: Air filters/Exausts/Carbs

[terry skinner]

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
I'd definitely like to richen it up a little as I'm also installing a K&N
air filter,
Thorley headers and Flowmaster mufflers - all of which I would think will
make the engine run leaner still(I'd love to hear any dissenting opinions on
this).

Patrick
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Now, these are just my opinions so take it as such.

In the Amsoil web page they offered a comparison of air filters and ( of
course) theirs came out first and the K&N came out last. Back in the
motorcycle days the K&N's were very popular but would not filter small
enough particulates and the oil covered foam would load up quickly. We went
back to paper filters. I am most impressed with the Idea of picking up the
air through a ventura mounted up in the grill and am pursuing this vane. I
hope it gets a lot more discussion. Being a mechanic type I can build it if
you guys design it.
The exhaust on the Dumpster REALLY impressed me. The Idea of going from
a set of headers to a "y" and then to a straight pipe all the way to the
back of the GMC and then dumping into a muffler sounds like the way to go.
Just think about how much heat you are removing from that engine/engine
compartment and allowing this heat to dissipate on the trip back. The lower
temperature lowers the speed of sound and makes it easier for the muffler to
do it's job. The engineer types can tell you more about that than I can.
The carberation on this rig is old hat. This system is over 30 years
old. There is no way that we can get it to work as well as a throttle body
injection system, and I want the security of a trouble free system. The
problem is that it's hard to justify all that money for a TBI considering we
only average 20,000 miles a year. I guess this is one of those things that I
will have to bite the bullet and hope that my heirs can get the money back.

Just MY .02

Terry Skinner
Webfooted in Washington
'76 Glenbrook

 

[blank]

> Now, these are just my opinions so take it as such.
>
> In the Amsoil web page they offered a comparison of air
> filters and ( of course) theirs came out first and the K&N
> came out last. Back in the motorcycle days the K&N's were
> very popular but would not filter small enough particulates
> and the oil covered foam would load up quickly. We went
> back to paper filters.

Terry, I've been using K&N filters for almost 20 years and they've always
been oil covered gauze and(according to K&N - so take it FWIW), they
actually filter better as particles accumulate. I've used them on both cars
and motorcycles with excellent results - never off-road tho', so filter
loading has never been an issue.

> The carberation on this rig is old hat. This system is
> over 30 years old. There is no way that we can get it to
> work as well as a throttle body injection system, and I
> want the security of a trouble free system.

I don't want to step on anyone's toes in the fuel injection camp, but I'm
just not sold on the "advantages" of fuel injection. When properly set up,
the ole Quadrajet does an excellent job and is the model of simplicity(Phil
Stewart's post today about his experience after C'bar worked on his Qjet
reinforces that opinion). TBI adds several levels of complexity, which IMO
is just more to go wrong - i.e., not exactly "trouble free". I realize that
there are several GMCnetters that have installed fuel injection and are
happy with it, but I think I'll stick with the Qjet for now.

Patrick

 

[richard waters]

I just got my bill from Cinnabar faxed to me this morning. I
was kind of suprised that it was not higher then it was considering
the amount of work they did. The proof will be in the pudding when
I pick up my GMC this Saturday. If the carburetor calibration they did
(they increased the jets 2 sizes larger ) prevents further exhaust manifold
problems and improves performance I will be really pleased. I'll
provide full details of my experiences after I get the coach back.
Richard Waters '76 PB, Troy, MI
- ----

>
> I don't want to step on anyone's toes in the fuel injection camp, but I'm
> just not sold on the "advantages" of fuel injection. When properly set up,
> the ole Quadrajet does an excellent job and is the model of simplicity(Phil
> Stewart's post today about his experience after C'bar worked on his Qjet
> reinforces that opinion). TBI adds several levels of complexity, which IMO
> is just more to go wrong - i.e., not exactly "trouble free". I realize that
> there are several GMCnetters that have installed fuel injection and are
> happy with it, but I think I'll stick with the Qjet for now.
>
> Patrick

 

[john dolan]

Richard said...

> If the carburetor calibration they did (they increased the jets 2 sizes
> larger ) prevents further exhaust manifold problems and improves > >
> performance I will be really pleased. I'll provide full details of my
> experiences after I get the coach back.

Thomas told us that's what needed to be done for free, and without a
'stinking' mobile gas analyzer...
- --
"I do whatever my Rice Krispies tell me to..." John said.

 

[richard waters]

John, my Rice Krispies didn't tell me a thing about my carburetor!

I learned about my carburetor the hard way before the GMCnet
made it public. If it was talked about on the GMCnet, it was before
I joined.

Therefore, I was not aware of the problems associated with
reformulated gas and the resultant lean mixtures that can cause
and their impact on EGT and exhaust manifolds in the GMC.
Of course this could all be a myth. What do I know? Only time
and the GMCnet will tell.

I still needed the services of the analyzer because I had no idea
of the state of the carburetor. While the previous owner had it
rebuilt by Cinnabar a few years ago I had no record of what new jets
and/or metering rods had or had not been installed. The rebuild
job was done before Cinnabar got their analyzer.

Besides, the main thing here is that I wanted no part of the work involved
with repairing the leaking exhaust manifolds. That's why I took it to
Cinnabar in the first place. I'll gladly tinker with my coach, but I didn't
really want to spend 2-3 days messing with exhaust manifolds. That's
what it would have taken me to do the job. Cinnabar just billed me for
4 hours plus parts to do both sides. For me that is a bargain. I can
imagine myself struggling with those rusted bolts. Having them break
on me one at a time. Then I would still have to take the manifolds
someplace to be machined flat or replaced.

Anyway that's what I did,

Richard Waters '76PB, Troy, MI
- ------------

> Richard said...
>
> > If the carburetor calibration they did (they increased the jets 2 sizes
> > larger ) prevents further exhaust manifold problems and improves > >
> > performance I will be really pleased. I'll provide full details of my
> > experiences after I get the coach back.
>
> Thomas told us that's what needed to be done for free, and without a
> 'stinking' mobile gas analyzer...
> --
> "I do whatever my Rice Krispies tell me to..." John said.

 

[john dolan]

>I learned about my carburetor the hard way before the GMCnet
>made it public. If it was talked about on the GMCnet, it was before
>I joined.

Relax, I only said that, partly in jest , because a few days ago
Thomas said, if you have the original carb configuration... go up two
sizes to compensate for the reformulated gas. We are still struggling
here on the net with two sizes from what size to what new size.

Maybe you can provide the specific information that is needed. What were
your original sizes (I know you said you didn't know... but maybe they
will tell you, now) and what sizes have they put in there? How much do
they charge for that carb calibration, anyway?

- --
"I do whatever my Rice Krispies tell me to..." John said.

 

[richard waters]

John,
Maybe I came at you a little too hard in my email. Sorry about
that, I was in a hurry this morning and I sometimes type faster
then I think.

Cinnabar is supposed to be saving all the parts for me. I'm going
to pick up my coach tomorrow morning (Saturday). It will
be interesting to see if it runs any different. I know it will sound
a lot different.

I'll report on my findings as soon as I get back to my computer.

Richard Waters '76 PB, Troy, MI

> >I learned about my carburetor the hard way before the GMCnet
> >made it public. If it was talked about on the GMCnet, it was before
> >I joined.
>
> Relax, I only said that, partly in jest , because a few days ago
> Thomas said, if you have the original carb configuration... go up two
> sizes to compensate for the reformulated gas. We are still struggling
> here on the net with two sizes from what size to what new size.
>
> Maybe you can provide the specific information that is needed. What were
> your original sizes (I know you said you didn't know... but maybe they
> will tell you, now) and what sizes have they put in there? How much do
> they charge for that carb calibration, anyway?
>
> --
> "I do whatever my Rice Krispies tell me to..." John said.

 

[philip l. stewart]

Richard and John,

One of the things that Cinnabar did with my Qudarajet when they had the 5 gas
analyzer hooked to my engine was to set the float more precisely. This was the
last step after the jets and metering rods had been changed out but the
analyzer still showed that the carb was running a little too rich. Also the
idle mixture needle valves were adjusted until the analyzer gave the fuel to
air mixture the mechanic was looking for. I don't know if these adjustments
could have been done any better using another method ---say by measuring the
float drop and / or the number of turns of the idle metering jets--- but the
analyzer appeared to give the mechanic doing the work "instant" feedback as to
the effect of his adjustments. So it seems to me that just changing the jets
and metering rods may not be all that is needed with every carb.

Phil Stewart
'76 Transmode, TN

 

[philip l. stewart]

> Did you move up two sizes or was this before the reformulation.
>
> --

John,
Sorry, I have no idea what had been done to the Qudrajet on my coach before
Cinnabar calibrated it with their analyzer. The carb had been "rebuilt"
before by someone else and it could have had different jets and rods
installed or they may have been the original ones. The carb is the right one
for a '76 Transmode, but that's about all I know.
Phil Stewart
'76 Transmode, TN

 

[john dolan]

Phil...

Glad to hear they were able to do a few other things (float and Idle Mix)
while they had the analyzer hooked up on your carb. I think you realized
that I was wondering, if all this Road and Track style mobile
instrumentation was necessary to say you need to go up two sizes larger,
because they reformulated the gas a while back. If one has a carb they
suspect was messed with and isn't running right now, this service is
probably the cheapest way to go. (Even though I don't expect Richard to
receive a cheap bill).

Did you move up two sizes or was this before the reformulation.

- --
Regards,
John

 

[richard waters]

I'm getting ready to leave to make the 80 mile drive up to
Sandusky to get the coach. I'll soon see if the calibration
work that Cinnabar did on my Qudarajet makes any noticeable
difference. Eric is the mechanic that worked on mine and he
told me that he had to make several trips with the analyzer hooked up
to my GMC to get the mixture correct. I'll assume that he adjusted
the float as well.
I'll report back on Sunday to those interested here on the GMCnet.
Richard Waters '76 PB, Troy, MI

> Richard and John,
>
> One of the things that Cinnabar did with my Qudarajet when they had the 5 gas
> analyzer hooked to my engine was to set the float more precisely. This was the
> last step after the jets and metering rods had been changed out but the
> analyzer still showed that the carb was running a little too rich. Also the
> idle mixture needle valves were adjusted until the analyzer gave the fuel to
> air mixture the mechanic was looking for. I don't know if these adjustments
> could have been done any better using another method ---say by measuring the
> float drop and / or the number of turns of the idle metering jets--- but the
> analyzer appeared to give the mechanic doing the work "instant" feedback as to
> the effect of his adjustments. So it seems to me that just changing the jets
> and metering rods may not be all that is needed with every carb.
>
> Phil Stewart
> '76 Transmode, TN

 

[philip l. stewart]

Lanier,
If I recall correctly (I'm too lazy to find the paperwork to be precise) the
cost for the work was between $180 and $200. That included parts like metering
rods, jets, gaskets, float and needle valve, etc. and about 4 hours of shop
labor using Cinnabar's expensive 5 gas exhaust analyzer. The mechanic had to
take the carb off the engine and re-install it twice, I believe, and there were
at least a half dozen 4 to 5 mile test runs made with analyzer attached to the
exhaust while I drove and the mechanic watched the intrument's readouts. I
remember that it was hard cramped work that the mechanic had to perform as he
labored on the carb. So I feel I got my money's worth and more for this
service. I certainly could not have done it myself. But as the say on the
Internet, your experience may vary. Good luck.
Phil Stewart
'76 Transmode, TN

> In a message dated 4/30/99 8:28:13 PM Central Daylight Time,

>
> >
> > One of the things that Cinnabar did with my Qudarajet when they had the 5
> > gas
> > analyzer hooked to my engine was to set the float more precisely. This
> was
> > the
> > last step after the jets and metering rods had been changed out
>
> What did Cinnabar charge for the carb work??
> Lanier

 

[richard waters]

I just picked up my coach after having the carb recalibrated by Cinnabar.
Besides sounding a lot better (I had the exhaust manifolds fixed) it really does
run a lot better. I guess it had been getting bad for a while, because there was
a noticeable improvement in performance. On the way to Cinnabar to drop off
the coach I tried to pass a gas tanker going about 40 MPH and couldn't do it!
When I floored the accelerator it just would not accelerate. After the work,
I tried it again and it accelerated around another slow mover up to 70. What a
difference. I hate to be part of a myth, but it does seem that the carb
recalibration
worked in my case. New spark plugs helped too I'm sure. I was charged close to
$180 for the work (which included new spark plugs, jets, air cleaner and assorted
gaskets). I would say that it was well worth the price. I also could not have done
it myself.
Richard Waters '76PB, Troy, MI

> Lanier,
> If I recall correctly (I'm too lazy to find the paperwork to be precise) the
> cost for the work was between $180 and $200. That included parts like metering
> rods, jets, gaskets, float and needle valve, etc. and about 4 hours of shop
> labor using Cinnabar's expensive 5 gas exhaust analyzer. The mechanic had to
> take the carb off the engine and re-install it twice, I believe, and there were
> at least a half dozen 4 to 5 mile test runs made with analyzer attached to the
> exhaust while I drove and the mechanic watched the intrument's readouts. I
> remember that it was hard cramped work that the mechanic had to perform as he
> labored on the carb. So I feel I got my money's worth and more for this
> service. I certainly could not have done it myself. But as the say on the
> Internet, your experience may vary. Good luck.
> Phil Stewart
> '76 Transmode, TN
>

 

[philip l. stewart]

> I just picked up my coach after having the carb recalibrated by Cinnabar.
> ....... it really does run a lot better. ...... I hate to be part of a myth, but it
> does seem that the carb
> recalibration worked in my case.

Richard,
Good to hear another success story. I don't think there is any mystery or "myth" as to
what Cinnabar does to these old carburetors----just good science and the experience of
well trained mechanics.
Phil Stewart
'76 Transmode, TN