ECR Posted February 12, 2002 Share Posted February 12, 2002 It's a two sided argument I know but should the timing belt cover on a 2.0L VX engine be removed or left fitted ? Those in favour of leaving it on say that it prevents the easy ingress of debris (usually kitty litter from gravel traps) to the timing beltcrank pulley area and so helps to stop timing belt slippage and very expensive damage to the engine. They also argue that if it wasn't needed then Vauxhall would not have fitted it ! A third point made is that it is a lot safer to work in the engine bay with the cover fitted. The counter argument runs like this: Yes it will help prevent debris getting in but once it is in (and there are areas in the cover where it is possible) the cover holds the debris in and makes problems more likely. Besides the cover is added weight and provided you know it has been removed the safety aspect is not too much of a problem. Finally it looks a lot "sexier" and makes jobs like replacement of the water pump and checking of the condition of the timing belt much easier and therefore much more likely to get done. I was a "cover on" man (just because that's the way I started out) but due to a recently discovered problem will now remove it. During the current upgrade I removed the engine and whilst removing the timing belt discovered what I first thought to be a pozidriv screwdriver bit resting in the timing belt/crank pulley vee. On removing it and after further investigation it became apparent that it had started life as one of the two 6mm ? dia pillars that are fixed to the cover backplate which allow fitment of the cam belt tensioning tool during belt refitting. It had snapped halfway down the hole (due to vibration ? There is no load on it at all when the engine is fitted and running), dropped behind the lower belt pulley and presumably sat there for goodnes knows how long. At some time it had worked loose and become entangled with the belt causing two large tears. This had happened without me loosing my cam timing (there is a God !). It won't happen to you will it ? (this is the first and only time I have heard of it) but check those two pillars just in case Having made the decision to go coverless I then began to wonder how the belt should be tensioned. Without the back cover there is no means of using the OEM tensioning tool. I have seen engines where the adjusting plate is removed from the tensioning pulley, the pulley moved onto the belt, tensioned by experience and locked in position by the central cap screw but I was always a little concerned that if the screw loosened at all then the pulley would slip on its slot and..... The answer is (apparently) to use a non slotted pulley (as fitted in the lower position) and tension the belt by turning the (eccentrically mounted) water pump. The belt tension can be checked with a spring balance and rule. Rather than throw away my slotted pulley I am proposing to bush it from the rear and convert it into a fixed type (saves upwards of £40.00). Any other ways of skinning this cat ? Edited by - ecr on 12 Feb 2002 12:47:56 Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted February 12, 2002 Share Posted February 12, 2002 That cam belt was one of the scarier things I've seen...... Link to comment Share on other sites More sharing options...
Animal Posted February 12, 2002 Share Posted February 12, 2002 It's kind of a roundabout way of saving money on rollers. I've been through exactly the same process with my engine. I'm currently running with the covers removed, because I've got the later style engine with the cam belt autotensioner. the plastic pulley's ahve been replaced with SBD metal replacements, and the auto tensioner replaced with a solid insert. The cam timing has to be done with the water pump, as you describe. There's no access to the water pump bolts with the back cover on, therefore it has to be removed for this to happen. I've not experienced any problems with this, apart from the bolts for the roller rusting slightly, as they're exposed to the elements. And like you say, it's much easier to see if there is any problems with the cam belt/tensioners etc. Spec Sheet for the Shed http://64.119.165.47/forums/showthread.php?s=&threadid=4473 Link to comment Share on other sites More sharing options...
philwaters Posted February 12, 2002 Share Posted February 12, 2002 No help to you, but I am glad I took mine off now! On the Zetec there is a hex slot in the tensioner pulley that you can use to get enough tension on the belt before locking it off. Would machining something suitable into your pulley be an option? Or fixing something to it - a bolt through maybe? Not very familier with the VX. I think you need a bit of leverage as I had the 6 A/F allen key and then a ring spanner on the end in order to get the right tension on my belt. Phil Waters Zetec is in and running wink.gif Edited by - philwaters on 12 Feb 2002 17:29:00 Link to comment Share on other sites More sharing options...
EFA Posted February 12, 2002 Share Posted February 12, 2002 With covers removed the best way to check the tension is to twist the belt between the cam pullies. You should not be able to twist it when held between thumb and forefinger more than 45 degrees each way. Tension adjustment is a combination of the water pump encentricity and one of the small idler pullies which has a slotted mounting for coarse adjustment. Idelly the "pointer" on the water pump body should be lined up with the edge of the bump on the block on the outside edge of the pump housing. This applies to the non low-noise version of the VX - newer versions (those with no disti) may be different. Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted February 12, 2002 Share Posted February 12, 2002 Not sure about V/X's, but the attrition rate on ali pulleys (Piper etc) from basic road dust/grit is amazing. Do covers help? Well totally sealed ones might but it's always going to be a case of six of one and a half dozen of the other (in old terminology!). Link to comment Share on other sites More sharing options...
AMMO Posted February 12, 2002 Share Posted February 12, 2002 I asked the same question before I fitted my Zetec. The best thing I ever did was to decide to put a belt cover on. I had to change the poly-vee belt on the alternator after only 1000 miles as it had loads of tiny stones imbedded in it. Some of the stones had perforated the belt. I have to say that the roads around where I live are particularly ****ty. I empty the space between the side skins and chassis on a regular basis. Upon checking the timing belt everything was clean and free of debris. Probably not a problem for the majority but I reckon belt covers are the way to go. AMMO Link to comment Share on other sites More sharing options...
EFA Posted February 12, 2002 Share Posted February 12, 2002 I've done over 15k miles in my car with the belt covers off. The pulleys are obviously marked but the tooth profile is undamaged. I've never really had any trouble with gravel, but then I tend to stay on the track (except at North Weald before you get that in again, Blackbirdman) If I do leave the track it tends to be in a big way! TGFTDI Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
stevefoster Posted February 13, 2002 Share Posted February 13, 2002 Any scrutineers out there? Care to comment on the need for timing belt covers or not? My VSCC race pal reckons you will not pass Nat B race scrutineering without covers?! Link to comment Share on other sites More sharing options...
paul jacobs Posted February 13, 2002 Share Posted February 13, 2002 I don't know about race scrutes, but I've never had a problem with sprint/hillclimb scrutineers. I've been running without a cover on my Vauxhall engine since 1994, first in an HPC and for the last 4 years in a 21. I've had a few offs, and stacks of stones in the side skins, but so far at least I've been lucky, including an off into the kitty litter at Copse on a Caterham track day a couple of years back [which some of you may remember!] It's a good idea to remember that the cover is off if you're working on the engine whilst it's running, the results could be very interesting otherwise... Link to comment Share on other sites More sharing options...
Chelspeed Posted February 13, 2002 Share Posted February 13, 2002 You can make the adjustable pulley non-adjustable by fitting a washer under the bolt, the washer needs to be full diameter of the bore of the pulley for total safety but I just used a normal size washer and tightened the bolt normally, it never moved. There are many variations on standard and modified idler set ups on the Vauxhall engine. Early cars are as described. Later cars have two idlers at the top of the block and an auto tensioner third idler on the top of the oil pump. I think introduction of this coincides with a change to tooth profile, is this the low noise belt? You can change from one arrangment to the other but you need to change all idlers, cam pulleys, water pump and crank pulley. The advantage is a lot more wrap on the crank pulley which is nice and reassuring if you have wild cams and strong valve springs. With this set up you can use this auto tensioner instead of the water pump for adjusting belt tension. At lots of revs it allegedly becomes unreliable so you can lock it with the solid spacer described, SBD sold mod, and go back to using the water pump. Then there's the metal sleeves to replace the plastic idlers which can fail and overheat, remember the high mileage cavaliers shedding cam belts on watchdog? I run the two top idler, locked lower idler and metal sleeves with no covers (almost forget what the original question was...). Works well. I saw some white plastic inserts used on a QED engine, they completely fill the gap inside the belts, presumably to reduce belt whip but they would also virtually preclude stone ingress to the toothed side. Not sure if they sell them or if someone else does and they just happened to be used on that engine. Never seen them for sale anywhere either. As they were for the old single idler arrangement I didn't bother asking. Link to comment Share on other sites More sharing options...
Marius Posted February 14, 2002 Share Posted February 14, 2002 Last week a friend of mine sucked up a piece of plastic-bag lying around on the street. Having no front-cover fitted for the first time in 6 years, the piece of plastic wrapped around one of the pulleys and threw the belt off. And that was that, sir...... I´m gonna fit my cover next week. Doesn´t look so sexy but the engine-rebuilder bill doesn´t either...... Marius Link to comment Share on other sites More sharing options...
ECR Posted February 14, 2002 Author Share Posted February 14, 2002 Marius Just when I had decided that I had made the right choice you come along...... Link to comment Share on other sites More sharing options...
Marius Posted February 14, 2002 Share Posted February 14, 2002 ECR, I believe there was a huge bag of bad luck involved. This happened to the same guy whos´ rods gapped for fresh air in Zolder 5 month ago. He had just fitted the new engine.....teeth.gif I REALLY like the look of the open pulleys & belt (don´t even think about the weight-saving) but if you´re doing trackdays on a kind of regular basis I´d definitly fit a cover. I stripped my 7 last week and couldn´t believe in which parts of the chassis I found large pieces of rubber, gravel, nuts & bolts, all picked up during 6 hours Spa and 4 hours Zolder. I didn´t even visit the gravel-trap...... I remember Swindon & Spiess building F3-engines and putting some kind of spacer between all Pulleys so that no stones or similiar could get below the belt. Looks good and seemed to work. Should be possible to get one done like that. Marius Link to comment Share on other sites More sharing options...
EFA Posted February 14, 2002 Share Posted February 14, 2002 Marius, You are just unlucky - I've run over many plastic bags in the last 8 yrs of being coverless, with no problem. Best way to prevne t gravel ingress is to fit covers to the underside of the chassis - aerodynamic benefit as well then....... Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
ECR Posted February 15, 2002 Author Share Posted February 15, 2002 I have verified that the scrutineering issue is not a real problem so... Bish Bash Bosh it's coming off (and I will drive around any wayward polythene bags) Link to comment Share on other sites More sharing options...
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