Watched a guru tune my carb yesterday...

[davepl]

My 427/390 (2+2 project) went on the dyno yesterday. Started out dead lean, even though it was supposed to be set up for stock, so I was lucky enough to be able to get Larry Webb to come out and tune it.

Larry spent SIXTY YEARS with GM as well as various race teams. He was at Alan Green Chevrolet up here. He's really the expert on Rochester Mechanical injection but obviously knows his way around a Q-Jet as well. They were turning rods down on the lathe to make custom ones, that's the level they were operating at...

Made 402/498 on a rated 390/460. What's interesting is that the 3% increase in displacement yielded exactly a 3% bump in rated power!

That's my brother holding up the wall watching, not me!

Also interesting to me was that it was leaning out and he didn't just fatten it up. He spent a lot of time looking over the dyno numbers and then decided it was a fuel delivery problem, which it turned out to be, the mechanical pump couldn't keep the bowl full. Imagine trying to sort that out by yourself, on the truck, without a dyno! You'd probably never know that you're truck only made 275hp instead of 400hp!

I'm really ambivalent because I've had the opportunity to meet some really fascinating and talented guys like Larry over the last several years, and none of them have apprentices. You'd really hope a guy like this would be teaching the next guy up, but alas I think most of that knowledge will die with them when they go!

[SeanB242]

That’s awesome. I’m afraid your right. When some of these guys with knowledge are gone, the next generation are either going to run it out of box or only run things that can be controlled by a computer.

[leddzepp]

The next generation won’t need the knowledge because carbs won’t be around forever...unfortunately

That’s cool you got a pro to set your carb up

[Ironangel]

Thats pretty cool Dave, and thanks for sharing the pic! I'm afraid your right about the apprentices and fear that Leddzepp is correct as well. As second generation retired Journeyman Ironworker, it seems only the skilled trades in the construction industry are the last of the apprenticeship programs and they're struggling in a world that dont know and dont care to know what a union is...As long as I'm alive there will be carburetor's on my vehicles, and at 59 trips around that sun, I'm still a Quadrajet apprentice... ~Ghostrider~

[Rufas]

Unfortunately what you are saying about their knowledge dying is true. Carbs will be around for years. But as EFI systems approach, and become cheaper then carbs, more folks will turn to the EFI systems. Younger folks seem less mechanically inclined and more computer knowledgeable. That will help drive the downfall of carbs. Now with the self learning EFI systems getting cheaper, I think you'll see more carbs going away.

Most, not all, of the fuel tuning you did with your engine being dyno'd, can now be done with the handheld from the EFI system.

I'm one of those that has moved away from carbs. Both my 67 Cutlass and my 70 GMC are running FiTech systems and I can honestly say I'm glad the carbs are gone. Driveability and performance has greatly improved with EFI.



1967 Cutlass with 468 BBC, 518hp/585tq

[davepl]

Originally Posted by Rufas

Most, not all, of the fuel tuning you did with your engine being dyno'd, can now be done with the handheld from the EFI system.

I'm one of those that has moved away from carbs. Both my 67 Cutlass and my 70 GMC are running FiTech systems and I can honestly say I'm glad the carbs are gone. Driveability and performance has greatly improved with EFI.

I run the whole spectrum. I've got an LS3 that I tuned the factory ECM in my Camaro, and I've got a BS3 MPFI setup on a ZZ502, and I've hacked a good deal on my BMW factory setup. But I still have a few carbureted units!

Properly set up the Q-Jet is so good it's hard to tell from EFI. Bust most people have never had the pleasure of driving a correctly calibrated, stock setup. And if they did it was often from the late 70s and early 80s when emissions were taking their toll.

But I had a stock Q-Jet on a 350/300 small block and it would start and run like EFI. Even cold starts in Canada were great. But they've got to be calibrated to the application, lest they unfairly become "Quadrajunks".

As soon as I can find a compatible tank I like I'm going to convert my other ZZ502 over to port injection, likely the Holley Sniper I'm thinking.

[KQQL IT]

You should see the younger drivers around here that cant get a carburetor car started with flooding it or killing a battery.
Haul cars for a living.