Injecting a bare 4.6

[101RRS]

If you had a bare basic 4.6 V8 long engine and wanted to inject it for a project car, what aftermarket manifolds and injector system would you consider? Just a standard build, nothing special.

Prefer comments from those with actual experience but hey it is a forum so all comments are good and welcome.

Just thinking things out aloud and looking for ideas I might have missed.

Thanks

Garry

[Bigbjorn]

Have a look at the Edelbrock, Hilborn, Speedway Motors web sites.

[shanegtr]

Im not farmilar with what aftermarlet manifolds are available, but if you can get something that suits a 4 barrel carb then theres no shortage of throttle body style injection kits from the likes of Fitech, Holley etc...

[PhilipA]

Why would you not use a 14CUX manifold?
They will flow heaps of power and injectors are cheap and easy to get.
The fuel rail fits perfectly and if not in a Land Rover , it is easy to get fuel to it.
The throttle body has a sensor attached which is compatible with most ECUs.
The OP could even use a 14CUX ECU, or any of the aftermarket stuff with a trigger on the harmonic balancer
Megasquirt is well known with starter maps available.
All of the USA stuff have quasy 4 barrel manifolds whish are not optimum for injection.
Regards Philip A

[101RRS]

Have a look at the Edelbrock, Hilborn, Speedway Motors web sites.


Im not farmilar with what aftermarlet manifolds are available, but if you can get something that suits a 4 barrel carb then theres no shortage of throttle body style injection kits from the likes of Fitech, Holley etc...

Thanks for that information - any experience in using this type of product.

Cheers

Garry

[101RRS]

Why would you not use a 14CUX manifold?

Regards Philip A

Yes - good question - why not use it? This is the type of options I am looking at.

I have one in my garage and could use it.

I know the throttle body being for a 3.9 is smaller than that for the 4.6 so I assumed it would strangle the engine a bit - if the air intake is smaller I assume the passages in the manifold are also smaller.

I am happy to give it a go as, as you said it uses the basic 4CUX ECU, rather than a complex ECU to run the Thor manifold/injection system. Though I guess a 4CUX could manage a Thor if the idle air valve system was changed.

Thanks for that input as I am wanting to look at alternatives than may be suitable.

Cheers

Garry

[PhilipA]

I am happy to give it a go as, as you said it uses the basic 4CUX ECU, rather than a complex ECU to run the Thor manifold/injection system. Though I guess a 4CUX could manage a Thor if the idle air valve system was changed.

You can use a 14CUX idle air valve with a bit of ingenuity and a few brass elbows and a bit of rubber hose.

I fitted a Thor to my 14CUX 3.9 using the 14CUX ECU and a Unichip to tailor the tune. If your build includes a mechanical automatic like a 4HP22 then it is a real PITA to arrange a kickdown cable. Probably the most time consuming part of my whole conversion.

Remember that there are hundreds of starting programs with factory ECUs,as I clearly remember when at Stockton one day when another bloke had a 4.6 in his Classic with a Motec ( very expensive) and he took about 1/2 an hour to start it when hot. Mine started first turn.
Regards Philip A

[Bigbjorn]

A simple, cheaper, and very effective alternative is an Edelbrock manifold and a Rochester Quadrajet. A Q-jet will supply far more air than a 4.6 can use and they do produce horsepower. With the small primary throats they are very tractable at lower engine speeds and really get going when the huge secondary throats are open.

[Pedro_The_Swift]

Not an Edelbrock,,,

http://www.mez.co.uk/wpimages/wp524e33d4_05_06.jpg


Rover V8 inlet manifold photo archive (http://www.mez.co.uk/ms12-new.html)

[101RRS]

A simple, cheaper, and very effective alternative is an Edelbrock manifold and a Rochester Quadrajet. A Q-jet will supply far more air than a 4.6 can use and they do produce horsepower. With the small primary throats they are very tractable at lower engine speeds and really get going when the huge secondary throats are open.

Thanks - again a good option - they only thing I have really heard against these and the holley injection is they are a bit heavy on fuel usage even with a light foot - but I dont know hence hopoing someone had actually used this gear.

Cheers

garry

[101RRS]

I fitted a Thor to my 14CUX 3.9 using the 14CUX ECU and a Unichip to tailor the tune.


So why did you decide to put the Thor on your 3.9? How did it go compared to the standard 3.9 manifold etc?

Cheers

garry

[Bigbjorn]

Not an Edelbrock,,,

http://www.mez.co.uk/wpimages/wp524e33d4_05_06.jpg


Rover V8 inlet manifold photo archive (http://www.mez.co.uk/ms12-new.html)

A Wilpower according to that link. Takes a spread bore carb, i.e. Rochester Quadrajet. A single plane manifold which gives good high end.

[shanegtr]

Thanks for that information - any experience in using this type of product.

Cheers

Garry
Not directly, but I've been looking at options for the future for power upgrades to my old Suburban with a 454 - its already got a factory throttle body injection setup but it cant really handle much more power than stock. These types of injection are really just an electronically controlled carb.

[PhilipA]

So why did you decide to put the Thor on your 3.9? How did it go compared to the standard 3.9 manifold etc?

Cheers
I was unhappy with the torque of a 3.9 Particularly towing.

I gained about 30% at 1500RPM tapering to about 10% at 3000 with just the Unichip.

The Thor gained another 20% at 1500-2000 to give a 50% gain but lost 10% at 4000 up. The Thor has over a metre from the port to the Throttle body vs the 14CUX which is only about 250MM.

To me that was a great trade! I have dyno sheets somewhere to prove it.

But even then my modded TD5 ****s on it on hills when towing.
Regards Philip A

[101RRS]

A Wilpower according to that link. Takes a spread bore carb, i.e. Rochester Quadrajet. A single plane manifold which gives good high end.

Is it a carb manifold or an injector manifold - they look like 8 injector ports are there - I assumed a plenum of some sort bolted on top.

[PhilipA]

THe usual deal is that a throttle body goes on top when they are used with injection.
The distance from port to throttle is very short so poor low down torque but lots of power up high.
Although you could of course bolt on a tube and put the throttle bosy where you wanted and have a much longer inlet track.
Look at Holley
https://www.holley.com/products/fuel_systems/fuel_injection/
Regard sPhilip A

[bee utey]

I can definitely state that a bog stock 14CUX injection system including inlet manifold goes very well on a slightly modified (cam, compression raise) 4.6. The son of a friend of mine had a 4.6 THOR P38 that got sicker and he ended up buying the 4.6 powered soft dash Classic that I had fitted the 4.6 to. The lad's opinion was "HOLY COW THIS THING GOES!!" Sure it might have lost a little off the top of the rev range but the middle range is solid as.

So don't fret the complexity, just bolt something simple on and enjoy the ride. Throttle body diameter on the 3.9 isn't that big a deal unless you're pushing the rev limit regularly. An early model Classic 14CUX loom only needs ignition, battery, earth and fuel pump connections on the harness plug and it'll run just fine.

[101RRS]

I can definitely state that a bog stock 14CUX injection system including inlet manifold goes very well on a slightly modified (cam, compression raise) 4.6.

Might be easier than what I was intending particularly as I already have the 14CUX system on my old 3.9, have got a new 3.9 fuel pump - all I need to get would be the 14CUX ECU and if I stay with the 4.6 timing cover just get a Megajolt to run the EDIS 8 ignition. Will easier to put LPG injection on as well compared with a Thor.

Thanks for all the contributions - a few options to consider.

Much appreciated.

Garry

[POD]

Can I recommend having a look at SDS fuel injection from Canada, this solved all the problems I had converting my 3.5 RR to 4.4 years ago and I'm sure their stuff is even better by now. Fully user programmable. Simple Digital System EM-5 (http://www.sdsefi.com/)

[101RRS]

Thanks for that link - looks interesting - might give them a call after Anzac day to discuss.

Thanks

Garry

[101RRS]

With the 14CUX (Hotwire) injection system how is the "speed" sensor information provided in vehicles that have an old style speedo cable rather than a more modern electronic speedo.

Also - in a D1 or RRC with Hotwire injection, where does the ECU take its ignition signal from? The low tension side of the ignition coil?

Thanks

Garry

[Homestar]

Yep, picks up from the ignition coil. Apart from that all you need is B+ and switched B+, and an earth - very simple setup to retrofit.

[PhilipA]

With the 14CUX (Hotwire) injection system how is the "speed" sensor information provided in vehicles that have an old style speedo cable rather than a more modern electronic speedo.

The speed sensor controls injection cut off at more than 1500RPM and throttle less than 0.49 volts and positive speed . IE down hill.

It also controls idle stepper at low speed (under 1500RPM ) when approaching stop ie throttle below 0.49. It holds revs to approx. 1200 to smooth the change to first in the auto.

It takes the signal from the speedo sensor. If you were really nerdy you could get a driveshaft sensor for a cruise control and set it up to give a pulse I guess, although the math may be interesting although I suspect it is only pulse vs no pulse.

But really the penalty for not having the injector cutoff and idle up is not all that great. My TPS was disconnected for about a year and I didn't notice ( although I did notice no injector cutoff as it was very pronounced with the Thor manifold) , but I had O2 sensors fitted which do all the mixture control at less than 1/2 throttle. I had over crimped a join in the TPS wires which cut a wire and negated the TPS signal.
Regards Philip A

[101RRS]

Thanks Philip and Gav,

Philip - on the speed sensor thing - I did read that the 14CUX ECU expects to see about 8000 pulses per mile but as usual cannot finds the reference right now - but I assume all it needs is to see lots of pulses when at speed and no pulses when stopped. I have an old cruise control kit at home that has tailshaft magnets and a pickup - might be suitable - also I believe signal generators that go on the speedo cable are available so some options there.

I dont have a dizzy on my engine and ignition is going to be controlled by EDIS 8 and Megajolt. I need to work out what the equivalent of B+ is on a traditional coil. My system has two coil packs (4 coils in all) but they are fed with a a common 12v positive with the system switching through the relevant coil low tension side to earth (just like B+ on a traditional coil) - so the number pulses going into the coil system is basically the same as a traditional dissy and coil setup.

Another aspect is to take a signal from what is called the SAW signal from the Megajolt unit. Basically, crankshaft sensor signals are received by the EDIS unit and then sent to the Megajolt Control unit (called a PIP signal) where this signal is delayed or advanced (normally advanced to advance ignition timing with increased revs etc) and this SAW signal is sent back to the EDIS system where it then fires the coils (wasted spark). This SAW signal should also work with the 14 CUX ECU but it may not be a 12v signal - dont know yet.

For those who do not know EDIS is a Ford system fitted to many late 90s - early 2000 cars - comes in 4, 6 and 8 cylinder versions - in Aust fitted to 90s Mustangs, 2000s Festivas, Focus and Modeos. The beauty of the Edis system is that it can still work if the car's ECU has failed as it is capable of running in a default mode of a fixed 10 BTDC. I dont have the Megjolt ignition module as yet but have been driving my 101 around on LPG (carbs not working) and EDIS in default mode with no issues - it is amazing that with fixed ignition timing all seems to work as per normal.

Plan is to get the carbs working - full ignition control then swap out the carbs for the 14CUX injection system - and injected LPG. I want each component to be working so that when I make changes I am only testing on new item not the whole lot.

Thanks

garry

[PhilipA]

I looked at EDIS for my 3.9 but By that stage I already had a Unichip fitted which took over the vacuum advance portion of the dizzy ( which I completely deleted) but left the centrifugal advance in effect electronically controlling advance and creating an electronic advance profile/map . I don't know why they didn't lock the dizzy at the same time but that was how it was done. I think you can buy a crank pulley sensor and Megajolt as a full kit from the UK

I would have fitted EDIS to the crank pulley but you would have a crank sensor position on a 4.6 along with a slotted flywheel/flex plate.

You get most fuel economy from the level of advance at light throttle/lower revs and the RV8 can take lots more advance. Apparently they limited advance at lower revs to reduce NOX emissions. So locked at 10degrees is not ideal as it can take 30 on light throttle.
Regards Philip A

[101RRS]

The speed sensor controls injection cut off at more than 1500RPM and throttle less than 0.49 volts and positive speed . IE down hill.

It also controls idle stepper at low speed (under 1500RPM ) when approaching stop ie throttle below 0.49. It holds revs to approx. 1200 to smooth the change to first in the auto.

It takes the signal from the speedo sensor. If you were really nerdy you could get a driveshaft sensor for a cruise control and set it up to give a pulse I guess, although the math may be interesting although I suspect it is only pulse vs no pulse.

But really the penalty for not having the injector cutoff and idle up is not all that great. My TPS was disconnected for about a year and I didn't notice ( although I did notice no injector cutoff as it was very pronounced with the Thor manifold) , but I had O2 sensors fitted which do all the mixture control at less than 1/2 throttle. I had over crimped a join in the TPS wires which cut a wire and negated the TPS signal.
Regards Philip A



Hi Philip - you seem to be the resident expert on the 14CUX. [smilebigeye]

I was speaking to a friend that has a 14CUX in his 101 and he confirmed that he does not have a speed sensor and his system works fine - idles etc with no issues however he was not sure of the specifics.

From you comments above you seem to think it is not all that important.

I am thinking of proceeding without it and see what happens. I am looking at getting one of Homestars GPS speedos for the 101 so will not need a speedo drive and Justinc has advised a TD5(LT230) speedo transducer will fit a LT95 so provide the speed pulses if the ECU actually needs them.

Cheers

Garry