I want to replace the qjet on my 1970 454 and would like some recommendations from the board. I guess I could he mine rebuilt but would like to get one with more performance. I realize that there was just a thread on what chokes do you run...but I need some expert advice for my application. Just a newbie question.

Thanks

 

One of the biggest things you need to consider is what will fit under that hood and with what air-breather.

Stock q-jet Pancake manifolds, for a Holley the LS6 (but has sqr ports) pancake and the torqII (single plane) are about it without modifying breathers etc

So anyway, a properly rebuilt q-jet is the easiest answer (less other stuff to change)

L88 hood opens the doors but that's a different story
M

 

I have been making my head hurt over the whole carb choice thing for a while now,
for decades I was in the camp that took a qjet off and tossed it in the dung heap,
But as I research more and more I learned much of the stigma surrounding the qjet is not really it's fault besides it being fairly complicated in both design and adjustment,
because it takes a special knowledge to tune one correctly it's not hard to understand why they take a beaten over the years and end up not working correctly.

I considered running that tried and true holley 750 VS or a clone of it but I keep coming back to interest in the qjet because for me it does something really cool, it has small primaries for cruising and most of my time driving but in those times I do wanna step on the pedal those huge secondaries open and it's like kicking in an afterburner,
I am not out doing things where I need a full tilt performance race carb.

in my case I do not have a known unmolested qjet to start with, so it really is a crap shoot that any core i buy will be any good to send out to one of the few rebuilders who can do the job like Lars or Ruggles , perhaps jet, even then I would have to get the lars tuning papers and the ruggles book and learn to adjust it.

If I was in your boat I would likely send it out, have one of those cats rebuild it and then you know it good to go, but if you really want it gone, think about the 750 vs holley types , the edelbrocks are very simple to tune but not a performance item,

 

Is Lars still in the business essential of carb rebuilding?

 

I don't think so but have heard both yes and no recently
Best to give him an email and see
v8fastcars@msn.com

HIH
M

 

To update some qjet rebuilder status: Lars doesn't do them currently and Ruggles waiting time is 1 year.

 

There's nothing wrong with a qjet. Simply changing carbs is not going to increase performance any more than the set of "Titanium tipped gold plated Racer's Special" spark plugs that I have for sale for only $500.(shipping not included) If you don't want to rebuild the carb yourself, send it out to a reputable shop such as lars or Cliff Ruggles. But the truth is that if your carb has not been hacked, you can rebuild it yourself. There are many manuals and books available-Cliff has a thorough one, and he will advise you on what, if any, mods should be done. Get a cheap carb from the bay or elsewhere (a member is selling one for $25) to practice with if you want to gain a little experience. Set the carb (and the ignition system) up properly and you'll have an engine with instant throttle response that will break the tires loose in 1st gear and pull strongly to the red line.

 

The spreadbore Holley is an excellent replacement carb for the Q-Jet. I put one on my otherwise stock 68 427/390 and it really woke the car up. It's a 650 with mechanical secondaries. Better starts, superior throttle response, more midrange torque. My Q-Jet wasn't right but I've had them when they are (on a 69) and prefer the Holley.

 

Henry Olsen is one of the very best.
http://olescarb.com/

 

I agree with the Holley spreadbore. It's a model 4175 with mechanical secondaries and an electric choke. No fitment issues with the hood and air cleaner. My '70 454 loves this carb. Easy to set up. I did go up a couple notches up on the jets from what came with the original set up.

 

Any idea on turnaround time for carb rebuild from OLES?

 

Which member is selling a carb for 25.....that would interest me as I would like to be able to perform my own tuning.

 

https://www.corvetteforum.com/forums...-jet-carb.html