K series cambelt change - in situ?

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murph7355
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K series cambelt change - in situ?

And so the numpty questions begin in earnest.

Can a K-series cambelt be changed in situ?

Have watched a couple of vids on how it's done but all have the engine out.

Assuming it can be done in situ, I'm assuming I get the timing marks aligned, put in a cam locking tool and change the belt?

Should I change the tensioner too?

garybee
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Yep, loads of room.  Do you have an apollo tank?  Only ask as one of the hoses will need removing if so.

I would suggest marking the pulleys and old belt with tippex then transferring the marks to your new belt.  Can't get it wrong that way.

I wouldn't bother changing the tensioner if I was only doing it on age, not mileage.   

 

edit: What spec is the engine?  Is it EU2 or EU3, VVC or fixed timing, wet sump or dry etc?

Wrightpayne
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If manual tensioner you can use the slightly wider VVC belt - part number is in the archives.

I've changed mine several times and always done the water pump (ensure it has metal impellors and a vent chamber) and the manual tensioner bearing. That said I'll take Gary's advice on the bearing next time!

Front crank pulley needs to come off - I wedge a big flat screwdriver against the ring gear. Dont be tempted to use the timing triggers on the flywheel! 
 

If it has verniers fitted the cams will need retiming. If its a VVC there is an extra rear belt to fit.

I found the Haynes manual for an appropriate Rover useful for engine stuff - procedures, torque settings etc.

Regards

Ian

SM25T
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Belt, tensioner, water pump. Spots of Tippex on pulleys (2 places on each toothed pulley) and accurately on belt edge. Transfer dots to new belt.
Bricol
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If you don't touch the cam pulley bolts, verniers or not, it won't need re-timing - they will stay correct to the cams.

Set the engine to whatever position the manual says (DVA site suggests 90 DBTC if I remember), mark the pulleys so you know where they ought to be and away you go - you don't NEED a locking tool (I don't have one) but I guess its easier.

I've seen a method of making you feel better mentioned with other engines, but I don't know if there's enough room on a k-series, I suspect not on the bottom pulley - push the existing belt back as far as possible - slide the new belt on . . cut the old belt off.

I undid the crank bolt in the car with it in gear, handbrake on and someone pressing the brake pedal - nothing broke, nothing twisted :)  Now I'd use a big air impact gun :) - although a guy in the USA used an even bigger one on a Lancia integrale enginer - commented that it had seized when he posted a piccie of his bust crank - the impact gun had sheared the end of the crank . . . thats when I mentioned it was a left hand thread . . . he hadn't checked or asked  . . . I can't remember if the K-series one is or not . . .

Wrightpayne
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There is about 7 degrees of movement on the bottom belt sprocket, which is free to move once the pulley bolt is undone. If it has verniers it will need the cams re-timing.

SM25T
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K-series crank pulley bolt is not a left hand thread.
murph7355
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Thanks all.  Good news it can be done in situ.

I was hoping to be abe to avoid re-timing...but it has Verniers :(

If each of the pullies is marked up fully, along with the belt, wouldn't that make it straightforward (with a bit of care) to ensure everything stays aligned?

Spec

  • 1800K Accralite forged pistons (11.1:1 cr)  
  • QED steel banded liners
  • Std. rods and crank
  • Lightened flywheel
  • Piper 740 cams
  • Piper Vernier pulleys
  • Fully ported head with 31.5mm inlet and 29mm exhaust Paul Ivey valves (could be the other way round!)
  • Solid followers
  • Mike Satur uprated head gasket
  • Jenvey DTH throttle bodies with 40mm trumpets, Pipercross sock filters and throttle linkage
  • VHPD injectors
  • Uprated fuel pump and regulator
  • Emerald ECU
  • AP Racing clutch
  • 4-2-1 SLR non-cat race exhaust
  • Mocal oil/water heat exchanger
  • Race aluminium radiator
  • Pace dry sump kit

Gives ~200bhp and very smooth delivery.

Will have a search for timing dials, but suspect that bit will be well beyond me...

murph7355
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btw, car has probably done 40k-50k miles on that spec (plenty of track use) and been that spec for around 22yrs.  Don't know if the tensioner has been changed in that time (have the servicing paperwork so can check).

Also, crank pulley bolt - what torque is needed to do it up properly?  

garybee
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Bricol and Wrightpayne are both right in that there are times when you do and don't need to time the cams after removing the crank pulley. 

With that spec of engine it will likely have been assembled with enough care that the slop in a standard crank pulley/key is enough to throw your timing out.  Some builders however will shim the pulley keyway so that there is no movement.  If that has been done then you do not need to time the cams so long as you reassemble the pulley/shim/keyway the same as it came apart.

So the answer for your engine specifically is that it depends what you find when you undo/remove the crank pulley.

Did that make sense?

7 wonders of th...
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I'd would be clocking the cams before removing the old belt to see what ball park the builder timed them at.