Engine and Transmission Tech

My Rover V8 project (actual '70 Rover 3500S) is about to the point where the rebuilt motor (stock with fast street cam) is going back in. All connections and the cool ram air filter setup for the SUs is still intact. HS6 carbs would have to be rebuilt. I do have a spare Holley 390 carb and manifold I got from Glen Towery. I have this carb on my MG with V6 and love it. Opinions needed on which carb setup to use? Not a show car and a weekend club driver only.

Hmmm where are you? Oh, there you are.

The change of cam may make the standard needles less than ideal. Now, it is possible to grind non-standard needles, I've seen a description on the TR Register forum of how a chap did it without a rolling road, but it was quite a palaver and that was just one needle for a supercharger setup, and you'd need two identical.

When Rover bought the V8 from Buick, they decided to fit SUs because there was the body of knowledge in the UK to manage them. In the US, the situation is reversed. There will be someone you can find, or perhaps you yourself, who can dial in a Holley (or Edelbrock if that's your preference), the jets the rods the springs n'all that says he vaguely never having had to do it, anyway all the fiddling about that makes the difference between it running, and running properly.

So in practical terms, although your SUs might be OK with the new cam, and if they're useable it would be worth just putting them on and trying it, what will you do if you rebuild them and then they aren't really OK? Flat spots, or pig rich at idle? Do you know someone with a rolling road and a big stock of SU needles?

If you want to get into it, here's an excellent post elsewhere about SU tuning.
[www.theminiforum.co.uk]
Google 'cam change +SU' and you'll find others.

On a show car, you'd pretty much have to go with the SUs, but you want to drive the car, not polish it.
Anyway, you see where I'm going with this, my opinion.

Ivor

(Rover V8 with SUs)

Reluctantly I would go with the Holley.
The SU's are a good simple carb that can be set up to run very well.
They are tuneable to just about any combination and they look right on the 3500.
The down side is that here in North America, almost no one knows how to tune them properly.
So they have gained a very poor reputation. More out of ignorance than anything else.
The other problem is the SU manifold for the 3500. It's not exactly what you would call a performance item.
While it can be improved some. It's never going to get to the level of a decent 4BBl manifold.
So the easy, can get parts anywhere, vast knowledge pool over here, says go with the Holley.
The looks cool, fits the car, not just anyone can pull this off crowd, says use the SU's.

Live like you mean it.
Fred

Not a fan of the SUs on a V8, so I vote for the Holley, as well.

I have ran SU´s, Holley 390 and currently Edelbrock 500. SU´s are nice and simple but the factory manifold and linkage is not so good. One big thing with Holley and Edelbrock is a proper acceleration circuit. No need for using choke, just pump the pedal a couple of times and start the engine. When cold, SU´s will need the choke applied. Again, depending on the linkage it´s either smooth or less smooth. I like SU´s and have them in Minis but will not use them on Rover engine unless required.

Power, or Originality? That's the real question here. Which one takes precedence? Since the car is more of a driver than a show car it would seem the first rather than the second and the Holley wins.

Jim

"Edlebrock 500", formerly Carter AVS. How do you get simpler to tune than this ? That adjustable Air Valve, makes it quite adaptable to smaller V8's. Good Luck, roverman.

That's easy Art,

A flathead screwdriver and some metering rods will let you tune a SU carb to just about any engine.
I like the AFB and use them a lot. They just take more tinkering to tune.

Live like you mean it.
Fred