Back Tracking.....
Discussion
I've been doing a lot of reading about carb conversions and bearing in mind the frankly abysmal sales values of the two 400's on ebay it seems clear I've caught a cold with this one albeit it has a rarity value lift.
So I'm seriously thinking of junking the the troublesome EFi and going carb. Love the look and throttle response of quad dellortos but fiddly to set up and linkages go out of whack regularly plus marginal power benefit against a 4 barrel but with Gazza's drinking tendencies. Very seriously thinking of biting the bullet on a 4 barrel carb conversion as no power loss against the flapper (obviously keep the EFi for next owner should they want to go back)
So I'm seriously thinking of junking the the troublesome EFi and going carb. Love the look and throttle response of quad dellortos but fiddly to set up and linkages go out of whack regularly plus marginal power benefit against a 4 barrel but with Gazza's drinking tendencies. Very seriously thinking of biting the bullet on a 4 barrel carb conversion as no power loss against the flapper (obviously keep the EFi for next owner should they want to go back)
Not sure where that's come from. You won't lose any peak power after the carb is rolling roaded against a flapper. Think about what you're saying - WOT AFR for max bhp will be the same for either carb or Flapper so unless the carb is restricting airflow in comparison to the Flapper there'll be no power loss. In fact there may be a little gain due to the restriction of the flapper itself - it's quite heavily sprung and there's nothing similar on an Edelbrock to overcome - secondaries are weighted but much easier to move. Plus the dual plane manifold gives one primary and one secondary per bank in terms of airflow rather than all flow coming throw that single bore AFM...
Only the latest injection systems give a gain over a tuned carb in terms of peak power and even then I was surprised to hear it was only in the order of 3% (according to a Land Rover R&D engineer anyway) - the real benefits of a modern EFi will be economy and better transitional response where it'll be far superior but as we know, the flapper is nothing like a modern EFi!
ATspeed are on my doorstep and they definitely know what they're doing with carbs as Henry will attest to
Only the latest injection systems give a gain over a tuned carb in terms of peak power and even then I was surprised to hear it was only in the order of 3% (according to a Land Rover R&D engineer anyway) - the real benefits of a modern EFi will be economy and better transitional response where it'll be far superior but as we know, the flapper is nothing like a modern EFi!
ATspeed are on my doorstep and they definitely know what they're doing with carbs as Henry will attest to
Edited by smash on Sunday 31st August 19:40
@Zig - well if that don't cure it I'm gonna have me the best November 5 ever!! 
I'm quite surprised at the support the flapper gets tbh - almost a blind faith in it's abilities. From what I read on here almost everyone who's had one on the rollers for serious tuning has never been able to get both mid range and WOT calibrated right - it's always one or the other - never both.
I absolutely accept the argument about MPG and cruising against a modern EFI - at the end of the day it's down to emulsifier tubes etc and drilling them for specific cruise modes and you can only calibrate for so many on a carb. It's just that realistically the flapper isn't any better - if you stick a mappable ECU like a mega squirt, then yep we're getting somewhere but not the stock ECU. After 30 years the injectors drift out, the components on the ECU and AFM drift and stock ECU has no idea.
Of course the only "proof" I have that carb conversion is successful is those who have done it and are more than happy i.e. GV
Blimey that's a long thread! Mostly about how shagged the engine is to start with as far as I can see - the carb bit only seems to have been a bad experience because he had a go at tuning it himself without wideband AFR and messed it up.
I think to own a wedge you really need to love them - I rally liked this one but as it turned out it was a bad decision to buy it for me personally -had all gone well I may have got the love for it to start rather than begrudging thrwoing money at it which is where I am now.
Realistically selling is out the window as values look to be non existant - PHJays 400 didn't even sell at £4750 - not sure about PJACS - was it pulled? So I'm stuck with it - and if I leave that flapper system off the road anotehr winter I think that'll be the end of it, loL! So if I'm ever gonna drive it I need to be able to trust it. I've yet to be stranded by a carb'd car where it was the carbs fault!
@RDJ - can I ask why you went over to Edlebrock?
I'm quite surprised at the support the flapper gets tbh - almost a blind faith in it's abilities. From what I read on here almost everyone who's had one on the rollers for serious tuning has never been able to get both mid range and WOT calibrated right - it's always one or the other - never both.
I absolutely accept the argument about MPG and cruising against a modern EFI - at the end of the day it's down to emulsifier tubes etc and drilling them for specific cruise modes and you can only calibrate for so many on a carb. It's just that realistically the flapper isn't any better - if you stick a mappable ECU like a mega squirt, then yep we're getting somewhere but not the stock ECU. After 30 years the injectors drift out, the components on the ECU and AFM drift and stock ECU has no idea.
Of course the only "proof" I have that carb conversion is successful is those who have done it and are more than happy i.e. GV
Blimey that's a long thread! Mostly about how shagged the engine is to start with as far as I can see - the carb bit only seems to have been a bad experience because he had a go at tuning it himself without wideband AFR and messed it up.
I think to own a wedge you really need to love them - I rally liked this one but as it turned out it was a bad decision to buy it for me personally -had all gone well I may have got the love for it to start rather than begrudging thrwoing money at it which is where I am now.
Realistically selling is out the window as values look to be non existant - PHJays 400 didn't even sell at £4750 - not sure about PJACS - was it pulled? So I'm stuck with it - and if I leave that flapper system off the road anotehr winter I think that'll be the end of it, loL! So if I'm ever gonna drive it I need to be able to trust it. I've yet to be stranded by a carb'd car where it was the carbs fault!
@RDJ - can I ask why you went over to Edlebrock?
Edited by smash on Monday 1st September 10:12
Edited by smash on Monday 1st September 10:13
Cheers
@zig Only joking, lol! (or am I?)
Have decided that, as John Eales built the engine 30 years ago, I should really ask his advice about potential carb setups as there are a few more options than I initially thought! The boxer SU set up looks interesting
@zig Only joking, lol! (or am I?)
Have decided that, as John Eales built the engine 30 years ago, I should really ask his advice about potential carb setups as there are a few more options than I initially thought! The boxer SU set up looks interesting
Edited by smash on Monday 1st September 12:27
Come on, good is pushing it! It doesn't know what cylinder's firing and just alternately squirts fuel into each bank. Sounds a bit like a carb!
Been looking for a Rovertec ECU on ebay but rare as...wouldn't I be better off going Megasquirt ECU tho as that's completely mappable and in theory should be able to dial out drift in the 30 year old components?
I just want an easy life! (yes I know I shouldn't have bought a wedge then )
I had a wideband AFR on my cobra rep - an Innovate one to dial in the Edelbrock. Only slight PITA is having to put a bung on each bank to really see they're both in line. I guess it should be easy to weld one in through the wheel arch?
Didn't fire it up this weekend at all so don't know really know where we're at post ignition switch. Already losing interest as weather starts to change. It's just on a hard standing out the back - no roof cover. Could possibly be the longest I've ever had a weekend toy for as usually change every year - I'm wondering what bedding plants would look best in the interior, lol
Very interesting posts on here from Chris Goodwin - the guy who developed the quad boxer SU that RPi sold.
http://mez.co.uk/forum/viewtopic.php?t=429 - you're right about one carb needing slightly different tune but there's apparently a very good reason for this according to him "CYLs 5&7 like to be 2 percent richer than the rest as the firing order on that pair are consequtive"
Been looking for a Rovertec ECU on ebay but rare as...wouldn't I be better off going Megasquirt ECU tho as that's completely mappable and in theory should be able to dial out drift in the 30 year old components?
I just want an easy life! (yes I know I shouldn't have bought a wedge then
)I had a wideband AFR on my cobra rep - an Innovate one to dial in the Edelbrock. Only slight PITA is having to put a bung on each bank to really see they're both in line. I guess it should be easy to weld one in through the wheel arch?
Didn't fire it up this weekend at all so don't know really know where we're at post ignition switch. Already losing interest as weather starts to change. It's just on a hard standing out the back - no roof cover. Could possibly be the longest I've ever had a weekend toy for as usually change every year - I'm wondering what bedding plants would look best in the interior, lol
Very interesting posts on here from Chris Goodwin - the guy who developed the quad boxer SU that RPi sold.
http://mez.co.uk/forum/viewtopic.php?t=429 - you're right about one carb needing slightly different tune but there's apparently a very good reason for this according to him "CYLs 5&7 like to be 2 percent richer than the rest as the firing order on that pair are consequtive"
Edited by smash on Monday 1st September 19:25
Cheers Stu - will email you.
Last word to the man who actually built my engine who says the main problem with the flapper 4CU is the harness. He recently had a new loom made up for a customer which with sorting out other settings resolved all problems and is now making better power than later hotwire system.
He also said the easy alternative is Edelbrock inlet and Weber 500 carb. Best power and throttle response will be quad webers but at expesne of mpg.
A new loom including fitting and tuning will cost £750 inc. VAT plus any other parts. Probably a grand including transport costs to get car there. So the cost of sorting the EFi by the original engine builder vs swithing to carb look similar. Decision time.
Probably best I don't post anything further until the engine is sorted (or the car is sold as is)
Last word to the man who actually built my engine who says the main problem with the flapper 4CU is the harness. He recently had a new loom made up for a customer which with sorting out other settings resolved all problems and is now making better power than later hotwire system.
He also said the easy alternative is Edelbrock inlet and Weber 500 carb. Best power and throttle response will be quad webers but at expesne of mpg.
A new loom including fitting and tuning will cost £750 inc. VAT plus any other parts. Probably a grand including transport costs to get car there. So the cost of sorting the EFi by the original engine builder vs swithing to carb look similar. Decision time.
Probably best I don't post anything further until the engine is sorted (or the car is sold as is)
Edited by smash on Tuesday 2nd September 11:35
Surprise - guess who? Should first apologise for the abuse on that other thread – I’m sorry about that. As V8Fettler said very perceptively the car had got under my skin completely and added with the varied points of view on offer about what was wrong/what should be tested I just flipped out. Again sorry.
What happened after that. Nothing for a long time I just left the car under its cover and forgot about it – simple as that – it just didn’t exist.
Then my brothers badgered me and kept badgering til in the end all three of us attacked it over a couple of wet days.
First thing first – massive over fueling. With plugs out it was sloshing out the bores on the left bank. Ended up with about 10 litres of very thin petrol y oil! Wiring continuity checks back to ECU were all good. We speculated as it appeared to be one bank and around number 1 in parituclar that it may be a stuck injector.
We pulled the injectors and sent them off for reconditioning. This is the report – a huge flow increase across the board but no stuck injectors.
Interesting they were in such an apparently bad way after just 56k miles tho. Whilst the injectors were out we pulled the dash to check all wiring and fixed some cracked insulation on a few wires whilst discovering the name of the person who put the interior together!
Injectors a back in and….same fecking over fueling. So off goes the ECU to ATP for remanufacture.
If anyone ever suggests resoldering your ECU just in case it has dry joints just don’t! (Maston – you listening?!) – I think this is what did for my ECU TBH.
Anyway on the ECUs return the car starts on the button – hot or cold and the very rich smell it always had on idle is gone.
A trip round the block reveals two things – 1) Holy f
k what happened to the brakes?! Lots of pedal travel. And 2) it’s missing under any kind of load.
Running a spark gap jump test reveals a less than impressive spark and checking distributor operation reveals a completely blocked vac advance port on the plenum easily cleared.
At this point the car has a cheap aftermarket new dizzy on so I decide to order a genuine lucas ignition amp and fit to the old dizzy and reinstall.
While all this was going on the MOT ran out in June and that’s where we’re up to. It’s still under it’s cover.
I know I moaned about the wheel refurb I had done last year but I’m now bloody glad I had them diamond cut and lacquered rather than polished as they still look mint.
Plan now is refit old dizzy – possibly try direct live to coil and see what that does then MOT it (should pass).
In 2 years I’ve probably driven it less than 20 times. If anyone is genuinely interested in taking the car on to finish it then message me with offers. It has to go it's as simple as that. Fully poly bushed, adjustable suspension, massive history file, lovely, John Eales engine - pre NCK. re veneered dash and door handles etc. etc.
What happened after that. Nothing for a long time I just left the car under its cover and forgot about it – simple as that – it just didn’t exist.
Then my brothers badgered me and kept badgering til in the end all three of us attacked it over a couple of wet days.
First thing first – massive over fueling. With plugs out it was sloshing out the bores on the left bank. Ended up with about 10 litres of very thin petrol y oil! Wiring continuity checks back to ECU were all good. We speculated as it appeared to be one bank and around number 1 in parituclar that it may be a stuck injector.
We pulled the injectors and sent them off for reconditioning. This is the report – a huge flow increase across the board but no stuck injectors.
Interesting they were in such an apparently bad way after just 56k miles tho. Whilst the injectors were out we pulled the dash to check all wiring and fixed some cracked insulation on a few wires whilst discovering the name of the person who put the interior together!
Injectors a back in and….same fecking over fueling. So off goes the ECU to ATP for remanufacture.
If anyone ever suggests resoldering your ECU just in case it has dry joints just don’t! (Maston – you listening?!) – I think this is what did for my ECU TBH.
Anyway on the ECUs return the car starts on the button – hot or cold and the very rich smell it always had on idle is gone.
A trip round the block reveals two things – 1) Holy f
k what happened to the brakes?! Lots of pedal travel. And 2) it’s missing under any kind of load.Running a spark gap jump test reveals a less than impressive spark and checking distributor operation reveals a completely blocked vac advance port on the plenum easily cleared.
At this point the car has a cheap aftermarket new dizzy on so I decide to order a genuine lucas ignition amp and fit to the old dizzy and reinstall.
While all this was going on the MOT ran out in June and that’s where we’re up to. It’s still under it’s cover.
I know I moaned about the wheel refurb I had done last year but I’m now bloody glad I had them diamond cut and lacquered rather than polished as they still look mint.
Plan now is refit old dizzy – possibly try direct live to coil and see what that does then MOT it (should pass).
In 2 years I’ve probably driven it less than 20 times. If anyone is genuinely interested in taking the car on to finish it then message me with offers. It has to go it's as simple as that. Fully poly bushed, adjustable suspension, massive history file, lovely, John Eales engine - pre NCK. re veneered dash and door handles etc. etc.
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