RV8 EFi conversion
Posted: Tue Jun 28, 2016 1:22 pm
Here is a summary of the EFi conversion I did during the winter. I ran the engine for years with Edelbrock carb and normal Mallory Unilite dizzy. I have some problems with the dizzy and finally got fed up. The plan was to replace the carb and dizzy with EFi By using Rover EFi mechanical components like intake and plenum with programmable ECU. I had bought the necessary parts during the past years but never got around to actually doing something.
Anyway, the main components: Haltech E6X ECU (bought new some 10 years ago (nowadays very much obsolete), Cooper S injectors, Bosch wasted spark coils (same as Range Rover), Triggerwheels 36-1 wheels, air and temp sensors, as well as Honeywell Hall sensor for crank position.
The intake was modified and fitted with shortened and larger 44 mm ID trumpets, again years ago. I can´t remember how much shorter they are but quite a lot anyway. No real science behind the final length, they just looked nice...
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I did not like the factory throttle body as the plenum was modified quite heavily. I used a generic 75 mm throttle body (Ford Mustang 4,6 litre, cheap chinese item) and fabricated a flange to fit it in the front. The 4,0 litre plenum was cut and welded heavily, actually too much given the distortion .
The fabrication was basically the easy stuff. The trigger wheel was fitted to the crank pulley and a bracket for the crank sensor fabricated from a 5 mm angle iron.
The first crank sensor bracket:
Fuel supply is a Bosch 044 in-tank pump, with AN -6 fittings, hoses and hard lines. The fuel rail is Rover item with a AN fitting welded to it. The injectors are from a Cooper S Mini, Siemens Deka with around 300 cc/min. These are a bit shorter than Rover ones so a set of adpaters were required. A bit complicated but a lot cheaper than getting a new set of injectors.
Coils were fitted to a bracket that´s located on the bulkhead. The ignition modules sit above the coils. I did not know what size the ehat sink should be so I made it of 3/8" thick aluminium sheet. Naturally the expansion tank used to reside here so it had to be moved. I chose to make a completely new one. Usually when you change one thing you need to change several others as well.
ECU was fitted in the passenger foot well. With all the wiring completed it was time to start testing. I first did the ignition and retained the carb. The logic was that in case of any issues they would be ignition related. And yes, issues is what I got.
The ECU would read all sensors except the crank sensor. Starting rpm was between 1000-2000 rpm which is a bit excessive. A lot of double checking and head scratching later I realised that Honeywell spec sheet says that tooth gap on the triggerwheel needs to be 3/8" minimum. Mine had only 1/4" or so. My friend has the same ECU and Motronic wheel so I asked him which sensor he has. I got the GM part number and bought a same sensor. Naturally these are physically different so another bracket was cut from a section of angle iron and duly fitted. Of course the connector was different as well so some wiring changes were required as well.
And this helped, partly... The ECU now got consistent RPM signal around but still did not start. The ECU would spark some of the cylinders but not all. IThe sensor could not read the home signal i.e. the missing tooth. A quick word with local Haltech rep and Haltech Australia and both replied that this particular ECU always had problems with Motronic wheels. A bit funny since Haltech manual lists Motronic wheels as one option. Final option was to ditch the Hall sensor and replace it with Ford VR sensor. Hey presto, some fiddling with the bracket and wiring and the engine started !!!
I did some primitive ignition map to verify that it runs and then removed the carb and intake. EFi stuff fitted, finalize the wirings and fuel lines and it was more or less ready.
Anyway, the main components: Haltech E6X ECU (bought new some 10 years ago (nowadays very much obsolete), Cooper S injectors, Bosch wasted spark coils (same as Range Rover), Triggerwheels 36-1 wheels, air and temp sensors, as well as Honeywell Hall sensor for crank position.
The intake was modified and fitted with shortened and larger 44 mm ID trumpets, again years ago. I can´t remember how much shorter they are but quite a lot anyway. No real science behind the final length, they just looked nice...
[/img]
I did not like the factory throttle body as the plenum was modified quite heavily. I used a generic 75 mm throttle body (Ford Mustang 4,6 litre, cheap chinese item) and fabricated a flange to fit it in the front. The 4,0 litre plenum was cut and welded heavily, actually too much given the distortion .
The fabrication was basically the easy stuff. The trigger wheel was fitted to the crank pulley and a bracket for the crank sensor fabricated from a 5 mm angle iron.
The first crank sensor bracket:
Fuel supply is a Bosch 044 in-tank pump, with AN -6 fittings, hoses and hard lines. The fuel rail is Rover item with a AN fitting welded to it. The injectors are from a Cooper S Mini, Siemens Deka with around 300 cc/min. These are a bit shorter than Rover ones so a set of adpaters were required. A bit complicated but a lot cheaper than getting a new set of injectors.
Coils were fitted to a bracket that´s located on the bulkhead. The ignition modules sit above the coils. I did not know what size the ehat sink should be so I made it of 3/8" thick aluminium sheet. Naturally the expansion tank used to reside here so it had to be moved. I chose to make a completely new one. Usually when you change one thing you need to change several others as well.
ECU was fitted in the passenger foot well. With all the wiring completed it was time to start testing. I first did the ignition and retained the carb. The logic was that in case of any issues they would be ignition related. And yes, issues is what I got.
The ECU would read all sensors except the crank sensor. Starting rpm was between 1000-2000 rpm which is a bit excessive. A lot of double checking and head scratching later I realised that Honeywell spec sheet says that tooth gap on the triggerwheel needs to be 3/8" minimum. Mine had only 1/4" or so. My friend has the same ECU and Motronic wheel so I asked him which sensor he has. I got the GM part number and bought a same sensor. Naturally these are physically different so another bracket was cut from a section of angle iron and duly fitted. Of course the connector was different as well so some wiring changes were required as well.
And this helped, partly... The ECU now got consistent RPM signal around but still did not start. The ECU would spark some of the cylinders but not all. IThe sensor could not read the home signal i.e. the missing tooth. A quick word with local Haltech rep and Haltech Australia and both replied that this particular ECU always had problems with Motronic wheels. A bit funny since Haltech manual lists Motronic wheels as one option. Final option was to ditch the Hall sensor and replace it with Ford VR sensor. Hey presto, some fiddling with the bracket and wiring and the engine started !!!
I did some primitive ignition map to verify that it runs and then removed the carb and intake. EFi stuff fitted, finalize the wirings and fuel lines and it was more or less ready.