New 350 crate motor delivered today!

[68GMCCustom]

$1475 w/$100 GM rebate on ebay HERE

[Chevyman680063]

Dumb question, but I was always wondering how they deliver a crate motor to your house when it's shipped freight. What do they do if no one's there when it's delivered?

[chevydog66]

Chevyman, they can't deliver it when no one is home. If it's a residential delivery, the truck will have a liftgate on it. Oh, and Demon carbs have been dyno proven to produce more hp than any competitors identical cfm carb. Just my .02

[Chevyman680063]

Didn't think they could but wasn't sure if they would do like UPS/FedEX and just leave it, which would be stupid.

[Billla]

If I'm going too far OT, someone kick me - I'm pretty opinionated on this topic too

a Q-Jet, if tuned - jetted - metered - etc properly, there's nothing like it or that can even compare to it.

Nothing can even touch it...how? Power? Fuel economy? Driveability? Any correctly configured, functioning and sized carb will equal or exceed a Q-Jet.

enter in your trucks exact specs, and they send you a Q-Jet tailored to your application.

And then send it back to them every time you make a change.

It will only use the cfm that your application calls for.

True of every vacuum secondary carb. Next.

The Edels and holleys are great basic carbs. They perform, but they will yield fuel efficiency and performance.

Interested in your proof regarding this, and hard metrics. "Perform" how and at what cost of economy. I can't see how it can "Perform" but "yeild performance", so clue me in on that one

Edels and holleys are for those who don't want a challenge.

Go and find me a full set of Q-Jet metering rods and jets, adjust the air valve for a cam change and then try to get a bigger pump shot....now THERE'S a challenge. I can do all of these on a Holley or Edelbrock before you even have a list of the part numbers you can't get any more for a Q-Jet.

Bottom line in my direct experience - Q-Jets are fine for stock or mildly built engines, and if the engines aren't going to change. If you're going to be upgrading (adding headers, cams, etc.) over the years you'll be beating your head against the thing constantly.

Finally, count the number of performance vehicles in Hot Rod or Car Craft this month sporting a Q-jet.

Not saying anyone's wrong - I'm just sharing my experience.

[Billla]

Originally Posted by Jim_PA

getting main jets right
getting rods CLOSE
picking the right power piston spring (this part is pretty much calculated by vacuum properties).

What's your source for these parts? I can get the Holley and Edelbrock stuff right off of Summit. Edelbrock sells a kit with a few of these parts you note for their Q-jets...for $138. Edelbrock sells a complete tuning kit for...$38.

I'll drop it (really) and unsub to the thread - but yeah, the OP should definitely look at what it takes to get the parts to tune these carbs over time...

[68Stepbed]

I had the Edelbrock EPS intake with a Holley Street Avenger 570. It ran better than two different Edelburp 600 carbs.

I run this same setup now, but I installed a different cam and roller tipped rockers.

If you REALLY want an Edelbrock carb, I suggest a 500 cfm on that motor. You would be VERY surprised how well a stock 350 runs with a 500 carb, great throttle response,not to mention better gas mileage.

[Billla]

IMHO, no carb is going to be right on out of the box - Edelbrock Performers and Holly's Street Avengers are going to be the closest...but I always say that adding $250 to the build for a good tune is money well spent. ANY properly configured, properly operating and correctly tuned carb can deliver great performanc (in all aspects) - I'm always surprised at swapping carbs to get "one that works" when a tune would have made the old one work. Sometimes

The 500 is just a TOUCH small IMHO. Depending on gears, you could be tickling the secondaries at high cruise...which is murder on fuel economy.

CFM = ((CI x RPM)/3456) x VE

Definitely agree that the smallest carb is often the best choice!

[Jim_PA]

Originally Posted by Billla

What's your source for these parts? I can get the Holley and Edelbrock stuff right off of Summit. Edelbrock sells a kit with a few of these parts you note for their Q-jets...for $138. Edelbrock sells a complete tuning kit for...$38.

I'll drop it (really) and unsub to the thread - but yeah, the OP should definitely look at what it takes to get the parts to tune these carbs over time...

I bought the $100 Qjet Edelbrock kit (the old edelbrock qjets used the same parts as the rochester qjet -- In fact, I think edel qjets used the molds from the 7x-80's rochester carbs). It comes with all the rods, jets, hangers, step-up springs, high perf pump/needle and seat, and probably other things I'm forgetting.

Now, granted - I don't know how much longer Edelbrock will offer the Qjet tuning kit, but I can't imagine I'll ever have to buy any rods, jets or hangers ever again. To get a bigger pump shot, get a high perf. accelerator pump (which is included in the Edelbrock kit), and you can also shorten the pump rod to increase the shot further.

I've never had an Edelbrock carb, so maybe the pains of tuning a qjet aren't worth the extra time. But I do know that my qjet runs clean, has excellent throttle response, and the huge secondaries really give a big kick in the pants.

[Jim_PA]

Originally Posted by Billla

If I'm going too far OT, someone kick me - I'm pretty opinionated on this topic too

You usually seem to be a down to earth "use the best part" type of person... The Qjet is a very sophisticated metering device, and it's surprising to me that you would downplay and shun such a highly efficient and tuneable piece of equipment for an off-the-shelf aftermarket alternative.

So, I guess you disappoint me, Bill. Granted, I don't know you any better than the fly on the wall outside the office, but from reading your opinions and thoughts on everything else, you seem like the kind of guy that needs to get your hands dirty with one and see the light

[orange72blazer]

For you guys with the 260hp crate engine what did you guys do to plug the extra dipstick hole in the block?

[67ChevyRedneck]

Originally Posted by Chevyman680063

$1400 from the dealership?!? I work at the local GM dealership and they told me it would cost me $1700+. Summit wants $1700 for it now, not including shipping or tax, but Jegs still has it for around $1500 plus $150 shipping and whatever tax would be.

There's a ton of info in this thread:

http://67-72chevytrucks.com/vboard/s...ht=crate+motor

Basically, there's a 250 and 290 HP crate engine.

The 250HP one is GM part number 10067353

Here it is on GMpartsdirect.com:

http://www.gmpartsdirect.com/results.cfm

You have to type the parts number in the "enter part #" box.

...and the 290 HP engine: 12499529

According to GMpartsdirect.com you can get the engines for $1,342 and $1,893, respectively.

[Billla]

Originally Posted by Jim_PA

You usually seem to be a down to earth "use the best part" type of person... The Qjet is a very sophisticated metering device, and it's surprising to me that you would downplay and shun such a highly efficient and tuneable piece of equipment for an off-the-shelf aftermarket alternative.

So, I guess you disappoint me, Bill. Granted, I don't know you any better than the fly on the wall outside the office, but from reading your opinions and thoughts on everything else, you seem like the kind of guy that needs to get your hands dirty with one and see the light

Ouch.

I've worked with Q-jets for a few decades and built and tuned more engines that I can count...so my hands are plenty dirty with them. I didn't "downplay" or "shun" the Q-jet - read carefully. I do feel that there are better choices with modern technology - and stated my reasons for saying so. Your response is to tell me I'm wrong, question my experience/expertise and then note that I "disappointed" you. Are you running for President as a Democrat?

Can you share your specific experience, across multiple engines and build levels, tuning the Q-jet?

The primary issue with carbs is the owner's unwillingness to tune them...they just swap until they get something that works, then blame it on a particular brand or model. The unique design of the Q-jet as a GM OEM carb means that it's more suited to a broader range of engines - it has a higher tolerance zone than the aftermarket street carbs (generically tuned for a BROAD set of engines) and way more than the aftermarket race carbs (tuned for race use). So typically it provides pretty darn good performance "out of the box", and people love that. In the end, my observation remains that aftermarket street carbs are easier and less expensive to tune for the average owner and will offer better driveability, economy and performance when properly tuned. Doesn't mean the Q-jet isn't a great carb, or that it can't ALSO be tuned to deliver great driveability, economy and performance, nor am I failing to acknowledge that it will almost always be closer out of the box than an aftermarket street carb.

I have a preference based on my experience - you have a preference based on yours. Neither of us are "wrong", so neither of us should be "disappointed".

I knew I shouldn't have jumped in on the Q-jet religious war. Everyone go throw away their carbs and install fuel injection. Or, perhaps we should swap the thread to something less contreversial like politics or sex

[crazy longhorn]

Originally Posted by Jim_PA

You usually seem to be a down to earth "use the best part" type of person... The Qjet is a very sophisticated metering device, and it's surprising to me that you would downplay and shun such a highly efficient and tuneable piece of equipment for an off-the-shelf aftermarket alternative.

So, I guess you disappoint me, Bill. Granted, I don't know you any better than the fly on the wall outside the office, but from reading your opinions and thoughts on everything else, you seem like the kind of guy that needs to get your hands dirty with one and see the light

Just in to add a little on the Q jet(often called the quadra-junk,Quadra bog, ect). The rochester Q -jet is a fine carb, if properly tuned. With the small primarys, it gives excellent performance/economy, & has great throttle response. the huge secondarys give you a a great kick in the "giddyup" ......if tuned properly The problem is that they are not easy to tune for a beginner, or even a seasoned mechanic, that just hasnt had much experience with that type carb. I have tuned a couple Q -jets , been into the edelbrocks, & tuned more Holleys than I can count. The Holley ,or Edelbrock are pretty simple to tune, but I doubt you will see the mileage that the Q jet will give (properly tuned). In veiw of the rising fuel costs, I may try my hands on another Q jet......but I like tuning things. If you want or need "plug & play", & are running pretty close to stock specs, I would reccomend an Edelbrock 1406 (600 cfm/elect choke), on a Performer, or Perf EPS intake.......if you like to tune, you might look at the Q-jet , on a performer intake. crazyL

[Billla]

A quick note on GMPARTSDIRECT - they show very low prices...and then add a huge "handling charge" that brings the price up to what a GMPP dealer would charge.

Summit et al have great prices on the GM crates, but you definitely want to talk to your local GMPP dealer if you have one - the list of GMPP dealers is in the back of the catalog on the GMPP web:

http://www.gmperformanceparts.com/

Many of these dealers have these engines in stock, and those that don't will get it for you if you a) ask nice and b) don't have a hard date in mind. I get "trade price" at the local GMPP dealer, but I always walk in with my P/N and charge card and let them know I'm in no hurry. They bulk it in with their standard order, and I pay no shipping.

[67ChevyRedneck]

Originally Posted by Billla

A quick note on GMPARTSDIRECT - they show very low prices...and then add a huge "handling charge" that brings the price up to what a GMPP dealer would charge.

Summit et al have great prices on the GM crates, but you definitely want to talk to your local GMPP dealer if you have one - the list of GMPP dealers is in the back of the catalog on the GMPP web:

http://www.gmperformanceparts.com/

Many of these dealers have these engines in stock, and those that don't will get it for you if you a) ask nice and b) don't have a hard date in mind. I get "trade price" at the local GMPP dealer, but I always walk in with my P/N and charge card and let them know I'm in no hurry. They bulk it in with their standard order, and I pay no shipping.

I've called a couple different local dealers and they have given me basically the same price as the GMPP catalog price. They'll even get it shipped in for free.

[Jim_PA]

Originally Posted by Billla

Ouch.

Bill, I'm just ribbing you -- In carb choices of today, what is better (more efficient and tuneable) than a Qjet? I'm willing to try something different if such a thing exists.

And I have zero tuning experience other than my Qjet on the current engine, and the 650 double pump on other 350s.

[Billla]

Originally Posted by Jim_PA

Bill, I'm just ribbing you -- In carb choices of today, what is better (more efficient and tuneable) than a Qjet? I'm willing to try something different if such a thing exists.

And I have zero tuning experience other than my Qjet on the current engine, and the 650 double pump on other 350s.

Cool Jim - didn't "feel" that way.

I think I've already said this...many times...but IMHO the Edelbrock Performer line and the Holley Avenger line are more efficient and more (read: less expensively, easier) tunable than a Q-jet in my experience. I'm certainly not suggesting you (or anyone) toss your Q-jet, especially since it's working - just that if I was buying a new carb...which is what the OP is doing - I'd recommend something else.

Can you describe what you've done for tuning on your Q-jet, and some specs about the engine it's on? You're making the case that it's very tunable...so share the tuning What guide are you using for tuning?

As a comparison in context for the installation of an Edelbrock Performer #1406 on my '72 with a 350 making about 350 HP (which I bought used for $125) , I had to go one level lighter on the secondary springs from the stock calibration (*3* lighter than what was in it...which might explains why the previous owner sold it as a "dog") based on "SOTP" tuning (bog) and then go 2 stages leaner than stock for the primaries, 1 stage richer on the secondaries...all done using the manual below and my trusty Innovate. The secondary spring changes take about 1 minute and can be done on the car. The rod and jet changes took about 5 minutes - also on the car.

http://www.edelbrock.com/automotive_...406_manual.pdf

[chevydog66]

Use silicone to plug the extra dipstick hole. In side by side dyno comparisons with identical advertised cfm carbs, Demon's will give more hp and tq.

[Jim_PA]

Originally Posted by Billla

Cool Jim - didn't "feel" that way.

I think I've already said this...many times...but IMHO the Edelbrock Performer line and the Holley Avenger line are more efficient and more (read: less expensively, easier) tunable than a Q-jet in my experience. I'm certainly not suggesting you (or anyone) toss your Q-jet, especially since it's working - just that if I was buying a new carb...which is what the OP is doing - I'd recommend something else.

Can you describe what you've done for tuning on your Q-jet, and some specs about the engine it's on? You're making the case that it's very tunable...so share the tuning

SMI did the jetting and resized idle channels and air bleeds, I've only tuned with APT, and the idle mixtures, so I've never had to open this one up to see exactly what was re-sized inside.

[Billla]

Originally Posted by chevydog66

In side by side dyno comparisons with identical advertised cfm carbs, Demon's will give more hp and tq.

Source of information?

[Billla]

Originally Posted by Jim_PA

SMI did the jetting and resized idle channels and air bleeds, I've only tuned with APT, and the idle mixtures, so I've never had to open this one up to see exactly what was re-sized inside.

Umm...never adjusted the air jet?

Soooo...your position that the Q-jet is very easily tuneable is based on....?

Not trying to be a d*ck (really )

[Jim_PA]

Originally Posted by Billla

Umm...never adjusted the air jet?

Soooo...your position that the Q-jet is very easily tuneable is based on....?

Not trying to be a d*ck (really )

I didn't say it was easy. They have more variables to play with than any other carb I'm aware of. Get them all working right, and I bet it will outperform and get better mileage than any other carb.

[68Stepbed]

orange72blazer, your engine should've come with two plugs for either side if you bought it new. If you didn't get them, call the dealer you got it from and find out where it is.

[Billla]

Originally Posted by Jim_PA

I didn't say it was easy. They have more variables to play with than any other carb I'm aware of. Get them all working right, and I bet it will outperform and get better mileage than any other carb.

I need to do a level set before I dive in again I'm a critical thinker, sometimes to extremes. I question data, sources and everything - it's part of my process to understand. It really comes across as personal, but it's not...at all...but I do expect that if a claim is made there's real data or experience to back something up. If it helps, I do the same thing to myself

OK; so "not easy" - there's one reason not to get one...which was one of my points. It's not "highly...tunable" if it's not easy. This is why, combined with the availability of parts, that you need to send Q-jets to an expert to tune. If you have to ship your carb everytime you change something and need a tune...then what's the point of having that carb?

More variables....how? They have an air jet screw for secondary opening adjustment, which is very limited in scope and a b*tch to adjust (if you got your hands dirty on one, you'd know ) They have primary and secondary metering rods and jets - same as the Edelbrock, and not needed on the Holly as it's a different design but jets can be changed easily. So what does the Q-jet have that these other carbs don't?

The Edelbrock and Holly is available in many different sizes, the Q-jet in...one? The original GM units were all over the map, but I think the 780 CFM model is the foundation for just about everything available new today. Also MANY easy options for accel pump shot volume on both the Edelbrock and the Holley, dififcult to change on the Q-jet without epoxy and some patience.

In the end, if a "bet" is all you can offer to back up your position...you've never tuned your carb, never worked on Q-jets on different engines and never done any work with Edelbrocks or anything other than a 650 DP Holley (hardly a street carb) then I guess I'm the one that's maybe a little disappointed...