Outer Limits 4x4 Board

My 81 Rangie has a Holley carb on the 3.5 V8. Everyone tells me these can be problematic on slopes etc. Mine isn't yet on the road so I haven't experienced that yet.

However I spied an ad for a Holley Off-Road Carby in the latest 4WD Monthly. Has anyone used one of these? Any comments?

Its just something for me to keep in mind should I find problems with mine. I know there are other tricks like mounting the existing one backwards etc but this off-road Carb has got me interested for other reasons too (like electric choke).

all reports I have seen from the US is they are the next best thing to EFI

Still can not beat EFI but this is up there for a carby

I think you will need a few more cubes to than you have to use one but not sure they come in smaller cfm sizes

PlanB off this board was running one on his 350.

As an aside, there was a guy on the board a while back (maybe v8grunt??) who did mods to a Holley to make them work really well offroad.

Look in the ooooold stuff

Here is the Holley tech stuff

http://www.outerlimits4x4.com/PHP_Modul ... ght=holley

look at the end of the aus 4wd monthly magazine (latest issue) , there is a holley carby (i think its holley) for offroad use

hottiemonster wrote:look at the end of the aus 4wd monthly magazine (latest issue) , there is a holley carby (i think its holley) for offroad use

No Sh1T...

http://www.outerlimits4x4.com/PHP_Modul ... highlight=

(did you read the first post...)

maybe i should read the whole post

I have done all of the MODS that V8Grunt said in this post and the Holley now works ok. Not brillant but much better then a stock one.

A lot cheaper option is to get a secondhand quadrajet from a holden v8 and a holley to qjet adaptor plate.

Bush65 wrote:A lot cheaper option is to get a secondhand quadrajet from a holden v8 and a holley to qjet adaptor plate.

but how good are the quadrajet? I have one on my 308 that is going in this week, I hear they are ok but do you need to do anything to them first?

Fieldsy wrote:

Bush65 wrote:A lot cheaper option is to get a secondhand quadrajet from a holden v8 and a holley to qjet adaptor plate.

but how good are the quadrajet? I have one on my 308 that is going in this week, I hear they are ok but do you need to do anything to them first?

I am running the QJet on my 253 and it is much better than the original carb. But its certainly not as good as EFI or LPG

I think I am going to try running my QJet backwards. I have read a bit about it on here and Pirate. Not much info on it but it can't hurt to try

I was just reading the add for the holly off-road carb in 4wd monthly and It says 40 deg climb and 30 deg side and nose down. that dosent sound that crash hot to me. It's aiight but i wouldn't say awesome. I am sure I would get better with my stock 2F.

But then I could be wrong

Let us know how you go with the backward Qjet

Fieldsy wrote:I was just reading the add for the holly off-road carb in 4wd monthly and It says 40 deg climb and 30 deg side and nose down. that dosent sound that crash hot to me. It's aiight but i wouldn't say awesome. I am sure I would get better with my stock 2F.

But then I could be wrong

Let us know how you go with the backward Qjet

yeah i read that was thinking that same thing. Those angles arnt all that huge, cause when we drive it, we DRIVE IT so those angles will be little more help than the standard Holley.
Plus did u read that this Holley comes out in 670 CFM and 770CFM which is miles to big for standard Holden V8's. You would need a worked Chev to run one.

quadrajets are about 450CFM equivelent and are wat is recommended for the 253 and 308 holdens and smaller Chevs, and they have th benefit over Holley of not flooding and starving quite so easily, but they still do it eventually

I run mine on Duel fuel so 95% of the time its on LPG in the 308 and i havnt got any major probs with my quadrajet. It just got reconditioned and tuned so we will c how we go when it starts to wear in

my 2 cents

Screwy

Screwy_ScrewBall wrote:
quadrajets are about 450CFM equivelent and are wat is recommended for the 253 and 308 holdens and smaller Chevs, and they have th benefit over Holley of not flooding and starving quite so easily, but they still do it eventually

Screwy

I have read that Qjets are 795CFM in stock form and can be made to flow even higher with a few mods (easy one is to thin down the butterfly shafts so they give less drag over the butterflys at full throttle) I could be wrong about the 795 though depending on what you mean by 'equivalent'.

Flipping the Qjet puts the float pivot behind the float. In stock orientation the floats come up too soon and shut off the fuel on steep uphill gradients. Also, it puts the jets at the rear of the float bowl so they don't get starved. The brass jets can be seen at the bottom of the bowl in this pic http://www.stratagaz.com/Quadrajet/19%20-%20Power%20piston%20installed.jpg

Worth remebering that what you gain one way you lose the other, so stalling is more likely on downhill gradients.

Ben

2car wrote:

Screwy_ScrewBall wrote:
quadrajets are about 450CFM equivelent and are wat is recommended for the 253 and 308 holdens and smaller Chevs, and they have th benefit over Holley of not flooding and starving quite so easily, but they still do it eventually

Screwy

I have read that Qjets are 795CFM in stock form and can be made to flow even higher with a few mods (easy one is to thin down the butterfly shafts so they give less drag over the butterflys at full throttle) I could be wrong about the 795 though depending on what you mean by 'equivalent'.

Flipping the Qjet puts the float pivot behind the float. In stock orientation the floats come up too soon and shut off the fuel on steep uphill gradients. Also, it puts the jets at the rear of the float bowl so they don't get starved. The brass jets can be seen at the bottom of the bowl in this pic http://www.stratagaz.com/Quadrajet/19%20-%20Power%20piston%20installed.jpg

Worth remebering that what you gain one way you lose the other, so stalling is more likely on downhill gradients.

Ben

Im pretty sure that standard Quadrajets are between 450 to 500 CFM though i could be wrong. I know u can make them go bigger but not sure how much. They wouldnt be 795 CFM cause quadrajets came standard on 253 and 308 holdens and a 650 Holley is a little too much of a carbi for them, so 795 would be way too much for a standard holden so a quadrajet cant be that big.

screwy

I used to run a Qjet on my305 chev but went to the 350 holly with an off road kit fitted to it..........much better all round.

my q jet is 650cfm

my truck avenger (as pictured in the mag) is 670cfm

i havent fitted it yet,

there was an interesting article in petersons a while back re; truck avenger

they concluded that the holley was as good as the q jet, but not better

holley sent me a high flow fuel pump ith it as well and said that without it, the offroad performance wouldnt be as good

planb wrote:my q jet is 650cfm

my truck avenger (as pictured in the mag) is 670cfm

i havent fitted it yet,

there was an interesting article in petersons a while back re; truck avenger

they concluded that the holley was as good as the q jet, but not better

holley sent me a high flow fuel pump ith it as well and said that without it, the offroad performance wouldnt be as good

so your gonna be running an electric Holey fuel pump with it?
Did u run an electric pump originally or just the standard one?

screwy

Screwy_ScrewBall wrote:

planb wrote:my q jet is 650cfm

my truck avenger (as pictured in the mag) is 670cfm

i havent fitted it yet,

there was an interesting article in petersons a while back re; truck avenger

they concluded that the holley was as good as the q jet, but not better

holley sent me a high flow fuel pump ith it as well and said that without it, the offroad performance wouldnt be as good

so your gonna be running an electric Holey fuel pump with it?
Did u run an electric pump originally or just the standard one?


screwy

nope, its a mechanical pump, 110 GPH

According to "Rochester Carburetors" from HPBooks, Qjets are 750cfm or 800cfm. Difference is 800cfm has slightly larger primary venturies.

From the same book, for fuel starvation on steep uphills (float closes off sooner), you can reshape the float by cutting the rear bottom away at an angle (where the fuel runs to). The float is closed cell foam but exposed cells should be sealed with shellac or similar for longer life. Also float level will need adjusting after shaping. This should achieve similar results to reversing the carb.

planb wrote:

Screwy_ScrewBall wrote:

planb wrote:my q jet is 650cfm

my truck avenger (as pictured in the mag) is 670cfm

i havent fitted it yet,

there was an interesting article in petersons a while back re; truck avenger

they concluded that the holley was as good as the q jet, but not better

holley sent me a high flow fuel pump ith it as well and said that without it, the offroad performance wouldnt be as good

so your gonna be running an electric Holey fuel pump with it?
Did u run an electric pump originally or just the standard one?

screwy

nope, its a mechanical pump, 110 GPH

yeh? very interesting......

my holy stals going up car ramps if i dotn give it shit

Bush65 wrote:According to "Rochester Carburetors" from HPBooks, Qjets are 750cfm or 800cfm. Difference is 800cfm has slightly larger primary venturies.

From the same book, for fuel starvation on steep uphills (float closes off sooner), you can reshape the float by cutting the rear bottom away at an angle (where the fuel runs to). The float is closed cell foam but exposed cells should be sealed with shellac or similar for longer life. Also float level will need adjusting after shaping. This should achieve similar results to reversing the carb.

Are they really 750 or 800? thats really odd because numorous ppl have told me that a 650 Holley is too much for a 308 Holden
Man im confused, can i run a 650 holley vacuum on a standard 308 or not?

screwy

Screwy_ScrewBall wrote:

Bush65 wrote:According to "Rochester Carburetors" from HPBooks, Qjets are 750cfm or 800cfm. Difference is 800cfm has slightly larger primary venturies.

From the same book, for fuel starvation on steep uphills (float closes off sooner), you can reshape the float by cutting the rear bottom away at an angle (where the fuel runs to). The float is closed cell foam but exposed cells should be sealed with shellac or similar for longer life. Also float level will need adjusting after shaping. This should achieve similar results to reversing the carb.

Are they really 750 or 800? thats really odd because numorous ppl have told me that a 650 Holley is too much for a 308 Holden
Man im confused, can i run a 650 holley vacuum on a standard 308 or not?

screwy

Yeah, Ive read 750 were made for passenger cars and 795 for trucks. 650 probably is too big for a 308 but it doesn't mean it won't work.

A mate of mine was running a 780 holley on a 253 for a while the only problem with it he had to bigger jets in it and it was running to rich. Once he put in some smaller jets it went like a cut cat. Q jet are just vachum secondays so they would only open up when needed not like mechanicals which open up once you open the throttle

Zeyphly wrote:A mate of mine was running a 780 holley on a 253 for a while the only problem with it he had to bigger jets in it and it was running to rich. Once he put in some smaller jets it went like a cut cat. Q jet are just vachum secondays so they would only open up when needed not like mechanicals which open up once you open the throttle

My Qjet is stock and it has mechanical secondaries.

ive just been doing abit of research and apparently rochestors come out in 3 sizes, 600, 750, or 800 CFM.
Concidering that a 650 CFM Holley is too big to put on a 308 that would mean that im running a 600CFM Q Jet.

Was just confused cause couple of u guys said Q jets only came out in 750 and 800 and that doesnt make sence if they come standard on 308 holdens and u say a 650CFM holley is too big.

So i did end up finding out there is a smaller size which would have to be one my rig, which is the 600.

yeah, i think that makes sence.

screwy

some interesting comments from the US about these

http://www.jeepsunlimited.com/forums/showthread.php?s=&threadid=560827

I know a fella whos fittin one to there shorty GQ comp ute with a worked TB42 in it. Will tell you how it goes after its first comp. The Alpine!!

Or you just stick a gas (LPG) kit on and dont have to worry about angles. Run petrol for road / grunt use and the gas for offroad.

Alec