k.russell Posted May 11, 2007 Share Posted May 11, 2007 martin that looks good, im wondering how much pressure it needs and how much travel to activate the switch, but very interesting. kevin R black-ali HPC Link to comment Share on other sites More sharing options...
IanJ Posted May 11, 2007 Share Posted May 11, 2007 Stu, Do you happen to have a photo showing how you have mounted your microswitch rigged to the belt tensioner pulley? I have a microswitch sitting at home, but haven't worked out the most elegant way of mounting it yet! Thanks in advance. Ian 😬 1.6K SS Superlight #006 Penn Sevens Here Link to comment Share on other sites More sharing options...
Ash.Bailey Posted May 11, 2007 Share Posted May 11, 2007 when was the last recorded belt failier on a K series Caterham dry sump system ??? and was the driver alerted to a problem , not by the lack of pressure but by the 4 L of oil all over his chops 😬 assuming that an idiot doesnt put the wrong belt on or that the idiot puts the wrong alternator belt on and that takes out the dry sump belt ...... If It aint yellow, wonky and wobbly................ 😬 Link to comment Share on other sites More sharing options...
Beelzebub Posted May 11, 2007 Share Posted May 11, 2007 Interesting point Wonky's made. Has anyone ever suffered a belt failure on the Pace system 🤔 I'd be interested to know. I change mine on an annual basis & to my untrained eye the old ones "look" fine. Dave. Link to comment Share on other sites More sharing options...
Mick Day Posted May 11, 2007 Share Posted May 11, 2007 Pace test fit every pump to their tame block to ensure belt tension is correct, however their block was produced from one of the many casting moulds which means there will be small differences in the machined surfaces. When I fitted my system I could flick the belt off with my little finger. Received advice was that I would have to fit some spacers & ended up using 0.5mm shims. I know of one instance where the belt snapped through overtension & this is possibly the weakest link. Belts from different manufacturers will also show variance in belt length. I had my completed system checked by Pace & yes I will change the belt every year. Ali engines "grow" so belt tension will increase once hot. A wider belt would help & I think Pace are able to supply a wider crank pulley to enable this. Link to comment Share on other sites More sharing options...
Bob Simon Posted May 11, 2007 Share Posted May 11, 2007 I'd have to agree with Dave. The thrown belt warning system is really only worth considering if you have an internal pressure pump. Unfortunately, external pressure pumps have a built in warning system that sometimes works very similar to a hand grenade in a portaloo. But that's where this thread started, isn't it? The biggest cause of thrown DS belts is probably thrown accessory belts or plastic grocery bags/flotsam sucked into the pulley works. Physically guard this from happening and problem solved. -Bob 94 HPC VX Evo III Link to comment Share on other sites More sharing options...
k80rum Posted May 11, 2007 Author Share Posted May 11, 2007 I'm with you Bob - and mitigation of the problem is arguably better than telling if it's happened after the event in any case. I'm going to make up some shielding to reduce the risk of FOD to the belt, I'll keep to a regime of replacing the belt regularly and ensuring the tension of succesive belts is okay. If anything happens after that I'll chalk it up to bad luck. In a similar vein to belt tension, i've just binned a brand new Piper cambelt because even with the tensioner fully adjusted, two revolutions of the crank was enough to put the cams *ever so slightly* out of alignment. 4 revolutions meant they were out a smidgen more. not much in itself, but after a few hundred revolutions, I shudder to think what the difference would have been. Put another belt on and everything's perfectly aligned Darren E With an all-new website K80RUM Superlight R #54 Link to comment Share on other sites More sharing options...
MartinWoodham Posted May 11, 2007 Share Posted May 11, 2007 and was the driver alerted to a problem , not by the lack of pressure but by the 4 L of oil all over his chops ref belt failures, I'd guess the majority run with the CC system, and most of those are race cars, which are almost certainly running a sealed system anyway ie breather from the top of he DS tank and no breathers from the head. In which case oil-free chops. I'm with Bob as well, mitigation is best. The MGF system has a substantial rim on the crank pulley, and is completely enclosed by a plastic cover, so it'd be pretty hard to imagine debris getting in there. And in any case it's scavenge only, not pressure. Martin Aero'd supersported ex-Roadsports B...anyone got a cheap LSD? Link to comment Share on other sites More sharing options...
Bob Simon Posted May 11, 2007 Share Posted May 11, 2007 When you think about it, most of our engines rely on a cogged timing belt to keep the various reciprocating parts from becoming intimate with each other in a most expensive way. (you Duratec guys shush up for a minute here) A belt failure warning would be quite pointless in this application, yet we merrily motor about in our Sevens and tintops without a thought. Is that the "cam belt cover removal" chestnut I smell burning? Link to comment Share on other sites More sharing options...
k.russell Posted May 11, 2007 Share Posted May 11, 2007 Alternator belt failure or it coming off is the problem with the vx, as this takes of the DS belt, and considering the fact that quite a few alternator/engine brackets have been known to crack and distort this can be a worry i have modified my alt/eng brkt for this reason but would still feel happier with a belt failure warning. cracked mounting brkt here and here kevin R black-ali HPC Link to comment Share on other sites More sharing options...
Mick Day Posted May 11, 2007 Share Posted May 11, 2007 The MGF system has a substantial rim on the crank pulley, and is completely enclosed by a plastic coverAny pics? Edited by - Mick Day on 11 May 2007 18:14:53 Link to comment Share on other sites More sharing options...
MartinWoodham Posted May 11, 2007 Share Posted May 11, 2007 Mick, or anyone else who's interested for that matter, PM me your email address and I'll send pics. Don't get too excited though - the MGF system was only fitted to the cup race cars (~30 IIRC) and I only stumbled over a spare DS kit by chance. I don't suppose there are many in existence. Advantages are twin scavenge but using the original pressure pump, toothed belt ie no tensioner, and fully enclosed belt. Disadvantage is I need a new engine mount with three holes in it for oil lines.... Plus the front pulley and sump needed machining. And I don't know which port is which on the pump, but that's a minor detail! Martin Aero'd supersported ex-Roadsports B...anyone got a cheap LSD? Link to comment Share on other sites More sharing options...
Mick Day Posted May 11, 2007 Share Posted May 11, 2007 Martin You might be interested in this here. Blatmail on it's way. Mick Link to comment Share on other sites More sharing options...
k80rum Posted May 11, 2007 Author Share Posted May 11, 2007 This is all getting a bit circular! It's actually a sump pan of Martin's that I'm using Mick (he had two, one of which was surplus to requirements). I should've credited you on my site Martin...will do so in the next site update 😬 Am now waiting on Pace for the pump, who are taking forever to sort out my order, having lost the first one and failed to mail me back on progress now, after Angie said she would. twice ☹️ 😔 Darren E With an all-new website K80RUM Superlight R #54 Link to comment Share on other sites More sharing options...
MartinWoodham Posted May 12, 2007 Share Posted May 12, 2007 Hi Darren- apart from my thumb appearing in one of your photos I don't think there's anything to credit! I have to say my phone calls to Pace in the past have generally been met with delay and failed promises to call back. Good luck. Martin Aero'd supersported ex-Roadsports B...anyone got a cheap LSD? Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted May 12, 2007 Leadership Team Share Posted May 12, 2007 IanJ, Bracket Microswitch Bracket & switch fitted to tensioner Installed The install was done by Nig Marston who originally built my car - he also took the photographs. It's a very simple system - if the belt fails or jumps off, the tensioner will swing upwards, releasing the microswitch arm. It'll only work though with an auto-tensioner, not the earlier manual one. The microswitch needs to be wired to be open-contact when pressed. Having been out for a blat this morning in a mix of sun and rain, I'm still not convinced that I'd see the warning light in bright sunshine - I'm definately looking into the concept of a method of soft or hard cut on the ignition. Hard cut can be cheap and chearful - I guess coil low tension through a relay. Also, for the K-Series d/s install, Caterham now include an aluminium flanged pulley to use in place of the non-flanged Rover plastic pulley that my car has. I can only guess why 😳 Stu. www.superse7ens.co.uk..........the rebuild 😬 Edited by - sforshaw on 12 May 2007 15:42:33 Link to comment Share on other sites More sharing options...
IanJ Posted May 14, 2007 Share Posted May 14, 2007 Stu, thanks very much. Photos are perfect - exactly the kind of solution I was looking for! Ian 😬 1.6K SS Superlight #006 Penn Sevens Here Link to comment Share on other sites More sharing options...
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