New 350 crate motor delivered today!

[crazy longhorn]

This always gets good , on "what carb"? If you guys want to tune a Q jet, get a copy of ROCHESTER CARBS, from H.P. BOOKS, by Doug Roe & Bill Fisher& do a bunch of reading. I built 1 from "scratch", that I ran on a 425 Caddy that was in my longhorn around the mid 90's. I started with a rebush on the primary throttle shaft(Brigggs & Stratten valve guides).....yea thats what I said. Put a kit in the old turd, set the secondarys to open quicker(by the perf section in the rochester book), set the air door over the secondaries, & spent a week or better playing with jets/needles/ hangers. After all was said & done, a kick on the throttle on that old Caddy left nothing but rubber smoke rollin from under my old truck . I say yes it is a highly tunable carb.....but you had better be one really stubborn mofo , if you dont know a bunch about it(or bucks down) I traded that carb for a new 650 spreadbore holley, & the holley didnt work near as well! Back on topic, I think that GM crate was a nice choice.....let us know how it all works out crazyL

[Jack_71C10]

Thanks for all the info on carbs, but I still want to keep my rochester.
I was wondering if anybody has bought a carb from these guys before.
http://www.nationalcarburetors.com/cat-chevytruck.html
they seem really inexpensive.

[Billla]

Originally Posted by crazy longhorn

I say yes it is a highly tunable carb.....but you had better be one really stubborn <guy>

I traded that carb for a new 650 spreadbore holley, & the holley didnt work near as well!

Everything you note can be done EASILY on an Edelbrock or Holley without being a stubborn <guy>

What specifically didn't "work near as well"? What tuning did you do to make it work, given that you had to do so much tuning the Q-jet (week+) to make it work?

[crazy longhorn]

Originally Posted by Billla

Everything you note can be done EASILY on an Edelbrock or Holley without being a stubborn <guy>

What specifically didn't "work near as well"? What tuning did you do to make it work, given that you had to do so much tuning the Q-jet (week+) to make it work?

Totally agree (stubborn & broke are the same at times) I didnt mess with the Holley too much.... crazyL Just for the record tho, I didnt say <guy>.....I said MOFO!

[berencam]

i ran a edelbrock performer carb, intake and air cleaner on the same crate you have and heres what it looks like and does....

YouTube - 1969 c-10 burnout

[chevydog66]

A friend of mine works for Dart, and has worked for John Lingenfelter, builds Pro Stock motors, has been in the business for over 20 years. He has built and dynoed many sbc's, recommends Demon carbs. Like I said, side by side, identical cfm carbs, Demon has outperformed the others. Another friend of mine who works for a different company, building and dynoing engines also recommends Demon carbs for out of the box performance.

[rick0312]

Wow! Thanks Berencam!! awesome video and pics Truck sounded great i can't wait to install the crate motor. Man it seemed I opened up a big 'ol can of worms with my intake and carb question. Great stuff on the carb debate though.

[rick0312]

oh i forgot....the motor comes supplied with a plug in order to plug the dipstick hole you don't use.

[Jim_PA]

Originally Posted by Billla

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...

If you are satisfied with the older simpler design of the Edelbrock then stay with it. But looking at the 2 side by side tells me that the spreadbore carb with small primaries and huge secondaries has the ability to provide better throttle response and economy while backing it with more punch on the top end.

And no, I don't need to be an expert tuner to figure that out

[ColoradoK5]

With all the talk about carbs what does everyone think about the new E-85 carb from demon? http://www.barrygrant.com/news/articles/bgproducts.aspx

[Billla]

Originally Posted by Jim_PA

If you are satisfied with the older simpler design of the Edelbrock then stay with it. But looking at the 2 side by side tells me that the spreadbore carb with small primaries and huge secondaries has the ability to provide better throttle response and economy while backing it with more punch on the top end.

And no, I don't need to be an expert tuner to figure that out

You didn't answer the question that I asked regarding your claim that the Q-jet has more tuning variables - saying the Edelbrock is "older simpler" isn't going to cut it. If you're going to make claims, then back them up. Otherwise it's just BS - reverting to "bets" and "looking"...and noting again that experience/expertise means nothing.

If you're not a tuner...i.e., you don't really know how carbs work in the real world because you've never made changes and seen what happens (by your own admission...after telling ME to get MY hands dirty with one)...then how can you look at a carb and "know" it's better?

Small primaries...that often don't meet the needs of the engine at cruise, and so gets into the secondaries on engines making more-than-stock power...which murders fuel economy. Huge secondaries...that will flow to 780 CFM...which a 350 making 350 HP would need to turn 9000+ RPM to use, and are the most common cause of bog unless the air valve is adjusted correctly.

If I recommended a 780 CFM Holley 4160 Model 3310 for a mild street engine you'd call BS - rightly so.

In your opinion the Q-jet is a better carb. With my experience/expertise I disagree. I guess we can leave it there.

[Jim_PA]

Originally Posted by Billla

You didn't answer the question that I asked regarding your claim that the Q-jet has more tuning variables - saying the Edelbrock is "older simpler" isn't going to cut it. If you're going to make claims, then back them up. Otherwise it's just BS - reverting to "bets" and "looking"...and noting again that experience/expertise means nothing.

If you're not a tuner...i.e., you don't really know how carbs work in the real world because you've never made changes and seen what happens (by your own admission...after telling ME to get MY hands dirty with one)...then how can you look at a carb and "know" it's better?

Small primaries...that often don't meet the needs of the engine at cruise, and so gets into the secondaries on engines making more-than-stock power...which murders fuel economy. Huge secondaries...that will flow to 780 CFM...which a 350 making 350 HP would need to turn 9000+ RPM to use, and are the most common cause of bog unless the air valve is adjusted correctly.

If I recommended a 780 CFM Holley 4160 Model 3310 for a mild street engine you'd call BS - rightly so.

In your opinion the Q-jet is a better carb. With my experience/expertise I disagree. I guess we can leave it there.

Bill, I'll make another mental note that you take the internet way too seriously, and I'll try to remind myself of that before typing a reply in-jest ever again. Maybe I didn't put enough at the end of my 1st reply that got your feathers all ruffled?

I think you are right, the Edelbrock carb is the best out there :cheers:

[Billla]

Originally Posted by Jim_PA

Bill, I'll make another mental note that you take the internet way too seriously, and I'll try to remind myself of that before typing a reply in-jest ever again. Maybe I didn't put enough at the end of my 1st reply that got your feathers all ruffled?

I think you are right, the Edelbrock carb is the best out there :cheers:

I do take seriously people that profess expertise and experience, offer guidance/claims based on that...and then admit they have no experience and no expertise, can't back up the claims...and then try to make it personal.

[EDIT]
I'm evidently going too far here, so I'll drop. I have no problem with a personal preference for a particular carb - that's all good and I have my own preferences for gaskets, RTV, etc. But if you're going to make a specific statement/claim, then in my book you should be prepared to back it up with objective data.

[Jim_PA]

I don't recall proclaiming to be an expert, sorry to everyone else for this getting way off base - I'm obviously not qualified to speak about this subject -- sorry for spouting all my BS!

[Billla]

Originally Posted by Jim_PA

I don't recall proclaiming to be an expert

I suggest you go back and read your own posts...you talk about the tuning kit you bought (which you later admitted you'd never used), how easy it is to change jets and rods (which you later admitted you'd never done) the many more tuning variables of the Q-jet (even though you've never tuned one and couldn't articulate what they were) and that you thought maybe I should get my hands dirty (when you haven't had your hands in your Q-Jet).

Sounds to me like someone proclaiming big-time that they have actual experience tuning a Q-jet. You're pretty big on innuendo, not so much on actual information.

In Texas they say: "Big hat. No cattle."

[Jim_PA]

Originally Posted by Billla

I suggest you go back and read your own posts...you talk about the tuning kit you bought (which you later admitted you'd never used), how easy it is to change jets and rods (which you later admitted you'd never done) the many more tuning variables of the Q-jet (even though you've never tuned one and couldn't articulate what they were) and that you thought maybe I should get my hands dirty (when you haven't had your hands in your Q-Jet).

Sounds to me like someone proclaiming big-time that they have actual experience tuning a Q-jet. You're pretty big on innuendo, not so much on actual information.

In Texas they say: "Big hat. No cattle."

You have quite a way with reading into things.

I never opened up my current SMI Qjet. That doesn't mean I didn't dig into it before I had it sent out for a complete refurb including fixing the warped top plate, and redoing throttle shaft bushings. It ran good, but it had loose throttle shafts, and was leaking gas. I'm sorry I don't feel obligated to sit here and post my resume on carb tuning, I really have nothing to prove, and for the last time, I'm NOT an expert...

Yes, I've used my kit, and sucessfully built 2 qjets. The first one I had on my truck, and the second that a friend of mine is running on his tow rig. What else can I do for you Bill? Leave it alone already.

I have a 3rd one in my garage right now, that I plan on disassembling and performing some mods on besides the jet, rod and step-up spring tuning I've done in the past.

[Billla]

Originally Posted by Jim_PA

You have quite a way with reading into things.

I'm NOT an expert...

Reading things into...your words. Interesting spin.

Looks like we agree on a couple of things, including this being a dead horse.