Vintage-and-Classic
Active Member
I'd beg to differ: Rover knew what they were doing with the original set up and fitting the aftermarket filters to an otherwise standard engine will only make it go worse, mainly but not only because the standard needles aren't callibrated for that setup It will sound more dramatic with those filters and that may be enough to convince the wishful thinking that it is going better.
If you really want aftermarket filters on a standard engine then you can fit them and get the whole thing set up on a rolling road to return the performance to standard. Better still keep the K&N s etc for internally modified engines. Certainly if you ever want to get the thing sorted out don't ever start down the route of modifying things to try and overcome a fault. I'd get the engine running properly first before thinking about any mods..
The sort of fuel injection fitted to standard road going vehicles does not improve power. The internal tune of factory standard injection engines does improve power which is one of the reasons why fitting a 3.9 camshaft to a 3.5 engine makes a nice difference. Far fewer people seem to make a pig's ear of setting up EFI compared to carbs because it seems to be rather easier: I never get any carb V8s coming to me which run well but I often see EFI engines which do. Therefore all though you do not need EFI unless you wish to improve emissions and economy then it may be the pragmatic thing to do if you can't find anyone to set the engine up.
Note that I say "set the engine up" which is exactly what needs to be done. Everyone heads straight for the carbs first but they should in fact be the very last part of the external setup that you work on.
If your camshaft is badly worn enough to affect performance then you will probably have one or both of these symptoms: 1) a clattery sound for the first few seconds of running, particularly after more than a day or two standing idle. 2) Slight misfiring under load.
If you don't have these symptoms then most likely the camshaft won't be the cause of such poor performance although it still may well be worth changing it for longevity reasons.
Hope this helps!
cooltide
sheep fancier
+ 20bhp low comp +40bhp high comp rv8 compared to strombergs
Vintage-and-Classic
Active Member
Go on - I'm interested: I should clarify when I carelessly said "fitted to road going vehicles" that I meant factory original fuel injection and by that I mean that you can usually get more power with carburettors than you can with factory original fuel injection. I didn't neccesarily mean Strombergs. Neither am I comparing throttle body type injection against carburettors.
That said, which factory original engines are you comparing like for like to get those figures?
Vintage-and-Classic
Active Member
It's true that the fuel injected Range Rover produces more power than the Stromberg carburated Range Rover.Range rover.
Just saying like
But are those two engines identical other than the carburettors?
I accept that I worded my original post quite loosely, however I still maintain that putting carbs on a "factory original injection engine" will usually increase the power.... not neccesarily Stomberg ones though
jamesmartin
Well-Known Member
you can tune a carb to throw in more fuel but that still wont be as good as tuning by efi or direct injection as will beIt's true that the fuel injected Range Rover produces more power than the Stromberg carburated Range Rover.
But are those two engines identical other than the carburettors?
I accept that I worded my original post quite loosely, however I still maintain that putting carbs on a "factory original injection engine" will usually increase the power.... not neccesarily Stomberg ones though
Vintage-and-Classic
Active Member
You can tune a carb to throw in more fuel but that will just make the thing go worse because the mixture will be too rich.
I'd go for tuning a carb to produce the stoichiometric ratio with correct progression enrichment and leave it at that. If more performance is required then a fixed venturi compensated instrument like a Weber or Dellorto will produce better flow and deliver more of the correct fuel / air mixture than the factory original fuel injection systems produced by nearly all manufacturers. It won't be able to cater so well for all engine conditions and fuel economy will suffer quite badly.
The best performance will be gained by throttle body type fuel injection which is also not factory original and will outperform carbs
jamesmartin
Well-Known Member
efi will allways be better than a mechanical carb just as electronic ignition with knock sensors etc is better than dizzy,technology produces a nearer match to ideal across the rev and power range, which is why you dont see carbs anymoreYou can tune a carb to throw in more fuel but that will just make the thing go worse because the mixture will be too rich.
I'd go for tuning a carb to produce the stoichiometric ratio with correct progression enrichment and leave it at that. If more performance is required then a fixed venturi compensated instrument like a Weber or Dellorto will produce better flow and deliver more of the correct fuel / air mixture than the factory original fuel injection systems produced by nearly all manufacturers. It won't be able to cater so well for all engine conditions and fuel economy will suffer quite badly.
The best performance will be gained by throttle body type fuel injection which is also not factory original and will outperform carbs
Vintage-and-Classic
Active Member
Depends what you mean by better. If you mean more efficient then yes, it will. If you mean lower emissions then yes it will. If you mean more powerful then not neccesarily. It *can* be more powerful but factory fitted efi, good as it is, isn't just designed for power. Since very few people have any idea how to set up carburettor engines these days efi is going to be a better bet. Loads of people replace factory fuel injection with Weber carbs for circuit use for good reason.
Modern race cars don't use the same sort of fuel injection systems as road cars. Why not? Because they don't produce the best power. I still maintain that high performance carburettors will usually produce better power than road going fuel injection and throttle body fuel injection will produce the best power of all. Poorly set up carburettors (most of the ones I've seen) produce poor power.
Vintage-and-Classic
Active Member
No, that's probably because the engine wasn't set up correctlyThat's why my holley 650 dp bogged before it launched like a whippet with a rocket up its arse
jamesmartin
Well-Known Member
on all fronts ,tech is better it has the ability to produce the ideal for all engine conditions thats just a fact, the tune for any engine will vary depending on whats needed, a carb cant be altered so many times a second like modern system taking into account the numerous variables
Vintage-and-Classic
Active Member
We'll have to disagree on that one then. I'd say that on all fronts tech *can* be better but it depends what tech is aiming for. I'd also say that I disagree most strongly with people who blame the old designs for their own lack of competence. Engines with distributor contacts and carburettors produce good power without flat spots, hesitations, misfires or "bogging down"... or unreliability. These are symptoms produced by engines in faulty condition, whatever their design.
Quite simply we are not comparing like with like in this discussion: I am saying that high perfomance carburettors can produce more power than Bosch Motronic. That's not saying that they are better, just that they are engineered to do a different thing. Motronic is not engineered to produce maximum power. High perfomance carburettors do not produce more power than say Weber fuel injection throttle bodies because that is comparing like for like. This last comparison illustrates that modern technology can do better. A 1966 Ford GT40 goes a hell of a lot faster than a Toyota Prius. It's not that the technology was better in 1966 it's just that those two cars are trying to do different things and you wouldn't want to take the GT40 shopping (although I once had a customer who did.....)
cooltide
sheep fancier
The flow limitations of the rv8 cylinder heads also make it a better bet
