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| modern engine swap [message #304100] |
Sun, 24 July 2016 10:00  |
ns1113
Messages: 2
Registered: March 2016
Karma: 0
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Junior Member |
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Hello,
I have read trough the forums where there is some mention of LS engine swaps and diesel swaps. I wondering if there is a trend to go with a more modern LS 8.1 engine rather the rebuild existing 455, adding FI etc...? I appreciate keeping things original, but wouldn't mind the improvements a more modern engine can offer. I might own this another 30-40 years and was thinking possibly better mpg, better performance and reliability.
With the diesel swaps it sounds like heavy frame fabrication is needed. With an 8.1 it appears that it should drop right in, can run the factory wiring harness and get adapter plates for the transmission. Any thoughts are appreciated.
Thanks,
Nick
Below are the specs I found for each engine. Which I am not sure accurate due to how they measured HP/Torque back in the 70's compared to now guessing there is a bigger discrepancy.
LS 8.1
Horsepower: 330 @ 4200 RPM
Torque: 450 @ 3200 RPM
455
Horsepower: 265 @ 4300
Torque: 375 @ 2800
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| Re: modern engine swap [message #304102 is a reply to message #304100] |
Sun, 24 July 2016 10:11  |
Scott Nutter
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
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Senior Member |
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Great question because these coaches will be on the road for the unfoeseeable future.
I think Manny and Jim B are doing something with the GM Diesel engine. Scott
Scott Nutter
1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI
Houston, Texas
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| Re: [GMCnet] modern engine swap [message #304103 is a reply to message #304100] |
Sun, 24 July 2016 10:20 |
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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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Keep in mind that the passenger side axle extension has to clear the main bearings and connecting rod throws. Plus you'll have to
fabricate an oil pan as well.
Regards,
Rob M.
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Nick Scheider
Sent: Monday, July 25, 2016 1:00 AM
To: gmclist@list.gmcnet.org
Subject: [GMCnet] modern engine swap
Hello,
I have read trough the forums where there is some mention of LS engine swaps and diesel swaps. I wondering if there is a trend to
go with a more modern LS 8.1 engine rather the rebuild existing 455, adding FI etc...? I appreciate keeping things original, but
wouldn't mind the improvements a more modern engine can offer. I might own this another 30-40 years and was thinking possibly better
mpg, better performance and reliability.
With the diesel swaps it sounds like heavy frame fabrication is needed. With an 8.1 it appears that it should drop right in, can run
the factory wiring harness and get adapter plates for the transmission. Any thoughts are appreciated.
Thanks,
Nick
Below are the specs I found for each engine. Which I am not sure accurate due to how they measured HP/Torque back in the 70's
compared to now guessing
there is a bigger discrepancy.
LS 8.1
Horsepower: 330 @ 4200 RPM
Torque: 450 @ 3200 RPM
455
Horsepower: 265 @ 4300
Torque: 375 @ 2800
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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: modern engine swap [message #304105 is a reply to message #304100] |
Sun, 24 July 2016 10:26 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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Nick,
There have been many amazing engine replacements along all these years. The cleanest is Dave Lenzi's 8.1, but before you consider doing any of this, you had best talk to those that have done it. Less you start with an engine that already mates to the TH425, you have a lot of engineering to look forward to.
If Mary were to hit the lottery sometime soon, I might roll a bunch of money in the coach. Changing out the main engine would be WAY down that list.
Matt
ns1113 wrote on Sun, 24 July 2016 11:00Hello,
I have read trough the forums where there is some mention of LS engine swaps and diesel swaps. I wondering if there is a trend to go with a more modern LS 8.1 engine rather the rebuild existing 455, adding FI etc...? I appreciate keeping things original, but wouldn't mind the improvements a more modern engine can offer. I might own this another 30-40 years and was thinking possibly better mpg, better performance and reliability.
With the diesel swaps it sounds like heavy frame fabrication is needed. With an 8.1 it appears that it should drop right in, can run the factory wiring harness and get adapter plates for the transmission. Any thoughts are appreciated.
Thanks,
Nick
Below are the specs I found for each engine. Which I am not sure accurate due to how they measured HP/Torque back in the 70's compared to now guessing there is a bigger discrepancy.
LS 8.1
Horsepower: 330 @ 4200 RPM
Torque: 450 @ 3200 RPM
455
Horsepower: 265 @ 4300
Torque: 375 @ 2800
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: modern engine swap [message #304108 is a reply to message #304100] |
Sun, 24 July 2016 10:35 |
mrgmc3
Messages: 210
Registered: September 2013
Location: W Washington
Karma: 2
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Senior Member |
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ns1113 wrote on Sun, 24 July 2016 10:00Hello,
I have read trough the forums where there is some mention of LS engine swaps and diesel swaps. I wondering if there is a trend to go with a more modern LS 8.1 engine rather the rebuild existing 455, adding FI etc...?
Some confusion here. You have combined two distinct engine families. The "LS" family generally refers to the '97 and later generation of "small block" V8 found in displacements of 4.8, 5.3, 5.7, 6.0, 6.2 and 7.0 liters. I think a 6.0L version would be the best candidate for repower as it is the workhorse version found in 14,000 gvw chassis cab and van cutaway trucks.
The 8.1 was the last version of the "big block" V8, that is now out of production. As mentioned, a couple of theses swaps have been done.
Chris Geils - Twin Cities / W Wa
1978 26' Kingsley w/ very few mods; PD9040, aux trans cooler, one repaint in stock colors, R134a, Al rad, Alcoas, 54k mi
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| Re: modern engine swap [message #304133 is a reply to message #304100] |
Sun, 24 July 2016 14:11 |
A Hamilto
Messages: 4508
Registered: April 2011
Karma: 39
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Senior Member |
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ns1113 wrote on Sun, 24 July 2016 10:00Hello,
I have read trough the forums where there is some mention of LS engine swaps and diesel swaps. I wondering if there is a trend to go with a more modern LS 8.1 engine rather the rebuild existing 455, adding FI etc...? I appreciate keeping things original, but wouldn't mind the improvements a more modern engine can offer. I might own this another 30-40 years and was thinking possibly better mpg, better performance and reliability.
With the diesel swaps it sounds like heavy frame fabrication is needed. With an 8.1 it appears that it should drop right in, can run the factory wiring harness and get adapter plates for the transmission. Any thoughts are appreciated.
Thanks,
Nick To answer your question, there is no trend to go with any other engine rather than rebuild the existing 455. But when Manny starts selling his diesel conversion setup, that will be the least painful replacement powerplant. An 8.1L would be the best gas engine, but it is a big job. "Big" doesn't really capture the full magnitude of the job. But pair that with a 273 final drive and low stall torque converter and that would be a quiet ride.
If you go with a diesel powerplant, you need to either convert the genset to propane or replace it with a diesel version.
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| Re: modern engine swap [message #304145 is a reply to message #304100] |
Sun, 24 July 2016 17:19 |
mrgmc3
Messages: 210
Registered: September 2013
Location: W Washington
Karma: 2
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Senior Member |
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For my money, no question I'd rebuild the Olds 403 or 455. The olds 455 V8 in particular can be built to make just as much power and torque as an appropriate 454 Chev. Mondello and others have built them to 400 hp and near 500 lb ft of torque. Now there is nowhere near the aftermarket support for the Olds, but there are aluminum heads, intakes and cam shafts. When you consider the ease with which an Olds drops in (no mods necessary whatsoever!) and the choice is easy. The naysayers may disagree but the Olds V8 has a long history of being a workhorse in marine and irrigation pump applications as well as racing (look it up). The Achilles heal that will undermine an Olds is the cooling system. As long as the cooling system has capacity and maintenance the engine will provide a long service life (but if a rebuild, well it is only as good as the builder!). Now the one area where the Olds falls down compared to the 6.5 diesel or the GM Performace 454 is there are no longer any new Oldsmobiles.
Chris Geils - Twin Cities / W Wa
1978 26' Kingsley w/ very few mods; PD9040, aux trans cooler, one repaint in stock colors, R134a, Al rad, Alcoas, 54k mi
[Updated on: Sun, 24 July 2016 17:45] Report message to a moderator |
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| Re: [GMCnet] modern engine swap [message #304159 is a reply to message #304152] |
Sun, 24 July 2016 18:43 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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He worked for Chevrolet for 25+ years. He knows the difference between a
454 Chevrolet and a high nickel alloy 455 Olds. That is what led him to AM
General. Hell for strong, better fuel economy, available, fits the engine
bay, lots more, too.
Jim Hupy
Salem, Oregon
78 GMC ROYALE 403
On Jul 24, 2016 4:30 PM, "Jon Payne" wrote:
> Agreed the Olds engine is a great engine and a real workhorse, no
> question! My concern is they 40+ years old and quality parts are few and
> more
> expense. The 454 is still being produced today and there are lots of high
> quality parts available.
>
> Would love to see Manny produce a engine swap kit for this engine. HELLO
> MANNY :lol:
>
>
> --
> Jon Payne
> 76 Palm Beach
> Westfield,IN
>
> _______________________________________________
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| Re: [GMCnet] modern engine swap [message #304162 is a reply to message #304145] |
Sun, 24 July 2016 18:50 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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It's about how much your willing to spend.
The latest figures I came up with a new GM crate engine, with all the parts
and modifying the oil pan,etc. $ 14,000 for that portion and $ 3500 labor.
There is nothing wrong with the 455 Olds engine as long as you gear it to
take advantage of the torque curve and do few things to make it more
dependable. We can do the whole thing for 7-8K total.
If you install a diesel, how did you come up with the concept of needing a
heavier frame?
Manny T has the Diesel set up ready, but your going to pay the price. Call
him.
On Sun, Jul 24, 2016 at 3:19 PM, Chris Geils
wrote:
> For my money, no question I'd rebuild the Olds 403 or 455. The olds 455
> V8 in particular can be built to make just as much power and torque as an
> appropriate 454 Chev. Mondello and others have built them to 400 hp and
> near 500 lb ft of torque. Now there is nowhere near the aftermarket support
> for the Olds, but there are aluminum heads, intakes and cam shafts. When
> you consider the ease with which an Olds drops in (no mods necessary
> whatsoever!) and the choice is easy. The naysayers may disagree but the
> Olds V8 has a long history of being a workhorse in marine and irrigation
> pump
> applications as well as racing (look it up). The Achilles heal that will
> undermine an Olds is the cooling system. As long as it has capacity and
> maintenance the engine will provide a long service life (and if a rebuild,
> well it is only as good as the builder!). Now the one area where the Olds
> falls down compared to the 6.5 diesel or the GM Performace 454 is there
> are no longer any new Oldsmobiles.
> --
> Chris Geils - Twin Cities
> 1978 26' Kingsley w/ very few mods; Headers, Progressive Dynamics 9040,
> aux trans cooler, one repaint in stock colors, R134a, Al rad, 49k mi
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: modern engine swap [message #304166 is a reply to message #304100] |
Sun, 24 July 2016 19:23 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Many will say the Olds was a better engine (and 1 cube bigger ha ha) than the Mark IV Chevy BB. Especially in terms of valve trane geometry and longevity. If you go new crate and feed it with a carb I just don't see the advantage. Also aren't these crate motors more for motor sports than 11,000# barge moving all day long?
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: [GMCnet] modern engine swap [message #304168 is a reply to message #304166] |
Sun, 24 July 2016 19:43 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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I don't have sufficient knowledge of the differences between the Olds 455
and the Chevy 454, or the other options under discussion, to make a
judgement. But I do recall from my SOB-owning days that the general
attitude of RV dealers toward any coach with a 454 was "don't want it if
it's got over 50,000 miles on it". Was that because engine troubles
increased exponentially after that range of miles? My RV dealership-owning
close friends contended so.
I owned 4 different SOB's with 454's and never had any trouble with them --
but didn't run them much beyond 50,000 miles either.
Ken H.
On Sun, Jul 24, 2016 at 8:23 PM, John R. Lebetski
wrote:
> Many will say the Olds was a better engine (and 1 cube bigger ha ha) than
> the Mark IV Chevy BB. Especially in terms of valve trane geometry and
> longevity. If you go new crate and feed it with a carb I just don't see
> the advantage. Also aren't these crate motors more for motor sports than
> 11,000# barge moving all day long?
> --
>
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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] modern engine swap [message #304169 is a reply to message #304168] |
Sun, 24 July 2016 20:19 |
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J Green
Messages: 36
Registered: July 2016
Location: Arizona
Karma: 1
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Member |
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Pardon my ignorance, but does anyone know why the later model GMCs have the
403 in them as opposed to the 455? Was that an option choice or just that
the 455 phased out of production?
Just curious.
On Sun, Jul 24, 2016 at 5:45 PM Ken Henderson
wrote:
> I don't have sufficient knowledge of the differences between the Olds 455
> and the Chevy 454, or the other options under discussion, to make a
> judgement. But I do recall from my SOB-owning days that the general
> attitude of RV dealers toward any coach with a 454 was "don't want it if
> it's got over 50,000 miles on it". Was that because engine troubles
> increased exponentially after that range of miles? My RV dealership-owning
> close friends contended so.
>
> I owned 4 different SOB's with 454's and never had any trouble with them --
> but didn't run them much beyond 50,000 miles either.
>
> Ken H.
>
>
> On Sun, Jul 24, 2016 at 8:23 PM, John R. Lebetski >
> wrote:
>
>> Many will say the Olds was a better engine (and 1 cube bigger ha ha) than
>> the Mark IV Chevy BB. Especially in terms of valve trane geometry and
>> longevity. If you go new crate and feed it with a carb I just don't see
>> the advantage. Also aren't these crate motors more for motor sports than
>> 11,000# barge moving all day long?
>> --
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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J Green
Phoenix, AZ
'77 Kingsley - aka Edna "Big Bertha" Green
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| Re: [GMCnet] modern engine swap [message #304178 is a reply to message #304172] |
Sun, 24 July 2016 22:30 |
gladius
Messages: 48
Registered: November 2015
Karma: 0
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I think the Cadillac 425/472/500 is the overall best swap, in terms of ease of installation and the quality of motor you get. The motor has a number of advantages over the Olds 455, particularly its ports and combustion chamber design. It's a more efficient engine, and you will get better gas mileage, and can swap in lower gears without sacrificing performance. 3.07 gears would work just fine with a mild 472/500. The 425 is lighter than a 455 and with 3.2-3.3 gears I bet you'd pull down 12-13 MPG at 60-65 mph with good performance. As far as parts availability goes, everything you need to build one to 500+ HP is available on the internet, and anything you'd need to maintain one is at the local parts store. The motors are generally found to be in good condition from the donor car with little cylinder wear due to the hard nickel blocks, and with a quick re-ring, valve lap, new timing set, gaskets, Eldo oil pan/mounts, and other needed parts, you could get one swapped in for $1,500 or less including price of engine core. A good low compression late 500 with ported heads and intake and mild cam will make 350+ HP and 500+ ft-lbs through the factory exhaust manifolds, giving many years of reliable, trouble free service.
[Updated on: Sun, 24 July 2016 22:38] Report message to a moderator |
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| Re: [GMCnet] modern engine swap [message #304186 is a reply to message #304178] |
Mon, 25 July 2016 00:42 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Nathan,
Your correct with the Cad engine.
I have found that things like the water pump and fuel pump are not stocked
at the auto stores as they are slow turners.
The Warehouse does stock them, usually a next day delivery.
I do have a 540 cid, twin turbo, EFI,intercooled. Must have over 800,000
miles on them.
On Sun, Jul 24, 2016 at 8:30 PM, Nathan Cline
wrote:
> I think the Cadillac 425/472/500 is the overall best swap, in terms of
> ease of installation and the quality of motor you get. The motor has a
> number
> of advantages over the Olds 455, particularly its ports and combustion
> chamber design. It's a more efficient engine, and you will get better gas
> mileage, and can swap in lower gears without sacrificing performance. As
> far as parts availability goes, everything you need to build one to 500+ HP
> is available on the internet, and anything you'd need to maintain one is
> at the local parts store. The motors are generally found to be in good
> condition from the donor car with little cylinder wear due to the hard
> nickel blocks, and with a quick re-ring, valve lap, new timing set, gaskets,
> Eldo oil/pan, and other needed parts, you could get one swapped in for
> $1,500 or less.
> --
> Gadsden, AL
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: modern engine swap [message #304248 is a reply to message #304244] |
Mon, 25 July 2016 23:16 |
hal kading
Messages: 642
Registered: February 2004
Location: Las Cruces NM
Karma: 4
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Senior Member |
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Don't forget the GM 502 (8.2) which has been used in several conversions. I believe it is still being produced for marine use. I took out a turbo-charged Gen V 454 (failed) from my Buskirk Stretch and replaced it with a NA 502.
Hal Kading 1978 Buskirk Stretch 502 Las Cruces NM
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