DaveyLC
Member
Registered: 8th Oct 08
Location: Berkshire
User status: Offline
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Common rail diesels are a different kettle of fish to the retro Isuzu lumps you are talking about 
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Daveskater
Premium Member
Registered: 29th Apr 08
Location: Oxford, UK Drives: Jap wagon
User status: Offline
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There we go then  They had a bar under the injectors to send the excess fuel back to the tank, I suppose they don't do that any more either 
Numberwang!
Originally posted by AlunJ
I like you Dave, you are a man of men
Originally Whatapp'd by Neo
Dave's maybe capable of a drive-by cuddle
Look at my pictures
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pow
Premium Member
Registered: 11th Sep 06
Location: Hazlemere, Buckinghamshire
User status: Offline
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I also have a return line
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Daveskater
Premium Member
Registered: 29th Apr 08
Location: Oxford, UK Drives: Jap wagon
User status: Offline
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Numberwang!
Originally posted by AlunJ
I like you Dave, you are a man of men
Originally Whatapp'd by Neo
Dave's maybe capable of a drive-by cuddle
Look at my pictures
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sand-eel
Member
Registered: 15th Mar 07
Location: carluke/braidwood--IRNBRULAND
User status: Offline
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quote:
Originally posted by pow
I have one.
sure its not an air mass meter? as diesels have the same airflow forever as they have no throttle butterfly.
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deano87
Member
Registered: 21st Oct 06
Location: Bedfordshire Drives: Ford Fiesta
User status: Offline
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quote:
Originally posted by Nic Barnes
quote:
Originally posted by deano87
Some answers I needed
this in relation to why you cant compare a 90k 1llitre 12v to a diesel engine from last night by any chance?
Kind off  but I was never comparing a 90k 12v to a diesel Vectra
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John
Member
Registered: 30th Jun 03
User status: Offline
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quote:
Originally posted by sand-eel
quote:
Originally posted by pow
I have one.
sure its not an air mass meter? as diesels have the same airflow forever as they have no throttle butterfly.
They still measure the airflow, MAF's don't measure the air mass directly, they are used in combination with other sensors.
If the flow never changed there would be no point using a turbo.
The engine still draws in more or less air depending how much fuel is being injected.
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Warren G
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Registered: 14th May 06
Location: Kent
User status: Offline
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deisel engines are built stronger - due to the torque they put out
but iv seem a few bent conrods, even though they are massive! normaly desiel hydrualic
due to the lower revs it will last alot longer than petrols
ie a petrol at 80mph is doing about 4000rpm and a desiel is doing 2500rpm
which technology desiels are the furture, so much more fine tuning is avaible, doing the high pressure and the way combustion takes place,
turbos on petrols you have to lower the compression to stop preigntion, but desiels work with self combustion, (pre igntion) meaning you can run alot of boost!
petrol turbo - 9.0:1 compression ratio
desiel turbo - 20-25:1 compression ratio
also the new 2.0 turbo bio turbo runs 16:1 which is low for a derv, but must run massive boost!! prob make over 250bhp with a remap!
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daymoon
Premium Member
Registered: 1st Aug 08
Location: Selby, North Yorkshire
User status: Offline
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while we talking about diesels.. at what revs on average should the gear be changed?
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VegasPhil
Premium Member
Registered: 16th Jan 05
Location: Fareham, Hants Drives: Octavia VRS
User status: Offline
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Redline
Corsa 2.0 16v Vegas - Sold
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AK
Member
Registered: 5th Jul 00
Location: Aberdeen City
User status: Offline
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they dont rev nearly as much as petrol engine... revs are what normally wears an engine
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Chris Bingham
Member
Registered: 30th Mar 02
Location: In Scotland
User status: Offline
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i always thought that the main reason for buying a diesel was MPG...so people buying them for that reason must be doing lots of miles therefore thats why you always see lots of high mileage diesels.
You wouldn't buy a diesel if you could get the same MPG out of a petrol..would you?
Also, perhaps the reason that they handle the miles well is cause they are mostly motorway miles and that doesn't wear a car as much. Never thought they were stronger than petrol, just more down to the way they were driven.
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AndyKent
Member
Registered: 3rd Sep 05
User status: Offline
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quote:
Originally posted by daymoon
while we talking about diesels.. at what revs on average should the gear be changed?
Depends. My Golf has a 6k redline I think, but the turbo runs out at about 3.5k, so I rarely rev beyond that.
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deano87
Member
Registered: 21st Oct 06
Location: Bedfordshire Drives: Ford Fiesta
User status: Offline
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Just like a petrol car, it has optimum points in the rev range. It's just lower down I guess.
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sand-eel
Member
Registered: 15th Mar 07
Location: carluke/braidwood--IRNBRULAND
User status: Offline
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quote:
Originally posted by John
quote:
Originally posted by sand-eel
quote:
Originally posted by pow
I have one.
sure its not an air mass meter? as diesels have the same airflow forever as they have no throttle butterfly.
They still measure the airflow, MAF's don't measure the air mass directly, they are used in combination with other sensors.
If the flow never changed there would be no point using a turbo.
The engine still draws in more or less air depending how much fuel is being injected.
oh yeah I forgot about the turbo
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Mertin
Member
Registered: 12th Oct 05
Location: Scotland
User status: Offline
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Already been answered but yes diesel engines are built alot stronger, so they can handle the torque
You dont see petrol driven generators either do you? All big engines are diesel
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Daveskater
Premium Member
Registered: 29th Apr 08
Location: Oxford, UK Drives: Jap wagon
User status: Offline
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quote:
Originally posted by aPk
quote:
Originally posted by daymoon
while we talking about diesels.. at what revs on average should the gear be changed?
Depends. My Golf has a 6k redline I think, but the turbo runs out at about 3.5k, so I rarely rev beyond that.
The redline in the Corsa C Combo I used to drive at work was just over 5k, I took it near that a few times, but the turbo tuns out at 4k so once you get past that it barely pulls at all
It was a 1.7DI, but still good enough to spin the wheels when the clutch is dumped at 2.5-3k rpm
Numberwang!
Originally posted by AlunJ
I like you Dave, you are a man of men
Originally Whatapp'd by Neo
Dave's maybe capable of a drive-by cuddle
Look at my pictures
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DizzyRebel
Member
Registered: 2nd Jan 09
Location: Lincoln
User status: Offline
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Diesels run higher compression so usually run a fully forged bottom end. Everything is usually over engineered in them to take the strain so they usually last a fair few miles.
they rev low because unlike petrol engines they produce peak power at low RPM due to the extra potency of the highly compressed a/f mixture.
But please, no one compare power and torque together or say one is better than the other or an engines tuned for more torque than power...
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