Home » Public Forums » GMCnet » GMC Power Train Conversion (GMC Power Train)
| GMC Power Train Conversion [message #143041] |
Mon, 12 September 2011 00:03  |
gedupont
Messages: 5
Registered: September 2011
Location: Prosper, TX
Karma: 0
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Has anyone done a conversion to a diesel engine? What about a more efficient multi-speed automatic transmission?
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| Re: [GMCnet] GMC Power Train Conversion [message #143045 is a reply to message #143043] |
Mon, 12 September 2011 00:45  |
gedupont
Messages: 5
Registered: September 2011
Location: Prosper, TX
Karma: 0
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Junior Member |
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I'm just starting to kick tires. I just have a problem with a gas 455 that
only gets 8 mpg.
George E. Dupont
1400 Harvest Ridge Lane
Prosper, TX 75078-9130
Home: 214-585-0108
Cell: 214-232-5170
georgeedupont@gmail.com
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-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Rob Mueller
Sent: Monday, September 12, 2011 12:39 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] GMC Power Train Conversion
George,
Yes, a number of people have converted to diesel engines. The have all been
hooked to the OEM TH-425 transmissions. This subject has been discussed MANY
times here's a link for you to investigate:
http://tinyurl.com/3opms23
The transmission issue has also been brought up a number of times and as far
as I know there aren't any current generation multi speed front wheel drive
transmissions capable of handling the torque output of a large V-8.
If you're near someone that has done the conversion you could look at them.
Where are you?
What year / model GMC do you have?
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428 USA '75 Avion-Double Trouble
TZE365V100426
-----Original Message-----
From: George E. Dupont
Has anyone done a conversion to a diesel engine? What about a more
efficient multi-speed automatic transmission?
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| Re: [GMCnet] GMC Power Train Conversion [message #143048 is a reply to message #143047] |
Mon, 12 September 2011 02:01 |
gedupont
Messages: 5
Registered: September 2011
Location: Prosper, TX
Karma: 0
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Junior Member |
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I can't talk for Australia, but most RV's in the US today use either LP or
diesel generators. I don't know of a one that uses gasoline any longer.
And that brings up another problem that you probably don't have in Australia
and that 10% ethanol blended fuels. That E10 will eat the living shit out
of all the carb gaskets, rubber o-rings, etc. That's why all the boaters
will NOT use it. Gas powered generators will start biting the dust if you
use E10 or the new E15 that Obama wants mandated. To give you an idea of
how bad the ethanol is/was, all the US stations had to put in new tanks for
the E10. To go with E15, they'll have to replace the E10 tanks. Ethanol
just sucks up every vapor of water it can find and destroys carburetors not
specifically designed for that. Many people in the US are just starting to
figure out why their lawn mowers, weed whackers, etc. aren't lasting like
they used too.
If I had to replace a 455 or rebuild one I'd certainly want to consider a
diesel engine.
George E. Dupont
1400 Harvest Ridge Lane
Prosper, TX 75078-9130
Home: 214-585-0108
Cell: 214-232-5170
georgeedupont@gmail.com
Confidentiality Notice:
This email and any files accompanying its transmission are intended only for
the recipient to whom it was addressed. This email may contain information
that is legally privileged, confidential, or exempt from disclosure under
applicable law. If you are not the intended recipient, be advised that the
unauthorized use, disclosure, duplication, distribution, or the taking of
any action in reliance on this information is strictly prohibited. If you
have received this in error, please notify the sender by return email and
then remove it immediately from your system.
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Rob Mueller
Sent: Monday, September 12, 2011 1:38 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] GMC Power Train Conversion
George,
I don't know of anybody in Texas that has a diesel powered GMC.
Frankly what it will cost you to convert to diesel will take you quite a
long time to recover in fuel savings.
Keep in mind that the Onan runs on gasoline.
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428 USA '75 Avion-Double Trouble
TZE365V100426
-----Original Message-----
From: George E. Dupont
I'm just starting to kick tires. I just have a problem with a gas 455 that
only gets 8 mpg.
George E. Dupont
1400 Harvest Ridge Lane
Prosper, TX 75078-9130
Home: 214-585-0108
Cell: 214-232-5170
georgeedupont@gmail.com
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| Re: [GMCnet] GMC Power Train Conversion [message #143061 is a reply to message #143048] |
Mon, 12 September 2011 07:17 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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George,
Most of us long-time GMCers (possible exceptions are farmers) share your
hatred of ethanol. But its effects on the GMC are certainly nowhere near as
dire as you fear. We've been able to remedy most of the effects on seals,
gaskets, and other rubber components. There's a continuing problem with
deterioration of fuel lines, but as more of us transition to barrier hoses,
that should pretty much go away. When a long-idle coach is resurrected, the
ethanol loosens the old deposits accumulate before ethanol and during
storage, sometimes causing a lot of fuel supply problems. But hose changes,
frequent filter changes, and carburetor rebuilds take care of those. I
haven't seen a single one of the 150 GMC's here at the GMC International
Convention in Goshen, IN pouring fuel all over the ground.
Many people are still having vapor lock problems attributed to ethanol, and
other changes in fuel formulation. But we're slowly learning to deal with
those by re-routing fuel lines, installing electric "pusher" fuel pumps,
converting to electronic fuel injection, etc. Perhaps the ultimate today is
the installation of high pressure fuel pumps in the tanks feeding multi-port
fuel injection. Personally, with only a few of those remedies, I've never
experienced vapor lock with my 455 during 80,000 miles or so from Key West
to Fairbanks, over some of America's highest roads.
As for gas mileage, "you're going to get 8-10 mpg, depending on how you
drive" is a universal mantra among GMC owners. And it's been repeatedly
proven with 403's, 455's, Cadillac 500's, 8.1 Vortec's, and others. Hauling
around 11,000-15000 lbs of house just takes that much energy. Trying to
avoid that fuel cost is too expensive, IMHO, to be worth the effort.
The transmission situation is that the TH-425 is the only viable option. At
least one very capable GMC owner bought and put a lot of study into a
Northstar drive train before abandoning the idea.
Welcome aboard, but if you can't live with 8-10 mpg, I'm afraid you'll
abandon us soon.
JMHO,
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
On Mon, Sep 12, 2011 at 3:01 AM, George E. Dupont
<georgeedupont@gmail.com>wrote:
> I can't talk for Australia, but most RV's in the US today use either LP or
> diesel generators. I don't know of a one that uses gasoline any longer.
> And that brings up another problem that you probably don't have in
> Australia
> and that 10% ethanol blended fuels. ..
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] GMC Power Train Conversion [message #143062 is a reply to message #143061] |
Mon, 12 September 2011 07:40 |
gedupont
Messages: 5
Registered: September 2011
Location: Prosper, TX
Karma: 0
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Junior Member |
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Ken:
Thanks for the intuitive answer. I greatly appreciate it.
George E. Dupont
1400 Harvest Ridge Lane
Prosper, TX 75078-9130
Home: 214-585-0108
Cell: 214-232-5170
georgeedupont@gmail.com
Confidentiality Notice:
This email and any files accompanying its transmission are intended only for
the recipient to whom it was addressed. This email may contain information
that is legally privileged, confidential, or exempt from disclosure under
applicable law. If you are not the intended recipient, be advised that the
unauthorized use, disclosure, duplication, distribution, or the taking of
any action in reliance on this information is strictly prohibited. If you
have received this in error, please notify the sender by return email and
then remove it immediately from your system.
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Ken Henderson
Sent: Monday, September 12, 2011 7:17 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] GMC Power Train Conversion
George,
Most of us long-time GMCers (possible exceptions are farmers) share your
hatred of ethanol. But its effects on the GMC are certainly nowhere near as
dire as you fear. We've been able to remedy most of the effects on seals,
gaskets, and other rubber components. There's a continuing problem with
deterioration of fuel lines, but as more of us transition to barrier hoses,
that should pretty much go away. When a long-idle coach is resurrected, the
ethanol loosens the old deposits accumulate before ethanol and during
storage, sometimes causing a lot of fuel supply problems. But hose changes,
frequent filter changes, and carburetor rebuilds take care of those. I
haven't seen a single one of the 150 GMC's here at the GMC International
Convention in Goshen, IN pouring fuel all over the ground.
Many people are still having vapor lock problems attributed to ethanol, and
other changes in fuel formulation. But we're slowly learning to deal with
those by re-routing fuel lines, installing electric "pusher" fuel pumps,
converting to electronic fuel injection, etc. Perhaps the ultimate today is
the installation of high pressure fuel pumps in the tanks feeding multi-port
fuel injection. Personally, with only a few of those remedies, I've never
experienced vapor lock with my 455 during 80,000 miles or so from Key West
to Fairbanks, over some of America's highest roads.
As for gas mileage, "you're going to get 8-10 mpg, depending on how you
drive" is a universal mantra among GMC owners. And it's been repeatedly
proven with 403's, 455's, Cadillac 500's, 8.1 Vortec's, and others. Hauling
around 11,000-15000 lbs of house just takes that much energy. Trying to
avoid that fuel cost is too expensive, IMHO, to be worth the effort.
The transmission situation is that the TH-425 is the only viable option. At
least one very capable GMC owner bought and put a lot of study into a
Northstar drive train before abandoning the idea.
Welcome aboard, but if you can't live with 8-10 mpg, I'm afraid you'll
abandon us soon.
JMHO,
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL www.gmcwipersetc.com
On Mon, Sep 12, 2011 at 3:01 AM, George E. Dupont
<georgeedupont@gmail.com>wrote:
> I can't talk for Australia, but most RV's in the US today use either
> LP or diesel generators. I don't know of a one that uses gasoline any
longer.
> And that brings up another problem that you probably don't have in
> Australia and that 10% ethanol blended fuels. ..
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| Re: [GMCnet] GMC Power Train Conversion [message #143063 is a reply to message #143048] |
Mon, 12 September 2011 08:07 |
k2gkk
Messages: 4452
Registered: November 2009
Karma: -8
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Senior Member |
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Diesel powered RVs will naturally use Diesel fuel for generators.
Gasoline engined RVs generally use LP generators for convenience
and safety. Carbon monoxide is a pervasive problem with gasoline
powered equipment and therefore quite hazardous for provision
of power in living spaces. Onan quit marketing gasoline generators
for boats quite a few years ago for that problem.
The BIGGEST problems with boats and ethanol-bearing gasoline arises
when "plastic" fuel tanks are attacked by the ethanol which tends to
dissolve the resins in the fiberglass reinforced plastic (FRP) and
that is reportedly what is clogging engines, etc.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~~ ~ D C "Mac" Macdonald ~ ~~
~ ~ Amateur Radio - K2GKK ~ ~
~ ~ USAF and FAA, Retired ~ ~
~ ~ ~ Oklahoma City, OK ~ ~ ~
~~ ~ ~ "The Money Pit" ~ ~ ~~
~ ~ ~ ex-Palm Beach, 76 ~ ~ ~
~ www.gmcmhphotos.com/okclb ~
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
> From: georgeedupont@gmail.com
> To: robmueller@iinet.net.au
> Date: Mon, 12 Sep 2011 02:01:21 -0500
> CC: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] GMC Power Train Conversion
>
> I can't talk for Australia, but most RV's in the US today use either LP or
> diesel generators. I don't know of a one that uses gasoline any longer.
> And that brings up another problem that you probably don't have in Australia
> and that 10% ethanol blended fuels. That E10 will eat the living shit out
> of all the carb gaskets, rubber o-rings, etc. That's why all the boaters
> will NOT use it. Gas powered generators will start biting the dust if you
> use E10 or the new E15 that Obama wants mandated. To give you an idea of
> how bad the ethanol is/was, all the US stations had to put in new tanks for
> the E10. To go with E15, they'll have to replace the E10 tanks. Ethanol
> just sucks up every vapor of water it can find and destroys carburetors not
> specifically designed for that. Many people in the US are just starting to
> figure out why their lawn mowers, weed whackers, etc. aren't lasting like
> they used too.
>
> If I had to replace a 455 or rebuild one I'd certainly want to consider a
> diesel engine.
>
> George E. Dupont
> 1400 Harvest Ridge Lane
> Prosper, TX 75078-9130
> Home: 214-585-0108
> Cell: 214-232-5170
> georgeedupont@gmail.com
>
>
>
>
> -----Original Message-----
> From: gmclist-bounces@temp.gmcnet.org
> [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Rob Mueller
> Sent: Monday, September 12, 2011 1:38 AM
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] GMC Power Train Conversion
>
> George,
>
> I don't know of anybody in Texas that has a diesel powered GMC.
>
> Frankly what it will cost you to convert to diesel will take you quite a
> long time to recover in fuel savings.
>
> Keep in mind that the Onan runs on gasoline.
>
> Regards,
> Rob M.
> Sydney, Australia
> AUS '75 Avion-The Blue Streak TZE365V100428 USA '75 Avion-Double Trouble
> TZE365V100426
>
> -----Original Message-----
> From: George E. Dupont
>
> I'm just starting to kick tires. I just have a problem with a gas 455 that
> only gets 8 mpg.
>
> George E. Dupont
> 1400 Harvest Ridge Lane
> Prosper, TX 75078-9130
> Home: 214-585-0108
> Cell: 214-232-5170
> georgeedupont@gmail.com
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| Re: [GMCnet] GMC Power Train Conversion [message #143074 is a reply to message #143048] |
Mon, 12 September 2011 10:10 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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George,
E-10 has been introduced here in Australia and there are lots of diesel powered motorhomes with diesel generators, not sure about
LPG generators.
AutoGas (60% LPG 40% Butane) is quite common. Ford sells a UTE that runs ONLY on AutoGas. I'm not sure if the program is still
available but at one time if you bought a vehicle that ran on AutoGas the Federal Government would give you a $1000 payment. If you
converted a vehicle to run on AutoGas they would give you $2000. Unfortunately that didn't extend to motorhomes. Despite that I am
building a Caddy 500 to run on AutoGas.
The current fuel prices are; Petrol is $1.37 ± per litre; Diesel is $1.47± P/L, and AutoGas is around $0.57 ± P/L! Yes, you burn
about 10-15% more but AutoGas is still the cheapest! By the way as I noted in my previous message even with that dramatic price
difference I'll probably NEVER recoup my investment.
You are correct E-10 is a PITA for GMC owners just as it is for any vehicle from that era. We also have problems with motor oil that
doesn't have sufficient levels of ZDDP for flat tappet cams.
I see Ken has responded regarding your concerns regarding ethanol.
There is one thing you may not be aware of, a great percentage of the individuals that frequent this Forum are gear heads. Tinkering
with these old "Gals" is just as much fun to many of us as using them for travel. We also have LOTS of rallies where we get together
to share our camaraderie.
The point of my comments were not to discourage you from getting a GMC just to provide you with information about the realities of
building a diesel powered GMC from cost of ownership standpoint.
Hope you stick around and find yourself a GMC so you can join us!
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: George E. Dupont
I can't talk for Australia, but most RV's in the US today use either LP or
diesel generators. I don't know of a one that uses gasoline any longer.
And that brings up another problem that you probably don't have in Australia
and that 10% ethanol blended fuels. That E10 will eat the living shit out
of all the carb gaskets, rubber o-rings, etc. That's why all the boaters
will NOT use it. Gas powered generators will start biting the dust if you
use E10 or the new E15 that Obama wants mandated. To give you an idea of
how bad the ethanol is/was, all the US stations had to put in new tanks for
the E10. To go with E15, they'll have to replace the E10 tanks. Ethanol
just sucks up every vapor of water it can find and destroys carburetors not
specifically designed for that. Many people in the US are just starting to
figure out why their lawn mowers, weed whackers, etc. aren't lasting like
they used too.
If I had to replace a 455 or rebuild one I'd certainly want to consider a
diesel engine.
George E. Dupont
1400 Harvest Ridge Lane
Prosper, TX 75078-9130
Home: 214-585-0108
Cell: 214-232-5170
georgeedupont@gmail.com
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: GMC Power Train Conversion [message #143109 is a reply to message #143041] |
Mon, 12 September 2011 16:12 |
GeorgeRud
Messages: 1380
Registered: February 2007
Location: Chicago, IL
Karma: 0
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Senior Member |
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A while ago, JimB had a video showing a propane conversion, and I have read that others have done the same.
That may be a cheaper alternative if you want to change from the currently available fuels (I have trouble calling E-10 gasoline).
Enjoy your project in good health!
George Rudawsky
Chicago, IL
75 Palm Beach
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| Re: [GMCnet] GMC Power Train Conversion [message #143114 is a reply to message #143109] |
Mon, 12 September 2011 16:50 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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George,
Yes, JimB built that GMC for a guy in England and it was still there last year. Not that Jim did anything wrong, IIRC the guy that
commissioned it had problems at his end.
I just checked LPG prices at Flying J in the USA and the lowest was in Ogden, UT @ $3.19 and the highest was $3.39 in Pearl, MS.
Since it takes 10-15% more LPG than gasoline to run an engine it's doesn't appear to be cheaper. Cleaner burning, better for the
engine, better for planet, yes, better for your wallet - nope!
Also since LPG is not widely available in the USA you'd have to plan fuel stops.
Regards,
Rob M.
Sydney, Australia
-----Original Message-----
From: George Rudawsky
A while ago, JimB had a video showing a propane conversion, and I have read that others have done the same.
That may be a cheaper alternative if you want to change from the currently available fuels (I have trouble calling E-10 gasoline).
Enjoy your project in good health!
--
George
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: GMC Power Train Conversion [message #143151 is a reply to message #143041] |
Mon, 12 September 2011 20:25 |
bobby5832708
Messages: 237
Registered: November 2006
Location: Winter Springs FL
Karma: 3
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Senior Member |
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George,
you wrote:
"but most RV's in the US today use either LP or
diesel generators. I don't know of a one that uses gasoline any longer"
I just looked over at my neighbors yard and his current RV is a 2011 Jayco Greyhawk 31SS and it's got a gas Onan 4kw generator. I called him to verify, I try not to spread mistruths.
His previous RV was a 2005 Coachmen Freelander, also had an Onan gas generator, he thinks it was also a 4kw, not positive on the size.
There are lots of newer class C's around here in Florida like my neighbors, come to think of it I was in Houston in June and there were plenty of class C's there too. I would think most of them had the same gas Onans or something similar, correct me if I'm wrong.
Both of his RV's use a Ford E450 chassis with the 6.8 V10 engine. He always complained that the Coachmen got 7 to 8 mpg when the dealer said it would do 10. The new Jayco he says isn't really any better on gas. They go to NASCAR tracks around the southeast so it's mostly highway driving they do. That said, my 455 with QJet gets right on 10 mpg on trips when I keep the speed between 65 and 70 and don't do too much stop-and-go. City driving kills the mileage.
The newer gas engines may be somewhat more efficient than the old 455 but I think the overhead cams and 3 valves/cyl just lets you burn more gas to get the power when you need it rather than use more cubic inches like the older engines, point being that to move something as heavy as our RV's a smaller engine may not really get better mileage as you have to burn gasoline to make power. Naturally a diesel would be better for fuel economy but is the cost of retrofitting worth it? I can buy a heckuva lot of gas for the cost of the diesel transplant.
I haven't had any of the issues that are blamed on E10. I used Gates fuel hose when I replumbed my fuel system 5 years ago. This past summer I did some more fuel system modifications and cut open a piece of that old, used Gates hose and it looked and felt fine. The QJet was rebuilt by me with quality parts not purchased from one of the large auto parts stores, it works fine. Jim Bounds has been in my GMC a few times and he has never complained about the way it ran. I buy the same cheap regular gas everyone else uses and try to get it from busy stations to avoid getting stuff that has sat around collecting moisture and gunk. Naturally I would like to see no alcohol in the gas but I think the E10 gets blamed for much more than it should. If your fuel system is marginal - old hoses or cheap chinese carb parts - then E10 may cause problems. Solution: use quality parts!
Anyway, the GMC's are fun to tinker with and use and don't cost a fortune to run and maintain. Mine has been very reliable for the 5 years I've had it, never had to be towed. If you want an RV that you just gas-and-go and let someone else maintain and repair you might want a late model rig with a warranty, maybe with a diesel engine if getting the absolute best mpg is important to you. It depends on what you want.
Just my opinion!
Bob Heller
2017 Winnebago 29VE
Winter Springs FL
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| Re: [GMCnet] GMC Power Train Conversion [message #143185 is a reply to message #143151] |
Tue, 13 September 2011 06:47 |
Jim Bounds
Messages: 842
Registered: January 2004
Karma: 0
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Senior Member |
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It really depends on why you wanna make a "drive train conversion". If you want to do it because you want to, I would say that's really the best reason to do it. If it's to "save money" forget about it! The cost of the conversion then the coast of maintenance (probably will have to be done by you yourself or spend big bucks for a tech to understand what you did everytime before he digs into it), there really isn;t much savings in doing it-- been there, done that and have the scars to prove it.
Heck, even look at a quality gas conversion like the 454 Dave L. did-- the time & money he put into really "doing it right", heck that would really pay for enough gas to probably drive you for a very long time!
He's too modest to say it but Bob has the diestiction of holding the 1/4 mile speed record in his totally bone stock drive train. No smoke and mirrors, just a properly tuned, maintained set up dusted everyone like a dirty ledge. A direct port, set up with serpanitne belt, hopped up diff got left in the dirt by his stock grocery getter. Gets better mileage than most of you and is so flippn reliable it fires every time, runs on the sludge gas and purrs like a kitten on steroids!
I believe that a normally aspirated, well tuned and maintained original engine (I must say though I do like a little more umph off the line so the cam we use does that) but you will not see much improvement if any deviating anywhere from the stock 455 or 403 motors. Just ain;t happenen, it take grahomas to pull weight and that's what our drive trains have. They have age and that's where maintanance and tuning come into play. Bob is a killer on that. His power plant runs perfect, has no variable MSD, FI, or any of that. He drives realistic and for the record drives it often which I also feel is a reason his runs so well. Let them sit and they screw up, exercise a pony and he rides better and I think it's the same way with our vintage RV's. Never leave the stable and you have a "trailer queen".
I feel the best way to get the most from your coach is to make it work well with what you have, drive it often and keep up with the maintenance. We really do have a perfectly balanced motorhome, it's why they put all that engineering on the front end and who are we shadetree guys piddling think we can do better. I like new ideas, technologies but I still feel you need to understand what was done right. If you prepare for E-10, you can live with it, if you don't--- you won;t!
The new RV's on the road don;t do much if any better than 10 MPG, if it does-- it's a "downsized" platform that is personally simply too small to enjoy. Just depends on what you want,
Jim Bounds
-----------------------------
----- Original Message -----
From: Bob Heller <rheller@cfl.rr.com>
To: gmclist@temp.gmcnet.org
Cc:
Sent: Monday, September 12, 2011 9:25 PM
Subject: Re: [GMCnet] GMC Power Train Conversion
George,
you wrote:
"but most RV's in the US today use either LP or
diesel generators. I don't know of a one that uses gasoline any longer"
I just looked over at my neighbors yard and his current RV is a 2011 Jayco Greyhawk 31SS and it's got a gas Onan 4kw generator. I called him to verify, I try not to spread mistruths.
His previous RV was a 2005 Coachmen Freelander, also had an Onan gas generator, he thinks it was also a 4kw, not positive on the size.
There are lots of newer class C's around here in Florida like my neighbors, come to think of it I was in Houston in June and there were plenty of class C's there too. I would think most of them had the same gas Onans or something similar, correct me if I'm wrong.
Both of his RV's use a Ford E450 chassis with the 6.8 V10 engine. He always complained that the Coachmen got 7 to 8 mpg when the dealer said it would do 10. The new Jayco he says isn't really any better on gas. They go to NASCAR tracks around the southeast so it's mostly highway driving they do. That said, my 455 with QJet gets right on 10 mpg on trips when I keep the speed between 65 and 70 and don't do too much stop-and-go. City driving kills the mileage.
The newer gas engines may be somewhat more efficient than the old 455 but I think the overhead cams and 3 valves/cyl just lets you burn more gas to get the power when you need it rather than use more cubic inches like the older engines, point being that to move something as heavy as our RV's a smaller engine may not really get better mileage as you have to burn gasoline to make power. Naturally a diesel would be better for fuel economy but is the cost of retrofitting worth it? I can buy a heckuva lot of gas for the cost of the diesel transplant.
I haven't had any of the issues that are blamed on E10. I used Gates fuel hose when I replumbed my fuel system 5 years ago. This past summer I did some more fuel system modifications and cut open a piece of that old, used Gates hose and it looked and felt fine. The QJet was rebuilt by me with quality parts not purchased from one of the large auto parts stores, it works fine. Jim Bounds has been in my GMC a few times and he has never complained about the way it ran. I buy the same cheap regular gas everyone else uses and try to get it from busy stations to avoid getting stuff that has sat around collecting moisture and gunk. Naturally I would like to see no alcohol in the gas but I think the E10 gets blamed for much more than it should. If your fuel system is marginal - old hoses or cheap chinese carb parts - then E10 may cause problems. Solution: use quality parts!
Anyway, the GMC's are fun to tinker with and use and don't cost a fortune to run and maintain. Mine has been very reliable for the 5 years I've had it, never had to be towed. If you want an RV that you just gas-and-go and let someone else maintain and repair you might want a late model rig with a warranty, maybe with a diesel engine if getting the absolute best mpg is important to you. It depends on what you want.
Just my opinion!
--
Bob Heller
1974 X-Canyonlands 26ft
Winter Springs FL
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| Re: GMC Power Train Conversion [message #143234 is a reply to message #143041] |
Tue, 13 September 2011 19:08 |
Chr$
Messages: 2690
Registered: January 2004
Location: Scottsdale, AZ
Karma: 1
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Senior Member |
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You'll get 6MPG if you ruin 85MPH from Phoenix to Quartzite with the windows open. VBG.
I love my GMC. My foot loves the Carb.
-Chr$: Perpetual SmartAss
Scottsdale, AZ
77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
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| Re: [GMCnet] GMC Power Train Conversion [message #143246 is a reply to message #143234] |
Tue, 13 September 2011 20:12 |
Dolph Santorine
Messages: 1236
Registered: April 2011
Location: Wheeling, WV
Karma: -41
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Senior Member |
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I can only imagine the look on the officers face for that ticket(g)
Dolph Santorine
Dolph@DolphSantorine.com
Phone: 304-219-3100
Cell: 740-312-5342
Http://www.DolphSantorine.com
On Sep 13, 2011, at 8:08 PM, Chris Choffat <cchoffataz@yahoo.com> wrote:
>
>
> You'll get 6MPG if you ruin 85MPH from Phoenix to Quartzite with the windows open. VBG.
>
> I love my GMC. My foot loves the Carb.
> --
> -Chr$: Perpetual SmartAss
> Scottsdale, AZ
> "The Escape Pod" A 77 Ex-Kingsley Featuring: Olds 455, Manny Power Drive, 3:21, Rockwell, Jim B QJET, Quadra bag. Still needs paint!
>
> Photosite: Chrisc "It has Begun"
> _______________________________________________
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| Re: [GMCnet] GMC Power Train Conversion [message #143263 is a reply to message #143048] |
Tue, 13 September 2011 21:32 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| gedupont wrote on Mon, 12 September 2011 03:01 |
I can't talk for Australia, but most RV's in the US today use either LP or diesel generators. I don't know of a one that uses gasoline any longer. = A
And that brings up another problem that you probably don't have in Australia and that 10% ethanol blended fuels. That E10 will eat the living shit out of all the carb gaskets, rubber o-rings, etc. That's why all the boaters will NOT use it. = B
Gas powered generators will start biting the dust if you use E10 or the new E15 that Obama wants mandated. To give you an idea of how bad the ethanol is/was, all the US stations had to put in new tanks for the E10. To go with E15, they'll have to replace the E10 tanks. Ethanol just sucks up every vapor of water it can find and destroys carburetors not specifically designed for that. Many people in the US are just starting to figure out why their lawn mowers, weed whackers, etc. aren't lasting like they used too. = C
If I had to replace a 455 or rebuild one I'd certainly want to consider a diesel engine. = D
George E. Dupont
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George,
You have openned a number of issues here, and I am going to respond based on my personal and verifiable knowledge.
A = Lots of new RV are gasoline powered. They are class B+ and C. New class A coaches are usually diesel because they are either stick and staple on bus chassis or upfitted bus shells. Some of the Cs built on Dodge/MB/Freightliner chassis have a choice at a significant premium cost. That premium can be recovered in just a little less that 200,000 miles (give or take).
B = KenH addressed the fuel line issues, and Rochester Carburetor is supplying kits that are as ethanol compatible as is possible with current materials. Around here (there are a few powered pleasure boats on the great lakes) and the owners buy the ethanol-free fuel (currently ~4.50/gal) mostly because the old engines have not had the advantage we have had of testing and development required to be compatible. Many also have installed the upgrades and so can run road fuel. Bertram is one of the very few upscale powerboats with polyester resin based fuel tanks and they are in real big trouble.
C = Yes, E-10 is causing trouble all over, but the government and the pseudo-greenies don't care. They just point and scream.
D = Go ahead and consider a diesel engine. Before you do, study up on "rear face of block" and what it means. There is very little that a TH425 can be bolted up to and vice-versa. Nobody has yet identified a replacement for that.
Good to see you are thinking. It is the most cost effective thing you can do.
By the by, I am a Detroit engineer that has been driving diesel passenger cars and taking care of small diesel boats for a very long time.
Matt
The information contained in this message and any attachment may be proprietary, a partial fabrication, marginally in error or just plain bullshit. If the reader of this message is not the intended recipient and/or does not know or care who is, he is free to ignore and delete it just as the intended recipient probably would. If you have received this communication in error, please don’t notify me this won’t even be close the biggest screw up of my day. Thank you.
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] GMC Power Train Conversion [message #143273 is a reply to message #143263] |
Tue, 13 September 2011 22:00 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Matt,
Your response is up to your usual standard but your "disclaimer" at the end of the message is absolutely PRICELESS!
Regards,
Rob M.
-----Original Message-----
From: Matt Colie
The information contained in this message and any attachment may be proprietary, a partial fabrication, marginally in error or just
plain bullshit. If the reader of this message is not the intended recipient and/or does not know or care who is, he is free to
ignore and delete it just as the intended recipient probably would. If you have received this communication in error, please don't
notify me this won't even be close the biggest screw up of my day. Thank you.
--
Matt
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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