Thread: Injecting a bare 4.6

Originally Posted by Pedro_The_Swift

Not an Edelbrock,,,




Rover V8 inlet manifold photo archive

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

Originally Posted by 101RRS

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.

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

Originally Posted by Bigbjorn

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.

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

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.

Originally Posted by 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.

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

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