Sierra v8 conversion.

[shiftizzle]

I'm soon to be putting a 3.5 rover v8 in my sapphire and need some advice on the best carbs to use,transmission etc.I really want to do this and it's been on my wishlist for a long time, and I don't want to curse word it up so any advice is useful. Cheers.also can anyone tell me what the value of 2.0 dohc efi engine would be.cheers in advance.

[sowen]

You can get complete 3.9 with the efi system lifted off a Discovery for a few hundred £££'s if you look around, in good condition about 180bhp out of the box and a half decent engine to develop further. The downside is you still need to find a saloon spec gearbox, bellhousing, flywheel, gear selector etc.

The 3.5 carb'd engines are ok, but don't expect much more than 150/160bhp without throwing money and time at them, the SU's are easy to mess about and get running and can be made to work very well.

The factory gearbox was an LT77, they came in lots of BL cars of the time, but get one with a bellhousing, which alone goes for over £100 on ebay now due to desirability, and complete long SD1 type gear selectors are also getting up to that value. The LT77 gearbox itself is generally cheap and plentiful to get hold of.

Don't try and be clever by 'adapting' the Land Rover transmissions, just don't go there.

[jikovron]

I tried to 2wd a awd lt77,,quickly abandoned as a daft idea once the mainshaft output was noticed to be massively different!

Whats the budget for this conversion? , insurance almost always want at least uprate brakes as a minimum for bitsa cars ive noticed so that's really the first job imo.
the basic list of stuff for a bare minimum conversion may include
sd1/p6 engine ,gearbox, new clutch, modified propshaft, custom exhaust system, fuel pump and lines if its not already got a mech pump in the timing cover, modified sump, engine mountings, engine rebuild parts (which virtually all rover v8s are desperate for, rad hoses etc

if you score a load of parts on the cheap it could be done for circa 500quid with no rebuild etc but imo it would be a disappointment as I found out with mine first time round, if I was going to finance a 24mpg thirst I didn't enjoy being outgunned by ordinary 1.8 zafiras !

I learnt from the above and spend loads on a 3.9 which then developed liner problems so promptly put all the good parts from that into a 3.5 which is approximal performance wise in an 1100kg car to a mk1 audi s3 and can top 28mpg if gentle footed

in summary if I was going to do it again I'd spend a little more and get a late 80s 302 which is a great all rounder classic v8 wise

[shiftizzle]

I've got the 3.5 engine already.gone for the twin carb model as of not a fan of efi,we talked about using the gearbox out of my Sierra and fabricating a conversion plate as I think it can be teamed up quite easily. Am I being clever,overly ambitious or just plain stupid?

[sowen]

Type 9? No personal experience, but with a carb'd 3.5 I doubt it would put out enough power to shred the Ford 'box anytime soon especially if you have some mechanical sympathy.

[jikovron]

mt75 or type9,,,if the latter its a well trodden path and easy to do with a bw35 auto bellhousing and plate to mate it to the front of the T9,,the latter would be abit more complex but doable with a recessed plate or the bellhousing machined off as the bellhousing is smaller than the flywheel, hence the usual auto bellhousing lark

it would be certainly cheaper retaining the sierra running gear! but also one thing to note would be a higher final drive would certainly make it more relaxed to drive as they certainly dominate noise wise if revving unnessecarily fast when cruising

[zippyobrien]

Seems a dear way of not going that quick

I'd buy a manual 3.0 omega ( 3.2s can be had aswell in police spec) and chuck the whole lot in.

[squonk]

I've got to say that a carbed 3.5 RV8 is going to give so little performance gain over and injected 2.0 DOHC it just isn't worth the effort and cost, or the insurance hassle it will probably cause. An injected 3.9 will give at least 35% more power than a carbed 3.5 and the injection system only needs a couple of wires connecting up to make it work so if you want to go the RV8 route would at least make the conversion worthwhile!

As said above, a Ford 302 V8 (or better yet a 351) would be a far better idea. Surprisingly they are cheaper to rebuild and to tune than a RV8 is.

[Kieran]

Lexus ls400. Cheap as chips, smaller than a Rover, 250 / 290 bhp.

Auto box is a downer, but conversions are available

[funkymonkeybooze]

Take the head off, port it, get some twin side draft carbs, will probably perform just as good as a V8?

Had an old 2.0L EFi 4x4 estate once with that engine is DOHC 8V?, great car, always wondered if there were more ponies to be had just from head skimming, porting + throttle bodies + [££megasquirt]. Turbocharging probably easier. Cooler still; turbo + twin blow-through carbs.

[colnerov]

Hi, it's not just about the power, there is a modest increase in BHP but there is nearly twice the torque and that is noticeable much more driveability. And of course the sound!!

Colin

[squonk]

Nov 1, 2014 18:31:39 GMT colnerov said:

Hi, it's not just about the power, there is a modest increase in BHP but there is nearly twice the torque and that is noticeable much more driveability. And of course the sound!!

Colin

The 2.0 DOHC 8V was renowned in its day for low down torque (174 Nm @ 2500 rpm) and the carbed early 3.5 RV8 was around 250 Nm so really only a 40% increase. The surprising thing is that both engines develop max torque at 2500 rpm. Even so its a ridiculous amount of money and effort for so little gain when for the exactly the same effort and cost a 3.9 injected RV8 or a Ford V8 could be fitted that would give a significant gain.

It's just the wrong engine for the car when so much more could be had for the same amount with a better engine choice.

[sowen]

Nov 1, 2014 18:50:45 GMT squonk said:

Nov 1, 2014 18:31:39 GMT colnerov said:

Hi, it's not just about the power, there is a modest increase in BHP but there is nearly twice the torque and that is noticeable much more driveability. And of course the sound!!

Colin

The 2.0 DOHC 8V was renowned in its day for low down torque (174 Nm @ 2500 rpm) and the carbed early 3.5 RV8 was around 250 Nm so really only a 40% increase. The surprising thing is that both engines develop max torque at 2500 rpm. Even so its a ridiculous amount of money and effort for so little gain when for the exactly the same effort and cost a 3.9 injected RV8 or a Ford V8 could be fitted that would give a significant gain.

It's just the wrong engine for the car when so much more could be had for the same amount with a better engine choice.

I completely agree with this, I've got an injected 3.5, and for the noise from the big tailpipe it's embarrassingly slow for the fuel it uses. The SD1 weighs approx 1440kg and the Sierra approx 1120kg from a quick google search, so yes it would go a bit better with the least powerful variant, but I doubt it would push you back in your seat like any v8 should. I can be outrun by most diesel saloons and even some eco-city cars!

With a car that came from the factory with an efi engine, there will be a suitable efi fuel system already installed that would just need hooking up to a mid 90's 3.9 v8, even less messing about!

[Battles]

This was a common conversion "back in the day" (I've got grey bits in my sideburns and a baldy bit on my head so I can say that) and I knew a few guys who did it. Back in the late 80s and early 90s, a 20%-30% performance hike was amazing. Nowadays, there are better options.

With work like this, unless you have an unlimited budget and just really fancy an RV8 Sierra for nostaligic reasons, don't let the fact you already have the RV8 sitting (was it free? I don't think you mentioned) force you down that road.