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| Re: Gadabout Restoration - 403 Engine Dyno Results [message #276657 is a reply to message #276609] |
Fri, 24 April 2015 19:51   |
Gadabout
Messages: 124
Registered: March 2013
Location: Edmonton
Karma: 2
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Senior Member |
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Hi Harry,
Yes, the engine was built in Edmonton.
I will have another 403 and 455 built and ready as spares should someone be in a bind for one.
Carl Harr : Driver NASCAR Pro Series #2
1978 Gadabout-Restoring
1978 Palm Beach
1976 Glenbrook
Prevost Featherlite H3-45
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| Re: Gadabout Restoration - 403 Engine Dyno Results [message #276659 is a reply to message #276609] |
Fri, 24 April 2015 20:13 |
Gadabout
Messages: 124
Registered: March 2013
Location: Edmonton
Karma: 2
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Senior Member |
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Hi Jerrod,
If my information is correct, the Factory rating for the 403 was around 200HP @3600 with 330Trq @2400
These would be considered as NET numbers meaning they include the overhead of all accessories that the engine has to deal with such as emission control, waterpump, alternator, mufflers and exhaust system.
The numbers I provided from our Dyno test are in GROSS , no overhead , no mufflers and headers instead of exhaust manifolds.
There is a good article here http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/ on the history of how HorsePower ratings changed over the years.
Carl Harr : Driver NASCAR Pro Series #2
1978 Gadabout-Restoring
1978 Palm Beach
1976 Glenbrook
Prevost Featherlite H3-45
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| Re: [GMCnet] Gadabout Restoration - 403 Engine Dyno Results [message #276690 is a reply to message #276672] |
Sat, 25 April 2015 08:59 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Depends upon the dyno. We used to have a Clayton chassis Dyno in the shop
where I worked, it pumped antifreeze solution through a variable resistance
hydraulic valve to load the tires. It wasn't worth much at low rpm. More
modern Eddy Current load cells are much better at lower rpm. But, 2000 rpm
is just idle speed for most high performance stuff. We need accuracy from
1250 to 3200 or so with our coaches the way they are geared. Not an easy
thing to achieve with dropped center intake manifolds and great big valves
and cylinders with fairly low compression and almost no squish area. I'm
surprised that they do as well as they do.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On Apr 24, 2015 8:54 PM, "Rob Mueller" wrote:
> Carl,
>
> Nice looking dyno run, however, why does it start at 2600 rpm and there is
> no data below that.
>
> I may be all wet but wouldn't data off idle to 2600 rpm show how a GMC
> would accelerate up to highway speed?
>
> Regards,
> Rob M.
>
> -----Original Message-----
> From: Carl
>
> For those who have asked (and those interested) here is the dyno results.
>
> These are Gross results on the engine dyno (not a chassis dyno.)
>
> No major performance modifications were made during the rebuild, heads
> were cleaned up and
> a 3 angle valve grind. Stock Carb and distributor.
>
> Carl Harr
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: [GMCnet] Gadabout Restoration - 403 Engine Dyno Results [message #276711 is a reply to message #276690] |
Sat, 25 April 2015 16:26 |
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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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Jim,
1250 to 3200 = SPOT ON!
Regards,
Rob M.
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of James Hupy
Sent: Sunday, April 26, 2015 12:00 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Gadabout Restoration - 403 Engine Dyno Results
Depends upon the dyno. We used to have a Clayton chassis Dyno in the shop
where I worked, it pumped antifreeze solution through a variable resistance
hydraulic valve to load the tires. It wasn't worth much at low rpm. More
modern Eddy Current load cells are much better at lower rpm. But, 2000 rpm
is just idle speed for most high performance stuff. We need accuracy from
1250 to 3200 or so with our coaches the way they are geared. Not an easy
thing to achieve with dropped center intake manifolds and great big valves
and cylinders with fairly low compression and almost no squish area. I'm
surprised that they do as well as they do.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On Apr 24, 2015 8:54 PM, "Rob Mueller" wrote:
> Carl,
>
> Nice looking dyno run, however, why does it start at 2600 rpm and there is
> no data below that.
>
> I may be all wet but wouldn't data off idle to 2600 rpm show how a GMC
> would accelerate up to highway speed?
>
> Regards,
> Rob M.
>
> -----Original Message-----
> From: Carl
>
> For those who have asked (and those interested) here is the dyno results.
>
> These are Gross results on the engine dyno (not a chassis dyno.)
>
> No major performance modifications were made during the rebuild, heads
> were cleaned up and
> a 3 angle valve grind. Stock Carb and distributor.
>
> Carl Harr
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
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Unsubscribe or Change List Options:
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_______________________________________________
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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: Gadabout Restoration - 403 Engine Dyno Results [message #276803 is a reply to message #276781] |
Mon, 27 April 2015 08:23 |
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thesmith
Messages: 589
Registered: February 2015
Location: Cary, NC
Karma: 6
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Senior Member |
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Dennis S wrote on Sun, 26 April 2015 21:06Carl
Just curious -- is the plan to restore the coach to as close as factory original as possible or restore/modified?
Dennis
Given that it was a very low volume design, I'd keep interior and exterior as stock as possible, but upgrade the mechanicals.............new airbags systems,disks all around, electric wipers , TBI, 3.7 Diff etc...........afterall Coke likely did not care less about those items at all...........
Pete
Cary, NC
1978 Center Kitchen Royale.
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| Re: Gadabout Restoration - 403 Engine Dyno Results [message #276833 is a reply to message #276609] |
Mon, 27 April 2015 13:46 |
Gadabout
Messages: 124
Registered: March 2013
Location: Edmonton
Karma: 2
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Senior Member |
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Hi Dennis and Pete,
The Gadabout will be restored as close as to factory as possible.
I was able to obtain a skid of NOS parts from a dealership so anything that cannot be rebuilt to "as-new" is being replaced with new parts.
The frame and clip assembly is progressing well, I will post some updated photos soon.
Carl Harr : Driver NASCAR Pro Series #2
1978 Gadabout-Restoring
1978 Palm Beach
1976 Glenbrook
Prevost Featherlite H3-45
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| Re: Gadabout Restoration - 403 Engine Dyno Results [message #276836 is a reply to message #276833] |
Mon, 27 April 2015 14:07 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Gadabout wrote on Mon, 27 April 2015 13:46Hi Dennis and Pete,
The Gadabout will be restored as close as to factory as possible.
I was able to obtain a skid of NOS parts from a dealership so anything that cannot be rebuilt to "as-new" is being replaced with new parts.
The frame and clip assembly is progressing well, I will post some updated photos soon.
Carl
Thanks for explaining --
I believe it's important some of the coaches are restored as you are planning.
While I have a limited number of spares that might work - please post any needs as I would like to contribute and see you progress.
Look forward to the photo update.
Dennis
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] Gadabout Restoration - 403 Engine Dyno Results [message #276883 is a reply to message #276803] |
Tue, 28 April 2015 03:02 |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
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Senior Member |
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Juicy i
Emeryj
> On Apr 27, 2015, at 7:23 AM, Pete Smith wrote:
>
> Dennis S wrote on Sun, 26 April 2015 21:06
>> Carl
>>
>> Just curious -- is the plan to restore the coach to as close as factory original as possible or restore/modified?
>>
>> Dennis
>
>
>
> Given that it was a very low volume design, I'd keep interior and exterior as stock as possible, but upgrade the mechanicals.............new airbags
> systems,disks all around, electric wipers , TBI, 3.7 Diff etc...........afterall Coke likely did not care less about those items at all...........
>
> Pete
> --
> Cary, NC
>
> No Coach yet but decided it will be wet bath.
> perhaps a 1978 Kingsley....
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclistuy
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