miniature wrote:
As some of you well know, I'm tearing my Mini down to the bare shell and as such, I'm thinking ahead on every possible modification that I might want and whether I want to do it. Another one that I'd like to seek advice from some of you is a belt-drive conversion for the timing belt.
I've heard that in addition to being more precise than a simplex/duplex chain setup, it's also quieter. Since this mod is not exactly the cheapest of mods, I wanted to get peoples' opinions on whether this is a modification for a road car where tangible and noticible benefit can be derived.
One big question I also had was what the expected lifespan is of a timing belt. I've read that kevlar-reinforced ones can last up to 50k miles. How long does a simplex/duplex chain last?
I've heard that in addition to being more precise than a simplex/duplex chain setup, it's also quieter. Since this mod is not exactly the cheapest of mods, I wanted to get peoples' opinions on whether this is a modification for a road car where tangible and noticible benefit can be derived.
One big question I also had was what the expected lifespan is of a timing belt. I've read that kevlar-reinforced ones can last up to 50k miles. How long does a simplex/duplex chain last?
I have run a 1310 then a 1360 with a belt drive for the last 13 years or so- it was on the S motor when I got it.
I got 40,000 miles from an original Pirelli Dayco belt, when I changed it the belt teeth were still like new.
Currently I have a MiniMania supplied kevlar one on it.
It should go 50K miles or beyond, no worries.
The only other belts available now are Chinese made- I tried one and it was pretty loose on the sprockets so I sent it back and got a Kevlar one.
Benefits of a belt vs chain-
less noise
no stretch and timing variation
no spark scatter (with electronic dizzy, anyway)
more HP, probably.
Disadvantages of timing belt on a road motor:
1. you need to remember to change it
2. take care you don't bruise the pulleys when fitting or removing them, it will mark the belt and cause premature failure
3. the front seal is less forgiving of misalignment, will leak unless you use the crank pulley to line it up before tightening the housing bolts.
4. Cost, the kits are expensive for what they are.
Chains:
The single row (simplex) ones wear too fast on performance motors.
A duplex chain and sprockets is a good all round proposition for a modified road motor.
Best duplex chains are the German `Iwis' ones, the rest available now are pre-worn when bought. This includes the AE (UK??) ones
If you buy a Rollmaster duplex kit, it includes this chain and nice light steel sprockets.
It's vernier adjustable, too.
) break whereas belts may if not replaced regulary...
