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

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Forum: GMCnet
 Topic: Carb fuel connection
Re: [GMCnet] Carb fuel connection [message #327197 is a reply to message #327169] Sun, 17 December 2017 02:14
Ken Burton is currently offline  Ken Burton   United States
Messages: 8381
Registered: January 2004
Location: Hebron, Indiana
Karma:
Senior Member

Thank you Rick

Ken B.

Richard Denney wrote on Sat, 16 December 2017 09:06
Ken, I did not reinstall the filter can, but instead used an adapter from
the large filter-can threads to an AN-6 flare. Then, I used a hose with a
right-angle AN-6 flare fitting. I have an inline filter in an AN-6 metal
body in the aircraft hose just upstream from that point. The hoses are
rated at high enough temperature for that application.

Rick "or you could buy a metal line for a mechanical fuel pump from JimK
and cut off the flare and bend at the carb end, etc." Denney






Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 Topic: Re: [GMCnet] The impact of extra weight on GMC handling
Re: [GMCnet] The impact of extra weight on GMC handling [message #327198 is a reply to message #327176] Sun, 17 December 2017 03:05
johnd01 is currently offline  johnd01   United States
Messages: 137
Registered: July 2017
Location: Sacrameot
Karma:
Senior Member
Re: I pull a 9,000 lbs enclosed trailer with a car/shop behind a 12,000 lbs 403 powered Royale
Are you saying the trailer contains a car/shop?
What brakes does the trailer have?
Does the trailer effect your stopping distance?
What is your final drive ratio?


Johnd01 John Phillips Avion A2600 TZE064V101164 Rancho Cordova, CA (Sacramento)
 Topic: Power Drive
Re: [GMCnet] Power Drive [message #327194 is a reply to message #327193] Sun, 17 December 2017 00:05
jimk is currently offline  jimk   United States
Messages: 4509
Registered: July 2006
Location: Belmont, CA
Karma:
Senior Member
On Sat, Dec 16, 2017 at 9:27 PM James Hupy wrote:

> The TM 425 was originally designed to move a 4000 pound car. We are asking
> it to move a 12,000 pound motor home. The same old formula, F x D = Torque
> applies in both situations. The motor home is at a three to one
> disadvantage weight wise to the cars. Thus, the power drive and different
> gearing in the final drives. Manny T sells the power drive and builds
> transmissions too. Good guy, knows his stuff. Good friend to the whole GMC
> community. The power drive is hell for strong, like the rest of the TM-425.
> I wouldn't worry about it.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
> On Dec 16, 2017 8:53 PM, "Bill Wevers" wrote:
>
>> Sounds like you have a good set-up.
>> Most people prefer final drive ratios between 3.50 and 3.70.
>> The power drive is equivalent to having 3.50.
>> The 3.21 will bump it up to 3.66 equivalent.
>>
>> With the 3.07 gears, the carburetor power enrichment circuit
>> kicks in a lot because of the low manifold vacuum.
>>
>>
>>
>> --
>> Bill Wevers GMC49ers, GMC Western States
>> 1975 Glenbrook - Manny Powerdrive, OneTon
>> 455 F Block, G heads
>> San Jose
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>> why don't you go back to 3.07 then tell me your experience.

some have done that but too proud to admit the mistake.
All the RV units that use chassis from suppliers run 4.11 /4.55 using the
same wheel and tire.GM , Ford and Chrysler know more than us

>
> _______________________________________________
> GMCnet mailing list
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>
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> B

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk-AT-appliedairfilters-DOT-com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk-AT-appliedairfilters-DOT-com
www.appliedgmc.com
1-800-752-7502
Re: Power Drive [message #327195 is a reply to message #327192] Sun, 17 December 2017 00:55
NextGenGMC is currently offline  NextGenGMC   United States
Messages: 3
Registered: December 2017
Location: Washington State
Karma:
Junior Member
bwevers wrote on Sat, 16 December 2017 20:52
Sounds like you have a good set-up.
Most people prefer final drive ratios between 3.50 and 3.70.
The power drive is equivalent to having 3.50.
The 3.21 will bump it up to 3.66 equivalent.

With the 3.07 gears, the carburetor power enrichment circuit
kicks in a lot because of the low manifold vacuum.




I must admit that carburetors are a mystery to me... I feel much easier with computers and fuel injection (conversion project is going to happen some day). Would it be beneficial to change a final drive ratio to bring it closer to a 3.55 combined number?
Re: [GMCnet] Power Drive [message #327196 is a reply to message #327194] Sun, 17 December 2017 01:02
NextGenGMC is currently offline  NextGenGMC   United States
Messages: 3
Registered: December 2017
Location: Washington State
Karma:
Junior Member
[quote

some have done that but too proud to admit the mistake.
All the RV units that use chassis from suppliers run 4.11 /4.55 using the
same wheel and tire.GM , Ford and Chrysler know more than us

[/quote]

Are you referring to making a mistake of lowering final drive ratio on the GMC?
As far as box RVs - yes, they run a much higher final drive ratios, but that it because output shaft on transmission comes out at a very different speed from what we have going on in our GMCs
Re: [GMCnet] Power Drive [message #327199 is a reply to message #327196] Sun, 17 December 2017 03:29
johnd01 is currently offline  johnd01   United States
Messages: 137
Registered: July 2017
Location: Sacrameot
Karma:
Senior Member
[quote title=NextGenGMC wrote on Sun, 17 December 2017 01:02][quote

some have done that but too proud to admit the mistake.
All the RV units that use chassis from suppliers run 4.11 /4.55 using the
same wheel and tire.GM, Ford, and Chrysler know more than us

[/quote]

Are you referring to making a mistake of lowering final drive ratio on the GMC?
As far as box RVs - yes, they run a much higher final drive ratios, but that it because output shaft on transmission comes out at a very different speed from what we have going on in our GMCs[/quote]

Are you saying that both transmissions do not have a 1 to 1 ratio in high gear?


Johnd01 John Phillips Avion A2600 TZE064V101164 Rancho Cordova, CA (Sacramento)



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