so, would this mean that the rotor in dist cap should point at cyl one? whereas mine points at cyl 3 at this point!


Thanks in advance!
AStockley is offline   Reply With Quote

Old 17-11-2011, 21:49   #15
AStockley
Registered User
 

Join Date: Feb 2006
Location: South West London
Car: 214Si 16v '94 M
Posts: 45
ah well, no need for reply (wasnt any anyway!) but my issue wasnt timing - though it was a smidge out. It was lack of compression on cyl 3. suspect badly fitted replacement head gasket, gonna try MLS type after a mild skim
AStockley is offline   Reply With Quote

Old 03-12-2011, 08:45   #16
ogriboy
Registered User
 

Join Date: Nov 2011
Car: Rover 25
Posts: 3
just a small point, if the crank rotates clockwise surely the pulley mark is 90 deg after TDC based on mark on back cover which shows it closing up to TDC from clockwise position rather than BTDC as stated here?
ogriboy is offline   Reply With Quote

Old 06-03-2012, 09:59   #17
ged 21
Registered User
 

Join Date: Mar 2012
Car: MG ZR
Posts: 1
do i do this to do tappets

i do this to do tappets
ged 21 is offline   Reply With Quote

Old 24-04-2012, 12:16   #18
dodgealpine
Registered User
 

Join Date: Jan 2010
Car: MG ZS
Posts: 11
Since doing my head gasket (twice) Ihave had an issue at low revs. When setting off there is a loss of power then it kicks in & sets off like a scalded cat! If I rev it as i raise the clutch it sets off ok, but a bit fast. I checked the timing once again & seemed to be a tooth out (advanced) on the exhaust pulley. I fixed this but it is just the same.
dodgealpine is offline   Reply With Quote

Old 07-05-2012, 18:43   #19
Erki
Registered User
 

Join Date: Jan 2011
Car: Rover 45
Posts: 1
I was going to change the the timing belt, when I saw the first picture, I realized that mine is reversed. In other words, the inlet on the right hand side and the exhaust on the left hand side. Is that possible? I have a Rover 45 1.8 from 2003.
Erki is offline   Reply With Quote

Old 08-05-2012, 22:52   #20
HotTubRepairer
Registered User
 

Join Date: Jan 2007
Location: Lincolnshire
Car: Astravan 165
Posts: 12,190
Send a message via MSN to HotTubRepairer
Is the crankshaft pulley aligned correctly?
HotTubRepairer is offline   Reply With Quote

Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Timing marks (cam belt change) nt801 MG ZS / Rover 45 & 400 1 12-12-2010 10:12
Urgent help cam timing marks SockRocker MG ZR / Rover 25, 200 & Streetwise 3 30-04-2010 21:15
1.4 8v series timing marks for cam crank??? passatcruiser MG ZR / Rover 25, 200 & Streetwise 5 27-02-2009 14:49
Timing Marks indy992000 MG ZS / Rover 45 & 400 1 05-04-2008 13:24
timing marks indy992000 MG ZS / Rover 45 & 400 8 30-03-2008 22:12


All times are GMT. The time now is 13:31.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
ShowCase, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.