16 replies to this topic

[1293gt]

Hello all,

I have an old (I'm pretty sure it's Minispares although there are no markings) belt drive cam setup.

I have it properly shimmed so it's perfectly aligned but my question is what stops the belt from moving side to side on the pulleys?

There seems to be nothing to keep it in place and I'm concerned it may wander off and start rubbing on the cam cover. Any ideas or is this normal and they just stay put?

Thanks in advance.

 

[Spider]

Of all the Belt Drives I've seen, including the Mini Spares types, they have a flange on opposing sides of each pulley to keep the belt on track. I've put a red arrow on them here;-

 

 

If they don't have this feature (and some had then machined in, some were separate plates), I don't think it would be wise to use the set up.

[Ethel]

They stay put. I've seen some with a pressed on steel rim, but only on the inside edge of the pulley.

 

Seen  Spider beat me to it, maybe my memory's not so good. I've had two and I'm sure they had differences 

[Homersimpson]

Most modern cars that I have worked on have no guide on the pulleys apart from the bottom one on the crank which is usually just because its between the bottom pulley and the end of the engine, why would the mini cam belt kit be any different to this?

 

I'm interested in this because I have a mini engine in the garage with a cam belt, are they still available and if so are they likely to be different between kits? I have no idea who made the one I have.

[Spider]

Belts are still available though the best ones to get are the Kevlar ones from Mini Mania in the US. Being so short, they do have a short life, or short period between recommended changes (20 000 km for the original belts).

 

As far as I am aware, Trigger in Italy were the first to offer these back in the mid 1980's. Most are variations on these. I've ran a few over the years, but have gravitated back to chain drives. Lower maintenance and less 'risk' with the bigger cams. If these belt drive kits leak Oil (and they are prone to this), the belts don't last too long at all.

[Homersimpson]

Belts are still available though the best ones to get are the Kevlar ones from Mini Mania in the US. Being so short, they do have a short life, or short period between recommended changes (20 000 km for the original belts).

 

As far as I am aware, Trigger in Italy were the first to offer these back in the mid 1980's. Most are variations on these. I've ran a few over the years, but have gravitated back to chain drives. Lower maintenance and less 'risk' with the bigger cams. If these belt drive kits leak Oil (and they are prone to this), the belts don't last too long at all.

Thanks for the info, aside from being possibly a bit quieter is there any reason to fit one of these? It does seem like a solution to a non existent problem - a modification for modifications sake.

[carbon]

Main reasons to fit a belt drive are:

- less noise

- no chain stretch

But as mentioned above belt drives aren't perfect. If you're looking for a fairy bullet-proof setup then the duplex with Iwis or similar high quality chain is probably the way to go.

[Spider]

Thanks for the info, aside from being possibly a bit quieter is there any reason to fit one of these? It does seem like a solution to a non existent problem - a modification for modifications sake.

 

I gotta say, I've not found the Duplex Chains at all noisy, or none that I've noticed.

 

I think Carbon has covered most of it. They do also hold the Cam Timing quite 'tight' and accurate for a long time, but when they go out, they do so with no warning and in a huge way (belt breakage !).

 

I have a few of these, none that are permanently fitted these days though. There is one set that I did fit often but only temporarily to various engines that has a removable peg and will allow for timing changes in 1 degree increments. I use this to do final settings on various engine configurations to fine tune the cam timing to suit that particular engine, as it's very easy to access and change, without going through boxes of gaskets and making a mess. After settling on a particular Cam Timing, I then swap back to a Chain Drive.

 

Overall, I agree with your comment though - " It's a solution to a non-existent problem "

[Magneto]

The new Ford Ecoboot 1L turbo motor runs the cam belt in the oil bath.....must be a differnt kind of belt material? I haven't heard of any issues with it and it supposed to last the life of the engine.....with engine life on modern cars approaching 300K miles - that's a long time.

[carbon]

Cautionary note. If you do fit a Triger belt drive then the steel bracket holding the front left subframe mount really needs to be modified. The crank damper and puley sits about 3-4mm further out, and I found that this was too tight to get the fan belt through the reduced gap without damaging the fan belt.

 

It also means that the crank pulley is slightly misaligned with the alternator and water pump pulleys, but this does not seem to cause any problems.

[bluedragon]

Today belt drives solve a "non-existent" problem, but that wasn't the case 40+ years ago when these things first came out. Back then, the chains started wearing dramatically practically from the moment they were installed and running, and as they wore, they did affect accurate timing (and made noise.) The belt drives and duplex chains were the response to this, and even the duplex chains (the cheaper ones) started to wear before too long.

 

It wasn't until the last 7-10 years or so that improved quality simplex chains have become available like the IWIS that don't wear much at all, and thus hold their accuracy and timing far better. I don't even know if those quality chains even need a tensioner (the need for a tensioner being another sign of the lower quality of the older chain technology.)

 

 

Dave

Edited by bluedragon, 04 September 2018 - 07:20 AM.

[bluedragon]

The new Ford Ecoboot 1L turbo motor runs the cam belt in the oil bath.....must be a differnt kind of belt material? I haven't heard of any issues with it and it supposed to last the life of the engine.....with engine life on modern cars approaching 300K miles - that's a long time.

 

Definitely a different kind of material - the oil bath is suppose to make it last longer. How that works on a belt I'm not sure, I'd like to see what it looks like. But any conventional belt, Mini/Triger or not, will die very quickly upon prolonged exposure to oil.

 

 

Dave

[Spider]

The new Ford Ecoboot 1L turbo motor runs the cam belt in the oil bath.....must be a differnt kind of belt material? I haven't heard of any issues with it and it supposed to last the life of the engine.....with engine life on modern cars approaching 300K miles - that's a long time.

 

Interesting. I've not seen or heard of that type of a belt.

 

I have noticed though a trend among manufactures in general away from Belts and back to Chain is recent years.

[Ethel]

Being a cynic, a belt setup would have to be cheaper for car manufacturers, with a nice bonus for the dealerships replacing belts. Customers, fleet ones in particular, now have enough experience to be put off by additional ownership costs.

 

That and electronic control of ignition (and injection) has alleviated the timing gear of its most accuracy critical task.

 

 

... not sure I see the short belt, short life hypothesis - it is s short, but there are other engines about that have a much more tortuous path for each lap of the belt. I'd guess the pulleys were made to fit a stock belt that itself wasn't specified for use on an engine. Lack of as extensive testing and the expectation that a modified engine is like to have a more arduous life would have you erring on the side of caution.

[Ethel]

 

 

 

I have a few of these, none that are permanently fitted these days though. There is one set that I did fit often but only temporarily to various engines that has a removable peg and will allow for timing changes in 1 degree increments. I use this to do final settings on various engine configurations to fine tune the cam timing to suit that particular engine, as it's very easy to access and change, without going through boxes of gaskets and making a mess. After settling on a particular Cam Timing, I then swap back to a Chain Drive.

 

 

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