Hi anyone fitted a MST serpentine pulley belt ? I'm trying to crank the engine out of the vehicle using the alternator wheel and its slipping despite the belt being at full tension. Can it be turned this way or does it have to be crank wheel? Sent from my SM-G975F using Tapatalk
I would use the crankshaft pulley anyway to turn it. It’s directly connected to the engine. Sent from my iPhone using Tapatalk
It does look loose but press on the long part of the belt with your finger to tighten if you're turning with a spanner. ...but it isn't right, google MST serpentine pulley and look at the pictures, if there is no more adjustment you need a shorter belt.
These things are pants too IME. The one I had didn't fit the case and after revving it beyond 6,000 rpm the tensioner bearings gave up. I went back to stock. I see they make that tensioner wheel much bigger now and I bet that's why, mine must have been spinning 10-20x the engine speed and 100,000rpm is too much!
If you can move the tensioner further right, so the idler wheel lifts up the belt, or use a shorter belt, the tension will increase. But you may have to work out a way of lifting the idler so it doesnt just slide back to the left when you try to tighten the bolts again. As it is in that picture, the tensioner is doing very little more than pushing the belt onto the lower pulley. But when the engine is running, the belt on the right hand side will be pulled tight just like on a stock system with a slack belt and it will perform exactly as well as two tin pulleys and some washers.
Thanks everyone, I'll see if there's anymore adjustment to be had by I don't think there is, the belt is the recommended vw one that came with the kit, I think it's 1/2" to long but maybe there not designed to crank the engine via the alternator pulley like the original v belt, the reason I wanted to is the mst crank nut is a for sided job designed for a 'wrench' which is style over substance. I'll have to try a shorter belt if I can source one, failing that it's back to stock Ps it's a 1641 Cc so don't see it's going upto 6000rpm think the highest is 4500 Sent from my SM-G975F using Tapatalk
Pps here's 2 other setups where the tensioner seems low as well? Sent from my SM-G975F using Tapatalk
I must admit I use an adjustable spanner to turn over my engine on the crank pulley, so I do not care about the actual size . However having a 4 sided nut is stupid because it means you cant reach it properly at some angles unless you have a differently cranked head on the spanner.. for a 6 sided nut the angle is 15 degrees so you can get the spanner on every 30 degrees by turning it upside down. Or use a ring spanner for even more choice.. For that square nut you need 22.5 degrees crank and you can only get it on every 45. Which given you may have stuff in the way that stops you turning the crank more than 90 degrees at a time makes the whole serpentine belt even more annoying on a low revving bus engine. Just find a chromed 6 sided nut or clean up a stock nut.. it only has be tight enough to stop the pulley falling off, and for aluminium pulleys stop the Woodruff key from fretting away the pulley. I think I have run a stock steel pulley for a while with the nut loose.
Agreed 4 sided nut is crap, I'll look for a six sided job or fit the old one, sort my tdc and then whack it back on Sent from my SM-G975F using Tapatalk
However they are just pictures. You don't know if thet ran like that? There are plenty more pics showing it tensioned more and riding much higher. As said, if you ran out of adjustment you ran out of adjustment so the belt is too long for YOUR installation.
Dunno why people fit these kits , the chances of failure are far greater than stock . The extra pulley contact area is probably great for big bore/race engines where they run higher compression with better cooling and components are constantly checked . Ok , yes , they're pretty , but pretty useless unless they're an improvement over the standard set up , which they aren't.... Sent from my SM-G960F using Tapatalk
Marketing budget x usefulness is a constant ? Functionality x bling is a constant ? The parts that make up the tensioner look good, should work.. but may be off the shelf engineering components not designed for that use. The way they are arranged with that belt, the tensioner has run out of effectiveness. It should be pointing more horizontally. The smaller second pic looks like its better by riding a few mm higher. It should make it a right game to get the belt off and on again unless you mechanically wind it back and clamp it firmly while it tries to bite your fingers off by snapping down..
Then there are pictures like this... another MST version. These photos are possibly all for marketing. If they were unable to tension the belt they took a picture anyway? This one look more "right" to me. What happens when you rev it higher? Does the tensioner tighten up (rise) or loosen (fall) ?
They hold the belt further around the circumstance of the bottom pulley to prevent slippage - tosh ... In the grand scheme of things it's another case of rectifying a problem that doesn't exist on a stock engine . I have a remote filter fitted which means the gallery has been tapped and the elbow is very snug against the pulley, so tight belt replacement means taking the pulley off so I'd benefit from fitting a serpentine system but have no intention of fitting one - too much to go wrong ... Sent from my SM-G960F using Tapatalk
