Holley or Q'jet?

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Heath
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Holley or Q'jet?

Postby Heath » Sun Sep 28, 2014 2:51 pm

Time to put the cat among the pigeons and get a good old fashioned debate going

With my time being taken up with sanding and generally mind numbing tasks I have been considering my options with the carb on my 350 Chev.

I have a few Q'jets to play with, a pile of bits and books on rebuilding etc but I need to put to bed the notion that maybe going down the Holley vac secondary road would be a better option (parts, tuneability etc being considerations).

Anyone gone from one to the other? Benefits of one over the other? I realise for some it is a love hate relationship either way so please comment something other #### is crap you should use a @@@! If you feel that way about them can you back it up with some first hand knowledge to prove your point.

I know the Qjets are able to get great mileage figures when they are set up correctly but they can be complicated and frustrating to get to that point.

I'm told Holley's are simple to work with (relatively speaking), parts are everywhere and just about anyone can tune them.

The reason I ask is the Qjet/jets will all need rebuilding before use and then I wont know if it is setup right until it is on the engine running at which point I may have to pull it apart again to "tune it". Unfortunately getting parts to adjust the q jet is hard and I will have to import them from the US (yes probably can get some bits in NZ if I look hard enough). all this mucking around is going to cost extra $$ and maybe I would be better off selling all the qjets and accumulated bits and using the $$$ to offset a nice simple 600cfm holley vac sec.

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Pedro
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Re: Holley or Q'jet?

Postby Pedro » Sun Sep 28, 2014 3:19 pm

or fuel inject it!!

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Heath
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Re: Holley or Q'jet?

Postby Heath » Sun Sep 28, 2014 3:50 pm

Pedro wrote:or fuel inject it!!


Too expensive for my blood. Old school is cool for my hj45 project.

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S1V8
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Re: Holley or Q'jet?

Postby S1V8 » Sun Sep 28, 2014 8:04 pm

Holly truck avenger 4bbl is the way to go especially if it's in a 4x4

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Re: Holley or Q'jet?

Postby Weemsy » Sun Sep 28, 2014 8:25 pm

I had a Holley on my 350 hilux and it was pants. High fuel consumption, kept bogging and stalling on hills and sidlings.
Got an off road 'kit' put in it, a whistle kit or something I think it was called. It was still hopeless. Every trip out required constant 'tuning'. A mate had an 'off-road avenger' (I think) and that was no better.
I replaced it with 2 other holleys before speaking to the jet boat guy in hastings who told me not to bother with holleys for what I wanted to do.
So I tried the quadrajets
Put several q'jet carbs on (kept buying 'mint' condition ones off trademe and finding they were cracked or other problems) until I finally dropped on a good one.
It was bloody brilliant. Much better on fuel, easier to start, rarely needed tweaking, reliable, ran on all angles (even when the truck was on its side :lol: )
If it's for off road, my go would be q'jet every time.

If you want to try injection though, I have a 2 jet injection kit for a 350, with Ecu etc :D may part with it?
Its better to keep your mouth shut and appear stupid than to open it and remove all doubt.

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prado_boon
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Re: Holley or Q'jet?

Postby prado_boon » Mon Sep 29, 2014 3:01 pm

A new Holley out of the box will work... It might need minor tweaking, but generally it will be fine for a 350. Go Holley if you can't be bothered with a decent carb :wink: :wink: :wink:

On the other hand QJet's are a great carb. They are "on demand" and will draw as much fuel as they need, so great fuel economy on the small primaries and will ROAR when the secondaries open up... tuning the transition is pretty easy too. Overall tuning a QJet is pretty straight forward - read the books and I think you'll find they are a really good carb.

Main problems with them is air leaks. So that is your first check... make sure it's airtight! Another tip is check the numbers on the carb and see what it came off originally, if it's a 350 then I bet it "just works" sweet.

I've been playing with them for a while now so if you have any questions send me a PM. Also have loads of parts too (plus different jets, hangers, rods, pumps etc)

Cheers

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prado_boon
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Re: Holley or Q'jet?

Postby prado_boon » Mon Sep 29, 2014 3:03 pm

Here's what I usually do (if I can't be bothered) - If the QJet doesn't run nicely then slap a new or good Holley (600 vac sec) on it and it will just go... most likely will guzzle gas... but hey it's a V8 right ?

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Re: Holley or Q'jet?

Postby curly12 » Mon Sep 29, 2014 4:14 pm

Used to run a 600 vac secondaries on my 350, PITA, then went to 750 double pumper with an off-road kit, still a PITA, sold the wagon after that and went back to diesel :roll: :roll: .

My last dealings with a 600 were on Jumpers 40 with 350, his face as I hit the float bowls with a hammer to free up the float valves was priceless. Carb had been on there for about two hours from new. It worked thou for the day but didn't like the hills.

Another one was Sadam (who has been missing in action from here for a while, bugger me if he wont' come back on due to his wealth of knowledge and being a good ####, must ring him) from what I remember he put a off-road kit in his and it went ok.

Still would look at the Q'jets and would run one myself next time or injection, would not willingly chose a Holley :wink:
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Heath
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Re: Holley or Q'jet?

Postby Heath » Mon Sep 29, 2014 5:15 pm

All good info so far. I should have said it is for a road going project only. So sidlings etc shouldn't be an issue, if they are I am in the shit...

I might have a go at fixing this one (or one of the 5 I have), its on the 350 so should be right. Might just rebuild it. If I cant get it sorted I will go the holley way.

Of course that all depends on the price of doing the carb.

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Re: Holley or Q'jet?

Postby Lchundy » Mon Sep 29, 2014 5:41 pm

My stock standard old school 350 runs a 2 barrel holley,nice simple carb.Works all good and resonable on fuel.

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Pedro
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Re: Holley or Q'jet?

Postby Pedro » Mon Sep 29, 2014 7:32 pm

a well set up holley is a good simple carb, off road kit ala whistle cures most issues off road, works a lot better if you epoxy the whistle in to seal around it, if you don't it will just slowly flood the motor,
if it is jetted correctly then they are pretty good on fuel, there is a Vac enrichment valve i think, screw around with that from stock at your own peril,
Vac secondries are better than double pumper, they only open when you actually need them!!! and don't flood the motor when you are bouncing around at low speed,

i had a 600 vac holley on a 383 chev and that thing ran at all angles, sidelings, up hill, down hill, started easy hot or cold, with no problems at all, if you vaseoline the gaskets then it enables you to pull it apart if shit makes it into the fuel bowl from fuel tank, i remember some one lifting the lid of a Q jet and seeing a shitload of needles hanging there,

I think personally if you go the holley route, get a new one out of the box, then it has not be fucked with a bogan who thinks he knows better than holley and drilled the ports out for more fuel!!!!!
and as for any improvement in fuel economy get it dynoed, and this would be true for both setups.

Pedro

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Heath
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Re: Holley or Q'jet?

Postby Heath » Mon Sep 29, 2014 7:56 pm

Not a daily driver (cruising toy) so fuel economy isnt a primary concern. If it was I would have sourced a nice quiet 4 cylinder engine (or electric motor for my hot rod - actually thats not a bad idea...) and wrapped it in a little barina.

But unfortunately I am not clever and I love the sound of a bent 8 engine on song and if it has open headers then it is almost spritual. :wink:

I think i'll have play with the Q but if the kiwi dollar drops too much before I can get the bits I need maybe a new Holley is on the cards...although the price of those will go up too - Bugger. I wouldnt buy second hand unless it is brand new in box, never fitted (- yeah right), I have 5 q jets that are second hand and I have no idea how buggered they are or if they were messed with.

Might have to give my "mate" Cliff Ruggles an email and get some bits from him sooner than later. :mrgreen:

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Re: Holley or Q'jet?

Postby bombaybasher » Mon Sep 29, 2014 8:49 pm

I have rebuilt a lot of holleys, easy to get kits for but rubbish durability, I had a 750dp on a heavily modified 308 , rev limit 7000rpm and made 400hp at flywheel, got sick if it leaking and bought a Quick Fuel carb 650dp from segedins for $780 5 years ago and never touch it ever! Didn't even need to jet it straight out of the box float levels were perfect as we're jet sizes when checking it with a lambda, idled really good with a pretty brutal cam and never fumes , just recently put a Quick Fuel 550 vac secondary on a stock 302 in my dad's falcon after binning the Demon carb and same result, great idle , no flat spot and haven't had to touch it out of the box, I highly recomend these carbs though are a little pricey

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