Why new injectors?
Discussion
I've got a car going in to noble motorsport with the sole intention of finding out once and for all if the air flow meter adds or detracts from the hp capability of he RV8.
It's a mildly tweaked example runing fully mappable omex system so we can optimise it for both scenarios, it will give us the definitive answer
After that I'll be trying the injector changes.
It's a mildly tweaked example runing fully mappable omex system so we can optimise it for both scenarios, it will give us the definitive answer
After that I'll be trying the injector changes.
Hi trackcar,
the test I was going to do is measure the atmospheric kpa, run the car at Wide Open Throttle with the maf in and see what the KPa is in the manifold, if its not at atmosphere then its restricting the flow, my 3.5 Flapper setup was dreadfully restricive, but that wasnt a hotwire. If you get your test done quicker than me let me know the results, save me some time,
Phil
the test I was going to do is measure the atmospheric kpa, run the car at Wide Open Throttle with the maf in and see what the KPa is in the manifold, if its not at atmosphere then its restricting the flow, my 3.5 Flapper setup was dreadfully restricive, but that wasnt a hotwire. If you get your test done quicker than me let me know the results, save me some time,
Phil
trackcar said:
I've got a car going in to noble motorsport with the sole intention of finding out once and for all if the air flow meter adds or detracts from the hp capability of he RV8.
It's a mildly tweaked example runing fully mappable omex system so we can optimise it for both scenarios, it will give us the definitive answer
After that I'll be trying the injector changes.
Do me a favour then Joolz whilst its there, if its still running with the 5AM do a back to back with the mesh on/off the front of the AFM, just to see what diffenrence is.
Obviuosly that could be easily done with a standard ECU car, not sure if the full omex runs off a MAP sensor or not though.....I hear
. Harry
Harry,
I dont think the mess is going to restrict flow that much.
Back to the injectors, my mate just mailed me, he has read this thread and recognised the part number for the TVR injectors I posted, they are the same as the set he had in his 3.9 hotwire setup, I flow tested those and they gave 210cc/Min, which is 20LB injectors. This equates to fueling for about 280 BHP, anything more and your running lean Im afraid. OK, the ones I tested were old (100K +) so untill I measure a new set I cant be sure the values are correct, but I bet they aint far out, Id be surprised if they can fuel 300BHP, so I will be fitting 26LB Ford Motorsport injectors if thats the case, these are around £90 for a set of 8 from the states, good for 340-350BHP,
Phil
EDITTED: Oooppss, keep thinking in terms of superchargers, these are NA !! Silly me, that makes them capable of 300BHP not 280, sorry!!
>> Edited by daxtojeiro on Thursday 21st July 20:18
I dont think the mess is going to restrict flow that much.
Back to the injectors, my mate just mailed me, he has read this thread and recognised the part number for the TVR injectors I posted, they are the same as the set he had in his 3.9 hotwire setup, I flow tested those and they gave 210cc/Min, which is 20LB injectors. This equates to fueling for about 280 BHP, anything more and your running lean Im afraid. OK, the ones I tested were old (100K +) so untill I measure a new set I cant be sure the values are correct, but I bet they aint far out, Id be surprised if they can fuel 300BHP, so I will be fitting 26LB Ford Motorsport injectors if thats the case, these are around £90 for a set of 8 from the states, good for 340-350BHP,
Phil
EDITTED: Oooppss, keep thinking in terms of superchargers, these are NA !! Silly me, that makes them capable of 300BHP not 280, sorry!!
>> Edited by daxtojeiro on Thursday 21st July 20:18
Jools - a sincere thank you for what you have said. I had absolutely no idea that you felt so negative about me. Since we have known each other for a long time, I am also surprised that you could jump to such conclusions.
You have given us all an interesting insite into your business on this thread:
www.pistonheads.com/gassing/topic.asp?f=13&h=0&t=191458 "Your Dealer's Hourly Rate".
When I heard that you were closing Joospeed, I was genuinely sorry to hear it. Although we do things somewhat differently, IMHO the TVR world was enhanced by your contribution. Obviously your loyal customer base thought so too, and were sorry to see it go. You shared your reasons with me in a private e-mail, and I respect that.
If I am guilty of anything, then it must be offering you unsolicited business advice. If this is how it appeared then I can see how you would take offence, although the intention was purely to offer any information and help that may be useful to keep Joospeed going. This was based on an initial assumption that you wanted to keep it going, which was mistaken.
However I think you have misunderstood the way I run my business, and I must quickly address this issue. Make no mistake - I love what I do and I have a passion for the motors, cars, technology, and the owners.
However I have found out the hard way that technical excellence is not enough to ensure a healthy business. Funding the development and research of new products is very expensive, and the cost of time doing e-mails and phone calls is also a significant drain. This requires a financially sustainable business to support it.
A balanced focus on the financial side of the business is just a necessary tool to achieve these long-term aims.
Yes I do use my business to pay my mortgage. I feel no need to apologise for that, and after all that is why most of us have jobs or businesses. Apart from crime, I'm unaware of any other ways to pay it! My clients are intelligent people who expect me to make a fair and reasonable profit, so that I will be there to offer them support and new developments in future.
With regard to my comments about the Emerald, you have again missed my point. I think your customers would be horrified to find that you didn't make any money on either the ECU or the mapping since they both went out at cost price. You told me that you didn't even charge for the time to deliver the car to Nobles, where they fit and map system for you. This also means that you have not even covered the time you spent in selling the system initially, which all adds up to an unsustainable financial loss for the business.
I merely suggested that it may be good business practice to make some money on the transaction. If you were to ask your customers, I'm sure they would all say they would rather you had charged more - and kept Joospeed going. Nobody would resent you making a decent living in return for the help and support you provided, least of all me. It is the reward for your contribution.
Overall this does not help the industry, because it ensures reduced or zero profit for you and the other players. It would appear that Joospeed made a loss on an Emerald transaction, and that it artificially held down the price of competitive offerings. You did say that you had adopted this strategy (price fixing?) in order to compete with Austec's remapping service for Cerbies, although I find it hard to see how it helps anyone.
Hopefully this clears up a misunderstanding, and we can all take off our flak jackets. The other PHers are clearly and understandably getting sick and tired of it. So I will not make any attacks on other traders or individuals, no matter what the provocation. I believe people are intelligent enough to read between the lines and work it out for themselves.
BTW - although Bosch injectors are expensive they are always sold at well below their list price, with a very small markup. Please note that most people buy their injectors from Austec or Mech Repairs, meaning that I don't make anything on them!
Mikey Mongoose - have you measured the duty cycle on the 300+BHP cars running standard injectors? Maybe you'd like to post the results of your testing. Personally I have found that with TVR heads they are nearing their acceptable duty cycle limit at around 285BHP.
>> Edited by Mark Adams on Thursday 21st July 22:20
You have given us all an interesting insite into your business on this thread:
www.pistonheads.com/gassing/topic.asp?f=13&h=0&t=191458 "Your Dealer's Hourly Rate".
When I heard that you were closing Joospeed, I was genuinely sorry to hear it. Although we do things somewhat differently, IMHO the TVR world was enhanced by your contribution. Obviously your loyal customer base thought so too, and were sorry to see it go. You shared your reasons with me in a private e-mail, and I respect that.
If I am guilty of anything, then it must be offering you unsolicited business advice. If this is how it appeared then I can see how you would take offence, although the intention was purely to offer any information and help that may be useful to keep Joospeed going. This was based on an initial assumption that you wanted to keep it going, which was mistaken.
However I think you have misunderstood the way I run my business, and I must quickly address this issue. Make no mistake - I love what I do and I have a passion for the motors, cars, technology, and the owners.
However I have found out the hard way that technical excellence is not enough to ensure a healthy business. Funding the development and research of new products is very expensive, and the cost of time doing e-mails and phone calls is also a significant drain. This requires a financially sustainable business to support it.
A balanced focus on the financial side of the business is just a necessary tool to achieve these long-term aims.
Yes I do use my business to pay my mortgage. I feel no need to apologise for that, and after all that is why most of us have jobs or businesses. Apart from crime, I'm unaware of any other ways to pay it! My clients are intelligent people who expect me to make a fair and reasonable profit, so that I will be there to offer them support and new developments in future.
With regard to my comments about the Emerald, you have again missed my point. I think your customers would be horrified to find that you didn't make any money on either the ECU or the mapping since they both went out at cost price. You told me that you didn't even charge for the time to deliver the car to Nobles, where they fit and map system for you. This also means that you have not even covered the time you spent in selling the system initially, which all adds up to an unsustainable financial loss for the business.
I merely suggested that it may be good business practice to make some money on the transaction. If you were to ask your customers, I'm sure they would all say they would rather you had charged more - and kept Joospeed going. Nobody would resent you making a decent living in return for the help and support you provided, least of all me. It is the reward for your contribution.
Overall this does not help the industry, because it ensures reduced or zero profit for you and the other players. It would appear that Joospeed made a loss on an Emerald transaction, and that it artificially held down the price of competitive offerings. You did say that you had adopted this strategy (price fixing?) in order to compete with Austec's remapping service for Cerbies, although I find it hard to see how it helps anyone.
Hopefully this clears up a misunderstanding, and we can all take off our flak jackets. The other PHers are clearly and understandably getting sick and tired of it. So I will not make any attacks on other traders or individuals, no matter what the provocation. I believe people are intelligent enough to read between the lines and work it out for themselves.
BTW - although Bosch injectors are expensive they are always sold at well below their list price, with a very small markup. Please note that most people buy their injectors from Austec or Mech Repairs, meaning that I don't make anything on them!
Mikey Mongoose - have you measured the duty cycle on the 300+BHP cars running standard injectors? Maybe you'd like to post the results of your testing. Personally I have found that with TVR heads they are nearing their acceptable duty cycle limit at around 285BHP.
>> Edited by Mark Adams on Thursday 21st July 22:20
Harry I really like that idea of using the AFM to compare before/after induction mods. Did you find it difficult to get a clear signal off the AFM? You've got me thinking now, and I'm toying with the idea of connecting the datalogger to the AFM to see whether I can get a good reading off it.
I've carried out a few runs using a boost gauge to crudely measure the manifold depression at peak power, I was surprised to find there was a significant depression towards the top of the rev range at full throttle. It was hard to get an accurate reading off the gauge because things happened so quickly at full power, but I reckoned I was getting around -1.5 psi static pressure (in the plenum). Doing the sums I estimated that probably about half off this would could be accounted for by the dynamic pressure drop across the AFM choke.
I also changed the 5AM for the slightly bigger 20AM, and managed to convince myself that the pressure drop was slightly smaller. Very hard to get measurements that I have any great confidence in though under these conditions. It does suggest though that there may be a significant pressure drop across the intake to the plenum, 1.5 psi corresponds to 0.1 bar so potentially somewhere round 10% loss in charge density and presumably torque.
Edited to add: just realize I already mentioned this a few days ago, my doesn't this thread run and run.
>> Edited by GreenV8S on Thursday 21st July 20:51
I've carried out a few runs using a boost gauge to crudely measure the manifold depression at peak power, I was surprised to find there was a significant depression towards the top of the rev range at full throttle. It was hard to get an accurate reading off the gauge because things happened so quickly at full power, but I reckoned I was getting around -1.5 psi static pressure (in the plenum). Doing the sums I estimated that probably about half off this would could be accounted for by the dynamic pressure drop across the AFM choke.
I also changed the 5AM for the slightly bigger 20AM, and managed to convince myself that the pressure drop was slightly smaller. Very hard to get measurements that I have any great confidence in though under these conditions. It does suggest though that there may be a significant pressure drop across the intake to the plenum, 1.5 psi corresponds to 0.1 bar so potentially somewhere round 10% loss in charge density and presumably torque.
Edited to add: just realize I already mentioned this a few days ago, my doesn't this thread run and run.
>> Edited by GreenV8S on Thursday 21st July 20:51
Peter : if you're measuring the pressure reduction in the plenum how much is due to the airflow meter and how much to the throttle butterfly.
i recently took off my carbon plenum and replaced it with a flowed trumpetless base and larger (jaguar aj6) throttle butterfly TIG welded to the original plenum.
The mixture went very weak immediately, and with the addition of an increased fuel pressure to get the mixture somewhere sensible I gained about 4-8hp in the 4-6k range, slight drop at lower revs.
this is on a 4 litre still keeping the airflow meter .. which leads me to suspect that the std throttle on the 4 litre is restrictive .. i can't believe all that extra airflow just came from blending the trumpet base ...
i recently took off my carbon plenum and replaced it with a flowed trumpetless base and larger (jaguar aj6) throttle butterfly TIG welded to the original plenum.
The mixture went very weak immediately, and with the addition of an increased fuel pressure to get the mixture somewhere sensible I gained about 4-8hp in the 4-6k range, slight drop at lower revs.
this is on a 4 litre still keeping the airflow meter .. which leads me to suspect that the std throttle on the 4 litre is restrictive .. i can't believe all that extra airflow just came from blending the trumpet base ...
Hi Dax
I just knew you weren't a new kid to this injection stuff!
BTW I really like the MS system, but it's not something I can do professionally due to product liability issues.
The standard Lucas disc injector is fitted to all Land Rover 13CU, 14CU and 14CUX installations (3.5, 3.9, 4.2), and all Lucas-GEMS engines (4.0 and 4.6). It is rated at 185cc/min, or 20lb in Yank speak at 2.5 Bar (35PSI). It is also used on the all 14CUX equipped TVR RV8s.
Incidentally a larger version of this injector is used in the Cerbie 4.5. It's main benefit is that it is chep to manufacture...
Since I have seen several thousand of these in the flow test machine now, it seems that the flow increases with age due to the wear under the disc seat. The higher flowing ones always die premature deaths, so we automatically bin them now.
On a 5 Litre RV8 motor, the 5AM meter IS a restriction in the TVR Griff/Chim layout. When I say no restriction then I am referring to the Lucas-Sagem 20AM or the Bosch version.
However each case has to be judged individually. On a 4.0 Litre motor, it does not represent a problem. Really you need test various AFM selections in conjunction with the trunking layout and air filter to find the best setup. My point is that a correctly selected AFM is no penalty.
I just knew you weren't a new kid to this injection stuff!
BTW I really like the MS system, but it's not something I can do professionally due to product liability issues.
The standard Lucas disc injector is fitted to all Land Rover 13CU, 14CU and 14CUX installations (3.5, 3.9, 4.2), and all Lucas-GEMS engines (4.0 and 4.6). It is rated at 185cc/min, or 20lb in Yank speak at 2.5 Bar (35PSI). It is also used on the all 14CUX equipped TVR RV8s.
Incidentally a larger version of this injector is used in the Cerbie 4.5. It's main benefit is that it is chep to manufacture...
Since I have seen several thousand of these in the flow test machine now, it seems that the flow increases with age due to the wear under the disc seat. The higher flowing ones always die premature deaths, so we automatically bin them now.
On a 5 Litre RV8 motor, the 5AM meter IS a restriction in the TVR Griff/Chim layout. When I say no restriction then I am referring to the Lucas-Sagem 20AM or the Bosch version.
However each case has to be judged individually. On a 4.0 Litre motor, it does not represent a problem. Really you need test various AFM selections in conjunction with the trunking layout and air filter to find the best setup. My point is that a correctly selected AFM is no penalty.
The problem is with all these comparisons is that it is very very difficult to draw any real conclusions as there are so many variables involved. Let's look at air flow meters. Unless the size is matched to that of the throttle, it will be a restriction. The problem is when does that restriction actually come into play? From input and experience I do thing that the 300 bhp mark is roughly where it does start to play but it is not black and white and other changes can often get around it.
The 520 went away from AFMs and all that Lucas stuff and is fully mapped by for fuelling and ignition. It has 8 throttle bodies and that with very big injectors is the way to go. It is not cheap though but it gives the engine tuner the best chance of really delivering power because the restrictions have been removed. I was persuaded by John Eales that it was the way to go because it was the only way that John could reliably deliver the power levels that I wanted without a big risk of blowing the engine. The engine has gone through a series of throttle sizes including single, triple and currently 8 throttle bodies withouit changing anything else in the engine. The power increase after mapping has been astonishing which does back up the general premise that more power means better induction which means more fuel. Under that general statment, there are a lot of different approaches. I have done the bigger air flow/injectors and Mark Adams got my original 3.9 litre engine upto the 250+ bhp level. I have standard injectors and big air flow and throttle on my Griff 500 and Mark got 300 bhp with that. So air flow and fuelling are extremely key to getting power.
There is no one recipe or magic set of ingredients. What I have learned is that you can stretch systems only so far before they become the limiting factor and either need changing or a new approach is needed to get beyond the limiting factors. It all depends on where the starting point is and where the finish is. For my competition car, the starting point is clear: fully programmable ignition and fuelling and downdraught throttle body for each cylinder. Plenums, AFMs and other stuff just get in the way. For the Griff shopping trolley, it was keep with the standard stuff basically but improve the induction. In the end of the day, you pay your money and you makes your choice.
Anyone for 16 injectors BTW?
The 520 went away from AFMs and all that Lucas stuff and is fully mapped by for fuelling and ignition. It has 8 throttle bodies and that with very big injectors is the way to go. It is not cheap though but it gives the engine tuner the best chance of really delivering power because the restrictions have been removed. I was persuaded by John Eales that it was the way to go because it was the only way that John could reliably deliver the power levels that I wanted without a big risk of blowing the engine. The engine has gone through a series of throttle sizes including single, triple and currently 8 throttle bodies withouit changing anything else in the engine. The power increase after mapping has been astonishing which does back up the general premise that more power means better induction which means more fuel. Under that general statment, there are a lot of different approaches. I have done the bigger air flow/injectors and Mark Adams got my original 3.9 litre engine upto the 250+ bhp level. I have standard injectors and big air flow and throttle on my Griff 500 and Mark got 300 bhp with that. So air flow and fuelling are extremely key to getting power.
There is no one recipe or magic set of ingredients. What I have learned is that you can stretch systems only so far before they become the limiting factor and either need changing or a new approach is needed to get beyond the limiting factors. It all depends on where the starting point is and where the finish is. For my competition car, the starting point is clear: fully programmable ignition and fuelling and downdraught throttle body for each cylinder. Plenums, AFMs and other stuff just get in the way. For the Griff shopping trolley, it was keep with the standard stuff basically but improve the induction. In the end of the day, you pay your money and you makes your choice.
Anyone for 16 injectors BTW?
GreenV8S said:
Harry I really like that idea of using the AFM to compare before/after induction mods. Did you find it difficult to get a clear signal off the AFM? You've got me thinking now, and I'm toying with the idea of connecting the datalogger to the AFM to see whether I can get a good reading off it.
.....
Peter as you know the AFM gives a nice DC voltage proportional to the mass of air passing it. I stick on the DVM and wind it up in 3rd/4th on the same stretch of dual. Tim monitors it and when I hit say 6Krpm I say to him "now" he tells me the voltage
, you'll be surperised how smooth and linear it can be in higher gears. Even better if you had a portable storage scope . It is quiet good to get an understanding of what really doesn't work and a good idea of what does. I've taken that through to subsequent RR sessions. My motor on a cold day pretty much tops out the 5AM before 6krpm
, luckily Mark has 'strapolated (sp?) that forward on my fuel maps, otherwsie I'd need a bigger measuring air device . Obviously because of the different environmentals, runs are normally back to back within the hour. I have been know to set off with three different induction intake set ups in the boot before now
. Added to the remote under bonnet temp gauge attached to the filter, I get a good feeling that what i have at present is probably the best arrangement possible on a V8S, this side of additional bonnet scoops that is. Harry
Don't know Joolz. I started off just trying to prove the theory that the filter I had was too restrictive - I quickly found that there was a significant drop, but it seemed to be downstream of the filter. Not sure exactly where, but when I ran through the numbers the expected dynamic pressure drop across the choke on the 5AM was quite a surprise. Looking at the shape of the intake downstream of the AFM there's no way that any pressure recovery is going to occur so this pressure drop is a dead loss, and in fact the energy probably dissipates in the plenum as heat to make things worse. The dynamic pressure drop should be proportional to V squared so I imagine that even small increases in cross sectin area at the narrowest part of the intake (the AFM in this case) would make a significant difference. And there's something like 5% power being lost here so worth getting some of it back I would have thought.
I still don't really see why the plenum system would give any particular power benefits, I guess it's cheap in terms of components, single AFM and throttle etc, but once you've got a given absolute pressure in the plenum, what happens upstream is pretty irrelevent isn't it? By the time you've averaged out eight cylinders I would thought pulsing effects upstream of the throttle would be negligeable?
I still don't really see why the plenum system would give any particular power benefits, I guess it's cheap in terms of components, single AFM and throttle etc, but once you've got a given absolute pressure in the plenum, what happens upstream is pretty irrelevent isn't it? By the time you've averaged out eight cylinders I would thought pulsing effects upstream of the throttle would be negligeable?
Very well said Steve!
Smaller droplet size is also related to charge cooling. For a given volume of fuel injected, the smaller the droplet size the bigger the surface area of fuel available. This improves it's ability to vapourise, hence enhancing the cooling effect.
Another little side effect of this is that cooling the fuel is also helpful to charge cooling. This is a hidden benefit of the aircon cars, which have a fuel cooler as part of the system.
Some of the really serious drag racers actually have a pot of dry ice in the fuel system for this very reason.
Smaller droplet size is also related to charge cooling. For a given volume of fuel injected, the smaller the droplet size the bigger the surface area of fuel available. This improves it's ability to vapourise, hence enhancing the cooling effect.
Another little side effect of this is that cooling the fuel is also helpful to charge cooling. This is a hidden benefit of the aircon cars, which have a fuel cooler as part of the system.
Some of the really serious drag racers actually have a pot of dry ice in the fuel system for this very reason.
What are the ignition requirements for small droplet charges mark? and how do you get over the fuel puddling in the port and on the valve back? I must say i'd overlooked that until Dax mentioned it, but the injectors spray 3 times longer with no port velocity then they do when the air's moving ..
Mark Adams said:
Mikey Mongoose - have you measured the duty cycle on the 300+BHP cars running standard injectors? Maybe you'd like to post the results of your testing. Personally I have found that with TVR heads they are nearing their acceptable duty cycle limit at around 285BHP.
At what fuel pressure Mark?I would guess that your talking about std pressure?At v8d theyve seen well above 320bhp using std injectors,by increasing the fuel pressure.Its also interesting to see that your safe duty cycle limit is also the lowest ive come across.Both rpi and omex,for example quote 90%.As you well know,the v8d stage 3 kit for the 5 litre cars does not include larger injectors,and also uses std tvr heads.I believe you developed a chip for this kit?They quote circa 320 bhp for this kit.As has already been mentioned,the minute extra gain isnt worth the money that bigger injectors cost,so it comes down to weather you've nothing better to spend your money on,or you do have a real need to flow more fuel.I'll be buying some bigger injectors when i need them,but if i had a std or lightly modified car,then i could think of better gains for my hard earnt to be spent on,as ive found out
. >> Edited by mongoose on Friday 22 July 19:13
Typically we need to reduce the ignition timing by 2-3 degrees on an RV8 5.0 Litre after fitting the different injectors. They don't pink with the old setting, just lose power (by loss of efficiency). The difference is even more pronounced on the 4.5 Cerbie.
Fuel puddling is incredibly hard to determine without any real means to see or measure it. It is known to be an issue with a cold manifold though, since hot valves and manifold walls will avaporate any fuel that comes into contact with it. That accounts for more than a little of the fuel enrichment needed on a cold engine.
Saab Turbo 16V motors use ann injector that sprays two jets of fuel, that are exactly aimed at the back of the inlet valve where the head meets the stem. They say that this cools the valve, and vapourises the fuel.
The most interesting thing is when you put a Lucas into the flow testing machine, next to a new Bosch one. The Lucas ones produce a jet of fuel that create a jet of bubbles that almost reach the bottom of the measuring burette. By contrast, the Bosch ones produce a mist over the top of the measuring fluid.
After the test is over, the large bubbles come out of the meausuring fluid very quickly under the Lucas disc injectors. The fluid under the Bosch injectors contains loads of really tiny bubbles that take quite some time to clear.
One can only assume that the smaller droplets will also stay suspended in the air for longer, although I have no chance of proving this one way or another. Obviously this is a benefit hot or cold. I'll have a dig through some old conference papers and see if anyone has done some work on it - they are bound to have!
If I could work out how to do it, I would stick on a little video clip of them in action! It is very convincing to see.
Fuel puddling is incredibly hard to determine without any real means to see or measure it. It is known to be an issue with a cold manifold though, since hot valves and manifold walls will avaporate any fuel that comes into contact with it. That accounts for more than a little of the fuel enrichment needed on a cold engine.
Saab Turbo 16V motors use ann injector that sprays two jets of fuel, that are exactly aimed at the back of the inlet valve where the head meets the stem. They say that this cools the valve, and vapourises the fuel.
The most interesting thing is when you put a Lucas into the flow testing machine, next to a new Bosch one. The Lucas ones produce a jet of fuel that create a jet of bubbles that almost reach the bottom of the measuring burette. By contrast, the Bosch ones produce a mist over the top of the measuring fluid.
After the test is over, the large bubbles come out of the meausuring fluid very quickly under the Lucas disc injectors. The fluid under the Bosch injectors contains loads of really tiny bubbles that take quite some time to clear.
One can only assume that the smaller droplets will also stay suspended in the air for longer, although I have no chance of proving this one way or another. Obviously this is a benefit hot or cold. I'll have a dig through some old conference papers and see if anyone has done some work on it - they are bound to have!
If I could work out how to do it, I would stick on a little video clip of them in action! It is very convincing to see.
Mark,
hmm so the standard injectors aint up to much at all, a mate just pointed out to me is this why the heads crack on the 5.0s and why the valves recess into the heads due to the engines running lean? RPI told me the valves recess by the way.
SHPUB,
Id love to see a picture of those throttle bodies, thats my plan for the winter, port the inlet manifold and stick 8 throttle bodies on it, would look really cool, dont care what it goes like if it looked that good :-) although Im certain it would go well!
ps Ive been told to buy a book from you I think
Phil
>> Edited by daxtojeiro on Thursday 21st July 22:46
hmm so the standard injectors aint up to much at all, a mate just pointed out to me is this why the heads crack on the 5.0s and why the valves recess into the heads due to the engines running lean? RPI told me the valves recess by the way.
SHPUB,
Id love to see a picture of those throttle bodies, thats my plan for the winter, port the inlet manifold and stick 8 throttle bodies on it, would look really cool, dont care what it goes like if it looked that good :-) although Im certain it would go well!
ps Ive been told to buy a book from you I think
Phil
>> Edited by daxtojeiro on Thursday 21st July 22:46
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