K series cambelt change - in situ?

[Wrightpayne]

The verniers are adjusted to alter the precise point the cams are on maximum lift in relation to the crankshaft (and by default piston position). When you unbolt the bottom pulley the belt sprocket can move (as shown in Andrews video). Therefore the precise relationship between crankshaft and cams is lost. 
 

Hope that makes sense.

 

Ian

[revilla]

It's about 6 degrees. No, not enough to get a tooth out, but that's not the point. It's enough to get up to 6 degrees of timing error even with the belt on the right tooth! And 6 degrees is a lot, especially on an engine with large cam lift and big valves.

[murph7355]

Thanks both.  Think I get it now.

Presumably if my pulley is shimmed and has no slack, that problem goes away?

(Feels like there's no getting away from the need to get them timed in again really).

[Geoff Brown]

As related in #19 my 1.6 K Series had verniers (from Oily Hands) along with Emerald & Jenvys. 

Aligned the marks on the verniers then locked with the locking block. The only disconcerting thing was the misalignment of the lower marks. But I had faith & carried out the belt change twice with the mods installed with no problems. Crank pulley play was not evident.

[Wrightpayne]

I wonder if Oilyhands could write a 'how to' shim the bottom belt sprocket? Or is it as simple as cutting a piece of x thou shim and filling the gap? 
 

Once the slop is gone, belt changes with verniers should be straight forward.

 

Ian

 

 

[Bricol]

Done correctly, you'd "fit" an over-size key.  

By "fit" I mean an engineering fitter would make it a precise fit "in situ, as required" - as all the best drawings say :)

[Wrightpayne]

Its not a traditional keyway - the crank has a flat on it and there is a corresponding one inside the pulley. It is the difference between these two D shapes that causes the play.

The oil pump is also driven by two flats on the crank.

[Bricol]

That why I don't remember a key then:)  I might have to go examine the spare crank now.

Not sure why I didn't see play - its an ex-Freelander engine I re-purposed.

Strangely, had a work conversation about keys this afternoon - seems we might not employ "fitters" anymore - complaints about having to "fit" long keys in the main shafts of one of our products - and now machine shop complaining about being given them to machine down - which now we know, probably explains some other issues we couldn't work out once the machine is in production the other side of the world!

[revilla]

A common problem I've found when rebuilding engines is where the corrosion has caused the pulley to seize solid onto the end of the crank. It's a real pain because the pulley seems to consist of solid body with flimsy flange tacked onto the back - you can't use any force to prise the pulley pulley forwards without bending the flange. If yours had seized onto the crank like this, you wouldn't have noticed any play. If you actually removed the pulley - ignore!

[JP]

I've been thinking about doing a cam belt change myself and been reviewing this thread with interest.  I'm going to have a go. 

Is there a recommended brand for a cam belt? 

I've seen kits on ebay that include a new tensioner and water pump.  Again, if I go for one of these, is there a recommended brand?  I've seen comments about getting a particular type of water pump - is it pot luck or do some kits come with a particular type of pump?

[Wrightpayne]

Gates for the belt, INA for the tensioner. Pump should have metal impellors. I also remember something about the better quality or OEM pumps having an evaporation chamber

There are two types of tensioner - manual and automatic and the belt (length and number of teeth) is specific to the tensioner type.

If its a non VVC engine with manual tensioner you can fit the slightly wider VVC belt which is Gates 5416XS and is 26mm wide.

Ian

(can you tell we have similar cars :-) )

[JP]

Ha!  Thank you Ian.  It is a non VVC - it's a 1.6KSS with verniers.  Are there particular brands of water pump that are known to have metal impellors?  Or are the part numbers different?

[Wrightpayne]

Ooo verniers - that adds an extra level of complexity as the cams will need re-timing. You might want to check out the section on fitting verniers on the DVA power website.

http://www.dvapower.co.uk/

[JP]

Thanks Ian - I know. 

Dave fitted my verniers many years ago and I am still thinking about just taking the engine to him - just waiting for an email from him to let me know if he can do it.  But on the other hand I should be able to do this myself.  I'm currently thinking maybe change the belt myself and ask Dave to retime later or see if Dave might be able to make me a set of his dial gauge mounting brackets (I don't have the tooling to do that), then buy some gauges and do it myself....

Or maybe, I'll be lucky and not have the slop in the sprocket when I remove the crank pulley...

[Silver Machine]

Rimmer Brothers have been able to supply me with metal impeller and evaporation  chamber water pumps in the past. Ring them up to make sure they don't send you a plastic impeller version as they stock both.

[JP]

Thank you #40.  I check that out.

[John Vine]

#39   ...see if Dave might be able to make me a set of his dial gauge mounting brackets (I don't have the tooling to do that), then buy some gauges and do it myself....

The brackets are easy to make, and no special tools are required.  All you need is some ally sheet, a hacksaw, a drill, a hammer, and a vice to hold the piece while you shape the 90-deg angles.  Dave's site has the necessary patterns.

If you decide to do it yourself, I can lend you my dial-gauge kit (not available until late June):

Note that there's only the one digital gauge, so you'll have to move it from inlet to exhaust as you proceed.

JV

[JP]

Thanks JV.  Part of me wants to get Dave to do this, but I do feel that I ought to be able to do it myself...Hopefully, Dave will offer me a date to do it before I get round to it!

[JP]

Having re-read everything on Dave's site, I think I'm going to give this a go myself.  Two questions:

1. Dial gauges vary enormously in price.  For this purpose will any old cheap one do?  I guess for the analogue "TDC" gauge, accuracy is irrelevant as it is the movement of the pointer that is important, so should a £10 cheapy one be fine?  But what about the digital "lift" gauge?  Any recommendations?

2. How do you tell if you have a manual or automatic tensioner?  I have a 1.6KSS.

 

[oilyhands]

Send a pic of your cambelt area with the cover off and I will tell you, if the engine is the original and pre-1999 then it is likely to be manual, if the engine is EU3 (no distributor cap), then it is likely to be an auto.

Oily

[JP]

Thanks Oily.

You have emailed me this morning and I have just replied.  I'll pop the cam cover off and take a photo once the rain stops, probably tomorrow.  But it's an EU2, with distributor.

[John Vine]

#44   I bought the gauges Oily recommended (from J&L Industrial): a cheap-o analogue one for TDC ("LINEAR" brand) and a good-quality Mitutoyo Absolute (543-682) digital for the cams.  The two together cost a princely £76+ 20-odd years ago.  It seems the 543-682 is a discontinued model now, but still available here for a very competitive "clearance" price.

JV

[JP]

Thanks JV.