RV8 EFi conversion

Post any info regarding parts for conversion and swaps.
and any posts regarding swaps help.

Moderator: phpBB2 - Administrators

Post Reply
minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

RV8 EFi conversion

Post by minorv8 »

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...

Image[/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 :lol: :lol: :lol: .

Image


Image

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:

Image


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.

Image


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.

Image

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.
Last edited by minorv8 on Wed Jun 29, 2016 10:32 am, edited 6 times in total.



DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

I'd say that regardless of the ECU used, getting a decent stable tach signal always seems to be the most common problem

MegaSquirt software these days includes the ability to log the tach pulses. Which does tell you if you have a problem, but not necessarily where.

It's where a 'scope is useful. You can look at the waveform from the sensor. And after it has been conditioned by the input stages. One problem is it seems impossible to provide a truly universal tach input, that will take any sensor signal and covert to to digits suitable for the processor to read.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Post by minorv8 »

Fuel system was a big dilemma because I could not choose whether to use in-tank pump or external pump. I had some spare time and stainless surplus stuff so I decided to do in-tank system. I cut a 1/4" thick plate and drilled holes for feed, return and wiring. I welded AN6 bungs to the plate for easy connections.

Image

The pump is fitted to a vertical rail which then was welded to the top plate. The pump is surrounded by a small bucket that is a sort of a surge tank. The return fuel is directed to this bucket.

Image

Image

The fuel feed hose run from the tank to a filter under the rear floor and hard lines run from the rear to the front. The hard lines are connected to the bulkhead fittings at the crossmember.

Image

Here you can see the bung welded to the factory fuel rail and a lot of wiring loom spaghetti waiting to be connected somewhere.

Image

Because I no longer have a distributor I had to get some sort of drive for the oil pump. I bought a used distributor and had some fun with angle grinder and a lathe. Here is what remains of the Lucas dizzy:

Image

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Post by minorv8 »

The air intake was a bit of a problem too. The easiest option would have been to stick a filter directly to the throttle body. There is plenty of space there but also a lot of hot air. I wanted to have cold air but there was no easy location. A few evenings later the location was created under the LH side wing. A large K&N filter sits in the fabricated air box and a 80 mm diameter steel piping runs between the throttle body and air box.

Image

Image

This is basically what the final package looks like:

Image

Image

Heater hoses had to be re-routed and here I used 5/8" 90 degree elbows and tube to create hard lines. All in all, quite a lot of little things to do.

The car spent 3 hours on dyno yesterday after I had done some fuel maps. They were good enough to drive the car to the dyno shop. I realised that getting any higher engine speed maps would be extremely dangerous to everyone around plus costly in case of speed control :lol:

So, what was the result ? For some reason a dip in the torque curve around 3500 rpm and total loss of spark at around 4600 rpm. Just like hitting a rev limiter. Not exactly what I expected... OK, now the car runs very nice and I have plenty of investigating to do to fix that spark problem. I would not be surprised to find out that it has something to do with crank sensor :lol:

Would I do it again ? Well, it has been a big learning session and has given me quite a lot of new knowledge. Also, now I have some extra space in the garage. Lots of parts from the shelves are now fitted to the car and some of the old parts sold further.

To be updated once I get the spark issue fixed...

Mark
Knows His Stuff
Knows His Stuff
Posts: 368
Joined: Fri Nov 17, 2006 11:34 pm
Location: Essex

Post by Mark »

Nice job on the conversion 8-)

Just a thought on the misfire, did you use shielded cable for the crank position sensor ?

The CPS needs a shielded cable, with the shielding earthed only at one end from what I've read on the subject.
302 V8 Sierra 5 door sleeper under way

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Post by minorv8 »

Yes, I have a Haltech loom and it has the correct shielded cable.

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

Do Haltech publish a schematic for the ECU? Be interesting to see how they do the VR sensor input. Might also be worth fiddling with the sensor gap. I generally set it to 1mm as a starting point, but don't really know the Haltech.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Post by minorv8 »

Apart from the wiring loom there is no schematics. The software has both adjustable trigger gain and filter for VR sensor, I just did not have time to check them yesterday. Maybe today.

The sensor gap is set at 1 mm There is a shim fitted between the sensor and bracket, I can substitute it with a slightly thinner one to reduce the gap. The sensor is a a generic one for Ford Zetec (IIRC), I dont know if the OE quality is any better.

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

1mm gap is a pretty good starting point. I'd first tweak the pots following the maker's instructions.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Post by minorv8 »

Problem solved. I tried the VR gain setting first but it only raised the rev limit to 5000 +. I then decreased the filter setting to zero and it solved it. I also rdduced the gain. It now hits the software rev limit. Basically a cheap fix !

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

Excellent result. I does seem to be a bit of a fiddle on most of them.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

minorv8
Knows His Stuff
Knows His Stuff
Posts: 571
Joined: Thu Nov 23, 2006 5:10 am

Post by minorv8 »

I finally got the car to a rolling road session last weekend. Saturday afternoon was spent on a local track, giving my son some seat time. He has never driven the car nor been on a track so it was good fun in many ways. No issues, apart from the small glitch that the seat was a bit too far back and did not allow enough adjustment for him.

Sunday them. The rolling road is at my friend´s place and I have been there quite often during the past years. We got to fine tuning the maps at high revs. I had the total timing at 30 degrees and this gave the hp peak at about 5200 rpm. After that the power started slowly dropping. We the tried to increase the timing to 32 degrees above 5000 rpm and the engine really liked it. The power peaked at 6000 rpm. timing set at 33 degrees did not give any increase so it was backed to 32 degrees.

I was pleased with the top end so we did some fine tuning for low revs. Pretty satisfying 3 hours ! The final "prank" was to run a 35 mm restrictor in front of the throttle body to see how much power it will restrict. It did but still gave 222 hp / 5000 rpm and 350 Nm / 4000 rpm. Still, it ran all the way to 6250 rpm !

Post Reply

Return to “Engine Swaps And Conversions Area”