Home » Public Forums » GMCnet » 455 Expected Engine Life (Assuming proper care, how many miles?)
| 455 Expected Engine Life [message #360417] |
Mon, 30 November 2020 17:59  |
dsmithy
Messages: 210
Registered: July 2012
Location: Lincoln Nebraska
Karma: 0
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Senior Member |
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"You guys that live in flat country have not a clue to the GMC's
requirements for climbing grades. You can cover 6 states in a day and not
break a sweat.
Try running the Tehachapi grade out of either California or
Arizona/Nevada, or the Grapevine coming North out of Los Angeles on
Interstate 5, or the Siskiyou summit a bit farther North. You will run out
of gears pretty darn quickly. I have a heavy 78 Royale with a 403 and 3:70
final drive, and it works really well. And I run it at 70 mph + most of the
time. 3400 rpm and that 403 is a happy camper. Over 130,000 miles on an
unmolested engine. Works for me.
Jim Hupy"
A question for you Mr. Hupy, et.al.
I bought my '73 in 1995 with 140K indicated miles. The PO had oversize tires on it so I think that's probably an underestimate. The engine, to my knowledge, has never been opened up. I have given it regular oil changes with Mobile 1, new water pump and timing chain, Thorley headers, new quadrajet from Paterson, new Pertronix, fuel and vacuum hoses, and a 4.70 final. I tend to drive her easy, cruising at 65 mostly, up to 80 only when I have to. Oil pressure settles a bit with warmup but the stock sender/guage are still quite lively, even at hot idle. I have not done a compression test. I'm guessing I've put around 2K miles annually on it since '95 which puts its current mileage around 200K. That's a guess for a lot of reasons, but probably about right.
I have not done a search to find out if this topic has been answered, but I think engine longevity may be somewhat a moving target with old hardware/modern fluids and newer opinions valuable. Is "drive it till it dies" a good idea? I was incredibly fortunate to be close to Larry Weidner for a transmission failure, I can't expect such luck going forward. Any wisdom?
Doug Smith
Douglas & Virginia Smith,
dsmithy18 at gmail,
Lincoln Nebraska,
’73 “Sequoia” since ‘95: "Wanabizo";
Quadrabag/6 wheel disks/3:70 final/Paterson QuadraJet/Thorley’s/Alloy wheels/Sundry other
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| Re: [GMCnet] 455 Expected Engine Life [message #360418 is a reply to message #360417] |
Mon, 30 November 2020 18:10  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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If you are religious about your oil changes and the rest of your
preventative maintenance, keep checking your compression regularly and if
everything measures within 10/15% of each other, my advice would be to keep
doing what you have been doing. New engines can and do blow up fairly
regularly. A well broken in engine with high mileage is a proven product.
If the oil consumption starts to go up, mileage drops, or idle gets rough,
stay on top of it. Those are warning signs.
Jim Hupy
Salem, Oregon
On Mon, Nov 30, 2020 at 4:00 PM Douglas Smith via Gmclist <
gmclist@list.gmcnet.org> wrote:
> "You guys that live in flat country have not a clue to the GMC's
> requirements for climbing grades. You can cover 6 states in a day and not
> break a sweat.
> Try running the Tehachapi grade out of either California or
> Arizona/Nevada, or the Grapevine coming North out of Los Angeles on
> Interstate 5, or the Siskiyou summit a bit farther North. You will run out
> of gears pretty darn quickly. I have a heavy 78 Royale with a 403 and 3:70
> final drive, and it works really well. And I run it at 70 mph + most of the
> time. 3400 rpm and that 403 is a happy camper. Over 130,000 miles on an
> unmolested engine. Works for me.
> Jim Hupy"
>
>
> A question for you Mr. Hupy, et.al.
> I bought my '73 in 1995 with 140K indicated miles. The PO had oversize
> tires on it so I think that's probably an underestimate. The engine, to my
> knowledge, has never been opened up. I have given it regular oil changes
> with Mobile 1, new water pump and timing chain, Thorley headers, new
> quadrajet from Paterson, new Pertronix, fuel and vacuum hoses, and a 4.70
> final. I tend to drive her easy, cruising at 65 mostly, up to 80 only when I
> have to. Oil pressure settles a bit with warmup but the stock sender/guage
> are still quite lively, even at hot idle. I have not done a compression
> test. I'm guessing I've put around 2K miles annually on it since '95 which
> puts its current mileage around 200K. That's a guess for a lot of reasons,
> but probably about right.
> I have not done a search to find out if this topic has been answered, but
> I think engine longevity may be somewhat a moving target with old
> hardware/modern fluids and newer opinions valuable. Is "drive it till it
> dies" a good idea? I was incredibly fortunate to be close to Larry Weidner
> for a transmission failure, I can't expect such luck going forward. Any
> wisdom?
> Doug Smith
>
> --
> Douglas & Virginia Smith
> dsmithy18 at gmail
> Lincoln Nebraska
> ’73 “Canyonlands” since ‘95: "Wanabizo";
> Quadrabag/6 wheel disks/3:70 final/Paterson QuadraJet/Thorley’s/Alloy
> wheels(finally!)/Sundry other
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: [GMCnet] 455 Expected Engine Life [message #360426 is a reply to message #360418] |
Mon, 30 November 2020 23:16 |
Mike Kelley
Messages: 467
Registered: February 2017
Karma: -2
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Senior Member |
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Like Jim Hupy said:
A well treated reliable engine is the best. I have a GMC Classics friend who got 300,000 miles out of his first engine. Top quality maintenance is the key!
Mike/the Corvair a holic
Not a mechanic but I know enough to treat my Coaches and my Corvairs rite!
Sent from my iPhone
> On Nov 30, 2020, at 6:10 PM, James Hupy via Gmclist wrote:
>
> If you are religious about your oil changes and the rest of your
> preventative maintenance, keep checking your compression regularly and if
> everything measures within 10/15% of each other, my advice would be to keep
> doing what you have been doing. New engines can and do blow up fairly
> regularly. A well broken in engine with high mileage is a proven product.
> If the oil consumption starts to go up, mileage drops, or idle gets rough,
> stay on top of it. Those are warning signs.
> Jim Hupy
> Salem, Oregon
>
> On Mon, Nov 30, 2020 at 4:00 PM Douglas Smith via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> "You guys that live in flat country have not a clue to the GMC's
>> requirements for climbing grades. You can cover 6 states in a day and not
>> break a sweat.
>> Try running the Tehachapi grade out of either California or
>> Arizona/Nevada, or the Grapevine coming North out of Los Angeles on
>> Interstate 5, or the Siskiyou summit a bit farther North. You will run out
>> of gears pretty darn quickly. I have a heavy 78 Royale with a 403 and 3:70
>> final drive, and it works really well. And I run it at 70 mph + most of the
>> time. 3400 rpm and that 403 is a happy camper. Over 130,000 miles on an
>> unmolested engine. Works for me.
>> Jim Hupy"
>>
>>
>> A question for you Mr. Hupy, et.al.
>> I bought my '73 in 1995 with 140K indicated miles. The PO had oversize
>> tires on it so I think that's probably an underestimate. The engine, to my
>> knowledge, has never been opened up. I have given it regular oil changes
>> with Mobile 1, new water pump and timing chain, Thorley headers, new
>> quadrajet from Paterson, new Pertronix, fuel and vacuum hoses, and a 4.70
>> final. I tend to drive her easy, cruising at 65 mostly, up to 80 only when I
>> have to. Oil pressure settles a bit with warmup but the stock sender/guage
>> are still quite lively, even at hot idle. I have not done a compression
>> test. I'm guessing I've put around 2K miles annually on it since '95 which
>> puts its current mileage around 200K. That's a guess for a lot of reasons,
>> but probably about right.
>> I have not done a search to find out if this topic has been answered, but
>> I think engine longevity may be somewhat a moving target with old
>> hardware/modern fluids and newer opinions valuable. Is "drive it till it
>> dies" a good idea? I was incredibly fortunate to be close to Larry Weidner
>> for a transmission failure, I can't expect such luck going forward. Any
>> wisdom?
>> Doug Smith
>>
>> --
>> Douglas & Virginia Smith
>> dsmithy18 at gmail
>> Lincoln Nebraska
>> ’73 “Canyonlands” since ‘95: "Wanabizo";
>> Quadrabag/6 wheel disks/3:70 final/Paterson QuadraJet/Thorley’s/Alloy
>> wheels(finally!)/Sundry other
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
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> Unsubscribe or Change List Options:
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| Re: 455 Expected Engine Life [message #360440 is a reply to message #360417] |
Tue, 01 December 2020 15:07 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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I assume you have a 4:10 final if it is in fact a 4:70 you need to tell us about it.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] 455 Expected Engine Life [message #360441 is a reply to message #360418] |
Tue, 01 December 2020 15:50 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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James Hupy wrote on Mon, 30 November 2020 18:10
If the oil consumption starts to go up, mileage drops, or idle gets rough,
stay on top of it. Those are warning signs.
Jim Hupy
So what is normal or acceptable oil consumption for a healthy engine with a few miles on it?
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: 455 Expected Engine Life [message #360442 is a reply to message #360417] |
Tue, 01 December 2020 15:51 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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You might consider sending an oil sample to Blackstone Lab. They seem to test a lot of GMC’s and you might get some insight/diagnosis into current engine condition.
Dennis
A question for you Mr. Hupy, et.al.
I bought my '73 in 1995 with 140K indicated miles. The PO had oversize tires on it so I think that's probably an underestimate. The engine, to my knowledge, has never been opened up. I have given it regular oil changes with Mobile 1, new water pump and timing chain, Thorley headers, new quadrajet from Paterson, new Pertronix, fuel and vacuum hoses, and a 4.70 final. I tend to drive her easy, cruising at 65 mostly, up to 80 only when I have to. Oil pressure settles a bit with warmup but the stock sender/guage are still quite lively, even at hot idle. I have not done a compression test. I'm guessing I've put around 2K miles annually on it since '95 which puts its current mileage around 200K. That's a guess for a lot of reasons, but probably about right.
I have not done a search to find out if this topic has been answered, but I think engine longevity may be somewhat a moving target with old hardware/modern fluids and newer opinions valuable. Is "drive it till it dies" a good idea? I was incredibly fortunate to be close to Larry Weidner for a transmission failure, I can't expect such luck going forward. Any wisdom?
Doug Smith
[/quote]
Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] 455 Expected Engine Life [message #360445 is a reply to message #360443] |
Tue, 01 December 2020 16:12 |
Mike Kelley
Messages: 467
Registered: February 2017
Karma: -2
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Senior Member |
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Agreed Larry - sounds like a typo!
I am not a mechanic but am convinced top quality maintenance goes a long way towards longevity of our engines, etc.
My Elly is a 76 w/ 455 rebuilt engine, rebuilt trans, 3:21 final drive, 227,000 total miles (about 70,000 on the engine rebuild and about 65,000 on the tranny rebuild) and runs like a champ.
I plan to sell her in a few months but only because we enjoy the extra room of our “Dream Machine” 76 Glenbrook stretch (2’ at the rear), about 14,000 # and runs like a scalded cat, that also has rebuilt 455, rebuilt tyranny and 3:21 FD.
Mike/the Corvair a holic
Sent from my iPhone
> On Dec 1, 2020, at 3:51 PM, Larry via Gmclist wrote:
>
> roy1 wrote on Tue, 01 December 2020 15:07
>> I assume you have a 4:10 final if it is in fact a 4:70 you need to tell us about it.
>
> IIRC, I think he (Doug) has a 3.70 FD. I'm not aware of a FD for our coaches that is as steep as a 4.70. I think it is probably a typo.
>
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
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> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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| Re: [GMCnet] 455 Expected Engine Life [message #360446 is a reply to message #360418] |
Tue, 01 December 2020 16:21 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Acceptable oil consumption would be (subjectively) 1 qt. per 1000 to 1500
miles. Any more than that, you have some worn rings, loose intake guide to
intake valve stems, worn piston ring lands, etc. Still ok to run it, but
the handwriting is starting to appear on the shop wall. Might be time to
start saving up some $$$$ for a rebuild.
Jim Hupy
Salem, Oregon
On Tue, Dec 1, 2020, 2:13 PM Mike Kelley via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Agreed Larry - sounds like a typo!
> I am not a mechanic but am convinced top quality maintenance goes a long
> way towards longevity of our engines, etc.
> My Elly is a 76 w/ 455 rebuilt engine, rebuilt trans, 3:21 final drive,
> 227,000 total miles (about 70,000 on the engine rebuild and about 65,000 on
> the tranny rebuild) and runs like a champ.
> I plan to sell her in a few months but only because we enjoy the extra
> room of our “Dream Machine” 76 Glenbrook stretch (2’ at the rear), about
> 14,000 # and runs like a scalded cat, that also has rebuilt 455, rebuilt
> tyranny and 3:21 FD.
> Mike/the Corvair a holic
>
> Sent from my iPhone
>
>> On Dec 1, 2020, at 3:51 PM, Larry via Gmclist
> wrote:
>>
>> roy1 wrote on Tue, 01 December 2020 15:07
>>> I assume you have a 4:10 final if it is in fact a 4:70 you need to tell
> us about it.
>>
>> IIRC, I think he (Doug) has a 3.70 FD. I'm not aware of a FD for our
> coaches that is as steep as a 4.70. I think it is probably a typo.
>>
>> --
>> Larry
>> 78 Royale w/500 Caddy
>> Menomonie, WI.
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
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| Re: [GMCnet] 455 Expected Engine Life [message #360449 is a reply to message #360441] |
Tue, 01 December 2020 17:57 |
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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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hertfordnc wrote on Tue, 01 December 2020 16:50So what is normal or acceptable oil consumption for a healthy engine with a few miles on it?
David,
Jim's numbers are real good. One of the things that he did not mention is that the coach engines have higher lube oil carry-over than the passcar application. This brings us to two important things:
If the lube oil level in the pan is too high, that carryover will be increased. While this is not damaging if you do not have a catalyst or an O2 sensor, it will cause the apparent lube oil consumption to be higher than it actually is. If you fill it to the "full" mark, that top quart will be gone in 500 miles.
For proper operation and longevity, the lube oil consumption of a 455 in coach service should be in the area of 1.5~2% of fuel. That should be about a quart in 1000~1200 miles. If it is less than that, then the rings are not lubricating as well as they might.
I had a un/fortunate situation. A couple of years back,the coaches lube oil consumption suddenly increased from less than a quart in 2000 miles to more than a quart in 500. The engine was exhibiting no other issues, so I kept pouring oil in it until we got back to base. I had no history other than old faded receipts that showed engine things at about 90+K in Mexico some years before. Now the Odo was at about (1)70K. I will not go into the quality of the internal work but to say that there were issues, but the cylinder bore and primary bearing wear were not issues. Had it not been for the failure of the lands of piston #7, the engine would not have needed service for at least another 70~80K. That being the case, If you were to take good care of an Olds BB in coach service, I should think that 150~200K would be very easily achieved.
If that is not the information you hoped to get, let me know as I have more.
Matt
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] 455 Expected Engine Life [message #360455 is a reply to message #360451] |
Tue, 01 December 2020 21:15 |
Rick Staples
Messages: 126
Registered: May 2014
Location: Johnstown, Colorado, USA
Karma: -1
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Senior Member |
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Ken,
I agree with your reference. If I read the P30 manual correctly, a vehicle getting ~10mpg (as most of our GMCs do on a good day) might be expected to consume up to 1 quart of oil in 600 - 700 miles. That jibes with my recollections from way back in the early '70s. IIRC, most manufacturers would not consider warranty work for excessive oil consumption unless a car used MORE than a quart in 800 miles. Modern oils, especially synthetics, probably will improve that somewhat. Still, as I used to say to my customers, unless oil consumption ha significantly increased, you can buy a lot of oil for the price of an overhaul.
My 2¢,
Rick Staples
Rick Staples, '75 Eleganza, Johnstown, CO
"Advice is a dangerous gift, even from the Wise to the Wise, and all paths may run ill." -Tolkien
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| Re: 455 Expected Engine Life [message #360457 is a reply to message #360440] |
Tue, 01 December 2020 22:44 |
dsmithy
Messages: 210
Registered: July 2012
Location: Lincoln Nebraska
Karma: 0
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Senior Member |
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My mistake Roy, it's a 3.70 from JimK. (I like it.)
Douglas & Virginia Smith,
dsmithy18 at gmail,
Lincoln Nebraska,
’73 “Sequoia” since ‘95: "Wanabizo";
Quadrabag/6 wheel disks/3:70 final/Paterson QuadraJet/Thorley’s/Alloy wheels/Sundry other
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| Re: 455 Expected Engine Life [message #360458 is a reply to message #360457] |
Tue, 01 December 2020 23:05 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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That is more like it. Mine had a 3:70 and with a relatively fresh engine ( 455 with 5,000 miles on it) using 15/50 Mobil one it used about 1 quart in 3000 miles just in time for an oil change
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: 455 Expected Engine Life [message #360463 is a reply to message #360417] |
Wed, 02 December 2020 09:34 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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I have to question why people still flock to 15W-50 oil despite research. Heavier means less oil to final destination as some is diverted a greater % of the time. Also more drag and gear wear along with more frictional heating. Also poorer throw of oil to cyl walls cold or at low RPM.
I also find oil use is not linear. It varies greatly with weather and load conditions. That’s why you should check after each fueling. It may appear to not budge then move downward after a day of headwinds, rolling hills or high temps.
Also, and this could just be confirmation bias, fresh oil seems ti be consumed at a lower rate than oil with over 2000 miles or so on it. You would think the lighter molecular elements would go off after that time and consumption would go down, but I have never found this to be the case.
Also due to fuel rate of almost 2x pass car consumption, I feel 3000 is like 6000 so try to change by 2000 unless on a long trip where not easy to do so. But there the oil time between service is low and it gets drained/filled upon getting home.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: [GMCnet] 455 Expected Engine Life [message #360466 is a reply to message #360418] |
Wed, 02 December 2020 10:28 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Actually, the clearances in the bearings, piston to cylinder wall, valve
guide to valve stems, etc. should determine oil viscosity more precisely.
More space allows for a bit thicker oil. Less space dictates that a lower
viscosity is appropriate. Worn engines SOMETIMES will consume less heavy
viscosity oils than they do the thinner stuff. Modern engines like accura
and Audi make are engineered for multi-viscosity oils like 5w-20 at any
temperatures except deserts in summer. Best advice, read what the
manufacturer tells you and go from there. Dino or synthetic? I ain't going
there. Both are good. One is much, much cheaper. Your money, spend it how
you choose.
Jim Hupy
Salem, Oregon
On Wed, Dec 2, 2020, 8:11 AM Mike Kelley via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Soo John L.:
> What oil do you recommend for these GMC’s?
> Mike/the Corvair a holic
>
> Sent from my iPhone
>
>> On Dec 2, 2020, at 9:34 AM, John R. Lebetski via Gmclist gmclist@list.gmcnet.org> wrote:
>>
>> I have to question why people still flock to 15W-50 oil despite
> research. Heavier means less oil to final destination as some is diverted a
> greater %
>> of the time. Also more drag and gear wear along with more frictional
> heating. Also poorer throw of oil to cyl walls cold or at low RPM.
>> I also find oil use is not linear. It varies greatly with weather and
> load conditions. That’s why you should check after each fueling. It may
>> appear to not budge then move downward after a day of headwinds, rolling
> hills or high temps.
>> Also, and this could just be confirmation bias, fresh oil seems ti be
> consumed at a lower rate than oil with over 2000 miles or so on it. You
> would
>> think the lighter molecular elements would go off after that time and
> consumption would go down, but I have never found this to be the case.
>> Also due to fuel rate of almost 2x pass car consumption, I feel 3000 is
> like 6000 so try to change by 2000 unless on a long trip where not easy to
> do
>> so. But there the oil time between service is low and it gets
> drained/filled upon getting home.
>> --
>> John Lebetski
>> Woodstock, IL
>> 77 Eleganza II
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
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| Re: [GMCnet] 455 Expected Engine Life [message #360469 is a reply to message #360463] |
Wed, 02 December 2020 10:11 |
Mike Kelley
Messages: 467
Registered: February 2017
Karma: -2
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Senior Member |
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Soo John L.:
What oil do you recommend for these GMC’s?
Mike/the Corvair a holic
Sent from my iPhone
> On Dec 2, 2020, at 9:34 AM, John R. Lebetski via Gmclist wrote:
>
> I have to question why people still flock to 15W-50 oil despite research. Heavier means less oil to final destination as some is diverted a greater %
> of the time. Also more drag and gear wear along with more frictional heating. Also poorer throw of oil to cyl walls cold or at low RPM.
> I also find oil use is not linear. It varies greatly with weather and load conditions. That’s why you should check after each fueling. It may
> appear to not budge then move downward after a day of headwinds, rolling hills or high temps.
> Also, and this could just be confirmation bias, fresh oil seems ti be consumed at a lower rate than oil with over 2000 miles or so on it. You would
> think the lighter molecular elements would go off after that time and consumption would go down, but I have never found this to be the case.
> Also due to fuel rate of almost 2x pass car consumption, I feel 3000 is like 6000 so try to change by 2000 unless on a long trip where not easy to do
> so. But there the oil time between service is low and it gets drained/filled upon getting home.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
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