GB, interested to hear of your 'tweaked' Cummins unit, 14 litre I guess?

I worked at Holset for 36 years; when Cummins bought the company in 1972 they replaced their own design of turbos with ours with improvements in efficiency.

In recent years we developed a Variable Geometry turbo for truck engines, unlike the swing-vane units on cars, these are not so prone to sticking due to carbon build up and aim to improve drivability and fuel efficiency. If you have used vehicles with these, did you notice any difference?

I haven't got a clue what turbos have been fitted to the lorries i've driven, you'd know more than me on that score, can only recall one turbo failure over a lifetime, i think, and can't recall if it failed on me or with another driver when i was on holiday, that was either a Scania or Volvo, whichever of the two not a patch on Cummins for industrial durability IMO.

Yes it was a 14 litre, 1984 build, rated officially as a big cam E320, but i suspect running around 350 with the upgrades, IIRC wasn't that running 90% of max torque from 800rpm, a proper drivers engine.

Turbo failures were unheard of, well with Brit built motors (unlike the foreign stuff) running Cummins and Rolls Royce engines...but vehicles were serviced properly then, no one had yet come up with Gucci oils designed to last for ever..:-) or rather 250k between turbo failures, whichever came first.

Unfortunately i haven't driven a Cummins since 1987, and probably unlikely to again, more's the pity.

I don't like the trend to smaller engines heavily blown, rather a big 14 litre jobbie like the good old C, blown gently, lasts forever and due in no small way to large cyl capacity has bags of low rev torque....which i what i was trying in vain to get across in the Kia Sorento lack of towing ability thread recently.

Can i ask you a question about modern turbos please Galileo?

I continue stubbornly to warm my lorry engine, and cool it down, before and after asking it to work hard, i know the hymn sheet of the day says i'm wrong and this is wasteful and no longer necessary, but my lorry engine condition/life (and turbo life) record to date, plus good fuel consumptions, tell me that looking after the vehicle the way we used to pays.

Am i right and is this still good basic practice in your opinion or am i wasting a thimbleful of fuel for no good reason?

The company i work for are refreshingly old fashioned and leave us alone to do our thing if it works, no box tickers here counting how many seconds the vehicle has been idling.

I did have a variable vane turbo on the 3 litre Hilux, that was a gem, power from very low revs, very sweet engine.

Edited by gordonbennet on 22/08/2014 at 16:42

For info, here is a link to details of VG turbos. www.myholsetturbo.com/vgt.html

Many thanks for that.

I've been in an MAN for the last 18 months, issued to me new but i'm not the only driver, others use it when i'm off shift and it gets used probably 3 nights a week as well.

It's going to be interesting as the vehicle ages to see if the turbo lasts the full 5 year lease period, one haulier on a lorry forum says the turbos on his MAN vehicles fail around 300k kms (but he freely admits he can't be bothered warming up/cooling down), mines now done 220k and its supposed to be on a 5 year lease, so we'll see if a bit of old school TLC works its magic.

the same school of expert driving prowess ;)

bwahahaha.....a worn out old wind break more like..:-)