Webers or Fuel Injection
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Topic author - Posts: 16
- Joined: Sun Jun 28, 2020 11:17 am
- Location: London
#1 Webers or Fuel Injection
Considering some engine upgrades over the winter months and wondered if anyone had any thoughts on either adding two sets of triple Webers or an injection System to improve performance and reliability.
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- Location: cheshire , england
#2 Re: Webers or Fuel Injection
12 chokes on 6 Webers, presumably IVA or the like, will ensure that I will be able to hear you coming from my house in Cheshire ! And if you need more performance than you have got, then I fear that you have the wrong car, because there is still ( despite the recent horsepower race ) virtually nothing to touch an E, whether 6 or 12 cylinders , for mid range performance, and on today's congested roads any more performance really is rather academic . I don't know what you are used to, but when I had a road car that would do 0-100mph in 8.5 seconds, the performance was completely unusable because it frightened people stupid as you overtook them. I don't want to dampen your enthusiasm, but I would advise that you concentrate on getting the best out of your present setup, or, if you really must make a change, go for 4 SUs
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#3 Re: Webers or Fuel Injection
Steve
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc
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#4 Re: Webers or Fuel Injection
To improve reliability, only 1 thing is needed: upgrade the ignition to something modern like Lumenition etc.antseries3etype wrote: ↑Tue Sep 15, 2020 4:56 pmadding two sets of triple Webers or an injection System to improve performance and reliability.
To improve performance, serious head and bottom end work is needed before you start spending money on carbs/efi.
I converted an ex-E S3 OTS to HE using 11:1 pistons, std HE heads, Lightweight flywheel and standard V12 HE EFI hardware although managed with Megasquirt. This car ran level with a 4.2L Supercharged XK....BUT....
It was seriously frustrating not having a deep overdrive and I constantly longed for another gear or two.
After all that,I concluded that the car is much more in need of an overdrive transmission than more power.
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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Topic author - Posts: 16
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#5 Re: Webers or Fuel Injection
Thank you so much for the very informed comments. Regards
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#6 Re: Webers or Fuel Injection
I have 6 IDA Webers on my XJS race car. Looks cool. But you have to remove them all to replace the spark plugs. And setting them up correctly took many hours on the dyno.
Webers will not offer any added reliability over Strombergs. And they are known for causing engine bay fires in V12s.
As above, the original Opus ignition system is a frequent cause of unreliability. It is by no means my area of expertise so others might comment on the best path to improvements there.
Having said this, were you considering moving to injection you might consider adopting a modern controller that provides programmable ignition as well. This is complex, but offers many potential advantages for getting the most out of your V12. I will probably head down this route with my XJS at some point.
Webers will not offer any added reliability over Strombergs. And they are known for causing engine bay fires in V12s.
As above, the original Opus ignition system is a frequent cause of unreliability. It is by no means my area of expertise so others might comment on the best path to improvements there.
Having said this, were you considering moving to injection you might consider adopting a modern controller that provides programmable ignition as well. This is complex, but offers many potential advantages for getting the most out of your V12. I will probably head down this route with my XJS at some point.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia
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#7 Re: Webers or Fuel Injection
I’m not an expert, but I wanted to go with the Weber kit, but I was basically told by several restoration shops that it is almost cosmetic as the velocity stacks needed would not clear the bonnet so the short ones that come with the V12 kit are fussy and not much gain. I went with EFI.
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#8 Re: Webers or Fuel Injection
Can you describe the EFI set up you chose? Some pics would be good too if that's possible.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia
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#9 Re: Webers or Fuel Injection
I am driving a Series III since 20 years.
If you want to improve the power output an the reliability, make these changes:
1. Don't do EFI. It is a long way, until it will work good. Marek has done it. His motor is running very good But Marek is intelligent, has a lot of knowledge and experience. 99% of all car-mechanics will be "lower".
2. Don't do Weber. I spoke with two person about this. One war the owner of a workshop, who sold AND mounted these kits to Car owners. He said t me at the Essen Oldtimer Fair: Don't try Weber carbs, They are not working well on the EV12.
Roger Bywater told a German workshop owner, that the velocity stacks you need for the carbs have to be MUUUUUCH longer, than you can mount under the bonnet. For a proper working in the range of 3500 und 5500 rpm, you need relatively long stacks. For a Lamborghini of Ferrari, which are revving up to 8000rpm, the trumpets can be shorter.
3. I have 4 Stromberg on my 6,0L HE-Motor. they are working very good, the motor has a lot of power. I have done two races against EV12 with EFI. Compared against a 5,3er with EFI ( my motor had also 5,3 in the past) and a 6 L with EFI, my motor with the Stromberg had MUCH more power in the rv range of 2000 - 4000 rpm. Above this, the EFI cars have been stronger.
4. If you remove the small (32mm inner diameter) trumpets to the air-filter boxes and add straight pipes with minimum 45 mm inner diameter, the motor will produce some ponies more.
5. If you make a whole of 45 mm inside the front silencers , that the will become straight through, this will also gain some ponies.
Both changes Nr. 4 und Nr. 5 will make the motor roundabout 20 - 25 hp stronger . The sound will also become a little bit more sporty.
BUT YOU NEED TO PRODUCE 4 DIFFERENT CARB NEEDLES, that the mixture will be okay. If not, the mixture will become MUCH to lean and the motor will work very bad in the upper range.
6. These needles I have produced by myself. You need equipment, experience and knowledge. 99% of the car mechanics can't help you with this work.
7. If you change to 4 SU HD8 carbs, you can BUY needles, which fit better for the motor with the higher breathing ability. But you must know, which to select. This is also a problem for every car mechanic, who has never done this SUCCESSFULLY.
8 . To change the ignition system from OPS to a modern system from Barratt, will rise the reliability.
I am driving this car since 20 years. I have some experience with rising the hp, WITHOUT big cost. I am very satisfied with the power of my motor. Also the gas consumption is low, because of the "long" Getrag and the "long" axle. If I am driving with 100 mph, the motor revs roundabout 3000 rpm.
I have a Getrag 5-gear box in my car and a 2,88er diff. This will make you happier, than a motor with EFi or Weber. A change to EFI is expensive. You need a man, who has done THIS before and is intelligent AND has experience. Otherwise it can become a long nightmare. A lot of people are telling you, that EFI is the best . They are correct, IF (!!!) the development of the motor plus EFI has been done from a big amount of car engineers NOT car mechanics. Otherwise the time of "debugging" will last long. One friend of me has done this. Three workshops worked on this project. It took roundabout 25000 Euro (!!!) and some years, until her was satisfied.
Or ask Marek how much you have to pay to him, if he is doing the conversion for you. You need somebody who has done this before Successfully ! ! ! "Doing with the mouth" will be not enough.
Excuse my poor English!
Regards Wolfgang Gatza
If you want to improve the power output an the reliability, make these changes:
1. Don't do EFI. It is a long way, until it will work good. Marek has done it. His motor is running very good But Marek is intelligent, has a lot of knowledge and experience. 99% of all car-mechanics will be "lower".
2. Don't do Weber. I spoke with two person about this. One war the owner of a workshop, who sold AND mounted these kits to Car owners. He said t me at the Essen Oldtimer Fair: Don't try Weber carbs, They are not working well on the EV12.
Roger Bywater told a German workshop owner, that the velocity stacks you need for the carbs have to be MUUUUUCH longer, than you can mount under the bonnet. For a proper working in the range of 3500 und 5500 rpm, you need relatively long stacks. For a Lamborghini of Ferrari, which are revving up to 8000rpm, the trumpets can be shorter.
3. I have 4 Stromberg on my 6,0L HE-Motor. they are working very good, the motor has a lot of power. I have done two races against EV12 with EFI. Compared against a 5,3er with EFI ( my motor had also 5,3 in the past) and a 6 L with EFI, my motor with the Stromberg had MUCH more power in the rv range of 2000 - 4000 rpm. Above this, the EFI cars have been stronger.
4. If you remove the small (32mm inner diameter) trumpets to the air-filter boxes and add straight pipes with minimum 45 mm inner diameter, the motor will produce some ponies more.
5. If you make a whole of 45 mm inside the front silencers , that the will become straight through, this will also gain some ponies.
Both changes Nr. 4 und Nr. 5 will make the motor roundabout 20 - 25 hp stronger . The sound will also become a little bit more sporty.
BUT YOU NEED TO PRODUCE 4 DIFFERENT CARB NEEDLES, that the mixture will be okay. If not, the mixture will become MUCH to lean and the motor will work very bad in the upper range.
6. These needles I have produced by myself. You need equipment, experience and knowledge. 99% of the car mechanics can't help you with this work.
7. If you change to 4 SU HD8 carbs, you can BUY needles, which fit better for the motor with the higher breathing ability. But you must know, which to select. This is also a problem for every car mechanic, who has never done this SUCCESSFULLY.
8 . To change the ignition system from OPS to a modern system from Barratt, will rise the reliability.
I am driving this car since 20 years. I have some experience with rising the hp, WITHOUT big cost. I am very satisfied with the power of my motor. Also the gas consumption is low, because of the "long" Getrag and the "long" axle. If I am driving with 100 mph, the motor revs roundabout 3000 rpm.
I have a Getrag 5-gear box in my car and a 2,88er diff. This will make you happier, than a motor with EFi or Weber. A change to EFI is expensive. You need a man, who has done THIS before and is intelligent AND has experience. Otherwise it can become a long nightmare. A lot of people are telling you, that EFI is the best . They are correct, IF (!!!) the development of the motor plus EFI has been done from a big amount of car engineers NOT car mechanics. Otherwise the time of "debugging" will last long. One friend of me has done this. Three workshops worked on this project. It took roundabout 25000 Euro (!!!) and some years, until her was satisfied.
Or ask Marek how much you have to pay to him, if he is doing the conversion for you. You need somebody who has done this before Successfully ! ! ! "Doing with the mouth" will be not enough.
Excuse my poor English!
Regards Wolfgang Gatza
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#10 Re: Webers or Fuel Injection
I agree. For the money and effort, rather do a 5-speed with overdrive 5th or in the very least a 2.88 diff.
I agree! The Strommies are excellent carbs, SU's too. The Strommies are just, to me, a more elegant, better designed carb.
I agree. Cut and paste the dual coil ignition system from an XJS or LUMENITION or Petronix. Add the JLM519 vacuum advance module if not already fitted for highly preceptible benefits when driving normally.
I agree, in respect of going for an overdrive transmission or the 2.88 diff. A 5-sp gearbox is not necessarily an overdrive transmission. I am leaning towards fitting a GM 700R4 to my S3. Just not sure how much body mods will be required - yet.
Last edited by jagwit on Mon Nov 16, 2020 7:20 am, edited 1 time in total.
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#11 Re: Webers or Fuel Injection
I have mounted the Getrag 265 with 5 gears. The fifth is 1: 0,81, therefore an "overdrive".
Regrds Wolfgang Gatza
Regrds Wolfgang Gatza
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#12 Re: Webers or Fuel Injection
My car is “in progress” so I can’t tell you the results yet. Sports Car Classics about 40 miles north of Los Angeles has been doing this for years. They have several levels of upgrades. The owner used to be some part of E-TYPE UK when he lived in the UK. As with any restoration, the budget went over rather quickly once we pulled all the junk off the top and saw some coolant that escaped one cylinder....which lead to the heads coming off..., which were fused to the steel studs, which found some scoring in 3 cylinders...you know how it goes.
The goal was to have something fun but drivable. I wouldn’t resto-mod a series 1 or 2 car, but I’m a bigger guy with a bad back and I appreciate the extra 9 inches of the Series 3 and the slight extra width. My dad had a Series 3 and a XJ12C growing up. I just retired and I wanted to make a Series 3 a bit more sporty and a bit less GT. My car will have 6.1L forged pistons, slightly more aggressive cams, ported heads, new valves, full EFI with all new electronics and aj6 (the company) exhaust, lightweight Fosseway starter and alternator along with Fosseway’s 6 piston calipers and all new brakes with 16” x 6” 205/65 Dayton wheels.
I have not decided on the 2.88 diff vs a 5 speed vs an overdrive. The car was stuck waiting on parts as it was started in January, pre-Covid, and everything got delayed. The pistons are licensed in the UK but made in California so for some bizarre reason they must go from California to the UK and back. The car just needs the pistons which should be in LA next week and then re-assembly. Hopefully, by November.
SCC just has a new website. Here is a link, though I am not going with the Jenvey EFI, but rather a proprietary one from SCC which is very similar to aJ6’s modified 6L XJS system. I can’t figure out how to upload the pictures but you can scroll through and see the “XJS” looking EFI pictures.
https://www.sportscarclassics.us/classi ... n-systems/
The goal was to have something fun but drivable. I wouldn’t resto-mod a series 1 or 2 car, but I’m a bigger guy with a bad back and I appreciate the extra 9 inches of the Series 3 and the slight extra width. My dad had a Series 3 and a XJ12C growing up. I just retired and I wanted to make a Series 3 a bit more sporty and a bit less GT. My car will have 6.1L forged pistons, slightly more aggressive cams, ported heads, new valves, full EFI with all new electronics and aj6 (the company) exhaust, lightweight Fosseway starter and alternator along with Fosseway’s 6 piston calipers and all new brakes with 16” x 6” 205/65 Dayton wheels.
I have not decided on the 2.88 diff vs a 5 speed vs an overdrive. The car was stuck waiting on parts as it was started in January, pre-Covid, and everything got delayed. The pistons are licensed in the UK but made in California so for some bizarre reason they must go from California to the UK and back. The car just needs the pistons which should be in LA next week and then re-assembly. Hopefully, by November.
SCC just has a new website. Here is a link, though I am not going with the Jenvey EFI, but rather a proprietary one from SCC which is very similar to aJ6’s modified 6L XJS system. I can’t figure out how to upload the pictures but you can scroll through and see the “XJS” looking EFI pictures.
https://www.sportscarclassics.us/classi ... n-systems/
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#13 Re: Webers or Fuel Injection
That is overdrive in my book too! I fitted a 2.88 and am pleased with the difference in revs on my four speed box but I am considering a five speed box too.
I find your comments very enlightening as I was also considering injection, however straight pipes to the airbox and possibly SU's or a setup on a rolling road for the Strombergs looks like a better option all being considered.
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#14 Re: Webers or Fuel Injection
Hello Colin,
"I find your comments very enlightening as I was also considering injection, however straight pipes to the airbox and possibly SU's or a setup on a rolling road for the Strombergs looks like a better option all being considered."
If you mount two pipes with a bigger diamter to the airfilterboxes and you make a hole of 45 mm longline in the two front silencers, the mixture is becomming weaker. Unfortunately too weak.
Can can't cure this with "turning srews" at the carb. You need 4 carb needles, which are less thick in the upper area (thin end of needle), the the small round cleft between the carb-needle and the jet is a very little bit bigger. Through thius bigger cleft, more gas can flow.
You need to measure the mixture, that you can see, if it is okay. You have to know, how much is okay. There is a book from Des Hammill "Tuning the SU-Cabrs). Buy thuis book !!! In this book he has a very clear desciption, how to change to shape of the needle, if you prepare a motor with different air-filters and different exhaust system for racing.
To measure the mixture, you have to mount a wide-band lambda measuring system into the car. I bought one from 'innovate' for roundabout 170 pound. You can drive with the car and can see JUST in time, how the mixture is. Depending of the position of the lambda-"Sonde' in the exhaust system, you can check one carb or two carbs of one side of the motor.
Invest this money and effort. The result for my car was, that in the rev range between 2000 und 4000 rpm, the motors with carbs was much stronger than the same motor of a friends car with EFI. I have done this test two times with the same result. 5,3 Vs 5,3 and later 6,0 vs 6,0.
If you don't want to shape needles with 1000er sanding paper, you can mount 4 SU Carbs. For SU carbs you maybe can find some needles which will "fit" and produce in different rev ranges and different throttle positions the correct mixture. S U offers 700 different needles.
I have produces 4 needles by myself It was a lot of work. But at the end I had a good result.
If you do all this correct, you never will miss EFI on your V12. Together with the 2,88 plus the long Getrag my 6,0 L HE car has a gas consumption of roundabout 19 mpg when cruising. Again no need for EFI.
'Empe'.
Regards Wolfgang Gatza
"I find your comments very enlightening as I was also considering injection, however straight pipes to the airbox and possibly SU's or a setup on a rolling road for the Strombergs looks like a better option all being considered."
If you mount two pipes with a bigger diamter to the airfilterboxes and you make a hole of 45 mm longline in the two front silencers, the mixture is becomming weaker. Unfortunately too weak.
Can can't cure this with "turning srews" at the carb. You need 4 carb needles, which are less thick in the upper area (thin end of needle), the the small round cleft between the carb-needle and the jet is a very little bit bigger. Through thius bigger cleft, more gas can flow.
You need to measure the mixture, that you can see, if it is okay. You have to know, how much is okay. There is a book from Des Hammill "Tuning the SU-Cabrs). Buy thuis book !!! In this book he has a very clear desciption, how to change to shape of the needle, if you prepare a motor with different air-filters and different exhaust system for racing.
To measure the mixture, you have to mount a wide-band lambda measuring system into the car. I bought one from 'innovate' for roundabout 170 pound. You can drive with the car and can see JUST in time, how the mixture is. Depending of the position of the lambda-"Sonde' in the exhaust system, you can check one carb or two carbs of one side of the motor.
Invest this money and effort. The result for my car was, that in the rev range between 2000 und 4000 rpm, the motors with carbs was much stronger than the same motor of a friends car with EFI. I have done this test two times with the same result. 5,3 Vs 5,3 and later 6,0 vs 6,0.
If you don't want to shape needles with 1000er sanding paper, you can mount 4 SU Carbs. For SU carbs you maybe can find some needles which will "fit" and produce in different rev ranges and different throttle positions the correct mixture. S U offers 700 different needles.
I have produces 4 needles by myself It was a lot of work. But at the end I had a good result.
If you do all this correct, you never will miss EFI on your V12. Together with the 2,88 plus the long Getrag my 6,0 L HE car has a gas consumption of roundabout 19 mpg when cruising. Again no need for EFI.
'Empe'.
Regards Wolfgang Gatza
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#15 Re: Webers or Fuel Injection
Carb vs efi? I think this discussion is comparing carbs with legacy efi? Surely, no reason a modern ecu couldn’t be programmed to do at least anything that carbs can do, if that’s what u want?
I’m hoping that, with modern efi, controlled by latest tech 4D fully sequential adaptive ecu, efi will outperform carbs across the board and be monstrously more efficient to boot. We shall see.
I am complicating things by trying to convert to dedicated LPG liquid-phase injection at the same time, i.e. not dual fuel, no petrol at all. It is proving very hard, the industry (Vialle, Icom) is very protective of their “tech.” e.g.:
Me: Hello, pls can you advise, what is the capacity of a Vialle PTS-70 pump?
Vialle: The flowrate etc. are details that are not given by us, they are never shared outside our organization. I hope that this is the answer you are looking for and it will help you with the system.
Also complicating things, I’m challenging myself to make it a “bolt-on” upgrade that will work on any efi V12. The secret is liquid (not gas) injection, at least 10% more power that with petrol, 50% reduction in fuel costs and Euro 5 or better emissions. Can’t do that with carbs. So imo, if you are not trying to be utterly original, evolve to efi.
Here is my latest prototyping effort, mounting the LPG injectors:
I’m hoping that, with modern efi, controlled by latest tech 4D fully sequential adaptive ecu, efi will outperform carbs across the board and be monstrously more efficient to boot. We shall see.
I am complicating things by trying to convert to dedicated LPG liquid-phase injection at the same time, i.e. not dual fuel, no petrol at all. It is proving very hard, the industry (Vialle, Icom) is very protective of their “tech.” e.g.:
Me: Hello, pls can you advise, what is the capacity of a Vialle PTS-70 pump?
Vialle: The flowrate etc. are details that are not given by us, they are never shared outside our organization. I hope that this is the answer you are looking for and it will help you with the system.
Also complicating things, I’m challenging myself to make it a “bolt-on” upgrade that will work on any efi V12. The secret is liquid (not gas) injection, at least 10% more power that with petrol, 50% reduction in fuel costs and Euro 5 or better emissions. Can’t do that with carbs. So imo, if you are not trying to be utterly original, evolve to efi.
Here is my latest prototyping effort, mounting the LPG injectors:
Regards,
ColinL
'72 OTS manual V12
ColinL
'72 OTS manual V12
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#16 Re: Webers or Fuel Injection
My car is set up really beautifully by a combination of M&C Wilkinson and AJ6 Engineering. Fitted with the very last 6 litre engine from the factory in 2005, XJS fuel injection metered via a AJ6 ECU. AJ6 throttle bodies, electronic ignition via Lumenition. Producing 380bhp, and a chassis set up by Eagle with Ohlins dampers and AP Racing brakes. As quick as you can use on our roads, fab handling and superb ride.
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#17 Re: Webers or Fuel Injection
Yep, read yr Classic Jaguars mag article. Imo you have the holy grail, an upgraded e-type that has increased value.
Regards,
ColinL
'72 OTS manual V12
ColinL
'72 OTS manual V12
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#18 Re: Webers or Fuel Injection
Thanks for that. Also, there was another similar article on my V12 in your Australian magazine called Jaguar. It was last year. Interesting what you are doing. Good luck with that.
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#19 Re: Webers or Fuel Injection
"Also complicating things, I’m challenging myself to make it a “bolt-on” upgrade that will work on any efi V12. The secret is liquid (not gas) injection, at least 10% more power that with petrol, 50% reduction in fuel costs and Euro 5 or better emissions. Can’t do that with carbs. So imo, if you are not trying to be utterly original, evolve to efi."
If you want to have 10% more power, you need 10% more AIR in the combustion chamber.
If you want Euro 5, you have to pay 10 ingeneers for 10 weeks programming the ECU.
I can read often that efi is wonderfull. I believe this 100%, IF a big amount of car engineers have done the work.
Efi is better than carbs. But until efi is working well, you have to spend a lot of time (money?) for debugging.
I still think because of my private eyperience, that the V12 motor with 4 Strombergs has more torque between 2000 and 4000 rpm. Upon this, the motor with efi has more. How would you like to drive your car ? All the time above 4000 rpm ?
A motor with 1400 ccm and 3 cylinder has a higher max torque than a motor with 6 cylinder and 1400ccm.
Also the max torque is in a lower rea of the "rev.-mountain".
A V12 with 4 Stromberg is sucking like 4 threecylinder motors.
A V12 with the original efi and different electronic is succing like two sixcylinder motors.
This is the rason, why the motor with efi have a higher max power and the motor with 4 Stromberg have a higher torque betwen 2000 and 4000 rpm.
The power of the efi motor in the brains of car-owners is higher because you often hear, that a Stromberg carb is a bad carb.
You have to TEST it on the street. Two times I have done this in my life and both times the efi-driver hav got very 'long faces'.
Regards Wolfgang Gatza
If you want to have 10% more power, you need 10% more AIR in the combustion chamber.
If you want Euro 5, you have to pay 10 ingeneers for 10 weeks programming the ECU.
I can read often that efi is wonderfull. I believe this 100%, IF a big amount of car engineers have done the work.
Efi is better than carbs. But until efi is working well, you have to spend a lot of time (money?) for debugging.
I still think because of my private eyperience, that the V12 motor with 4 Strombergs has more torque between 2000 and 4000 rpm. Upon this, the motor with efi has more. How would you like to drive your car ? All the time above 4000 rpm ?
A motor with 1400 ccm and 3 cylinder has a higher max torque than a motor with 6 cylinder and 1400ccm.
Also the max torque is in a lower rea of the "rev.-mountain".
A V12 with 4 Stromberg is sucking like 4 threecylinder motors.
A V12 with the original efi and different electronic is succing like two sixcylinder motors.
This is the rason, why the motor with efi have a higher max power and the motor with 4 Stromberg have a higher torque betwen 2000 and 4000 rpm.
The power of the efi motor in the brains of car-owners is higher because you often hear, that a Stromberg carb is a bad carb.
You have to TEST it on the street. Two times I have done this in my life and both times the efi-driver hav got very 'long faces'.
Regards Wolfgang Gatza
Last edited by Woolfi on Sun Feb 12, 2023 10:09 pm, edited 1 time in total.
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#20 Re: Webers or Fuel Injection
Up to 10% more air … with LPG liquid-phase injection that is effectively what happens. The LPG instantly vaporizes, its temperature switches to as low as 40 degC below zero, this chills the incoming air, increasing its density, volumetric efficiency is much improved.
Volumetric efficiency (and friction) is the reason a 3 cyl engine can output more torque than a 6 cyl engine of the same capacity, more so than the number of (interconnected) manifold segments?
Its’ not only volumetric efficiency, LPG has higher octane, 110 RON, compared to petrol’s 98, more ignition advance can be tolerated, so thermal efficiency is also improved.
Another benefit is that LPG is a naturally clean fuel, very clean compared to petrol. Means that, compared to petrol, achieving Euro-5 standard emissions should be relatively easy as long as yr engine is not too big, just tune to stoic, done.
So, if you must mod your car, imo step 1 = convert to efi, step 2 = convert to mono-fuel LPG liquid-phase injection?
Volumetric efficiency (and friction) is the reason a 3 cyl engine can output more torque than a 6 cyl engine of the same capacity, more so than the number of (interconnected) manifold segments?
Its’ not only volumetric efficiency, LPG has higher octane, 110 RON, compared to petrol’s 98, more ignition advance can be tolerated, so thermal efficiency is also improved.
Another benefit is that LPG is a naturally clean fuel, very clean compared to petrol. Means that, compared to petrol, achieving Euro-5 standard emissions should be relatively easy as long as yr engine is not too big, just tune to stoic, done.
So, if you must mod your car, imo step 1 = convert to efi, step 2 = convert to mono-fuel LPG liquid-phase injection?
Regards,
ColinL
'72 OTS manual V12
ColinL
'72 OTS manual V12
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