The V8 Owners Forum -

Hi guys,

first post, and apologies if this has been covered before, i've done a search but couldnt find what i was looking for:

i've just bought a 3.5 out of a rover sd1 v8-s. it was running well (i saw it) and its going to go in a lotus seven style kit car. (a vindicator)
the engine is going to be rebuilt for by a motor vehicle college but i dont know what to do with it. On the one hand i'm thinking to try and keep it standard, as i probaby wont need much more power. on the other hand if there are some basic upgrades i could make then i'd consider that.
i really fancy a weber carb and new manifold but the prices at RPI were scary! is this worth it? What differenmce would it really make? or should i just stick mwith the su's?
cheers

Paul

If it were mine I would be looking for a second hand EFI manifold and an aftermarket ecu (vems, megasquirt, emerald, etc) in the long run if you start tuning you will end up with this set up any way so save the money, you only have to buy it once. If you shop carefully it is cheeper than the 4 barrel route. The standard ecu is not worth it in the long run, modifying one is difficult and a poor compromise and you still end up with an aftermarket ECU.
Otherwise change the cam to let it breathe (others on here can list them by memory) and clean up the head casting (various posts on here) and you should be looking at a real 180 to 200 bhp and then save up for some aftermarket heads .
best of luck
Mike

hi mike,

thats really useful to know, and it sounds like a cosiderably cheaper way to go: the weber/holley/offenhauser/edelbrock combinations i looked at were in excess of £700. i guess the best places to buy the bits will be flebay and the like?

any recomendations for cam? i saw here mention of the real steel typhoon?
cheers
paul

Hi Paul
E-bay is a good bet for F/I bits, and the for-sale bit of this site. If its £700 for the webber and manifold you should be able to do FI and megasquirt for less and most of the others for about the same.. If you are going Megasquirt go for the extra set up http://www.extraefi.co.uk/ as by you have imported everything from the us it is little more and is run and suported by a chap on this site, Vems is worth considering for the same reason and a few guys have them on their cars (including mine host).
I cannot realy advise on cam for a lightweight kit car as my two rover engines were both in range rovers, but I hav an "R87" cam in one that was great fun but ran out of go at about 5800 revs. It really depends on a couple of things, haw much work you want to do to fit it (cutting valve reliefs and new valve springs, or just fit a cam, and what else you intend doing to the engine..... I believe it is not worth putting in a wild cam if the heads strangle the engine before it can make use of the extra lift and duration and with the rover the combustion chamber is a sows ear and the ports very restrictive even in stage 4 form, however there are those on here will disagree. I would go for a cam that has mas much lift as you can get moderate duration (225 to 235 deg at .05 lift), run at least 9.5 :1compression and go for modest power increase across the range, that is until you can save up for some good heads (wild cats!!).
Any way 200 break in a seven sized car with that amount of torque should be lots of fun on a wet roundabout in the wet to be getting on with!
Mike

I wouldn't go for a typhoon unless you want to change your heads as it needs stage 2 heads to work. I would look at something like a Piper 285 or a Hurricane.

Wildcat heads on a 3.5???? That would put the spark out M8 you need to be 4.6 plus 5.0 better before these heads work.

I've used a hurricane and it was a good cam, very strong in the middle and a decent topend yet with the manners of a standard cam down the bottom.

Marki
who's 3.5 has stayed at that capacity on this forum, itll be a 4.6 before you know it just like the rest of you.
High flowing ports do not have a "minimun" capacity they work with if you use fuel injection, they are only bacome a problem on carbs, just look at the GM ecotek engine or the kawasaki motorcycle engines or even the new chrysler hemi engines or the LS1, very high flowing ports relative to capacity under " conventional wisdome" but all work briliantly. good port flow is just that .
Mike

Don't agree with you, your right in that it isn't the engine size that matters its the amount of air you pull in. On a 3.5 you would need to be revving to 8-9000 rpm to get wildcats to work properly which is stupid. There is a reason why not many people run these heads and its not just down to the asking price. The guy is looking for basic mods to give him a boost and not build a £6000 engine.

Swanny the carb conversion on its own is not going make a huge difference to your power and the 500 is arguably too big for a stock(ish) 3.5 anyway. My recipe for a £600 3.5:

New cam and lifters
New timing chain
New valvesprings
Bullet valve guides and late type seals
Later type valves
Little bit of home porting and portmatching
Rebuild and tune standard carbs
New gaskets.

The valves are cheap as chips these days, you can get the seats machined to take them when you get the guides put in. This does assume you have 0216 casting heads, if you have very early heads then junk them and start with the 0216's. A couple of other worth while mods would be to check and upgrade oil pump gears and also do a leakdown test. If your bores have seen better days then a quick going over with the glaze busting "bog brush" hone and some new rings might be a good idea. You could just about get that lot done for £600ish and the results will be a whole lot better than just bunging a four barrel on what you've got.

hi Marki
you will see from my first post that I am recomenging a basic stage 1 tune up with Fuel Ijection, moderate clean up of ports and a mild cam to match.
Not discimilar to what hearbear is recomending later.
My point is that you can't make decent power with a decent powerband with poor head design, freed of carbs and their limitations on tunability and the constant compromise of port velocity that carburetor venturi force on you then the next logical stage with the Rover is to fix its biggest limitation to making power, the heads.
I can't see why people spend hundreads of pounds on stage n porting the standard rover casting, beyond a stage 1 clean up they are a waste of money that could be spent on a good basic casting. pity there is not somthing between the wildcats and a standard rover casting.
Mike

Real steel merlin heads if/when they finally come out but it looks like they are getting closer.

Do you think they will ever produce them??
Mike

The merlin heads are for 3.9 and upwards engines only.

The Weber is fine imho, theoretically it might pull 500 cfms max but the motor will only pull what it can get/what it needs at WOT. The Weber has smaller primaries than the Holley 390, so you get a slightly better response / 'pull' low down and I found the mpg's a bit better than the Holley (plus didn't need rebuilding every 5 mins! always a bonus!)

£700 is barmy. Get an s/h manifold for about £100, and carb for £150 ish give or take - might have to wait a bit though as it doesn't happen often. Plenty of cheap Holleys though.

Another cheapish option for more oomph, flog the 3.5 and go 3.9.

selling the 3.5 and going for a 3.9 is a non starter at the moment. i've wanted a v8 for years and theres finally one sitting in my garage, lets just say that we've bonded!

my long term plan for this engine might involve a bells and whistles approach at a later date and it will probably end up in something different to the car its going in first. i intend to keep playing with the egnine over the next 10 or so years. i know thats probably a much more expensive way of doing it, but it might be fun. on top of that for the car its going in a fairly standard rebuild will be fine for now.

the replies have been really helpful: i must say i expected to find second hand webers and manifolds on ebay, but didnt when i looked. for now i'll stick to hear bears list i reckon, when i have some time i'll price that up. is real steel the best place to go for bits?

cheers

paul