Listen Up Plug in Fuel Saving / Performance devices

[jeallen01]

As mentioned earlier, many "tuning boxes" / remaps can result in large increases torque at low engine revs - that tend's to encourage you to "upshift" at lower revs than previously, and THAT's what tends to knock out the clutches, especially on cars with dual-mass flywheels (DMF) that have already done quite a few tens of k miles because the DMF's fail (rather than the clutch plates themselves).
("been there, done that", twice!)

 

[ozumo]

Ended up behind a 1972 Fiat 500 the other day. You forget how small they were and how skinny the tyres were.

As clever as the packaging is I don't think I'd fit in one. A 600 Multipla might work though


@jeallen01 DMFs are the work of the devil. No one ever needed them and they're just another expensive consumable for the stealer to replace.

 

[Channel Hopper]

As clever as the packaging is I don't think I'd fit in one. A 600 Multipla might work though
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@jeallen01 DMFs are the work of the devil. No one ever needed them and they're just another expensive consumable for the stealer to replace.

One of my neighbours owned a Gardiniera , circa 1955 which I think had the same engine. Much more practical shape plus he could put ladders on the top.

 

[jeallen01]

@jeallen01 DMFs are the work of the devil. No one ever needed them and they're just another expensive consumable for the stealer to replace.

IIRC, DMF's were introduced, initially on diesels but now also on many petrol-powered cars, was/is to protect the engine crankshaft from very heavy shock-loadings when the clutch is suddenly engaged - probably more relevant on the higher power turbo (i.e. for extra low revs power) engines that are now very common.

FWIW, many years ago, the clutch on my "warmed up" 1600cc (petrol) Astra got "damaged" when I did somewhat of a "racing start" (was in a hurry that day!) and then failed a few miles later - but the damage to the crankshaft only became apparent several months later when, one morning on the way to work, the engine noise gradually increased to the point I had to pull over and call the breakdown service for a 50 mile lift back home (was working away at the time)!

I knew the damage sounded "terminal" and so bought another car - and later stripped the Astra engine to find that the crankshaft had completely broken across a big end or main bearing (can't remember which) because of a stress fracture caused by the above shock-loading event that then progressively turned into the breakage.

 

[jeallen01]

PS to the above

Engines are now "engineered down to weight & price limits", meaning they can be more fragile if not "treated carefully" - e.g. that Astra engine was the then current "B" spec with larger main bearings than the lower spec "A" units - a few years the crankshaft main bearing sizes on almost all of the European GM 1600/1800/2000cc engines were reduced to the same dimensions as the older "A" spec ones, whilst the power ratings were raised considerably and turbo-charging became far more common.

Draw your "own conclusions" from that about the need for DMF's on modern engines.

 

[Channel Hopper]

Unless I have got the wrong end of the stick, The Astra engines I worked on were produced by Isuzu and probably the best part of the Vauxhall.

 

[jeallen01]

AFAIK, GM built pretty much all the petrol engines - but the 1.7 (and maybe some other) diesels came from Isuzu

 

[PaulR]

The Isuzu diesel engines were a short term answer while GM sorted out their own diesel engine. IIRC they were indirect injection whereas the replacement was direct.

 

[jeallen01]

The Isuzu diesel engines were a short term answer while GM sorted out their own diesel engine. IIRC they were indirect injection whereas the replacement was direct.

They went on to buy a line of FIAT direct injection diesels, at least for those up to about 2l - don't know what that use nowadays.

 

[ozumo]

DMFs were all about noise, vibration, and harshness (NVH) AKA refinement. There was plenty of high power cars around in the 90s that managed perfectly fine with a solid flywheel. You certainly don't see them on race/track cars. If they were vital to reliability then engines with worn DMFs (when they begin to judder) would lunch themselves in no time - but they don't. I also know people who've replaced DMFs with solid flywheels and they have no problems at all.

P.S. Nine times out of ten when I see a car with a smokey engine it is a Vauxhall.

 

[Channel Hopper]

The Isuzu diesel engines were a short term answer while GM sorted out their own diesel engine. IIRC they were indirect injection whereas the replacement was direct.

Yes, the ones I owned (Combo Mk1 vans) were 1.7 diesels, they would run on almost anything, including petrol.
The gearbox was the first thing to fail in the drivetrain.

 

[jeallen01]

Yes, the ones I owned (Combo Mk1 vans) were 1.7 diesels, they would run on almost anything, including petrol.
The gearbox was the first thing to fail in the drivetrain.

They "went well" as well - got fed up being blown off by them on the M4, and that's one of the reasons I bought the Mk 1 1600cc Astra

BTW: I did around 50k in that Astra before the crank broke, and then nearly 200k in the following 3x Mk II Astra 1.8i SRi estates, and I never had any problems with the gearboxes or clutches on any of those 4 (although the Mk 1 went through several clutches), and those parts were still fine when I got rid of the cars - 1st was written off by someone else at 128k, and the other two succumbed to general age and/or tinworm at around 150k each, although both did get sold on to someone else!

 

[Lazarus]

I have dim memories off being blown off on the M4.

 

[PaulR]

Just like Gillian Taylforth?

 

[jeallen01]

Just like Gillian Taylforth?

Had to look her up = we NEVER watch "Deadenders" here!

 

[PaulR]

Neither do we (I always try to change channel to "Anything but Eastenders" before the first notes of the theme music) but the incident made national news at the time.