We are 100% WRONG about engine tilt. Carb doesn't set level. But forward.

B

Bob Dunahugh

New member
Sep 17, 2012
2,784
4
3
Tonight I want out to my GMC's nice warm house. ( It's 10 degre=
es outside. GMC's at 70. ) Anyway. My plan was to see if I could get my sto=
ck air filter to fit on the 454 TB. Set the carb, and TB on a board that wa=
s 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 ma=
nifold has to have a tilt toward the front. And yes it does. REALLY. So tha=
t means the 403/455 have to set level with the floor. Put a straight edge a=
cross the hatch opening. Checked the carb base. Then the valve covers. Engi=
ne sets dead level to the floor. This means that our carbs tilt forward. S=
o now I need to hang my head down in shame. Bob Dunahugh
 
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] On Behalf Of Bob
Dunahugh
Sent: Wednesday, January 4, 2017 5:22 PM
To: gmclist
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
 
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=
Subject: We are 100% WRONG about engine tilt. Carb doesn't set level. Bu=
t 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 w=
ith the bench ) Then put the stock air cleaner on both. Put a spacer on th=
e top of the TB. WHAT. Why is the air cleaner tilted toward the REAR. Thi=
s can't be. As the carb base on the 403/455 should be level with the coac=
h 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 va=
lve 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=
 
Rob. This manifold tilt has no relationship with ride height. It's bas=
ed on the carb base tilt in relationship to the floor. Just like car, and t=
ruck floors. Bob Dunahugh ________________________________ From: Bo=
b Dunahugh Sent: Wednesday, January 4, 2017 8:22 A=
M To: gmclist Subject: RE: We are 100% WRONG about engi=
ne tilt. Carb doesn't set level. But forward. I assumed that the 45=
5 air filter, and intake have the same tilt. So are the air filters for b=
oth engines interchangeable? Bob Dunahugh ________________________=
________ From: Bob Dunahugh Sent: Wednesday, Jan=
uary 4, 2017 12:22 AM To: gmclist 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 out=
side. 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 t=
he bench. ( to let the linkage not come in contact with the bench ) Then p=
ut 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 ca=
rb base on the 403/455 should be level with the coach floor. Because the t=
op 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 mean=
s 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 set=
s 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
 
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] On Behalf Of Bob
Dunahugh
Sent: Thursday, January 5, 2017 1:49 AM
To: gmclist
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
 
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

>
> 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] On Behalf Of Bob
> Dunahugh
> Sent: Thursday, January 5, 2017 1:49 AM
> To: gmclist
> 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
 
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] On Behalf Of Bob
Dunahugh
Sent: Thursday, January 5, 2017 1:22 AM
To: gmclist
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
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
 
Wouldn't you think the 3 air cleaners are:

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

Ken H.

> 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.
>
 
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] On Behalf Of Ken
Henderson
Sent: Thursday, January 5, 2017 10:31 AM
To: gmclist
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.
 
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