Original engineer had told the customer the Travel Power unit needed to be sent away for repair when actually there was no belt fitted! On this version of cocooned Beta 43 there is an idler pulley mounted on a swinging bracket which acts as the adjusting mechanism and it can be a pain. The idler pulleys bearings had worn into the steel causing the pulley to twist and damage the belt. Rather than replace the pulley we made up a different type of adjusting mechanism.
Heavy and agricultural Idler pulleys are frequently fitted to engines with Travel Power such as Beta 1903 and most Barrus and Nanni. It’s normally best to remove the pulley and fit a freewheeling pulley to the Travel Power which will increase the grip the belt can generate. If an idler pulley is also used to tension the belt then an adjusting arm like this can sometimes be used instead.
On this engine it wasn’t possible to fit the freewheeling pulley as alternator is mounted backwards and runs CCW.
This is part of the process in a typical rebuild on the Bosch Travel Power alternator. A new slipring is epoxied and then soldered on. An engineering firm turns the slipring down so it’s perfectly straight. New bearings are fitted and the rotor is re-magnetised. I have rotors rebuilt to this stage so a generator can be turned around more quickly. It’s not always necessary to replace a slipring – some tend to wear more than others. Only high quality parts are used.
It’s important a travel power alternator is serviced from time to time as it’s possible bearing failure can destroy an alternator. The rear bearings tend to fail more frequently than the front. If there’s any play or roughness bearings should be changed.
The earlier Bosch alternator is a re worked low voltage unit popular in the 70’s and 80’s and was never designed to run a poly-V belt system. It’s very easy for owners and engineers to over tension the belt which can lead to premature failure.
Beta Marine fitted soft aluminum alternator pulleys and often these wear and loose their poly v profile leading to belt slip and over tensioning. I have smaller 50mm freewheeling pulleys which run dramatically smoother than a fixed pulley, increase belt grip and lower the level of belt tension required.
I finished off the job after the original fitter fell out with the customer. The photo illustrates the adjusting arm used. I carry theses alternator adjusting arms with me in kit form with turn buckles, left and right hand stainless steel threaded bar, nuts, shims etc.. and good quality rod end bearings.
Called out to battery problems in Stone on a recently purchased narrowboat. Lucas A127 55amp alternator output poor and doing very little at tickover. Adverc ok. Tidy but badly installed system by well known and reputable boatyard (not in Stone) : cable sizes poor and Adverc battery sense fitted to common post of 1-2-both switch however long cable run (6mm cable/yellow crimps to domestic batteries) after the switch. Alternator pulley large. Fit a 90 amp marine alternator modified for Adverc. New long span laser cut curved adjusting arm, longer bolts, shims and 60mm custom XPA pulley. Gates Quadpower belt. All cable sizes including earth increased to 35mm and re-routed to shorter runs. Transformed alternator performance quickly jumping to 14.4V at low engine speeds.
The ST drives alternator at 1/2 speed off cam shaft alternator output is often poor at lower engine speeds. ST’s can often be improved relatively easily as the cam pulley is normally a reasonable size. I’ve fitted this alternator to 5 ST’s now with great results.
Call-out to Bollington to look at problems with a 4 cylinder Lister Alpha. Newly purchased narrowboat where the previous owner fitted the best equipment which looks good on paper. Smartgauge, Victron BMV, 2 large Victron AGM batteries, 24V 150A Mastervolt Alternator, Victron Multiplus etc.. Problem was with the ridiculously over spec’d Mastervolt alternator (like using a power station to supply a house). Mounting system was complicated and engine vibrations causing all the engine mounts and engine brackets to continuously work loose. This had been an ongoing problem. My solution was to fit a standard 60 amp 24V alternator with a smaller custom 65mm XPA pulley and single Gates Quadpower belt; Remove the 16mm charge leads (150A alternator!) and increase to 35mm due to lack of intelligent charging. Charging system is great and a match for the 220AH 24V battery bank. Engine runs smoothly and transforms the boat. Customers delighted.
Travelled to Chichester Marina to work on a beautiful and superbly restored classic 1960’s wooden racing yacht Blue Saluki. Re-engined with a Vetus M4.14 6/7 years ago and the charging system has never been good. Customer couldn’t find a local engineer who was used to working with Adverc systems.
The charging setup on this generation of Vetus engine has been badly thought out: The original factory fitted alternators have low output right across the engine rpm range. Alternator spec according to Vetus ranges from 40-60 amp (optimistic figures), alternator pulley size is large, crank pulley small and output at tickover pathetic. The replacement cost of this poor performing alternator from Vetus is extortionate.
My brief was to sort out the charging system. An Adverc system was already fitted with 1-2-Both switch. I fit a 160amp split charge diode; 90 amp Marine Alternator with custom smaller high speed pulley and Gates Automaster belt. Domestic charging cables increased to 35mm (some of original circuit was as small as 6mm). Rewire all batteries (3 domestic, 1 start) with new HD post terminals and marine spec 35mm cable. New Blue Sea isolator switches.
With jobs like this I tend to load my van with a range of different alternators/pulleys/belts etc… There seem to be some differences in the front timing cover & raw water pump of these Mitsubishi engines and it isn’t always possible to fit the one I intended. Have to play around with pulley sizes as Gates Automaster sizes are limited. Clearance between wet manifold and alternator stud terminals was incredibly tight. I had to grind terminals down slightly and fit all cables before I fitted the alternator. Access particularly poor – pretty sure some fitters would insist the engine lifted out to do a job like this.
Charging performance has been transformed and customer is delighted.