timbo_001

Hey guys
Have a mild 350 chev in my LX, prob around 350fwhp
Don't know most of the specs of the motor, but it has double hump fuellies, victor junior inlet, 2 inch open spacer, 750 Holley DP etc.
Seems to have good power after 3000rpm, but below that struggles a bit.
Just wondering whether you guys think I would be better off with something like a Holley 650 Vac, or something else to improve power down low?
Thanks in advance
Cheers
Timbo

tombstone

Quadrajet. Small primaries increase throttle response down low & the large secondaries give heaps of grunt mid range to top end. Even better get a quaddie modified to suit your engine.Better economy than a holley as well.
Sorry, just took a second look at your engine specs, the victor junior definitely wouldn,t be helping down low along with the spacer, its acting like a single tunnel ram, raising your power band up in the revs.. What do you use the car for, mostly street , or a bit of drag action as well? what cam have you got?

wabbit

you really need to know the cam specs before you can make judgement on what's causing the bottom end loss.

but I'd put my money on the double pumper.
i reckon you need to drop the carby size or go to a vacuum secondary.

personally i'd use a 750 vac sec. the 650 will probably cost you top end in either DP or VS and a 650 DP may still give you a bottom end loss

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timbo_001

thanks for the replies!
Car is a weekend street cruiser, and occasionally taken to the strip.
I ran a 13.02 at 105mph at calder on Friday night.
Unsure of cam specs as previous owner did the rebuild and was unsure
of the specs
I think I may have acess to a 650 DP so may try that and see how it goes
Thanks again
Timbo

Woodsy

Try the 650Dp without the spacer (or maybe a 1 inch instead). In my limited experience I would think that the victor junior would be too big for your application and the spacer would be moving your "powerband" (so to speak) even higher up in the rev range.

As with all things, engine parts need to be matched together to work properly as a unit.

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V8Man

I would use the 650 DP SP, EXELLENT FOR A MILD 350.

richo

driving a double pumper is def different to any vs carbi, before you change your carbi i'd take the spacer away and bolt straight to the manifold. as woodsy said the spacer changes your power range. remove the gap and that may help the situation
also when you drive a double pumper you can't just jump on the gas. meaning you can't just pound your foot to the floor they all tend to flood them selves.
as for the vacum secondary you can jump on the gas all day and they seem to love it.
when you take your air filter off and the car is not running look over the top of your carbi and open the throttle to full with one motion. you will see that all four jets are delivering fuel at the same time, this is why some DP carbi don't like getting pounded
i would give that a go cause sounds like you got a bit of fun under the hood and the torana's are good fun to chuck around, depending on if you know how to drive

Oldman

the spacer is causing part of the problem it makes it equilivilant to an 800 way to big as others said take the spacer first

Oldman

richo sorry but you are wrong with any carb if you can't stand on the loud peddel & get performance instantly the car isn't tuned properly

Coupethis

The carby is fine, the manifold however only really works from 3 grand up.

I had a 350 that was exactly the same as yours and I swapped my Victor Jnr for a Weiand Stealth Dual Plane. Heaps more response down low and felt the same up top too. If I had my time again I would have tried the Edelbrock Performer RPM dual plane manifold (if you have a bonnet scoop then get the Air Gap version).

Oldman

just spoke to WAs gurru wrong carb 750vac & no spacer is what is required

timbo_001

Thanks for the replies guys!
I also have an elderbrock torker manifold that I could put on
How would this compare to my victor jnr?
I have my eye out for a 750 Vac
Cheers
Timbo