belt driven cam

Post by **callyspoy** » Mon Nov 10, 2008 12:46 am

anyone got any experience with these? can i please get first hand answers of pluses and minuses please. and yes cost is a big minus!
oooh...that sounds really shirty doesn't it?? it's not meant to sorry!
but DO IT!

Post by **superchargedfool** » Mon Nov 10, 2008 9:20 am

I have been thinking about this for a while. Are you thinking of the adjustable or fixed type?

Apart from price I can't see any down side at all. No rattle, more aacurate, no oil leak.

Post by **MoggyTech** » Mon Nov 10, 2008 11:09 am

More hassle than it's worth IMHO. You would need to make the belt area free of oil, which means moding the block. Easiest way to stop rattle, is fit a duplex chain and solid crank pulley from ESM.

Post by **bmcecosse** » Mon Nov 10, 2008 11:16 am

Yep - I sold on the belt drive kit I got with a high power Mini engine. Far too risky -if the belt breaks - BANG. I have 'never' heard of a duplex chain breaking - although single chain with high lift cam and stupidly strong valve springs is certainly asking for trouble!

Post by **Matt** » Mon Nov 10, 2008 2:54 pm

I looked at these and decided against, mainly due to potential for cambelt failure, and it would be hard work to keep the oil out of that area. No reason why they should be more accurate than a chain, especially one with a tensioner.

All the cambelt kits I have seen havent had a tensioner either which I dont like!

Post by **callyspoy** » Mon Nov 10, 2008 3:48 pm

do you worry about the belt breaking on a modern cam belt? surely preventative maintenance says that if you change the belt when it has done some miles then it shouldn't really be a worry. so for me, that wouldn't be a worry! unless it snapped and then you could all slap me.
i do ponder the issue of oil leakage, seems a wee bit sketchy to me, that would be one of my main concerns, but...i am awfully tempted!
SCF...i was thinking adjustable, although double the price it makes more sense i thought?

Post by **Redmoggy** » Mon Nov 10, 2008 4:19 pm

Bad idea in my oppinion. Even car makers have realised they are a massive step backwards and are returning to chains. I've seen to many breakages for to many differant reasons and spent to much of other peoples money for me to even consider it. Fit a good quality duplex chain and you can forget about it.

Rod

Post by **superchargedfool** » Mon Nov 10, 2008 4:20 pm

adjustable was the way I have been thinking.

I have a mate with a 1380 med mini engine making about 110 bhp that has had awesome money spent on it and he swears by these belt kits for curing the oil leak front seal problem and they are quieter. He has had one on for at least 4 or 5 years now.

Post by **Matt** » Mon Nov 10, 2008 4:22 pm

Cambelts fail for all sorts of reasons Callum

I did my transit one (40,000 mile interval) 2000 miles later it slipped because of a tensioner failure. Fortuantely the transit doesnt bend valves, just pushrods, so it was a cheap fix. I dont know how an A series would react

Post by **callyspoy** » Mon Nov 10, 2008 4:25 pm

hmm...i've got a duplex ready to chuck on, admittedly a cheap one from ESM(i bought it before i was planning proper engine mods).
oh i'm all confused...

Post by **Mogwai** » Mon Nov 10, 2008 4:29 pm

I looked into getting a beltdrive they have a sandwich plate that forms the oil seal but there was no provision for a breather & as I have an A+ in mine there is nowhere else for it other than the timing cover

How about this for another alternative? £££
http://www.med-engineering.co.uk/produc ... ang_id=542

Post by **downsey** » Mon Nov 10, 2008 4:33 pm

Actually a lot of newish engines have non interference designs meaning if the belt breaks it doesn't trash the motor.

Post by **bmcecosse** » Mon Nov 10, 2008 4:41 pm

Not here they dont! Belt failure means HUGE bill. Many are now back to chain drive - thank goodness.

Post by **Luxobarge** » Mon Nov 10, 2008 4:54 pm

bmcecosse wrote:Not here they dont! Belt failure means HUGE bill. Many are now back to chain drive - thank goodness.

Absolutely - I think there are only one or two non-interference engines being sold in the European market at the moment.

Belts were originally devised to cope with mass-production OHC engines, as the long chain runs gave problems with tensioning them reliably, and also chain wear gave an unacceptable level of variance in valve timing - all problems which are easily overcome with a belt. Newer chain technology and better oils have largely overcome the chain wear problem hence as BMC says "Many are now back to chain drive - thank goodness".

IMHO there is little or no problem with a chain if the run is short as in an A-series, especially if you use a tensioner and duplex chain, I really can't see the point of going to all the aggro of a belt myself. However - each to their own!

Post by **callyspoy** » Mon Nov 10, 2008 5:04 pm

i like what richard put up! it's pretty! not that much more than the adjustable belt drive either!

Post by **IslipMinor** » Mon Nov 10, 2008 5:54 pm

I wanted some form of adjustable cam timing, other than the offset keys that I was already using, so trawled eBay for either a chain or belt set up, with a slight preference for belt on a high revving engine (7,000 red line, and occasionally more).

I bought it from eBay for a reasonable price a few years ago, and it is the MiniSpares unit with the dowel vernier adjustment and a breather connection, which I don't think the current ones do? Replaced the belt as a precaution last winter, and have had no problems from it at all.

Why did I buy it? Very easy cam timing setting and a perception of better oil sealing capabilities (so far so good!). Quieter? Not sure as the duplex chain was never noisy. Difficult to fit? Not at all that I remember.

Post by **rayofleamington** » Mon Nov 10, 2008 7:51 pm

do you worry about the belt breaking on a modern cam belt?

yes!
I've known one to break at 18k from the factory. The vehicle manufacturer's never been too happy as they can't get a low enough ppm (ppm = parts per million failure rate in the WARRANTY period). Added to that, aftermarket belts are a gamble. And if the car is second hand, do you know the belt was REALLY changed? I tend to change them anyway if the car is too expensve to scrap off.

Post by **minor_hickup** » Mon Nov 10, 2008 8:26 pm

I think its minisport do a vernier adjustable duplex timing chain kit for about £70 IIRC. That's the way I'm going on my engine.

Post by **simmitc** » Mon Nov 10, 2008 8:26 pm

"A" series engine was designed with a chain. I looked at a belt some years ago. All the comments above that are AGAINST belts are fully endorsed by me. A duplex change will last for the life of the engine. A belt needs regular replacement and cannot be guaranteed against failure. Ban the belt, champion the chain.

Post by **downsey** » Mon Nov 10, 2008 8:50 pm

A lot of Mazda and Toyota engines used non-interference designs ( the Toyota 4age and Mazda b-series do). I know Nissan switched back to chain.