[Cliff R]

From BG Tech: "Most engines regardless of how radical the camshaft is don’t respond to increasing the timing (at idle) past about 18 or 20 degrees as far as idle quality"

First and foremost, I personally think that it is quite admirable to come onto the board to help "clear the air" a bit, especially with all the "HEAT"!

Interesting comment above, BTW exactly what we see with tuning engines that have well chosen parts and a carburetor capable of supplying plenty of fuel at idle speed and the engines vacuum level, REGARDLESS of how radical the camshaft has the engine running!!!

There are those on this board, who would ATTACK me viciously for making the same statement. It's commonly posted on here that a Pontiac engine "wants, needs, requires, has to have, responds well too, etc, etc.) to having 30, 40 or even 50 degrees of initial timing at idle (combinations of initial timing AND adding in more with a custom adjustable vacuum advance hooked to a manifold source)....and that using manifold vacuum to the advance is REQUIRED, not an option to a ported source.

We'll see if "they" swoop down and blast your comments as they always do to mine, if not, then it must be more "personal" than trying to provide usable accurate information instead?.......Cliff

[Skip Fix]

Mike One thing I will add is try to find a wide band O2 sensor to borrow. You can see if your idle is lean or rich. I found out myoff idle stumble that squirters wouldn't fix ws because the idel circuit when set in neutral went lean in gear. Fatten the idle circuit up and no stumble with smaller squirters.

[Rugratman]

O.K. Suggestions....
First off, I will give you props for coming on here and standing up. Many other companies will not.

How about inspecting every carb, not just the flow for proper assembly, If a carb can leave your inspectors with bleed holes, not even drilled all the way or at all, Very flawed product, and very flawed inspection.

My carb, last year was full of metal shavings and junk in the float bowls, A good bit, I might add too. Impossible not to see this. Inspected, No way. It looked used and dirty. But I could have been 1 of a 100, a rarity.
If the carb is in fact not up to your standards then a full and complete refund should be in order. If my $500.00 carb needs to be sent back to you for repair, on a new carb.....Refund my money, as your company has failed all across the board. It was built wrong, It was never inspected, and I had to send it back.
Blocks installed back wards, stuff in the bowls, etc... all the stuff you heard here can not have passed your inspections. No way.
To me, It just doesn't seem that the product is put together with the care it deserves for the price, And for the price, BG should do a more stand up way of standing behind it.
Again thanks for coming on here, that is very commendable.
My basic point is, if you ship a unsatisfactory product, it should be refunded. Period. A new BG carb should not have to be repaired. And as you see, it does happen....More then you guy's want to believe it. If in fact you have put allot of work into straightening out the process, that is great, but you have burned alot of bridges with you past policies, so it's all up hill from here. Maybe something over the top to win back everyones confidence is needed. I have none, but your word.
Again, thanks for thinking of us Pontiac guy's. We are a small and tight knit group as you can see.

[Region Warrior]

Sooo...Cliff...are you saying 30* plus at idle may be what this engine needs/wants?
Using the adj vac can, but at the moment it's set at the starting position as per instructions.
I put a limiter on it(about 10*)
It has aftermrkt plate and wieghts , scrounging my spare distrib's for the right #'s to swap tomarrow.

BTY, this is a KRE engine. You know thier setups.

Thanks.

[Cliff R]

Mike, NOT at all. If you find your engine wanting, needing or responding well to TONS of initial timing, something is amiss. Either too much cam for the static compression ratio, or the carb is not capable of delivering enough idle fuel at the "low" vacuum signal from the engine, or combinations of both.

We seldom, if ever find ourselves using over about 14 degrees initial timing (most end up around 8-12 degrees), even on some pretty "seriously" cammed engine. We are able to tune them to idle perfectly in and out of gear without even using a vacuum advance at all, but usually have one installed and hooked to a ported source to add in a few more degrees timing at cruise. At best it's good for a few more mpg's, so we feels it's best to use one on anything that sees a lot of street driving.....Cliff

[Tom Vaught]

BGTECH, Thanks for posting.

I am glad you kept my e-mail address. I will look forward to chatting more after my holiday week off.

I agree that Venturi Diameter selection is one way to specify a given sized carburetor, but it does not take into account other variables like air horn design, booster design and frontal area, throttle blade diameter, and air cleaner design. All can have an effect on the airflow and the signal that the carb circuits receive.

It would be nice if we could use Mass Flow numbers like a EFI engine does, but not likely to happen.

The greater the pressure drop across the carb, the lower the DENSITY inside the intake plenum, and the less power you will make. One reason why a partially closed throttle will make less power vs a wide open throttle. Blow thru carbs have a boosting device creating a large density in the intake track which is why a rated 750 cfm carb can make 1000 hp.

We could discuss the fine points of carb design for months. Maybe you should come to a Norwalk event and join Cliff Ruggles and I in some carb tuning and design discussions.
Jon Hargrove (CARTER AFBs/etc) could join in too).

The deal here is that you have had some quality issues, (we all have at one point or another in companies), you are trying to resolve those issues and move on.

Keep posting.

As far as your age goes, I was just asking as my "Library" has "text books" that many times are older than the people I am discussing a subject about. Part of the OLDTIMERS disease. LOL!

Hope the 6 shooter Pontiac manifold deal is progressing well, have not seen an update in a while.

Tom V.

[Region Warrior]

Thanks Shaker455 for the carb info, and Cliff R., something you memtioned reminded me to think it through one step at a time.

GIT'R DONE!...

[shaker455]

ponchoshop,
I'm glad you got it straightened out and good chatting with you on the phone.

I hope you take the time to try the stock HEI centerplate and weights from your other dist as the generic aftermarket that you have in there now usally causes problems.

Doug from BG,
Are you guy's machining and assembling the carbs in GA?

[Skip Fix]

I won't totally disagree with you guys but when running NMCA where we had a vacuum rule at idle ALL the racers of all brands(Mopars, Ford FE, BBC) use manifold vacuum to pull more inches. I didn't at first but would pick up almost 3" at idle. Few motors I've been around didn't like a little more advance at idle, especially a big cam wanting to run power brakes.Most guys also had most of their centrifical in close to idle rpm for the same reason, mine was set up for 2000. At WOT vacuum advance isn't in the picture. Some of the FE and BBC were low 11s high 10s in these Top Stock classes. Some of these guys had pretty decent sized cams.

I've always set total and not worried about idle timing, as a lumpy cam might bounce around making a definitive setting off 2 degrees easily with a fast curve.With vacuum advance added I could usually turn down the idle setting and often re adjust the mixture screws since the blades were not as open. 36 total 20-24 in the distributor, let the idle be where ever as long as it isn't hard to crank, probably 12-16.

I'm not saying all motors do better with that set up, the factory used ported for alot of cars so they knew something also. And it can sure work better for some. There some guys here that even have their total timing locked out and set. So I think the opinions and feel is very individual.

My Q jet came back from the Carb Shop when Brad Urban was still there with shavings in the bowl also, as well as one of the ball bearings tapped in the idle bypass passages loose bouncing around.

[Cliff R]

Skip, good info. We certainly never intended to turn this thread into another vacuum advance debate. I'm surprised that no one jumped all over BG Tech for their comments, my comments on the subject are SELDOM, if ever allowed the same latitude.......so, it must be a "personal" thing, instead.

We have used MVA to help a few race cars that need to meet the vacuum advance rules by adding a lot more timing at idle, in combinations with more idle fuel, one can really "tame" down the idle quality.

It's a "hat trick" for the most part, as the increased rpm's usually get the advance weights moving out and adding in more timing, and the typical timing "falling out" when a slight load is placed on the engine, like placing it in gear.

We used to have a relatively high come back rate, back when I first started this business. Then we started running carbs on test engines, and racing some of them at the track to help us come up with better setting(s).

This took the come back rate from about 1 carb in 20, to about 1 in 300 or so!!!!

We see LOTS of carburetors that were wet flow tested, and most of them are not within specs, regardless of how sophisticated (and expensive) the equipment is.....FWIW.....Cliff

[shaker455]

Cliff,
I've been trying to contact you,

Did you get the "River Rat" and have you tried it yet?

[Cliff R]

Jeff, haven't opened up any shipments since Friday, been busy sorting out a few other things. I'll be here all day, and am signing off the computer now, if you want to give me a call?.....740-397-2921...Cliff

[hectore3]

A very nice thread going here! Now for my 02. cents. I went to my local speed shop (Belgrade Avenue Hot Rod and speed, Roslindale,ma) exactly 3 weeks ago.

Was picking up some parts and ran into an irate customer with his Mighty Demon. I helped to take this carb apart. And found as follows:

1. Metal shavings everywhere even embedded in the gaskets.

2. Emulsion bleeds were warped out of shape.

3. Varied orifces apeared to be drilled by someone who was using bad tooling.

When tech was called they treated us like we were stupid. As if were just some bumpkins who fell out of the tree. The fall off in quality is just F'ing amazing!

[shaker455]

Cliff,
Let me know when you open the box as I included accessories and tools and I'm sure your going to have a few questions.

hectore3,
I sent you a PM

I'm close to you guy's if you can get an exchange from Demon, let me know I can straighten it out as I did the one from this post.

[Geoff]

Cliff,
Here "they" come swooping in again for the ATTACK. Exaggerations from you again as usual. Find a post & quote it stating 50 degrees initial timing is recommended or used. You better re-read the BG Tech's post again. You missed an important word.
The masses are still waiting for you to explain why Pontiac got it wrong & didn't have to use manifold vacuum advance for years as they did, with the mild factory cams & 10+:1 comp ratios, but instead, should have used your method.

[Cliff R]

Geoff, there you are, wondered when you were going to wonder in and start critisizing my comments. I know now that it's PERSONAL, you just can't stand someone who disagrees with your "one size fits all" approach to tuning!

I don't think anyones waiting for me to explain anything? We know how to tune engines here, did it by getting dirty, not reading boat-loads of information from our hero's.

We use many methods to tune, we start first by setting up the carburetor to deliver the CORRECT amount of idle fuel for the owners engine combination AND set up the spark curve to provide optimum timing events at every rpm.....is there any other WAY????.....Cliff

[Tom Vaught]

Geoff,

We have communicated by e-mail several times over the years. Not saying that you are wrong or right but I can say that every carb sent out by Cliff has been on his engine for a road test and attempts were made to optimize the combinations he builds by strict track and dyno testing.

That said, Timing is a much, much more indepth subject vs simply where the vacuum source for the vacuum can needs to be hooked up or what the total timing should be. This is why we have three dimensional Timing Maps with EFI engines and some aftermarket companies offer timing computers.

How about we "agree to disagree" on the timing subject?

A "Urination Contest" really solves little (and I have been in the middle of a lot of them over the years). Both of you guys are well respected by the board members so let's let it go.

JMO

Tom V.

[shaker455]

Tom,
You and Cliff are going to be at Norwalk this year?

Also I wanted to follow up on that King Demon Lenny Caverly and I were tunning on his Enginemasters 505.

His engine was producing 17" of vacuum @ idle with a victor intake and we tried elimating the 3rd circurt and that did the trick.

Car ran a 10.4 @ 129mph May 5th and he only made one run that night due to a melted shifter cable.

[Region Warrior]

Ut-Oh, here we go again.
I'm with Cliff on this one.
Good acceleration, ruff idle, terrible fuel milage.
This is my 1st 4 corner idle deal, plus i'm a q-jet guy.
Always had best results with full manifold vacuum for street/strip.
After talking with Shaker455 on tuning the BG(much thanks), i went through my past engine combo's for spec's and notes. Cant believe how much i forgot.

The best so far on the street;
12 initial
12-14 centrifugal
10 vac can to direct port on carb(@13-14")
750 idle in drive(right now)

It drive's much tamer. Barely need to touch pedal for normal driving.
Shifts smoother in drive.
Had 3 open house's this weekend. Put on over 50 miles.
My son drove normal, and i had to show off for some by request. Need to practice shifting any how.
At one point he said; dad, the fuel gage must not be working right. It's not moving turns empty like last week.
Sure enough, at least 3 miles per gallon better.

[Skip Fix]

My newest Holley 4781 had a few metal shavings in the gaskets, none in the bowls.