[Mr T81]

Hello all,

when I bought my car, '69 GP, there was a Holley 750 in it.
I want to try a Q-Jet. The engine is a 428, edelbrock performer
intake, 2.5" exhaust, cam close to stock. Altitude here is 2200ft.

Summit has Q-Jets for sell. Anybody has experience with them?
http://www.summitracing.com/search/p...%20Carburetors

Just wondering, is a 750cfm enough?

any input would be really appreciated, thanks

[altfueler]

Thank you for doing the RIGHT thing & putting a Q-jet back on top of that 428!

IMHO, Cliff Ruggles of Cliffs High Performance in Ohio ( 740-397-2921 ) is THE Man to get your Q-jet carbs & carb parts from.

Cliff wrote the book on Q-Jets.....LITERALLY!!

Cliff is very helpful on the phone & also posts here very often.

Good luck.

[rexs73gto]

Yes , cliff is the very best sourse for a great Q-jet, but if all you want is a correct Q-jet with the correct numbers ,,, if you know them , you can get a new replacement Q-jet from Johnsons Speed wharehouse, they have several hundreds of new in the box from GM Q-jets at a reasonable price. These you can bolt right on adjust & go. They bought about 10,000 of them from GM several year back & still have a lot of the numbers you may need. Check them out on the web under their name & you can get one in just a couple of days .

[69FIREBIRD76MM]

X-2 ON THE SUMMIT QUADRAJET.
H-K MOTORSPORTS has tested them on his dyno-motor and they work good, if you go thru ruggles waiting time is 6-10 months at least...Jet Performance has them too

[t money]

Try 67cruiser from this forum he playing around with q jets looks like he does nice work

[PONTIAC-ONE]

You may need to tune/calibrate one of the new or boxed rebuilt stock spec carbs though...just adding a slightly larger cam, small bump in compression gave my '74 Formula 400 a lean bog from a dead start.
I lived with that for years because I didn't know how to fix it 20 years ago.
I currently have a Cliff carb on my 455, no bogs, stumbles or traction until 3rd

[rexs73gto]

I had made several changes to my 73 GTO including heads, cam , headers & exhaust , & when I got my first one from Johnson's Speed wharehouse I bolted it on & it was very close that it only about 25 min's to figure it out & adjust it. Yes later I did put in different primary rods & some larger jets( 2 sizes up) but it did work out fine. Now the big plus if the get one from JSW it will be a front inlet as should be on a Pontiac, but the ones that are the tricked out units that summit & Eldorbock & the others sell as the tricked out & they are not new they are rebuilt, which is fine but It really is better to start with a new unit . And I don't know about you but I don't want a chevy rebuilt carb on my car. If it's chey put it on a chevy, & if I want something on my car I DEMAND that It be Pontiac or specially designed for a PONTIAC. Pontiac Rules. ,

[ponjohn]

There is one for sale in the High perf section here.

[Mr T81]

Interesting comments, front fuel inlet is pretty important I guess.
I heard about Cliff's book and plan on getting one. But I cant wait
6 to 10 months for a carb. The Holley is not working properly and I
want to try a split bore carb. By the way, it does not really matter
to me if it's numbers matching or not.

[72LuxuryLeMansLa.]

Originally Posted by Mr T81

Interesting comments, front fuel inlet is pretty important I guess.
I heard about Cliff's book and plan on getting one. But I cant wait
6 to 10 months for a carb. The Holley is not working properly and I
want to try a split bore carb. By the way, it does not really matter
to me if it's numbers matching or not.

I called this guy and gave him the specs of my new build and he supposedly set up the carburetor accordingly. We shall see. I received the carburetor as promised and will use it on my new build. It looks great, every part has been refinished and it has the Adjustable Part Throttle.

http://www.smicarburetor.com/product.../productID/839

Karl

[Bruce Meyer]

Im pretty sure Cliff is the only rebuilder that properly fixes the leaky fuel well plugs on all Q-jets. Just putting epoxy over those plugs only lasts a year or so.

[Mr T81]

Maybe I'll get a carb from Summit Racing. If I have any problems with
the carb I can always send to Cliff for rebuild over the winter.

750 or 800 CFM

[Young Pontiac Guy]

There is a guy that uses all of Cliffs methods, recommends all of his kits and then rebuilds them over on Transamcountry.com. His name is Maryland Bandit. His turnaround time is 10-14days. If you get a core, he can redo it.

I would recommend calling Cliff for your kit and telling him what you have in terms of cam, heads, rear gear, tranny, plans for the car if you decide to use Maryland Bandit. As all know, he is the man! According to the link below, Cliff will drop ship the kit to Cliff for a rebuild.

Here is a link:
http://transamcountry.com/community/...?topic=38779.0

IMO- Summit will not be specifically dialed in for your car. If you call Cliff, it will be.

[rexs73gto]

As I said before ALL the summit carbs are chevy side inlet only. If you want a true Pontiac carb you have to use a true Pontiac carb. Also most all of the carbs after 76 have the APT valve built into them. Depending on who you talk to it may or may not be important to use. Again all Pontiac carbs after 76 also are the 800 cfm carbs, even the 301 carbs are 800 cfm carbs. The carb I run on my 500 HP 461 is from a 301 & it works great. I had to do a little bit of work on it as far as changeing the primary jets & the secondary rods, but it works fine. The car runs mid 11's with the 301 800 cfm carb.

[gregneun]

Competent carburetor rebuilders are not exactly an endangered species. The Q-jet has been around for over 45 years and most of the secrets are out there. It's not like there haven't been a couple million of them rebuilt since 1967.

What you need is a good core and a competent shop. The skills required to rebuilding these are somewhere between rocket science and brain surgery.

I mean no disrespect to Mr. Ruggles and I am a customer since I bought his book.

That said, I can name a few shops around here that could do a decent job of rebuilding one. People that work with these everyday become very good at what they do.

These guys are within 1/2 mile of my house and I don't think you could call them amatures or that they don't know what they are doing.

http://www.ebay.com/itm/290919920139...9#ht_282wt_917

Info on these carbs are all over, watch the redneck guy on YouTube explain them. Think he could do a competent job of rebuilding one?

Greg

[rexs73gto]

Yes, your right anyone can rebuild a Q-jet, I've done a couple hundred myself over the years & yes I can do it quite well, I was a line tech for about 7 years before I went into mgt. But knowing how to rebuild one & knowing how a Q-jet works & functions inside & knowing how & where & to & which parts will work for which combo is a complete different thing. I've got the one on my car close, but it's not 100%. I'm not an engineer to know excatly which circiut goes to which port & how each piece works when a different part (s) are added or taken away will affect how the carb works. I know the basic's of how to adjust one but there are VERY few that know how to make one work on any pictular engine by knowing what other parts have been changed on that engine. That takes the COMPLETE understanding of the inner works of a Q-jet & how eack hole, passage & lever works on that carb. I don't know cliff personally , but I've used his book several times when I want a carb to be correct. He wrote the book, he does what VERY few can do with a carb. He understands what is in that carb completely. I've been in this business for almost 45 years & if I had the money & wanted a carb to be PERFECT & had the time to wait for one ,,,,Cliff is the one I'd have do my carb, & as I said I can rebuild them myself & make them work fine. But some times fine is not enough. Thats when you call the person who wrote the book. IMO.

[gregneun]

provided the wrong link above, I meant this one.

http://www.customcarbs.com/

I bought Cliff's book because he participates here on PY and his info is so freely given, not because I was ever going to be an expert on carburetors. It is full of good information, especially to a novice like me.

If I needed one rebuilt, there are many competent shops that are in this areea and I probably would not have 6 months or more to wait. I agree that he is one of the foremost experts in the field.

Greg

[bsblguy]

I have a quadrajet that was on my '69 GTO when I bought it. I replaced it with the correct one for my car. The one I have has all the fittings in the correct place for a '69 auto trans car, correct choke, works well. Rebuilt sticker on it. Had the round tag but is missing so don't have the numbers for it. Was never calibrated correctly for my engine so had a slight nozzle drip at idle otherwise ran great. Cliff's book tells how to calibrate for your engine. I had to calibrate the carb I bought as it was exactly the same as this one and now runs great. I will sell it if you are interested.

[Cliff R]

I would avoid any commercially "remanufactured" carburetors from any source....FWIW.

I woln't even take them in the shop any more, pulled the plug on that deal recently. WAY too labor intensive, and the quality control just gets worse and worse on them.

Since my backlog of carb work usually exceeds one year, and my parts business is the main focus these days, I really don't have a "dog in the fight" so to speak, when it comes to making recommendations, giving advice, helping folks out with problems, etc. If I tell you someone, or someplace does poor quality work, it's not to steer anything in my direction.

There are at least half a dozen speciality shops offering q-jet rebuilding and restoration services these days, and at least twice that many "part timers" dabbling in the business when they aren't at their day job. Some of these shops due pathetic work, others OK, some fantastic, especially when it comes to the "cosmetic" aspect of the job. Most can get thru a "rebuild", but are completely clueless when it comes to setting up any particular unit for a custom application, or after engine modifications have been made to a stock application.

I know all this because at least 1/3rd of our work these days is taking a look at recent work from another source, that doesn't work well anyplace after the owner got it back. I actually like this work the best, as we don't have to do any cleaning, plating, bushing installation, etc. I can whip thru these jobs in a couple of hours, vs the 2 to 3 days it takes to do a full restoration with plated parts......Cliff

[1969GTO]

Cliff,
I don't mean to barge in......though
My question is Q-JETS [I have a Cliff Jet] and I see that you are also partaking in the STUMP PULLER thread.
Cliff have you noticed a common power valve spring or any thing special that you could advise on when using a Q-JET and the stump puller cam,either in an automatic or a stick car?
thank you for your time