Cold Air Intake

chuck blanford

New member
Feb 6, 1998
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Al,

I did a similar setup. Ragusa (GMCMM Advertiser) makes an aluminum inlet
air scoop that is designed to fit in the grill. I attached mine below the
bumper, and connected the outlet side of it to the snorkel on the air
cleaner, using 4" aluminum dryer hose. A coarse piece of Scotch pad in the
throat of the scoop keeps the big bugs out of the air cleaner. The goal
was to get cool 'ram-air' to the carburetor.

Chuck
77 Kingsley

- ----------
> From: William D. Minor
> To: gmcmotorhome
> Subject: Re: GMC: GMC 3.42 final drive and Monteagle Mounta
> Date: Thursday, September 10, 1998 10:17 PM
>
> Al,
>
> I replaced the stock paper air filter with a K&N Oiled Air Filter. As
> far as the 4" cold air intake, I attached a 4" hose to the air cleaner
> intake nozzle and ran it to the front side of the radiator. That way the
> carb gets cooler air.
>
> Bill
> '73 230
 
Jim/Paul

I don't disagree with your thoughts. My coach utilization is probably
atypical, as it is a "hangar queen" summer cruiser. I have one more
weekend trip scheduled this month, weather permitting, and then it's back
on the blocks until May. This coach averages 2,000 miles per year. The
cooler months are not a concern; I wouldn't consider travel in snow, and
avoid rain whenever possible.

I really can't quantify the benefit of the cooler intake air. When I
acquired the coach, I hit a deer on the first day of our maiden voyage.
She came back from a summer in the body shop with a complete paint job.
Since my travel season was over, I used the fall/winter/spring to install:

Doug Thorley Headers
3" Exhaust
16" Alcoa's and new Michelins
Cold Air system
SS Oil Cooler Lines
KYB Shocks
Air Bags and SS Protectors
Finned Aluminum Trans. & Final Drive covers for heat dissipation
Complete Tune-up
Change all fluids to synthetics
Grease Wheel Bearings
New Brake Pads/Hoses
Rectangular Headlights
2" Receiver Hitch
Tinted Windows

While in the paint shop, we removed the ladder, roof railing, and cargo
pod, to clean up the lines.

Since I did not have any base line history to compare to, and I changed so
many variables at once, I cannot attest to individual improvements. I can
only say that I am pleased with the performance, cruise at 70-75 mph, and
have run at 85 in Montana (briefly) with no problems. I purchase the
highest octane fuel that I can find. I have towed my Jeep Wrangler (3,600
pounds), and a utility trailer with 600 pound bike or ATV. The 403 and
transmission are original.

I received the SS brake lines this week, and will use the coming down time
to install. I also plan to have the a-frames rebuilt, thanks to a thread
on this list, and would like to acquire a set of Wallace hubs. I followed
Patrick's discussion with Will, and would appreciate a contact number for
Eaton RV or some other source.

YMMV

Chuck

- ----------
> From: Jim Davis
> To: gmcmotorhome
> Subject: Re: GMC: FW: Cold Air Intake
> Date: Friday, September 11, 1998 10:39 AM
>
> Just a thought, but cooler air especially during cooler months could mean
> less vaporization of fuel-air mixture, poorer mileage and
performance.Also
> the longer the tube, friction, less air, richer mixture. Just like
running
> with the choke partially on.Honda's engineering folks tried this on
> motorcycles and it didn't work out as they felt the mixture always was
> changing in relation to the speed of the bike. Boy, that ought to give
you
> all something to think about........Jim Davis
>
> ----------
> > From: Bartz, Paul
> > To: 'gmcmotorhome'
> > Subject: GMC: FW: Cold Air Intake
> > Date: Friday, September 11, 1998 8:22 AM
> >
> > Excuse me, I meant to address this to Chuck instead of Al.
> >
> > Paul
> >
> > From: Bartz, Paul [mailto:s9d3452]
> > Sent: Friday, September 11, 1998 11:18 AM
> > Subject: RE: GMC: Cold Air Intake
> >
> > Al:
> > Tell us if you noticed any improvement? If so, what?
> > Also, what did you use to secure the duct to the air cleaner housing
> > snorkel?
> > Paul Bartz
> >
> > From: Chuck Blanford [mailto:Chuck.Blanford]
> > Sent: Friday, September 11, 1998 8:41 AM
> > Subject: Re: GMC: Cold Air Intake
> >
> > Al,
> > I did a similar setup. Ragusa (GMCMM Advertiser) makes an aluminum
> > inlet air scoop that is designed to fit in the grill. I attached mine
> > below the bumper, and connected the outlet side of it to the snorkel on
> > the air cleaner, using 4" aluminum dryer hose. A coarse piece of
Scotch
> > pad in the throat of the scoop keeps the big bugs out of the air
> > cleaner. The goal was to get cool 'ram-air' to the carburetor.
> > Chuck
> > 77 Kingsley
> >
> > From: William D. Minor
> > Subject: Re: GMC: GMC 3.42 final drive and Monteagle Mounta
> > Date: Thursday, September 10, 1998 10:17 PM
> > Al,
> > I replaced the stock paper air filter with a K&N Oiled Air Filter. As
> > far as the 4" cold air intake, I attached a 4" hose to the air cleaner
> > intake nozzle and ran it to the front side of the radiator. That way
the
> > carb gets cooler air.
> > Bill
> > '73 230
 
Al:

Tell us if you noticed any improvement? If so, what?

Also, what did you use to secure the duct to the air cleaner housing
snorkel?

Paul Bartz

From: Chuck Blanford [mailto:Chuck.Blanford]
Sent: Friday, September 11, 1998 8:41 AM
Subject: Re: GMC: Cold Air Intake

Al,
I did a similar setup. Ragusa (GMCMM Advertiser) makes an aluminum
inlet air scoop that is designed to fit in the grill. I attached mine
below the bumper, and connected the outlet side of it to the snorkel on
the air cleaner, using 4" aluminum dryer hose. A coarse piece of Scotch
pad in the throat of the scoop keeps the big bugs out of the air
cleaner. The goal was to get cool 'ram-air' to the carburetor.
Chuck
77 Kingsley

From: William D. Minor
To: gmcmotorhome
Subject: Re: GMC: GMC 3.42 final drive and Monteagle Mounta
Date: Thursday, September 10, 1998 10:17 PM
Al,
I replaced the stock paper air filter with a K&N Oiled Air Filter. As
far as the 4" cold air intake, I attached a 4" hose to the air cleaner
intake nozzle and ran it to the front side of the radiator. That way the
carb gets cooler air.
Bill
'73 230
 
Excuse me, I meant to address this to Chuck instead of Al.

Paul

From: Bartz, Paul [mailto:s9d3452]
Sent: Friday, September 11, 1998 11:18 AM
Subject: RE: GMC: Cold Air Intake

Al:
Tell us if you noticed any improvement? If so, what?
Also, what did you use to secure the duct to the air cleaner housing
snorkel?
Paul Bartz

From: Chuck Blanford [mailto:Chuck.Blanford]
Sent: Friday, September 11, 1998 8:41 AM
Subject: Re: GMC: Cold Air Intake

Al,
I did a similar setup. Ragusa (GMCMM Advertiser) makes an aluminum
inlet air scoop that is designed to fit in the grill. I attached mine
below the bumper, and connected the outlet side of it to the snorkel on
the air cleaner, using 4" aluminum dryer hose. A coarse piece of Scotch
pad in the throat of the scoop keeps the big bugs out of the air
cleaner. The goal was to get cool 'ram-air' to the carburetor.
Chuck
77 Kingsley

From: William D. Minor
Subject: Re: GMC: GMC 3.42 final drive and Monteagle Mounta
Date: Thursday, September 10, 1998 10:17 PM
Al,
I replaced the stock paper air filter with a K&N Oiled Air Filter. As
far as the 4" cold air intake, I attached a 4" hose to the air cleaner
intake nozzle and ran it to the front side of the radiator. That way the
carb gets cooler air.
Bill
'73 230
 
Just a thought, but cooler air especially during cooler months could mean
less vaporization of fuel-air mixture, poorer mileage and performance.Also
the longer the tube, friction, less air, richer mixture. Just like running
with the choke partially on.Honda's engineering folks tried this on
motorcycles and it didn't work out as they felt the mixture always was
changing in relation to the speed of the bike. Boy, that ought to give you
all something to think about........Jim Davis

- ----------
> From: Bartz, Paul
> To: 'gmcmotorhome'
> Subject: GMC: FW: Cold Air Intake
> Date: Friday, September 11, 1998 8:22 AM
>
> Excuse me, I meant to address this to Chuck instead of Al.
>
> Paul
>
> From: Bartz, Paul [mailto:s9d3452]
> Sent: Friday, September 11, 1998 11:18 AM
> Subject: RE: GMC: Cold Air Intake
>
> Al:
> Tell us if you noticed any improvement? If so, what?
> Also, what did you use to secure the duct to the air cleaner housing
> snorkel?
> Paul Bartz
>
> From: Chuck Blanford [mailto:Chuck.Blanford]
> Sent: Friday, September 11, 1998 8:41 AM
> Subject: Re: GMC: Cold Air Intake
>
> Al,
> I did a similar setup. Ragusa (GMCMM Advertiser) makes an aluminum
> inlet air scoop that is designed to fit in the grill. I attached mine
> below the bumper, and connected the outlet side of it to the snorkel on
> the air cleaner, using 4" aluminum dryer hose. A coarse piece of Scotch
> pad in the throat of the scoop keeps the big bugs out of the air
> cleaner. The goal was to get cool 'ram-air' to the carburetor.
> Chuck
> 77 Kingsley
>
> From: William D. Minor
> Subject: Re: GMC: GMC 3.42 final drive and Monteagle Mounta
> Date: Thursday, September 10, 1998 10:17 PM
> Al,
> I replaced the stock paper air filter with a K&N Oiled Air Filter. As
> far as the 4" cold air intake, I attached a 4" hose to the air cleaner
> intake nozzle and ran it to the front side of the radiator. That way the
> carb gets cooler air.
> Bill
> '73 230
 
Jim,

I kept the 'hot air' diaphragm in my air cleaner snorkel, and adjusted
the snorkel thermostat to full open above 70 or so. that way I get air
from behind the radiator during cooler days but fresh air from the front
on warmer days.

As for Honda's ram air, the carb setup was difficult as a retrofit, but
it works fine on their motorcycles that are designed for it. The
biggest difficulty was because most bikes didn't have fuel pumps and the
added pressure wouldn't let the fuel flow to the carbs.

Bill
'73 230
 
Paul, I have not made the modification. I plan to try. I don't know if it
will help the throttle body injection, as it is running great, but I will
try and see if it changes anything. I am planning to put some panels on
the sides of the radiator so that all the air goes through the radiator and
not around it. That might help as well.

Al

> Al:
>
> Tell us if you noticed any improvement? If so, what?
>
> Also, what did you use to secure the duct to the air cleaner housing
> snorkel?
>
> Paul Bartz
>
> From: Chuck Blanford [mailto:Chuck.Blanford]
> Sent: Friday, September 11, 1998 8:41 AM
> Subject: Re: GMC: Cold Air Intake
>
> Al,
> I did a similar setup. Ragusa (GMCMM Advertiser) makes an aluminum
> inlet air scoop that is designed to fit in the grill. I attached mine
> below the bumper, and connected the outlet side of it to the snorkel on
> the air cleaner, using 4" aluminum dryer hose. A coarse piece of Scotch
> pad in the throat of the scoop keeps the big bugs out of the air
> cleaner. The goal was to get cool 'ram-air' to the carburetor.
> Chuck
> 77 Kingsley
>
> From: William D. Minor
> To: gmcmotorhome
> Subject: Re: GMC: GMC 3.42 final drive and Monteagle Mounta
> Date: Thursday, September 10, 1998 10:17 PM
> Al,
> I replaced the stock paper air filter with a K&N Oiled Air Filter. As
> far as the 4" cold air intake, I attached a 4" hose to the air cleaner
> intake nozzle and ran it to the front side of the radiator. That way the
> carb gets cooler air.
> Bill
> '73 230
 
Mine has 4" dryer vent for the cold air intake also. It runs up beside the
steering box and points down where it gets cool air but probably not much
ram effect. When I installed it I intended eventually to fashion a scoop
behind the Grill but that hasn't yet gotten to the top of my list. As with
the others I don't have any before and after comparisons but I consider it
to be good practice. If I were driving in the winter I would disconnect the
hose.

When I was tuning up last fall I found that my hot air diaphragm was
ruptured so I have no air temperature control. I checked a number of places
locally and could not locate one nor could anyone tell me where to look. The
air is starting to get cool enough to need it now so does anybody have any
idea of where to look for one?

Thanks

Dick

>Jim,
>
>I kept the 'hot air' diaphragm in my air cleaner snorkel, and adjusted
>the snorkel thermostat to full open above 70 or so. that way I get air
>from behind the radiator during cooler days but fresh air from the front
>on warmer days.
>
>As for Honda's ram air, the carb setup was difficult as a retrofit, but
>it works fine on their motorcycles that are designed for it. The
>biggest difficulty was because most bikes didn't have fuel pumps and the
>added pressure wouldn't let the fuel flow to the carbs.
>
>Bill
>'73 230
>
>
>