GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward.
[GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311809] Wed, 04 January 2017 00:22 Go to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member




Tonight I want out to my GMC's nice warm house. ( It's 10 degrees outside. GMC's at 70. ) Anyway. My plan was to see if I could get my stock air filter to fit on the 454 TB. Set the carb, and TB on a board that was on the bench. ( to let the linkage not come in contact with the bench ) Then put the stock air cleaner on both. Put a spacer on the top of the TB. WHAT. Why is the air cleaner tilted toward the REAR. This can't be. As the carb base on the 403/455 should be level with the coach floor. Because the top of the air cleaner is level to the floor. But NO. The air cleaner has a tilt built into it. Thus the carb mounting surface of the intake manifold has to have a tilt toward the front. And yes it does. REALLY. So that means the 403/455 have to set level with the floor. Put a straight edge across the hatch opening. Checked the carb base. Then the valve covers. Engine sets dead level to the floor. This means that our carbs tilt forward. So now I need to hang my head down in shame. Bob Dunahugh
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311811 is a reply to message #311809] Wed, 04 January 2017 01:23 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Might have something to do with the ride height?

Front: 13 1/8" +/- 1/4"
Rear: 11 11/16" +/- 1/4"

Front is 1 7/16" higher.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Bob
Dunahugh
Sent: Wednesday, January 4, 2017 5:22 PM
To: gmclist@list.gmcnet.org
Subject: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set
level. But forward.

Tonight I want out to my GMC's nice warm house. ( It's 10 degrees outside.
GMC's at 70. ) Anyway. My plan was to see if I could get my stock air filter
to fit on the 454 TB. Set the carb, and TB on a board that was on the bench.
( to let the linkage not come in contact with the bench ) Then put the stock
air cleaner on both. Put a spacer on the top of the TB. WHAT. Why is the
air cleaner tilted toward the REAR. This can't be. As the carb base on the
403/455 should be level with the coach floor. Because the top of the air
cleaner is level to the floor. But NO. The air cleaner has a tilt built
into it. Thus the carb mounting surface of the intake manifold has to have
a tilt toward the front. And yes it does. REALLY. So that means the 403/455
have to set level with the floor. Put a straight edge across the hatch
opening. Checked the carb base. Then the valve covers. Engine sets dead
level to the floor. This means that our carbs tilt forward. So now I need
to hang my head down in shame. Bob Dunahugh
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311821 is a reply to message #311809] Wed, 04 January 2017 08:22 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
I assumed that the 455 air filter, and intake have the same tilt. So are the air filters for both engines interchangeable? Bob Dunahugh


________________________________
From: Bob Dunahugh
Sent: Wednesday, January 4, 2017 12:22 AM
To: gmclist@list.gmcnet.org
Subject: We are 100% WRONG about engine tilt. Carb doesn't set level. But forward.





Tonight I want out to my GMC's nice warm house. ( It's 10 degrees outside. GMC's at 70. ) Anyway. My plan was to see if I could get my stock air filter to fit on the 454 TB. Set the carb, and TB on a board that was on the bench. ( to let the linkage not come in contact with the bench ) Then put the stock air cleaner on both. Put a spacer on the top of the TB. WHAT. Why is the air cleaner tilted toward the REAR. This can't be. As the carb base on the 403/455 should be level with the coach floor. Because the top of the air cleaner is level to the floor. But NO. The air cleaner has a tilt built into it. Thus the carb mounting surface of the intake manifold has to have a tilt toward the front. And yes it does. REALLY. So that means the 403/455 have to set level with the floor. Put a straight edge across the hatch opening. Checked the carb base. Then the valve covers. Engine sets dead level to the floor. This means that our carbs tilt forward. So now I need to hang my head down in shame. Bob Dunahugh
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311825 is a reply to message #311821] Wed, 04 January 2017 08:49 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member

Rob. This manifold tilt has no relationship with ride height. It's based on the carb base tilt in relationship to the floor. Just like car, and truck floors. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Wednesday, January 4, 2017 8:22 AM
To: gmclist@list.gmcnet.org
Subject: RE: We are 100% WRONG about engine tilt. Carb doesn't set level. But forward.


I assumed that the 455 air filter, and intake have the same tilt. So are the air filters for both engines interchangeable? Bob Dunahugh


________________________________
From: Bob Dunahugh
Sent: Wednesday, January 4, 2017 12:22 AM
To: gmclist@list.gmcnet.org
Subject: We are 100% WRONG about engine tilt. Carb doesn't set level. But forward.





Tonight I want out to my GMC's nice warm house. ( It's 10 degrees outside. GMC's at 70. ) Anyway. My plan was to see if I could get my stock air filter to fit on the 454 TB. Set the carb, and TB on a board that was on the bench. ( to let the linkage not come in contact with the bench ) Then put the stock air cleaner on both. Put a spacer on the top of the TB. WHAT. Why is the air cleaner tilted toward the REAR. This can't be. As the carb base on the 403/455 should be level with the coach floor. Because the top of the air cleaner is level to the floor. But NO. The air cleaner has a tilt built into it. Thus the carb mounting surface of the intake manifold has to have a tilt toward the front. And yes it does. REALLY. So that means the 403/455 have to set level with the floor. Put a straight edge across the hatch opening. Checked the carb base. Then the valve covers. Engine sets dead level to the floor. This means that our carbs tilt forward. So now I need to hang my head down in shame. Bob Dunahugh
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311837 is a reply to message #311825] Wed, 04 January 2017 15:45 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Bob,

HUH?

Are you saying that with the ride height in your GMC set as per the MM the
floor is level front to back?

Things as I understand them:

1) The front and rear ride height setting slots in the frame members are
located in the same position vertically.

2) The floor is parallel to the frame members.

2) The ride height settings are:

Front: 13 1/8" +/- 1/4"
Rear: 11 11/16" +/- 1/4"

Front is 1 7/16" higher than the rear

3) The floor is 1 7/16" higher above the front slot than the rear slot

4) The floor angles downwards slightly front to rear

5) If a level was to be placed on the top of the air cleaner with the bubble
fore/aft and the rear suspension ride height raised and lowered the bubble
would move indicating a change in angle.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Bob
Dunahugh
Sent: Thursday, January 5, 2017 1:49 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set
level. But forward.


Rob. This manifold tilt has no relationship with ride height. It's based
on the carb base tilt in relationship to the floor. Just like car, and truck
floors. Bob Dunahugh



_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311838 is a reply to message #311837] Wed, 04 January 2017 16:02 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
Messages: 4442
Registered: January 2004
Karma: 13
Senior Member
Rob
I don’t think that Bob is saying anything about the level of the floor or engine. He is really saying that the floor and engine are parallel but that the carb mount is not parallel to the floor or engine.

Emery Stora
77 Kingsley
Frederick, CO

> On Jan 4, 2017, at 2:45 PM, Rob Mueller wrote:
>
> Bob,
>
> HUH?
>
> Are you saying that with the ride height in your GMC set as per the MM the
> floor is level front to back?
>
> Things as I understand them:
>
> 1) The front and rear ride height setting slots in the frame members are
> located in the same position vertically.
>
> 2) The floor is parallel to the frame members.
>
> 2) The ride height settings are:
>
> Front: 13 1/8" +/- 1/4"
> Rear: 11 11/16" +/- 1/4"
>
> Front is 1 7/16" higher than the rear
>
> 3) The floor is 1 7/16" higher above the front slot than the rear slot
>
> 4) The floor angles downwards slightly front to rear
>
> 5) If a level was to be placed on the top of the air cleaner with the bubble
> fore/aft and the rear suspension ride height raised and lowered the bubble
> would move indicating a change in angle.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
> -----Original Message-----
> From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Bob
> Dunahugh
> Sent: Thursday, January 5, 2017 1:49 AM
> To: gmclist@list.gmcnet.org
> Subject: Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set
> level. But forward.
>
>
> Rob. This manifold tilt has no relationship with ride height. It's based
> on the carb base tilt in relationship to the floor. Just like car, and truck
> floors. Bob Dunahugh
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311839 is a reply to message #311821] Wed, 04 January 2017 16:03 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Bob,

There are three different air cleaners listed in Parts Book 78Z / Section 12
- Fuel / Page 12-7 / Figure 12.020 Air Cleaner

The part numbers reference five different engine part numbers which can be
found in Section 8 - Engine / Page 8-3 / Figure 8.001 - Engine.

It appears that the 403 air cleaner is not the same as the 455 air cleaner.

See what you think.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Bob
Dunahugh
Sent: Thursday, January 5, 2017 1:22 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set
level. But forward.

I assumed that the 455 air filter, and intake have the same tilt. So are
the air filters for both engines interchangeable? Bob Dunahugh


________________________________
From: Bob Dunahugh
Sent: Wednesday, January 4, 2017 12:22 AM
To: gmclist@list.gmcnet.org
Subject: We are 100% WRONG about engine tilt. Carb doesn't set level. But
forward.





Tonight I want out to my GMC's nice warm house. ( It's 10 degrees outside.
GMC's at 70. ) Anyway. My plan was to see if I could get my stock air filter
to fit on the 454 TB. Set the carb, and TB on a board that was on the bench.
( to let the linkage not come in contact with the bench ) Then put the stock
air cleaner on both. Put a spacer on the top of the TB. WHAT. Why is the
air cleaner tilted toward the REAR. This can't be. As the carb base on the
403/455 should be level with the coach floor. Because the top of the air
cleaner is level to the floor. But NO. The air cleaner has a tilt built
into it. Thus the carb mounting surface of the intake manifold has to have
a tilt toward the front. And yes it does. REALLY. So that means the 403/455
have to set level with the floor. Put a straight edge across the hatch
opening. Checked the carb base. Then the valve covers. Engine sets dead
level to the floor. This means that our carbs tilt forward. So now I need
to hang my hea
d down in shame. Bob Dunahugh
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311840 is a reply to message #311839] Wed, 04 January 2017 17:31 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Wouldn't you think the 3 air cleaners are:

1. 455 with ignition points
2. 455 with HEI
3. 403 with HEI
???

Ken H.


On Wed, Jan 4, 2017 at 5:03 PM, Rob Mueller wrote:

> Bob,
>
> There are three different air cleaners listed in Parts Book 78Z / Section
> 12
> - Fuel / Page 12-7 / Figure 12.020 Air Cleaner
>
> The part numbers reference five different engine part numbers which can be
> found in Section 8 - Engine / Page 8-3 / Figure 8.001 - Engine.
>
> It appears that the 403 air cleaner is not the same as the 455 air cleaner.
>
> See what you think.
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set level. But forward. [message #311841 is a reply to message #311840] Wed, 04 January 2017 18:36 Go to previous message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Ken,

Yep!

I've got too much on my plate at the moment to review the info in the Parts
Book and write it out it out in detail.

Anyone that wants to be 100% sure can go to the two references I provided
and figger it out.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Ken
Henderson
Sent: Thursday, January 5, 2017 10:31 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] We are 100% WRONG about engine tilt. Carb doesn't set
level. But forward.

Wouldn't you think the 3 air cleaners are:

1. 455 with ignition points
2. 455 with HEI
3. 403 with HEI
???

Ken H.


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Previous Topic: [GMCnet] Anyone put an aluminum intake manifold on a 403
Next Topic: [GMCnet] Found an original Olds aluminum intake manifold for my 403.
Goto Forum:
  


Current Time: Sat Sep 21 15:30:54 CDT 2024

Total time taken to generate the page: 0.00582 seconds