C3Paul

Just a thought:

Rather than spending $400 on a new Holley 770CFM carb. http://holley.com/0-80770 can I rebuild one of my two original 1980’s Q-jets for my new engine to deliver enough fuel and air to support 480HP/500Tq?

Little Mouse

Absolutely

63mako

If it fits your intake without an adapter. The holley is a square bore and the q-jet is a spreadbore. The adapters cost you HP and hood clearance.

C3Paul

My Edelbrock Performer RPM intake is drilled to accept bouth styles.

I can use Holley or Q-Jet

Tim H

NO.
But maybe 600 more replies and you will figure that out also.

Little Mouse

The q-jet is a very good street carb with plenty of capacity for what your doing. Holley is quicker to make adjustments on parts galore for it everywhere. But if your not hanging around the track quick changes do not matter.

I thought you had a square flange manifold simply wanted a new carb anyway.

C3Paul

Little explanation is in order:

I have two original 1980’s Q-jets with electric chokes, but the last time they were used was years and years ago.

This was the reason why we have used the machine shop owner’s Edelbrock 1406 to run my engine.

The Performer RPM intake is drilled to use both carb styles so, I can use either.

Ideally, I would like to use my Q-jet, but this is where I agree with TIM H that it takes some serious skills to make one work well.

BTW I have just bought:
http://www.amazon.com/Rebuild-Modify.../dp/1932494189

http://www.amazon.com/Rochester-Carb...578953-8719432

On the other hand Holley carb. is idiot proof and even I could make one work well.

Lastly: I am fitting AFR gauge http://www.google.co.uk/search?hl=en...w=1334&bih=647 to my custom to be exhaust to monitor and tune my fuel delivery.

Lastly 2, No point in arguing Q-Jet v Holley on this thread.

Lastly 3, I would prefer to use my Q-jet over Holley but..

gkull

Really the only thing that goes bad of q-jets is the casting wares out on the throttle blades and they just need a drill and bushing job. They flow 750 cfm so they are more than enough for even 500+ hp machines.

The rear throttle blades are wider than a Holley square manifold. So it requires and adapter. I used to have one on a single plane intake.

C3Paul

Well, I am in luck.

I have Performer RPM Q-Jet intake:
http://www.summitracing.com/parts/EDL-7104/?rtype=10

Shall we have a go at rebuilding and tuning my q-jet and leave the Holley behind?
(I would have to start a new thread, this is faaaaarrrr toooo long)

Little Mouse

Find any books on souping up moto guzzi's lol. I have this burning desire to buy a new V7.

larrywalk

The Q-jet on that manifold will work fine. With a bit of tuning, I've done a PB of 11.59 at 119mph with a Q-jet on that manifold and using 3.08 gears at 3510 lb race weight! (see my profile)

Tim H

Then why would you make it any harder on yourself by going with a quadrajet, is there some kind of diploma for working harder to make a quadrajet work verses just slapping on a Holley and drive???
I always miss the point of working harder not smarter????

C3Paul

You are 100% right and I fully agree with you, but there is always the element of a good challenge!

Well, give it 4 hours from now and I will find out which carb I am using.

Little Mouse

Q-jet has proven itself on millions of cars from 1966 to early eighties only fuel injection replaced it. Besides all the chevy cars they were on pickups, pontiac, buick, olds, cadillac. Probably close to ten times more Q-jets were used then holleys. Chrysler even came out with there version of it called the therma quad.

Nothing wrong with the holley and it has been improved on over the yrs by staying in production. Probably by the time you buy books, rebuild kit, carb cleaner, parts to modify. Your going to have $150.00, $200.00 in the Q-jet rebuild. Then you will never have the easy parts access. This is why majority of people simply go buy a new holley or edelbrock carb.

If money were not an issue i would want one of the new holleys with annular boosters. But these carbs go north of $600.00. I'm like you i have two old 800 dp carbs one of them will be plenty good enough to save me $600.00.

C3Paul

Well, my fuel delivery is sorted now:

Bought this Holley for £220 almost half the price of a new one.
http://www.ebay.com/itm/270945341526...84.m1497.l2649

Could not let it pass me for this price!

63mako

Good job!