Manifold Adaptors or 3.5 heads

[CQ Davo]

G'day all,

I have p76 v8 ready for installation into my 86 4dr rangie. Has anyone got idea's on the easiest way to get the fuel injection off the 3.5 onto the p76?

Installing manifold adaptors prob sound the easiest option assuming i can get a set but is it the most effiecient way of doing it. Or is it better to go the harder yards so to speak and transfer the heads and all off the 3.5 onto the 4.4.

What needs to be done to the heads/4.4 to bolt them on, or is it a relativily straight forward process? Or lastly is it maybe better to stuff around and get the manifold from the 4.4 setup with fuel rails, injectors etc?

Davo

[Loanrangie]

It doesnt matter what heads you use you will still need the adapters unless you convert the stock 4.4 manifold to efi , ie welding in injector bosses and getting a throttle body to suit. It would be more cost effective to use a 3.5 or 3.9 efi manifold with spacers and aftermarket ecu. I think the cheapest and easiest solution is to use the 4.4 manifold and get a throttle body injection unit off an ea/eb falcon ( which flows 500 cfm) and use either a mega squirt or other ecu. The falcon tbi is a 2brl and will only need an adapter plate to fit the 4.4 manifold. To fit 3.5 heds you need to drill an oil feed hole into block to supply oil to the rover rockershaft. Or others have just fitted the 3.5 heads and 4.4 lifters/ pushrods apparently to no detriment.

[Philip A]

Agree 100% Loanrangie. The TBI is maybe the cheapest and most reliable solution.

if you were Really keen, you can buy injector "bosses" from electromotive and drill and weld into the P76 manifold and they sell rails which can be drilled for the correct spacing. But this is a pretty big/expensive job unless you have the correct pillar drills etc. You could use a throttle body from a carb as the throttle body or buy one from a suitable car, Commodore 3.8?

The 3.5 injection manifold has a few expensive problems as the injectors are a really old type with little pipes on top and do not flow enough for a 4.4. So you have to get a 3.9 rail and injectors at the least. 3.9 injectors do flow enough for a 4.4. I do not know of any higher flow pipe type injectors. The air bypass valve on a 3.5 however is a good way for you to get idle up when cold.
I reckon it could cause problems to just use the P76 hollow pushrods and lifters as the Rover tappet gear relies on pressure to lubricate the bushes for the rocker pivots. I cannot see how much oil thrown around from the tappets is going to go into the rocker pivots, but sometime these things work. I would not like to be 300KM into the Simpson and have my rockers seize. Sort of terminal.
Regards Philip A
regards Philip A

[CQ Davo]

Thanks very much for the info guys. The body has a 2" lift. Do you know if there will be any clearance issues if i go down the Falcon tbi path? As the 4.4 is already higher than the 3.5.

I have managed to track down a set of adaptors and i have a haltech computer but it sounds like there will still be underfueling problems using the 3.5 injection. The tbi injection does sound the easiest.

[Loanrangie]

2" body lift should be enough as the tbi is no higher than the original 4.4 stromberg carb, on the megsquirt site there is a guy who used 1 tbi unit on a 460 BB ford so it will be good on a 4.4, bonus is you can use the matching filter housing for the tbi and then hook that up to a snorkle - i priced the tbi's at the wreckers and about $50 will get you one.

[THE 109]

what haltech ecu have you got?mine is a E6X and runs a holden v8 throttle body,to get it to fit was as easy as chopping the 3.5EFI throttle body off and welding a flange plate to the plenum chamber.then bolt the holden one on.now i have great idle control as the holden unit has a stepper motor built into it.there's no need for the extra air valve with this set up.as for getting enough fuel to it why can't you fit injectors out of an RB30(turbo),they are a straight swap for the 3.5 injector but flow heaps more.

[CQ Davo]

The haltech is on order. should be getting it next week so is the latest one available. I havent thought about throttle bodys as yet. Thanks for the advice though. Very much appreciated.