BlackC3vette

Your sharing of the data is greatly appreciated. I run both Q-Jet and Holley and whatever info I can get to make them perform better is a good, positive thing.

glen242

Are you still running the Lars' Q-Jets? The way you bad mouth the Q-Jets, I would think you would be running Holleys.

billla

You're confusing Ted H (nice guy) with Tim H (maybe not so much)

BKbroiler

I noticed a particularly nasty post in this thread from TimH yesterday, which was quickly deleted. I don't think we'll be hearing from Tim for a while.

lars

It's independent of rpm, and dependent on engine load and mass flow through the engine, which can vary greatly with rpm. Due to the air inlet duct and the bell mouth (containing the mass flow sensor) covering the carb, it's not possible to observe the airvalve operation on the dyno. Based on the way the engine sounds, and based on the dyno pulls starting at 2000 rpm at WOT, I'd say the airvalve is opening already at 2000 at WOT under hard dyno load: I base this on the mass airflow numbers through the carb at 2000 rpm - they look too high to be primary side only with the engine being pulled down by the waterbrake. Based on that somewhat subjective observation, I'd say the airvalve is "starting" to open at 2000, and is probably deep into its opening cycle at the "dip" point we saw on the torque/power curves, thus making the "long" tipped rods effective in correcting the lean-out issue in that range.

Keep in mind that a "long" tipped rod may not be the golden egg for all applications: I've thrown long rods into cars and had them fall flat on their face for an over-rich condition, too. But be aware of this simple tuning variable that can be very effective if the engine needs the extra fuel.

Lars

billla

Um...did you miss a) the back-to-back dyno run posted on this thread and b) the work Lars has done with Forum members all over the world?

TedH

Me thinks you have me confused with another 'Ted' on this forum

BlackC3vette

What is an "other"? A Coffee can with a hole in the bottom?

mds3013

Why build a Q-Jet some ask? Because some of us want our cars as original as possible while keeping the performance and driveability. The knowledge to improve the tuning of my Q-Jets is invaluable to me. Thousands of '60's-'70's and early '80's GM owners have been helped by some. Others have HELPED very little. mike...

Tim H

Now there is answer without bashing another carb.

marshal135

Hey I'm going to throw my hat in the ring.
C'mon peoples focus.
A man asks a q-jet question on the forum.
An experienced engineer is kind enough to respond with what
looks to me to be allot of work and testing to help the form member out.
By the time we reach the bottom of pg 1 we are in a pissing contest between members.
I get paid to bicker all day with people. I sign on here for enjoyment and knowledge. The last thing I want to do is spend 10 min. reading rant after rant. I would appreciate it if you (not picking on anyone contributor) would be part of the solution rather than part of the problem. Try and offer constructive advise on the thread and answer the OP question to the best of your knowledge.
I am not racing so a streetable carb thread I find informative.
If your back ground is racing than help a guy/gal out that's racing.
Lecture over! Thanks in advance.
Thee Marshal

Little Mouse

Lars told me just the other day edelbrock is the finest carb money can buy.

Little Mouse

All kidding aside. The 3310 holley lars tested is stuck in the 60's just like the Q-jet other updated holleys are available.

glen242

Sorry about that. I am old and easily confused. Thanks for setting me straight.

TedH

Not a problem. Yes, Lars' tuned q-jet is on my '80 L48. He set up the carb and distributor on a '69 L46 that I was owner for several years also. That was an incredible job of tuning and restoration. Even after Lars did my L48 carb rebuild, he helped dial the secondaries in with the correct metering rods with directions too. I've had 0 issues and it's been over 10 years. The car performs flawlessly. And, everything fits under the hood with OEM ram air system. I even installed a 700R4 from Bow-tie and, since I had the correct carb, the transmission linkage that mounts at the carb was a direct fit. I've owned a Holley-carb'd car in the past and had fun with it. But, for my C3, I wanted to try to keep it original where I could and improve/upgrade in other areas to freshen performance. Once I heard of Lars' rebuild service so many years ago, I leaped at the opportunity. What really impressed me is that Lars researches the carb application and if something is missing, bent, incorrectly installed, he corrects it. The carb I have on my car is not the original carb. Somewhere along the line, a PO replaced it with a service replacement from the dealer. So, I was not as concerned about 'original' as I was 'correct'... hey, it's an '80 L48, not a chrome-bumper car. But, it is my first and last C3 so it is special to me.

Always a work-in-progress. There is nothing like the feeling of hitting that garage door opener at the end of the day and seeing the C3 sitting there.

78anniversary

lars

You completely missed the joke.
Not surprising, since you completely missed the point of my other info posted here.

Lars

Mike Ward

Wow, just wow.

billla

This is the kind of stuff that just bums me out.

We're all part of this community for the same reason - we love Corvettes. It may be the only thing we have in common, but we do all have it in common - and if we're posting here, we're each doing the best we know how to help our fellow Corvette owners.

Given that, I just don't understand why a difference of opinion needs to turn into a personal attack. It is possible to disagree without being disagreeable - debate the idea, not the person as our excellent Mods always suggest.

Can't we be excellent to each other?

Go drive your Corvette.

Shark Racer

Regarding Tim; if you feed the fire, it will continue to burn. Don't give him any gasoline.

I'm very thankful, both that Lars is well on the road to recovery and that he is here posting. Also, that was some great research and I appreciate him taking the time to do it as well as post it.