Classic Cars DBS V8 vs AC 428
Discussion
In the new February edition of Classic Cars they have a twin test of a 1971 DBS V8 vs AC 428.
I was surprised to see that the DBS V8 was quoted as running four Weber 42DCOE Carbs with the performance quoted as 161 mph top speed and 0-60 in 6.0 secs yet they were unimpressed with the performance of the DBS V8 on test.
I thought that all the early V8's ran with bosch mechanical fuel injection and that they changed to Carbs in late 1973 / early 1974.
At the time Aston quoted the injected car with 161 mph but the carb version had a reported small drop back to 155 mph but they said that the car had a better overall power delivery on carbs.
At the time most motoring magazines of the day found the injected car would ease past 160 mph but they found that the carb cars were struggling to even hit 150 mph.
I later read that they never really wanted to swap the cars away from the injection set up but they had no choice as they could not pay the Bosch account who would not supply them any more until they paid up whilst Weber were happy to give them a new line of credit.
If what I had read and heard in the past is correct then the DBS V8 in Classic Cars has been converted to carbs which would be why the car was unimpressive on the performance front.
Does any of the experts on the forum know if what I read and heard is true regarding carb vs injection set up.
I was surprised to see that the DBS V8 was quoted as running four Weber 42DCOE Carbs with the performance quoted as 161 mph top speed and 0-60 in 6.0 secs yet they were unimpressed with the performance of the DBS V8 on test.
I thought that all the early V8's ran with bosch mechanical fuel injection and that they changed to Carbs in late 1973 / early 1974.
At the time Aston quoted the injected car with 161 mph but the carb version had a reported small drop back to 155 mph but they said that the car had a better overall power delivery on carbs.
At the time most motoring magazines of the day found the injected car would ease past 160 mph but they found that the carb cars were struggling to even hit 150 mph.
I later read that they never really wanted to swap the cars away from the injection set up but they had no choice as they could not pay the Bosch account who would not supply them any more until they paid up whilst Weber were happy to give them a new line of credit.
If what I had read and heard in the past is correct then the DBS V8 in Classic Cars has been converted to carbs which would be why the car was unimpressive on the performance front.
Does any of the experts on the forum know if what I read and heard is true regarding carb vs injection set up.
WilliamP your thread has arrived!Sorry to be a bore,
I just wondered if Mr Williams had returned to the forum and would be interested in this thread.
Surprisingly it does seem that only the current cars are of interest to the piston heads followers.
I find this quite surprising as I am not that old but like old cars as much as new ones and have had both.
I just wondered if Mr Williams had returned to the forum and would be interested in this thread.
Surprisingly it does seem that only the current cars are of interest to the piston heads followers.
I find this quite surprising as I am not that old but like old cars as much as new ones and have had both.
This also strikes me as strange. Perhaps classic Aston owners live somewhere else, but I've not found them.
In photos of the classic DBS, there are some prominent knobs low down just by the driver's right knee. Does anyone know what they control? They look like they are from a mid-70s hi-fi.
In photos of the classic DBS, there are some prominent knobs low down just by the driver's right knee. Does anyone know what they control? They look like they are from a mid-70s hi-fi.
Yep, Im only moonlighting here as I am interested in most Euro classics as well as Astons......No wrong info given there as there are some very informed members covering every model......
There are three knobs and two switches on that panel. The switches are for the front fog lights (one each) and the knobs..... one is wipers,(two stages) which when pressed sprays screen wash. One is for the ajustable rear dampers (four positions, hard to soft and the last one is for....er....er dash dimmer (will check that last one when I get home tonight and report back tomorrow as Ive forgot
There are three knobs and two switches on that panel. The switches are for the front fog lights (one each) and the knobs..... one is wipers,(two stages) which when pressed sprays screen wash. One is for the ajustable rear dampers (four positions, hard to soft and the last one is for....er....er dash dimmer (will check that last one when I get home tonight and report back tomorrow as Ive forgot
dbsdave said:
The switches are for the front fog lights (one each) and the knobs..... one is wipers,(two stages) which when pressed sprays screen wash. One is for the ajustable rear dampers (four positions, hard to soft and the last one is for....er....er dash dimmer (will check that last one when I get home tonight and report back tomorrow as Ive forgot
Respect!Sorry, I missed this thread the first time around- I have a newborn baby you see, and teaching him different engine notes is proving rather long-winded...
Anyhow, the DBS V8 were built from the factory with the Bosch FI system. The photos of the car used in the magazine all show this system, yet the information box listed carbs which were used later on. They are not the first to make this mistake, and wont be the last- it is inaccurate writing, but not unusual.
And its true that when new the road testers did find the Bosch FI system lacked grunt low-down the rev range, but proved to be really powerful further on the rev range. The carbs, and their softer cam settings gave the driver more low down torque, but lost lots of power. The carbs were also a lot easier to maintain.
When developing the V8 engine, they looked at carbs and electronic fuel injection (both were already used by Aston on the DB6) before settling on the Bosch mechanical system as this gave consistently good power, and Bosch were very willing to help- remember, when new the Aston was one of the fastest cars in the world- certainly the fastest with rear seats, so it was quite a prestigeous project for Bosch.
However, the Bosch system is complicated, takes a lot of time to set-up, needs regular maintenance and can destroy the engine if this is neglected. It was also very difficult to pass the US emissions.
The engineers finally cracked this nut, but a short time later the US emissions laws were made even tighter and the car would not pass. With Webers, the cars could pass (and did, enabling them to sell to the lucrative US market)
Back then there wasn’t the knowledge to properly set the system up, but find a good one now, have a specialist set the system up, fit modern ignition and the car will be reliable and very quick
As for not paying Bosch- this wouldn’t surprise me, as the company were in real financial trouble back then . There were probably a number of suppliers who they forgot to pay. But they knew the Weber carbs well, and it fitted with where they wanted the company to go, so its probably only part of the reason why they changed.
As for the knobs, correct: (from top to bottom) windscreen wipers, rear dampers control and dashboard brightness. Why have the windscreen wipers down by the knee? Well, one of the stalks is for the indicators (right hand side) and headlamp flash. The left hand stalk operates just the horn.
Hope this helps. Happy to answer any more questions- I have the workshop manual in front of me!
Anyhow, the DBS V8 were built from the factory with the Bosch FI system. The photos of the car used in the magazine all show this system, yet the information box listed carbs which were used later on. They are not the first to make this mistake, and wont be the last- it is inaccurate writing, but not unusual.
And its true that when new the road testers did find the Bosch FI system lacked grunt low-down the rev range, but proved to be really powerful further on the rev range. The carbs, and their softer cam settings gave the driver more low down torque, but lost lots of power. The carbs were also a lot easier to maintain.
When developing the V8 engine, they looked at carbs and electronic fuel injection (both were already used by Aston on the DB6) before settling on the Bosch mechanical system as this gave consistently good power, and Bosch were very willing to help- remember, when new the Aston was one of the fastest cars in the world- certainly the fastest with rear seats, so it was quite a prestigeous project for Bosch.
However, the Bosch system is complicated, takes a lot of time to set-up, needs regular maintenance and can destroy the engine if this is neglected. It was also very difficult to pass the US emissions.
The engineers finally cracked this nut, but a short time later the US emissions laws were made even tighter and the car would not pass. With Webers, the cars could pass (and did, enabling them to sell to the lucrative US market)
Back then there wasn’t the knowledge to properly set the system up, but find a good one now, have a specialist set the system up, fit modern ignition and the car will be reliable and very quick
As for not paying Bosch- this wouldn’t surprise me, as the company were in real financial trouble back then . There were probably a number of suppliers who they forgot to pay. But they knew the Weber carbs well, and it fitted with where they wanted the company to go, so its probably only part of the reason why they changed.
As for the knobs, correct: (from top to bottom) windscreen wipers, rear dampers control and dashboard brightness. Why have the windscreen wipers down by the knee? Well, one of the stalks is for the indicators (right hand side) and headlamp flash. The left hand stalk operates just the horn.
Hope this helps. Happy to answer any more questions- I have the workshop manual in front of me!
Thank you and congratulations on the new baby, will he gurgle Straight 6, V8 or V12 style.
What a wonderful wealth of knowledge that you have on these wonderful old cars. I have a modern car which is only a weekend car and I do get very tempted to swap to an original 1970's / 80's V8.
Back in August 1973 a family member collected a brand new bright red injected V8 from the Aston dealer called Lazenbys it was fabulous.
Unfortunately the car came to a sticky end when it was 18 months old when it was involved in an accident which put it on its roof in a ditch. As every body panel was creased or dented the insurance company wrote it of but I always wondered if someone did repair the car. I do not know the chassis number of the car but I always remembered that the registration number was NNR81M, so I wondered if you had any knowledge of this particular car.
Probably works service might know but sadly I do not get along with them at Newport Pagnell (see Grange Exeter post for some of the reasons).
Once again thanks for replying to my post.
What a wonderful wealth of knowledge that you have on these wonderful old cars. I have a modern car which is only a weekend car and I do get very tempted to swap to an original 1970's / 80's V8.
Back in August 1973 a family member collected a brand new bright red injected V8 from the Aston dealer called Lazenbys it was fabulous.
Unfortunately the car came to a sticky end when it was 18 months old when it was involved in an accident which put it on its roof in a ditch. As every body panel was creased or dented the insurance company wrote it of but I always wondered if someone did repair the car. I do not know the chassis number of the car but I always remembered that the registration number was NNR81M, so I wondered if you had any knowledge of this particular car.
Probably works service might know but sadly I do not get along with them at Newport Pagnell (see Grange Exeter post for some of the reasons).
Once again thanks for replying to my post.
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