Different injectors L & R Bank!?
Discussion
Hi all,
Bit confused...
...I've got the injectors out of my 4.2 to ultrasonically clean them, whilst doing so noticed that there were different codes on the injectors for the left and right hand banks.
I've checked the parts catalogue and it only specs one injector for the 4.2 (E1369), there is a visable difference when looking down the injector nozzle.
Anyone else found this, or does anyone have any explanation?
Thanks
Tim
Bit confused...
...I've got the injectors out of my 4.2 to ultrasonically clean them, whilst doing so noticed that there were different codes on the injectors for the left and right hand banks.
I've checked the parts catalogue and it only specs one injector for the 4.2 (E1369), there is a visable difference when looking down the injector nozzle.
Anyone else found this, or does anyone have any explanation?
Thanks
Tim
Simon, agreed on the serial number of the injector but - just researched the flow rating and found it to be pretty poor - Bosch 0 280 150 744 214cc/min@36.3psi 16.0ohms 43bhp per injector - this will support 344hp at 85% duty at that pressure. Confused? Guess the 4.2 injectors are pretty much maxed out as they are. Anyone have a serial number for the 4.5 ones???
The 4.2 Cerbie uses a good quality Bosch injector, but they should all carry the same number.
Sadly the 4.5 uses a horrible Lucas disk type injector, which is just a bigger version of the one used on the RV8. That's why it is only the 4.5 that benefits from an injector change - there's nothing to gain on a 4.2.
Changing from a Lucas to a Bosch gives benefits only because of the superior atomisation, and spray pattern.
For an ideal setup, you always want the smallest possible injectors that will do the job. This gives you the most stable injector dose, especially at idle and light throttle. So the standard 4.2 ones are well chosen, but you wouldn't want them any smaller! 85% duty cycle would be the maximum I would ever want to see.
>> Edited by Mark Adams on Sunday 30th October 17:33
Sadly the 4.5 uses a horrible Lucas disk type injector, which is just a bigger version of the one used on the RV8. That's why it is only the 4.5 that benefits from an injector change - there's nothing to gain on a 4.2.
Changing from a Lucas to a Bosch gives benefits only because of the superior atomisation, and spray pattern.
For an ideal setup, you always want the smallest possible injectors that will do the job. This gives you the most stable injector dose, especially at idle and light throttle. So the standard 4.2 ones are well chosen, but you wouldn't want them any smaller! 85% duty cycle would be the maximum I would ever want to see.
>> Edited by Mark Adams on Sunday 30th October 17:33
The basic part number is the same so they will have the same flow ratings. The nozzle size may have some impact on the spray pattern, but you'd need to talk to a specialist to find out what difference that would make. It doesn't look like a problem to me though.
>> Edited by GreenV8S on Monday 31st October 09:40
>> Edited by GreenV8S on Monday 31st October 09:40
From memory, mine are all like the one in the top right i.e. with the smaller radius throat outlet. Mark, what cc rating are your upgrade Bosch injectors for the 4.5? And why can't you simply use the 4.2 injectors in the 4.5, supposing the flow ratings are similar...?????? Anyone?? Basically, I'm rebuilding my 4.2 to 4.5 red rose spec, in my garage may I add, and this is just another of many issues I can't figure out. TVR Power don't quote a change on their upgrade, neither do they state the heads require changing. All this leads me to believe that you can build an AJP from pretty much any parts bin you've got and it'll work. This injector issue is a prime example. Cams are another issue.. people change cams from clatter to whisper with apparently radically different road manners but no ECU change?? I'm starting to think that there is no 'standard' for these engines - you get what you get - which is another reason why power figures vary so much, hence people's frustration....
TT Tim said:
Here are a couple of pics of the injectors.
Firstly the nozzels, clearly showing the differences:
and now the codes on the side:
Any comments?
Tim
I had this on my T350 when Mark looked at the car at Austec. I had one injector different. The spray patter was all wrong and the flow rate was different too to the other 5 injectors.
When I spoke my dealer, they said its not the first time they have seen this. TVR have sometimes just picked injectors from different batches when making the eingines.
Unfortunaly, most people will never know until they start to look at the engine for tuning. The downside was that even on the Speed six, you would have 'one bank' running lean, and the lambada sensors would have been fighting each other to try and sort the problem out since the car was build.
Conclusion, two new sensors, 6 new injectors and one thottle pod sensor to correct the problem. Cost... around £800.00.
Mr F
Several answers here!
Daggart - yes I'm really looking forward to this one. It'll be quite a lot of work, but very scientific and conclusive. It will be good to meet you and your monster motor at last.
Longbow - the 4.2 and 4.5 injectors are different flow rates. The Lucas (4.5) ones flow significantly more. Lucas disk-type injectors are attractive to manufacturers because they are cheap! 4.2 and 4.5 Cerbies also have different chips to account for this. When TVR Power do a Red Rose upgrade, they also do a chip change to suit.
Cerbie motors do vary wildly in Power/Torque blend, shape of the curves, and of course the peak figures. Because of this they also vary greatly in their fuelling and ignition requirements. At Austec they have mapped over 50 cars now (both AJP8 and Speed Six), and no two of them are the same.
Live mapping (changing the data whilst the engine is running) is the only way to tune the ignition properly, and this reveals how much the engines vary. Austec have invested around £20K in live mapping equipment for this very reason. The full load stuff is only about 3% of the job - part throttle driveability, idle settle, startup, etc., are extremely important on a road car. Part-throttle is another area where they vary hugely.
Mr Freefall - until recently, your dodgy injectors were still in Paul's Tamora! The engine has been pulled now (for some steroid treatment), and we are still testing better injectors on these motors. Watch this space.
TT_Tim - the differences you have shown in your (excellent) pictures are only the pintle caps. The spray pattern is formed by the shape of the tip of the needle itself. As ling as the caps are clear of the needle and orifice, they should not have any effect.
I must say though, that just knowing they are different would annoy me even if it doesn't matter! But then I am a bit obsessive about details (who said anorak???).
Daggart - yes I'm really looking forward to this one. It'll be quite a lot of work, but very scientific and conclusive. It will be good to meet you and your monster motor at last.
Longbow - the 4.2 and 4.5 injectors are different flow rates. The Lucas (4.5) ones flow significantly more. Lucas disk-type injectors are attractive to manufacturers because they are cheap! 4.2 and 4.5 Cerbies also have different chips to account for this. When TVR Power do a Red Rose upgrade, they also do a chip change to suit.
Cerbie motors do vary wildly in Power/Torque blend, shape of the curves, and of course the peak figures. Because of this they also vary greatly in their fuelling and ignition requirements. At Austec they have mapped over 50 cars now (both AJP8 and Speed Six), and no two of them are the same.
Live mapping (changing the data whilst the engine is running) is the only way to tune the ignition properly, and this reveals how much the engines vary. Austec have invested around £20K in live mapping equipment for this very reason. The full load stuff is only about 3% of the job - part throttle driveability, idle settle, startup, etc., are extremely important on a road car. Part-throttle is another area where they vary hugely.
Mr Freefall - until recently, your dodgy injectors were still in Paul's Tamora! The engine has been pulled now (for some steroid treatment), and we are still testing better injectors on these motors. Watch this space.
TT_Tim - the differences you have shown in your (excellent) pictures are only the pintle caps. The spray pattern is formed by the shape of the tip of the needle itself. As ling as the caps are clear of the needle and orifice, they should not have any effect.
I must say though, that just knowing they are different would annoy me even if it doesn't matter! But then I am a bit obsessive about details (who said anorak???).
TT Tim said:
Mark,
Thanks for the reply, like you this is going to bug the hell out of me, in fact I have 3 different 'sub' codes on the injectors.
Where would be the best/most economic place to get new injectors? I'm thinking about getting 4 to match the 4 of the same code.
Tim
I looked into getting some more injectors, just so I could keep my car on the road while my originals were cleaned. I found the 4.2 Bosch injectors are used on some Vauxhall 'red top' XE motors. You often see them on ebay, or maybe SBD motorsport could help.
In the end Longbow kindly lent me his set for a week, so I never bothered getting any.
Mark, here's one for you..... you're right - I'm upgrading from 4.2 to 4.5 so I will need to consider the fuelling issue. My 4.2 was a very healthy car, 359hp, 330lb, and drove very smoothly indeed on the standard chip, so for a 4.2, the fuelling map is bang on. With 4.5 liners/pistons and ported heads/intakes (am retaining the 4.2 induction BTW), the capacity goes up by approx 7%. With flowed inlets etc, let say another 2-3% increase in airflow. So, is there any major flaw in using 0 280 150 761 injectors from a 2.0 Saab Turbo, retaining my 4.2 ECU chip? These flow 238.1cc/min as oppose to 214.4cc/min for the '744' ones, approx 11% increase. Surely this would make it drivable enough post rebuild until I could get it mapped up. Plus, being realistic, I can't see it making more than 390ish hp anyway. Just a thought, advice appreciated!!!! I can't see why the 4.5 needs vastly increased flow rating injectors, as lets face it, they only make about 10% more than 4.2 in tuned states anyway.......
Hi Longbow. You are barking up the right tree. I'm not familiar with the Saab ones, and I can't find out much information about them either!
Apart from the volume, you need to look at spray pattern too. I think some of the Saab ones have a divided jet if used with a 16V engine. Also they need to be 14-16 Ohms impedance.
Since you are building to Red Rose spec, I would probably go a bit larger with the injectors. Maybe 250-270cc/min @ 2.5Bar?
Apart from the volume, you need to look at spray pattern too. I think some of the Saab ones have a divided jet if used with a 16V engine. Also they need to be 14-16 Ohms impedance.
Since you are building to Red Rose spec, I would probably go a bit larger with the injectors. Maybe 250-270cc/min @ 2.5Bar?
Cheers Mark, really appreciate your comments. Here is a link with lots of useful injector info http://users.erols.com/srweiss/tablei
longbow said:
Cheers Mark, really appreciate your comments. Here is a link with lots of useful injector info http://users.erols.com/srweiss/tablei
Interesting table, anyone know what the standard Lucas injectors are in the RV8 saving the walk to the garage
. H
Gassing Station | Cerbera | Top of Page | What's New | My Stuff