Thread: efi on a p76 donk

i recently looked into this but it was the 3.9 injection onto a P76, no shops in Brisbane were interested to doing it, so I just went with rebuilding the 3.9.

If you go ahead you will need the spacers - cylinder head to inlet manifold which are available from Melbourne as the V of the P76 is wider than the rover v8, the same shop also has the adaptors to the zf auto also if thats being fitted. fairly sure theres a thread in the technical section about this if not pm me you email address and I'll send the info that i found out

thanks guy........I found ritters and toorak tractors mentioned......is that who you meant? I'm going straight gas........so basically I'll just use the throttle body and manifold with a mixer ring.........crude.........but simple and effective

The spacers/adaptors that I found were from Rova Centre in Melbourne, they also have modified computers to run the P76's - not sure how sucessful they are (I have no experience with them but my mechanic has had issues??)

Ok, here are some of the posts from another forum, I'm sure there must be people out there who have successfully injected a P76 and at a reasonable price been able to do this, but you mainly seem to get the negative/expensive warning type replies to questions:

I'm going to post a reply I got from another forum - for others interested:

Post 1:

G'day Guy
I fitted a P76 4.4 motor to my 88 EFI (flapper type) Rangie about 3 years or so back. I'll share my expereiences with you so you know that it is not the simplest of things to do- this may turn out to be a long post.
I got the adapters from Dave at Rovacentre. For the 3.5, they are flat plates 19mm thick that bolt to the block over the top of the valley cover with allen head bolts recessed into the plates, the inlet manifold then bolts to the adaptor plates using the original bolts. The plates are not angled- all the Rover blocks have the same V angle of 45 degrees- the longer stroke of the 4.4 (19mm longer than the 3.5) means that the heads end up further apart. The ports in the plates are huge compared to those in the heads and manifold- I borrowed a die-grinder and matched the ports to the plates (this necessitated porting the valleycover as well), then used locating pins to ensure that everything seated in the matched position. This was a fair job in itself.
You need to make gaskets for the spacer-to-manifold joint. I ended up with vacuum leaks here- the bolts that hold the spacers to the heads are well off centre in the plates, I think the bolt arrangement results in less than optimal seating of the plates. When I removed everything to repair the leak, I stripped all the paper gasket off my tin valley cover and used Z-bond sealant instead of gaskets at all the inlet joints, including both surfaces of the valley cover. No more vac leaks.
Anything that bolts to both the block and the heads needs to be lengthened by 19mm- I remember extending the power steering pump bracket, don't remember if there was anything else. The engine mount brackets have to be modified by cutting, drilling and welding. You need a longer power steering belt, also longer aircon belt.
There is an adaptor for the rear of the crankshaft- simple enough to fit up. I had the motor out twice to replace the rear main seal- the black ones that come in gasket sets (even good quality gasket sets) are useless- make sure your motor has one of the good quality red seals in it before you fit it.
I managed to bend my exhaust system to fit the wider (and higher) position of the manifolds by hand in a vice, took a few goes in and out to get it right.
Once you have everything fitted and modified, the real difficulties start. I'm not sure about going from a 3.9 to 4.4, but going from a 3.5 to 4.4 meant that the injection system could not provide enough fuel for correct mixture under load or at high revs. The standard system simply will not provide enough duty cycle length to the injectors to run the bigger engine, resulting in dangerously lean mixtures under load. I was ill-advised to have a 'UNICHIP' system fitted. The unichip agent spent many hours stuffing around with the thing over a period of about 2 months, and on my last visit to him told me that he was closing down his business- with my car still not running right. I went to another UNICHIP agent about 1 1/2 hours drive from home(only their agents have the tuning software) who charged me about $250 to tune the car- when I picked it up from him it backfired constantly on overrun, then broke down half way home. I removed the UNICHIP and replaced all the butchered wiring from it's installation. $1300 down the drain, plus one muffler and 2 airflow meters destroyed by backfiring due to the way the unichip agent had wired the system, plus $250 for a rising-rate fuel pressure reg to try to increase the fuel feed (don't let anyone try to convince you that this will help). The unichip agent tried to tell me I needed bigger injectors- $200 each. Eight of them.
I ended up removing the airflow meter, ECU and all the wiring from the fuel system and fitting an aftermarket system (SDS- 'simple digital systems' from Canada) that utilises the original fuel pump, filter, lines, reg, TPS, piping and injectors with the addition of a MAP and inlet temp sensor and a fully user-programmable ECU. Also fitted a mixture meter to assist in the tuning process. The original injectors do the job just fine, duty cycle is never more than about 72% so bigger injectors are not necessary. This system has been completely trouble-free for about 3 years, from the moment I first started it - I could not be happier with it. It does not offer dual advance curves and such, like the Haltech systems, but one advantage is it has it's own hand-held programmer, and I did not have a laptop at the time, which you need to program the haltech, motec and others. From memory I think the system cost about $1300, plus the shock phone call from customs telling me I had to pay $300 import duty.
If you are on LPG that will also have to be tuned for the bigger motor.
All up, my 4.4 conversion cost me more than what I had been quoted for a complete 4.6 conversion including all the necessary electrics. I guess if you have a good motor sitting there, that is a good deal of the money already spent, but be prepared for the costs of getting the EFI system to run the bigger motor. The 4.4 has heaps of grunt, but probably does not go as hard as a 4.6. Fuel consumption (the term 'fuel economy' seems out of place when talking about Range Rovers) is pretty much the same as the 3.5; I run mostly on LPG and get 320km from 76L. When i had the LPG fitted to the car with the 3.5, it always ran more smoothly on gas. Now with the new EFI system it is a treat to run on petrol- smooth as a babies bum.
I did warn you thast this would be a long post, and I haven't even talked about how the engine reconditioner stuffed up the piston-to-bore clearances and had to start over with a replacement block when the first motor exhibited pronounced piston slap.
Anyway, hope some of this is useful to you.
regards

Post 2:

Tomorrow when i have time i will sit down i post up what it cost me with all the mistake verse what i know now. when i did it there was lots of theories and most sound good when they are not using your money. The motor i have is a stump puller and knowing now what is required is a lot cheaper then trying to work it out.
A 4.4 is a square motor and a good platform to work on. the vacuum leaks the above post spoke of i never had but there again my adapters where the first set Toorak Tractor made, after market cpu is the way to go wolf has one of the best setup going for price ( around $1500 ) you will have to wire it in yourself good diagrams and if you take your time it is pretty easy. You will need a 120 amp landrover alternator i tried a few other brands a waste of money and high pressure fuel pumps and new lines ( this is if your going from carby to EFI). lastly dyno tuning which depends on the shop u take it to verses how much it will cost you. To fit rover heads you need to drill the oil gallery hole thru the leyland block pretty easy with a mill. Use ford cortina engine mount which will lower the motor 10 mm so the bonnet doesn't hit. There is some other things like phrasing the dizzy in ( welding it up and removing mechanical advancement ) the wolf EMS takes care of it all.
just a few things i remember off hand

oh the running lean issues he had up the fuel pressure to 38 psi fixed it, and also the wolf does away with airflow meters etc so no chance of destroying them with back firing.

addition to post 2;

base motor rebuild ( first time ) $3000 including heads
Short motor with leyland pistons (includes machining) $1200
Adapters ( engine swapped for them free ) normal $350
Inlet manifold $150 with injectors and fuel rail
air filter box $50
Wolf V4 cpu $1200
Fuel pumps ( high pressure and high volume) and surge tank $1200
fuel lines $120
tuning $250 (first time useless) $800 second time pick up a few faults
Fuel pressure regulator $250
Alternator (vt commodore $130 waste of time)
Alternator landrover 120 amp $720 brand new important from england
then you have all the little thing you forget about $500

the mechanics fees were around 4 k by the end of it, tuning was around $1200 at the end. Lots of wrong advice cost me dollars but now if asked i would suggest 4.6 carby if you wanted injection much of a muchness. Personally i would go a 4.6 ( mine is roughly the same size with the boring etc ).

Hopefully the above is of some assistance.

Cheers Guy

thanks for that guy......hopefully going straight gas I am avoiding a few of the excess costs you seem to have incurred

Hi, no problems with the use of the 86 EFI setup on the P76 motor, EXCEPT... as the P76 block is taller than the 3.5/3.9 block it is wider at the top where the inlet manifold sits so you will need "spacer plates" between the manifold and the heads. I have seen these on the internet somewhere, and they turn up on e-bay from time to time. Otherwise buy a "Wilpower" manifold for the P76 (made here in aust for 4 barrel carb or Multi point injection and 4 barrel throttle body). This will probably require the use of an aftermarket EFI computer but you will get really good performance and can also look at alternatives for gas injection. I am looking at this for my 63 rover p5 sedan as it runs a p76 motor.

For what its worth dont worry too much about the flap/vane with gas it is only worried by backfiring and you can buy an anti-backfire valve to protect it. I have one in the shed if you want to see what I mean. I have gas on my 89 rangie but I gave now upgraded to hotwire EFI and 3.9L. Rover V8's run very nicely on gas.

You could even use a standard P76 manifold with a holley carb or even ford falcon SPFI setup and dual fuel or just go dedicated gas. I have twin tanks in place of my fuel tank and a small side petrol tank between the rear fender and chassis rail. The options are pretty good.

Cheers
Bret (89 RRC and 1963 P% 4.4V8 sedan)

at the moment I have to decide whether to p76 it...........253 conversion or build up another 3.5 for the old girl........... either way it will be dedicated lpg......have been told the p76 swap is slightly painful but straightforward, 3.5.....I'd prefer more torque( 4.6 is too dear this is going to be a budget project after all) and keep getting differing opinions on the 253 swap.

hey mate,

I did the p76 swap in mine, although the donor was a auto rangie anyway so i didnt have to do the extra bolt holes for the engine mounts.

But the p76 has a larger crank so u need to get a custom spigot bearing made and the flywheel remachined larger and different bolt holes and larger indentation where the bolts go so they fit ($200 by duggins engineering)

All up id do it again for sure, however if u decide on the holden engine conversion instead dont bother with a 253 there **** (dunno why they are popular in hilux's) go a 350 chev engine

I'm a little confused.
If you want straight gas, then why all the drama in setting up the efi stuff?
If it's injected gas - well that's a different story!

Just use the old carby as a throttle body.

If you want the efi for ignition mapping, then there are other options.