Offroad-Express

I want to get more grunt out of my 3.9l Rover V8 than a 1UZ-FE.

3.9l Rover - 180hp - 190hp

Lexus 250-260hp

So I think 300hp sounds like a good target.

I can do electronic ignition control and fuel tuning with my megasquirt II and plan to throw it on a dyno down the line once I have made some improvements.

Not that keen stroke or bore at this stage.

How to go about it?

Cheers,

Pete

oldyella wrote:I want to get more grunt out of my 3.9l Rover V8 than a 1UZ-FE.

3.9l Rover - 180hp - 190hp

Lexus 250-260hp

So I think 300hp sounds like a good target.

I can do electronic ignition control and fuel tuning with my megasquirt II and plan to throw it on a dyno down the line once I have made some improvements.

Not that keen stroke or bore at this stage.

How to go about it?

Cheers,

Pete

breathing is rover down fall, improve the intake manifold, headers, cam shaft, big valves, bore /stroke do a web search on rover V8 performance and a shite load of info it out there,

pedro

Get a 4.6 and the. Start moding

Found this table at this website

http://www.mez.co.uk/TuningTheRoverV8-pt4.html



It looks like 300hp N/A for a 3.9l rover is out of reach

What about a supercharger instead of the aircon pump?

Plenty of v6 Holden superchargers around. Eaton M90, is that right?

Here's one on trademe for $800 and there are plenty of others.

http://www.trademe.co.nz/Browse/Listing.aspx?id=477405286



Custom intake manifold required?

I know its not really applicable to what your trying to do and I know your only just getting towards the end of your project but for what its worth its a lot easier to just throw a big fawking grunty engine in with all the HP you want than lots of messing around trying to strangle as much HP out of a smaller engine you've already got



sorry I just had to get that off my chest

have to agree with sadam. Last thing you need is a highly strung motor have a melt down halfway up a hill in the middle of nowhere.

I'm going to buy another complete disco for spares which means I'll have a spare engine.

Planning on re-building the spare engine then do a swap.

Just trying to come up with a direction for the engine re-build and if i'm going to all that trouble, it needs to have more grunt than a 1uz-fe

Also leaning toward the supercharged option....

When i had the 3.9 rangie on the parts shelf was a p76 crank and ford 250 piston's and a centrifugal supercharger . brought the supercharger of the lotus guys out east Auckland . They towed there race cars with a rangie , said with the supercharger and a near 2t trailer it went like a stock rangie , but with fuel cons to match
never fitted it as the price of gas took off , but they are around and would be an easier fit than a m90 if you could find one .
If you are going to get a wreak and rebuild get a rangie with a 4.6 , going to rebuild it anyway and you have the megasquirt to run it .

Chris

I've had a bit of a search on the web.

It seems the first thing requiring improvement is the heads.

To go aftermarket Real Steel Merlin 85 heads from the UK at around 1315pounds which equals $3,136 inc gst excl freight.

Real steel also supply everything else you would need for a rebuild.

http://www.realsteel.co.uk/section1.pdf

Otherwise get the stock ones flowed and install larger valves etc which may be more cost effective...

Have done some more research and have found the following:

The Merlin 85 heads have the exhaust ports located differently on the head which means that your exhaust would need redone.

Also found that "V8 Developments" in the UK port heads on an exchange basis. They also do a lot of other V8 rover related stuff including blocks, plug'n'play megasquirt, cams, the list goes on.

http://www.v8developments.co.uk/

650pounds for ports tidied up

750pounds for ported heads with standard valves

1000pounds for ported heads with big valves

1250pounds for ported heads with really big valves

1500pounds for ported heads with really really big valves

Another place I have found is Wildcat Engineering

http://www.roverv8engine.co.uk/index2.htm

I believe these heads have the same issue of intake and exhaust ports being in slightly different locations but it may depend on what "stage" you get.

It seems that the Eaton M90 supercharger has been poorly applied to the rover engine previously

http://www.v8engines.com/engine-3b-big-1.htm#top-pic

What seems a life time ago i had a swb s3with a 3.5 rover mtr stock apart from a two barrel holley reved to 5ish .i put a cam in and some headers on it it perked up a bit.but not enough.so pulled heads off got them ported put the over a flow bench.did not change valves just put on stronger valve springs and fitted a small 4 barrel holley.made a huge diff the port job made.it screamed to ait over 7000rpm and pulled all the way to 7.as before would rev to 5and then flaten out.that was back in 98 and it cost $600. Im shore some one in nz would port and do some valve work for under 2k.

7grand, I bet that sounded mint.

It seems that porting the heads but leaving standard valves gives good performance gains then.

Off that table I posted up before:

3.9l Rover with mild Cam, Ported heads, 10.5 compression ratio gives:

235hp/175kw @ 5700rpm with 265ftlbs/360nm at 3800rpm

Still 25hp down on the lexus though...

For the that sort of money and save sending heads to England etc. you could get the work done locally cheaper. Theres heaps of (older) guys around that have raced the rover V8s, I know Trever crowe (Crowesport) used to rally a rear mounted rover v8 powered Skoda. Also rally guys have messed around with them for years, A fella Mike Verdoner in Balclutha used to Rally a Rover V8 Escort a few years back. Might be worth contacting one of them?

Back in the 70/80's era and could go later John Harcourt was a Rover V8 guru successfully building and racing Rover V8 powered cars, his motors also performed well in Boat racing and Speedway. At the time John had a workshop in Prebbleton, I don't have any contact details but someone on here may be able to help.

FITZY.

Thanks for the ideas,

Definately keen to build up a Rover V8 with better output.

Thinking of dyno'd where it is now which is stock with the MSII computer controlling fuel and decient exhaust. (Should hopefully be over 85kW at the wheels)

Then I should be able to see the difference a few modifications make and post them up.

Cheers,

Pete

Well I am still looking into some additional stages of perking up the 3.9l Rover V8 in the LR.

So far I have short headers, ported intake manifold to match heads, high torque cam which turns out doesn't really get interested until about 2500-2800rpm. Fuel injection with MSII, standard ignition with static timing set to 10deg BTDC running 96

I have a set of standard heads to flow and deck so I'm doing some research.

Got reading a this interesting article from the same fella that supplied the camshaft that I have already installed. Suspect the standard CR of 9.35:1 is reducing my low end torque now that the performance cam has been installed.

http://www.aucklandcams.co.nz/bulletins/compression_ratios/

There's an Old guy in Taranaki that used to build these engines for a F1 team that I spoke to. He said 300hp is very hard to reach even for the 5.0L engine in NA form. The 3.9L was the most reliable, he said bump up the compression, get a mild cam and be done with it as there are far better engines out there to get power from.

I can get his number if you want it, PM me.

One thing I noticed pulling apart one of these engines is how poor the casting quality is. On the intake manifold it looked like the casting core had slipped so the intake port didn't align with the ports on the manifold. I have heard that blueprinting can yield good results and I would believe it after seeing some of the parts.

Yep,

I have given up on thoughts of 300hp and am really just investigating avenues for improvement over stock. Staying N/A on this engine at least as I am just planning on swapping the new heads over one weekend, slight re-tune with the MSII and away laughing.

So, how's this, would need to be substantiated by measuring my actual as installed cam specs...

Bore 94mm
Stroke 71mm
Swept static volume 492.7cc
CR = 9.35cc
Working backward to calculate existing combustion chamber volume

492.7 / (9.35 - 1) = 59cc combustion chamber

I have a 0.28" lift cam as per the example in the article where he states the chamber is filled with 78.1% of air under dynamic conditions due to delayed closing of intake valve. I would check this figure before decking the heads I think.

Dynamic swept volume = 492.7cc x 78.1% = 384.8cc

Now he states that the dynamic CR should be max 8.3:1 for 96oct.

Therefore new combustion chamber volume is:

384.8cc / (8.3 - 1) = 52.7cc

New static CR is:

(492.7cc + 52.7cc) / 52.7cc = 10.35:1

So about a 10% increase in CR which should give a 10% increase in torque and give me back some bottom end which was lost after installing the performance cam.

Just out of interest is the standard motor you have now running properly? you know, starting ok when hot, idling all the time and not running hot when stressed off road. A good mate had all your thoughts 2 years or more ago, but in the end we couldn't manage to keep it running right in standard trim for any decent length of time (a full day out) never mind tuned. I know the landy boys will get all stressed now but I would really think twice about throwing $ at that motor. Buick designed the original, decided it was no good (and that's saying something for a US car manufacturer) so were over the moon I bet when Rover came along and bought it. Oh, and the standard drive line with its Cortina diffs is not up to the task either.
To make it reliable all you need to do is fit a Japanese motor, gearbox, transfer case, axles and wiring

Rip it out and place a lex in there..I know you want one.. even better super charge it.. then have some good powa atw

Not until this engine is toast then I think I would look into a S/C 4.6 with X-bolted bottom end. Probably move the front panel right out like a defender so I can put a massive radiator in there to keep it nice and cool

For now I'm looking into a second stage of:

Blue printing/reshaping intake & exhaust ports
Increasing CR (interestingly to compensate for the more aggressive camshaft as above)
Using MSII to control & optimize ignition timing

I don't see these modifications as reducing the life of the engine compared to stock. More making changes which would not otherwise be economic to manufacture on a large scale

It's my right foot that reduces engine life

Found some info on results of porting stock heads.

http://www.leylandp76.com/technical/tech-headflow.html

About halfway down is the comparison for 3.9l Rover V8 heads.

oldyella wrote:Not until this engine is toast then I think I would look into a S/C 4.6 with X-bolted bottom end. Probably move the front panel right out like a defender so I can put a massive radiator in there to keep it nice and cool

For now I'm looking into a second stage of:

Blue printing/reshaping intake & exhaust ports
Increasing CR (interestingly to compensate for the more aggressive camshaft as above)
Using MSII to control & optimize ignition timing

I don't see these modifications as reducing the life of the engine compared to stock. More making changes which would not otherwise be economic to manufacture on a large scale

It's my right foot that reduces engine life

If you are stripping it down for full blue print then consider a crank from the 4.2V8 to stroke it. Its basically only the crank and conrods that differs from a 3.9 to 4.2. Pistons, heads are same although there is some slight grinding of block for clearance.

I know the 3.9l's have two different crank main bearing sizes. A small and large bearing size essentially.

I'm guessing the 4.2l crank suits the larger bearing size.

The 3.9 I have has a the small crank bearing size, even though it is a later model serpentine belt model.

No the 4.2 still had the smaller main bearing journals. The larger size came with the 4.0 and the 4.6.

Interesting. So that's this 4.2l engine

Land Rover extended the 3,946 cc engine for the top LSE[6] specification of the Classic Range Rover. The 4.2 L engine had a displacement of 4,275 cc (260.9 cu in), and used the crankshaft castings from the failed "Iceberg" diesel engine project.[7] Bore remained the same at 94.0 mm (3.70 in), while stroke increased to 77.0 mm (3.03 in).

Applications:
1992–1995 Land Rover Range Rover

Probably not the most common engine around though.

I was thinking of a crank from the later 4.2 which has now got me thinking. At what point did Land Rover change the bellhousing bolt pattern of there V8's? Is this engine the same bellhousing bolt pattern as a disco 3.9l V8? Also wondering what would be involved in fitting a S/C from one of these engines to an older 3.9l [edit] heaps because this later engine is DOCH...

http://www.trademe.co.nz/motors/car-parts-accessories/landrover/auction-726134578.htm

Yeah the 4.2 Rover V8 was fitted to the Range Rover LSE, the engine fitted to that Range Rover is not a Rover V8. It is fitted with a Jaguar AJ-V8

http://en.wikipedia.org/wiki/Jaguar_AJ-V8_engine

The last Rover V8 fitted to a Range Rover were the 4.0 and 4.6 fitted to the P38 up until 2002