RV8 swapping carbs for efi
Discussion
Hi guys, I had a 3.5 rover v8 on carbs in my track day weapon mgb, but have now pulled it out as the block cracked during the super cold weather we had over the last month or so. Mega bummer as the project was about 2 weeks off completion!
So thought while i'm at it I may as well up the motor to a 3.9 efi or 4.2 efi if I can find one.
Question is what will i need to convert it, these are my thoughts thus far;
I can use the old coil
I will need an ecu
i will need an electric dizzy
and need to have a lambda sensor mount welded onto the downpipe of each header to mount em.
Will i need anything else or should that do the job?? Also where all the 3.9's (like in a disco) serpentine motors or is that just the later models, thanks eddy
So thought while i'm at it I may as well up the motor to a 3.9 efi or 4.2 efi if I can find one.
Question is what will i need to convert it, these are my thoughts thus far;
I can use the old coil
I will need an ecu
i will need an electric dizzy
and need to have a lambda sensor mount welded onto the downpipe of each header to mount em.
Will i need anything else or should that do the job?? Also where all the 3.9's (like in a disco) serpentine motors or is that just the later models, thanks eddy
retroracing said:
Hi guys, I had a 3.5 rover v8 on carbs in my track day weapon mgb, but have now pulled it out as the block cracked during the super cold weather we had over the last month or so. Mega bummer as the project was about 2 weeks off completion!
So thought while i'm at it I may as well up the motor to a 3.9 efi or 4.2 efi if I can find one.
Question is what will i need to convert it, these are my thoughts thus far;
I can use the old coil
I will need an ecu
i will need an electric dizzy
and need to have a lambda sensor mount welded onto the downpipe of each header to mount em.
Will i need anything else or should that do the job?? Also where all the 3.9's (like in a disco) serpentine motors or is that just the later models, thanks eddy
Only later ones were serp.So thought while i'm at it I may as well up the motor to a 3.9 efi or 4.2 efi if I can find one.
Question is what will i need to convert it, these are my thoughts thus far;
I can use the old coil
I will need an ecu
i will need an electric dizzy
and need to have a lambda sensor mount welded onto the downpipe of each header to mount em.
Will i need anything else or should that do the job?? Also where all the 3.9's (like in a disco) serpentine motors or is that just the later models, thanks eddy
Dizzy should come with the replacement motor. Don't just use anything as they are timed for that particular version of the motor.
You will need high pressure fuel pump, filter and a return pipe to the tank. The fuel regulator should come with the engine.
There is not much you can do in the way of mapping the efi as it has no chip. May be better to fit something like Megasquirt then you can bin the air flow meter and only need one lambda.
Steve
Only later ones were serp.
Dizzy should come with the replacement motor. Don't just use anything as they are timed for that particular version of the motor.
You will need high pressure fuel pump, filter and a return pipe to the tank. The fuel regulator should come with the engine.
There is not much you can do in the way of mapping the efi as it has no chip. May be better to fit something like Megasquirt then you can bin the air flow meter and only need one lambda.
Steve
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ok that doesnt sound like too much more hard work then lol. By 'high pressure' fuel pump i'm currently running a facet red top so I assume that will do. Is the fuel regulator built into the injection system on theses then? Worst case sinario, I guess I could fit an aftermarket one.
With the return pipe, i only have one outlet on my tank,and a breather, so could I put the return onto the breather??? Would I also need high pressure fuel hose or is this only on the injection system itself, as I had recently installed low pressure braided hose throughout!
The megasquirt looks like an idea, but might need afew more pennies!
retroracing said:
......By 'high pressure' fuel pump i'm currently running a facet red top so I assume that will do.
I believe Facet do both high and low pressure pumps so you need to confirm yours is high pressure.retroracing said:
......Is the fuel regulator built into the injection system on theses then? Worst case scenario, I guess I could fit an aftermarket one.
If you buy an engine with the EFI on it then the pressure regulator will be mounted on the fuel rail.retroracing said:
......With the return pipe, i only have one outlet on my tank,and a breather, so could I put the return onto the breather???
No, you will need the return and breather separate.
retroracing said:
......Would I also need high pressure fuel hose or is this only on the injection system itself, as I had recently installed low pressure braided hose throughout!
High pressure hose will be required anywhere after the pump but will not be required for the return so you could use your existing run as the return and just install a new HP pipe run.Steve
Hello,
If you are going for a mappable engine management system, why not use coil-packs (i.e.: mappable ignition) rather than a coil and distributor? We have done this on our TVR Chimaera and Range Rover Classic LSE (see http://www.lloydspecialistdevelopments.co.uk/devel... for more info) and have been very pleased with the results!
We currently use a Rover SD1 with a 4.0 litre Rover V8 on the original carbs (looking at an EFI conversion when we get time!) as our track car, it's great fun taking a British classic out on the track with more modern machinery!
Regards, Daniel
If you are going for a mappable engine management system, why not use coil-packs (i.e.: mappable ignition) rather than a coil and distributor? We have done this on our TVR Chimaera and Range Rover Classic LSE (see http://www.lloydspecialistdevelopments.co.uk/devel... for more info) and have been very pleased with the results!
We currently use a Rover SD1 with a 4.0 litre Rover V8 on the original carbs (looking at an EFI conversion when we get time!) as our track car, it's great fun taking a British classic out on the track with more modern machinery!
Regards, Daniel
To run an EFI aftermarket system you will still need all the plenum chamber and inlet manifold off (I suggest) the 3.9, plus the £1000 or so for the aftermarket ECU and coil packs. If you can get the whole assembly for a 3.9 with a 14CUX ECU, and loom you can bolt this on, but Im not sure how close the fuel mapping will be. This set up can run with or without lambda sensors (just select a resistor in the wiring loom to change fuel maps.) If you go for the lambda set up the ECU can cope with with the mapping being out a bit, as it can can adjust the fueling, but a stock 3.9 ECU on the non catalyst fuel map (non lambda) may not be that far out. Ther are aftermarket chips available, but expensive (like £400).
This site covers it:
http://www.britishv8.org/Articles/Rover-Hot-Wire-E...
The ignition is completely separate from the EFI system apart form a single signal wire, so you can keep your dizzy all be it a bit pre historic compared to coil packs and mapped ignition.
This site covers it:
http://www.britishv8.org/Articles/Rover-Hot-Wire-E...
The ignition is completely separate from the EFI system apart form a single signal wire, so you can keep your dizzy all be it a bit pre historic compared to coil packs and mapped ignition.
Edited by blitzracing on Friday 12th February 21:12
Edited by blitzracing on Friday 12th February 21:16
Does the flapper/hotwire intake manifold and plenum fit under a standard MGB bonnet? I seen to remember one would need the MG RV8 bonnet to clear the plenum & stuff?
If you're going aftermarket EFI you might want to investigate using a John Eales crossover manifold & throttle bodies...
If you're going aftermarket EFI you might want to investigate using a John Eales crossover manifold & throttle bodies...
The plenum set up does not work well with long duration cams, as you get cross contamination between cylinders during the valve overlap period, but you dont get this issue with throttle bodies with "socks", as this cross contamination does not take place. Even with longer duration cams how ever the overlap problem is really only apparent at low speed and the engine snatches. I suggest you get the Des Hammell book on tuning the RV8, lots in there about the various EFI setups.
blitzracing said:
The plenum set up does not work well with long duration cams, as you get cross contamination between cylinders during the valve overlap period, but you dont get this issue with throttle bodies with "socks", as this cross contamination does not take place. Even with longer duration cams how ever the overlap problem is really only apparent at low speed and the engine snatches. I suggest you get the Des Hammell book on tuning the RV8, lots in there about the various EFI setups.
It's where the butterfly is and its angle that gives TB's an advantage in those circumstances, whats above is fairly irrelevant IMO.Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff