Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-15-2008, 06:27 PM   #1
1 Rivet Member
 
1984 27' Airstream 270
Wayne , Ohio
Join Date: Jul 2007
Posts: 8
Engine Air Intake

I have a 1984 270 motorhome. My question is ,has anyone put a cold air intake air on their engine. I was driving in 80 degree plus temp, and the engine was cutting out bad. But when the temp. dropped it run great. So I thought the cold air intake would fix the problem. I tried to find one on-line, but no luck. Thank You for any suggestions.
__________________

__________________
tomjunw is offline   Reply With Quote
Old 10-15-2008, 06:52 PM   #2
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,189
80 shouldn't give you problems, I'd look into the ignition coil, fuel pump, filter, etc. The motorhome has run this long without one, there should be no reason it should suddenly need one.
__________________

__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
overlander63 is offline   Reply With Quote
Old 10-15-2008, 06:52 PM   #3
Rivet Master
 
TomW's Avatar
 
1967 26' Overlander
Huntsville , Alabama
Join Date: Dec 2003
Posts: 2,918
Images: 2
Cutting out is a different problem

Quote:
Originally Posted by tomjunw View Post
... has anyone put a cold air intake air on their engine. I was driving in 80 degree plus temp, and the engine was cutting out bad. But when the temp. dropped it run great. ....
I think you have mechanical problems up & beyond any benefit realized by a cold air intake.

Start with a tuneup AND replacing the corrugated hose between your air filter housing and the headlight mounting panel and go from there. It helped with my 454.

Tom
TomW is offline   Reply With Quote
Old 10-15-2008, 07:00 PM   #4
Incorrigible
 
Ike T's Avatar
 
1976 Argosy 24
-- , Georgia
Join Date: Jun 2007
Posts: 559
Cutting out as in "not running" or "just can't run at much speed"? The latter might be an air/vapor lock issue with your fuel system.

80 degrees is not usually hot enough to really aggrevate a vapor lock issue unless it's quite an air leak or you're really putting a demand on the engine.

Check all your fuel system connections and look for worn or split fuel lines.

Tim
__________________
Tim

1976 24' Argosy
1973 International Harvester Travelette 1210 4x4 'Bernard' 164" WB
1997 Georgie Boy 30' SuperDuty v10
Ike T is offline   Reply With Quote
Old 10-15-2008, 07:01 PM   #5
Vintage Kin
 
slowmover's Avatar
 
Fort Worth , Texas
Join Date: Nov 2006
Posts: 7,577
Images: 1
I have seen dryer hose, pvc pipe and other such as "adapted" pieces to the OEM filter housing. Done in such a way as to drain any water, and not collect any extra dust (engine fan on unpaved surface, etc). If the air filter housing -- on a carburated engine -- uses exhaust manifold heat and/or intake manifold exhaust heat crossover, then, FIRST, clean these and replace any of the operational devices. Removing the intake may seem a big problem, but it isn't that bad IF PICTURES are taken first of how throttle and transmission linkages hook up. (Also, get factory service manual for help:: HELM, Inc).

On a carb'd engine, keeping fuel atomized is a function of heated intake AIR, etc. GM used to spec 105-115F as ideal. Repair first, adapt second.

Here is an example of an aftermarket housing. But be aware that cold start and cruise mpg will be affected negatively UNLESS the carb is modified to take advantage of the new situation. The choke is also in need of changes.

http://www.ramairbox.com/http://www.ramairbox.com/

On my last old car I used a phenolic resin 4-hole spacer (4-V carb), with a big aluminum plate underneath, (cut to fit around other parts) that kept manifold heat to a minimum (cold carb, hot manifold and regulated-temperature air). I achieved excellent fuel mileage and performance over the stock configuration, but it was time-consuming to get it straight. I also insulated fuel lines and used a vacuum-referenced fuel pressure regulator to keep fuel psi low at idle and cruise (high vacuum situations) and then a big free-flowing pipe when I tromped on it (and the secondaries were opened).

Cold air seems like an easy fix, but carb jetting, ignition advance, fuel pressure, and PROPER TEMPS are all part of the equation.
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 9-cpm solo, 15-cpm towing
Sold: Silver Streak Model 3411
slowmover is offline   Reply With Quote
Old 10-15-2008, 07:04 PM   #6
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
basx


As dear Dad used to tell me...Keep it stupid, Simple.

Start out with the basics. A complete tune-up. Cap,rotor,plugs and wires, check the o2 sensor and EGR valve and don't forget the fuel and air filter.
__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 10-16-2008, 07:06 AM   #7
Rivet Master
 
87MH's Avatar
 
1978 31' Sovereign
Texas Airstream Harbor , Zavalla, in the Deep East Texas Piney Woods on Lake Sam Rayburn
Join Date: Jan 2003
Posts: 2,435
Images: 292
Quote:
Originally Posted by tomjunw View Post
I have a 1984 270 motorhome.....I was driving in 80 degree plus temp, and the engine was cutting out bad. But when the temp. dropped it run great. ...Thank You for any suggestions.
As others have indicated, there are a variety of reasons that your 270 is acting like that....it COULD be a function of the air intake temp, but some interesting questions/solutions about alternative engine problems are here:

http://www.airforums.com/forums/f159...ade-16849.html


and a few more here:
ignition module
(remember, the ignition module is INSIDE the rotor cap)

and here:
7.4l tune-up

and even more here:
Help - MH Can't climb hills

As with all things old, the probable cause of your problem is most likely from multiple system malfunctions, keep at it, repair/replace the old stuff, and eventually you will have a dependable ride. The best thing about self-repair is that you will be able to recognize and repair future failures in short order, either on the road or at your home base.

BTW - in an attempt to increase the deplorable MPG's my 345 beast gets, I routed an alternative air intake to the air cleaner (leaving the original intact) - no discernable benefits were noted.

Please keep the Forum posted on your progress.
__________________
Dennis

"Suck it up, spend the bucks, do it right the first time."

WBCCI # 1113
AirForums #1737

Trailer '78 31' Sovereign

Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.
87MH is offline   Reply With Quote
Old 10-16-2008, 07:00 PM   #8
1 Rivet Member
 
1984 27' Airstream 270
Wayne , Ohio
Join Date: Jul 2007
Posts: 8
Quote:
Originally Posted by TomW View Post
I think you have mechanical problems up & beyond any benefit realized by a cold air intake.

Start with a tuneup AND replacing the corrugated hose between your air filter housing and the headlight mounting panel and go from there. It helped with my 454.

Tom
My 1984 doesn't have the intake hose. The carb. is a new Holley Quad. replacement. The fuel pump, fuel filter. plugs. wires almost new, also all rubber fuel lines. EGR has been eliminated. The exhaust comes off the manifolds at 2 1/4" for short distance, then goes to 3" w/flowmaster 50s. Thanks
__________________
tomjunw is offline   Reply With Quote
Old 10-17-2008, 09:27 AM   #9
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,189
Quote:
Originally Posted by tomjunw View Post
My 1984 doesn't have the intake hose. The carb. is a new Holley Quad. replacement. The fuel pump, fuel filter. plugs. wires almost new, also all rubber fuel lines. EGR has been eliminated. The exhaust comes off the manifolds at 2 1/4" for short distance, then goes to 3" w/flowmaster 50s. Thanks
The ignition coil could be breaking down. It is the type that fits in the top of the distributor cap? Also, did this start happening right after insstallation of the carb, or some time after? What is the cfm rating of the carb?
__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
overlander63 is offline   Reply With Quote
Old 10-17-2008, 03:36 PM   #10
Rivet Master
 
TomW's Avatar
 
1967 26' Overlander
Huntsville , Alabama
Join Date: Dec 2003
Posts: 2,918
Images: 2
Carbon traces in the cap

Quote:
Originally Posted by tomjunw View Post
My 1984 doesn't have the intake hose. The carb. is a new Holley Quad. replacement. The fuel pump, fuel filter. plugs. wires almost new, also all rubber fuel lines. EGR has been eliminated. The exhaust comes off the manifolds at 2 1/4" for short distance, then goes to 3" w/flowmaster 50s. Thanks
You didn't mention cap & rotor. I let the parts guy talk me into replacing my black-in-color cap & rotor with a blue one, "You'll get more power from this brand!" I know that snake oil can sometimes be blue-in-color, but I bought what he was pushing because he was so enthusiastic, and there was no appreciable cost difference. As Terry probably knows, my Burb did not subsequently leap taller buildings than it previously did.

Terry had a good point about cfm. IIRC, lower cfm helps torque. Is the Holley rated higher than the OEM Rochester with regards to air flow?

Tom
TomW is offline   Reply With Quote
Old 10-21-2008, 07:22 AM   #11
Rivet Master
 
GlenCoombe's Avatar
 
1984 28' Funeral Coach
Belleview , Florida
Join Date: Jun 2005
Posts: 1,635
Images: 27
When was the last time the filter at the carb was replaced?

You can stuff a lot more cold air into the carb by removing the factory air cleaner and going with a remote cone type filter and a 4" air hose from the front grill.

Take a look at my photos of my remote filter and air intake fabricated from flashing aluminum. It's an easy DIY project.

http://www.airforums.com/attachments..._004_thumb.jpg
__________________
Glen Coombe AIR #8416
1984 28' Funeral Coach
Former Rolling Showroom & PuttLab (now party bus)
"I'm not an expert. But I did sleep in an Airstream last night."
GlenCoombe is offline   Reply With Quote
Old 11-02-2008, 07:29 PM   #12
1 Rivet Member
 
1984 27' Airstream 270
Wayne , Ohio
Join Date: Jul 2007
Posts: 8
I'm not sure, but what may be happening is on hills I loose vacuum, causing the heat riser & the heat baffle on the air cleaner to close. In turn all I get is hot air. The Ram Air looks like it will make a big differance, along with fixing my other problems. Thanks to all for your help.
__________________
tomjunw is offline   Reply With Quote
Old 11-03-2008, 12:27 PM   #13
Vintage Kin
 
slowmover's Avatar
 
Fort Worth , Texas
Join Date: Nov 2006
Posts: 7,577
Images: 1
Those items operate on temperature, and vacuum is used only to power them. Replace or repair them first, and have a first rate mechanic be sure the choke is operating properly. These problems were ones that caused a lot of people to trade a 1970's vehicle too early (to my benefit: $20 plus an hour or two, back then). Check that the air filter housing gasket (to carb) is new, and that the carb gasket (to intake) is not leaking.

It is generally a mistake to change the air intake system, for longest engine life. Regulated air temperature is key to performance, economy and reliability.

The cooling system is more than likely neglected, and a thorough cleaning -- plus component replacement (fan clutch, thermostat, water pump; all hoses and fasteners; possibly radiator) -- will pay long-term benefits. Gasoline engines run hot, and should have at least a 185-195F thermostat.

The exhaust system is more likely to be a source of lost performance (press-bent versus mandrel-bent pipes; the tightest bend is the actual diameter of the system).

As to losing power on a long, uphill pull I would suspect inadequate fuel pressure. I would replace the engine-mounted vacuum-diaphragm pump with an electric pusher (like a Holley "blue" pump) and install a pressure regulator. Duplicate the factory fuel lines with NEW PARTS. (That alone may "solve" the problem).
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 9-cpm solo, 15-cpm towing
Sold: Silver Streak Model 3411
slowmover is offline   Reply With Quote
Old 11-11-2008, 08:50 AM   #14
Rivet Master
 
GlenCoombe's Avatar
 
1984 28' Funeral Coach
Belleview , Florida
Join Date: Jun 2005
Posts: 1,635
Images: 27
Gee, on the up hill climb the angle can be quite extreme too.

The most overlooked fuel filter is the internal filter at the front of the carb. An extreme angle can cause sediment in the filter to block flow as it can in the inline frame mounted filters.
__________________

__________________
Glen Coombe AIR #8416
1984 28' Funeral Coach
Former Rolling Showroom & PuttLab (now party bus)
"I'm not an expert. But I did sleep in an Airstream last night."
GlenCoombe is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Has anyone ever removed their air conditioning from engine compartment Mr. D Mechanics Corner - Engines, Transmission & More... 19 06-07-2007 08:11 PM
Engine Air Conditioner Howard Lefkowitz Classic Motorhomes 6 10-23-2006 01:29 PM
Ford 460 Air Intake noiva Mechanics Corner - Engines, Transmission & More... 5 04-15-2006 08:19 PM
More intake air GlenCoombe Mechanics Corner - Engines, Transmission & More... 7 02-04-2006 08:15 PM
will atwood drain from cold intake 63air Water Heaters, Filters & Pumps 2 09-14-2005 05:50 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:47 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.