Home » Public Forums » GMCnet » Re: [GMCnet] Harnomic balancer/timing chain
| Re: [GMCnet] Harnomic balancer/timing chain [message #343363] |
Wed, 15 May 2019 23:56  |
BobDunahugh
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
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Senior Member |
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Skip. ( If your interested. I have a new one on hand cheeper then you can get one anywhere. )
That part is mostly an harmonic dampener. As about all internal combustion engine have RPM points. That cause damaging harmonics to build up in the crankshaft. And can break the crankshaft if unchecked. That's why the outside part is riding on rubber. I've made modifications to engine that change the original harmonic levels. And the RPM points. That's part of the reason some people break their crank.
And it's also a part of the balancing system. That's why it has an unusual shape.
The double roller will last a long time. ( But so will the stock chain. ) They where developed for higher RPMs, and heavier loads brought on by more aggressive cam lob profiles. As then with the more aggressive cam lobes. You then need higher valve spring pressures. Then it comes down to the fact that we don't have any of these conditions that the double roller chain was designed for to start with. Kind of negates the reason to install one. I replaced the original chain in a friends 78 Royale. That had about 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was the issue. Stuck with GM stock. Some builds put in the roller chains, High volume oil pumps, high strength rod bolts, and some Mondello high performance parts. Sounds like great upgrades. So if these items are great improvements. Why didn't the GM engineering department put these parts in to start with? GM built these engines to do a task. And we use them just as GM meant for them to be used as. And put a warranty on. I've built GMC engines just as GM did. I've build some GM engines that can run at 8,000 RPM's all day. Put out more then double the HP/torque that GM ever even dreamed of. These engines must have upgrades because of these extreme demands. This is in upgrade territory. Not in, as built for designed operation. Face it. GM knows more about their engines then anyone. If these so called upgrades were needed. GM would have used them in their build. I know enough to know that I'm NOT smarter then the GM engine engineering department. Bob Dunahugh
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| Re: [GMCnet] Harnomic balancer/timing chain [message #343366 is a reply to message #343363] |
Thu, 16 May 2019 02:23  |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
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Bob,
We aren’t cost-engineering our rebuilds the way the factory did. They used
plastic gears because it was quiet, cheap, and, they judged, good enough.
But they aren’t good enough for our application, which includes ownership
periods measured in decades, not years.
So this notion that if something was better, GM would have done or fails on
the evidence.
For the most part, they pulled parts from other vehicles that were good
enough. They weren’t going to reengineer every part for a
limited-production halo vehicle.
They got a lot right. But they were not infallible.
Rick “who sees no reason not to use a double-roller Cloyes chain” Denney
On Wed, May 15, 2019 at 9:56 PM Bob Dunahugh via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Skip. ( If your interested. I have a new one on hand cheeper then you can
> get one anywhere. )
> That part is mostly an harmonic dampener. As about all internal
> combustion engine have RPM points. That cause damaging harmonics to build
> up in the crankshaft. And can break the crankshaft if unchecked. That's why
> the outside part is riding on rubber. I've made modifications to engine
> that change the original harmonic levels. And the RPM points. That's part
> of the reason some people break their crank.
> And it's also a part of the balancing system. That's why it has an
> unusual shape.
> The double roller will last a long time. ( But so will the stock
> chain. ) They where developed for higher RPMs, and heavier loads brought on
> by more aggressive cam lob profiles. As then with the more aggressive cam
> lobes. You then need higher valve spring pressures. Then it comes down to
> the fact that we don't have any of these conditions that the double roller
> chain was designed for to start with. Kind of negates the reason to install
> one. I replaced the original chain in a friends 78 Royale. That had about
> 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was the
> issue. Stuck with GM stock. Some builds put in the roller chains, High
> volume oil pumps, high strength rod bolts, and some Mondello high
> performance parts. Sounds like great upgrades. So if these items are great
> improvements. Why didn't the GM engineering department put these parts in
> to start with? GM built these engines to do a task. And we use them just as
> GM meant for them to be used as. And put a warranty on. I've built GMC
> engines just as GM did. I've build some GM engines that can run at 8,000
> RPM's all day. Put out more then double the HP/torque that GM ever even
> dreamed of. These engines must have upgrades because of these extreme
> demands. This is in upgrade territory. Not in, as built for designed
> operation. Face it. GM knows more about their engines then anyone. If these
> so called upgrades were needed. GM would have used them in their build. I
> know enough to know that I'm NOT smarter then the GM engine engineering
> department. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
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| Re: [GMCnet] Harnomic balancer/timing chain [message #343368 is a reply to message #343366] |
Thu, 16 May 2019 06:39 |
Kingsley Coach
Messages: 2691
Registered: March 2009
Location: Nova Scotia Canada
Karma: -34
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Senior Member |
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Boys, ain't that the truth: "... ownership periods measured in decades, not
years "
Mike in NS.
On Thu, May 16, 2019 at 5:32 AM Richard Denney via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Bob,
>
> We aren’t cost-engineering our rebuilds the way the factory did. They used
> plastic gears because it was quiet, cheap, and, they judged, good enough.
>
> But they aren’t good enough for our application, which includes ownership
> periods measured in decades, not years.
>
> So this notion that if something was better, GM would have done or fails on
> the evidence.
>
> For the most part, they pulled parts from other vehicles that were good
> enough. They weren’t going to reengineer every part for a
> limited-production halo vehicle.
>
> They got a lot right. But they were not infallible.
>
> Rick “who sees no reason not to use a double-roller Cloyes chain” Denney
>
> On Wed, May 15, 2019 at 9:56 PM Bob Dunahugh via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> Skip. ( If your interested. I have a new one on hand cheeper then you
> can
>> get one anywhere. )
>> That part is mostly an harmonic dampener. As about all internal
>> combustion engine have RPM points. That cause damaging harmonics to build
>> up in the crankshaft. And can break the crankshaft if unchecked. That's
> why
>> the outside part is riding on rubber. I've made modifications to engine
>> that change the original harmonic levels. And the RPM points. That's part
>> of the reason some people break their crank.
>> And it's also a part of the balancing system. That's why it has an
>> unusual shape.
>> The double roller will last a long time. ( But so will the stock
>> chain. ) They where developed for higher RPMs, and heavier loads brought
> on
>> by more aggressive cam lob profiles. As then with the more aggressive
> cam
>> lobes. You then need higher valve spring pressures. Then it comes down to
>> the fact that we don't have any of these conditions that the double
> roller
>> chain was designed for to start with. Kind of negates the reason to
> install
>> one. I replaced the original chain in a friends 78 Royale. That had about
>> 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was
> the
>> issue. Stuck with GM stock. Some builds put in the roller chains, High
>> volume oil pumps, high strength rod bolts, and some Mondello high
>> performance parts. Sounds like great upgrades. So if these items are
> great
>> improvements. Why didn't the GM engineering department put these parts in
>> to start with? GM built these engines to do a task. And we use them just
> as
>> GM meant for them to be used as. And put a warranty on. I've built GMC
>> engines just as GM did. I've build some GM engines that can run at 8,000
>> RPM's all day. Put out more then double the HP/torque that GM ever even
>> dreamed of. These engines must have upgrades because of these extreme
>> demands. This is in upgrade territory. Not in, as built for designed
>> operation. Face it. GM knows more about their engines then anyone. If
> these
>> so called upgrades were needed. GM would have used them in their build.
> I
>> know enough to know that I'm NOT smarter then the GM engine engineering
>> department. Bob Dunahugh
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> --
> '73 X-Glacier 230 "Jaws"
> Northern Virginia
> Offlist email: rick at rickdenney dot com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Michael Beaton
1977 Kingsley 26-11
1977 Eleganza II 26-3
Antigonish, NS
Life is too short to hold a grudge; slash some tires and call it even !
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| Re: [GMCnet] Harnomic balancer/timing chain [message #343370 is a reply to message #343363] |
Thu, 16 May 2019 08:55 |
BobDunahugh
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
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Senior Member |
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I read some GM papers on the aluminum/plastic cam gear when it first came out in the 60's. The idea was that the chain would last longer. And run quieter then an iron gear. Because the plastic would be less abrasive on the chain then a cast iron gear. That the aluminum/plastic gear cost about 22% more to make. The iron gear was simpler to make. A casting that got machined. The aluminum/plastic used more expensive materials. And a more complicated process to produce.. They've held up extremely well. The problem now is. That gear was an improvement back then. That gear is now up to 41 years old. 40 plus years wasn't in their design paramotors. The term up grade is an intreating term. Some are just using a produce that has some different characteristics. Sound good. But have limited value in the application. EFI. Now that is a true up grade that wasn't available back then. Bob Dunahugh
________________________________
From: Bob Dunahugh
Sent: Wednesday, May 15, 2019 11:56 PM
To: gmclist@list.gmcnet.org
Subject: RE: Harnomic balancer/timing chain
Skip. ( If your interested. I have a new one on hand cheeper then you can get one anywhere. )
That part is mostly an harmonic dampener. As about all internal combustion engine have RPM points. That cause damaging harmonics to build up in the crankshaft. And can break the crankshaft if unchecked. That's why the outside part is riding on rubber. I've made modifications to engine that change the original harmonic levels. And the RPM points. That's part of the reason some people break their crank.
And it's also a part of the balancing system. That's why it has an unusual shape.
The double roller will last a long time. ( But so will the stock chain. ) They where developed for higher RPMs, and heavier loads brought on by more aggressive cam lob profiles. As then with the more aggressive cam lobes. You then need higher valve spring pressures. Then it comes down to the fact that we don't have any of these conditions that the double roller chain was designed for to start with. Kind of negates the reason to install one. I replaced the original chain in a friends 78 Royale. That had about 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was the issue. Stuck with GM stock. Some builds put in the roller chains, High volume oil pumps, high strength rod bolts, and some Mondello high performance parts. Sounds like great upgrades. So if these items are great improvements. Why didn't the GM engineering department put these parts in to start with? GM built these engines to do a task. And we use them just as GM meant for them to be used as. And put a warranty on. I've built GMC engines just as GM did. I've build some GM engines that can run at 8,000 RPM's all day. Put out more then double the HP/torque that GM ever even dreamed of. These engines must have upgrades because of these extreme demands. This is in upgrade territory. Not in, as built for designed operation. Face it. GM knows more about their engines then anyone. If these so called upgrades were needed. GM would have used them in their build. I know enough to know that I'm NOT smarter then the GM engine engineering department. Bob Dunahugh
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| Re: [GMCnet] Harnomic balancer/timing chain [message #343371 is a reply to message #343370] |
Thu, 16 May 2019 09:23 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Double chain is an overkill unless you feel the engine will last over
200,000 miles.
There are more important issues to address than the double chain.
Did you know that you can order the chain in different diameters to take up
the slack that is created when the block is line honed?
This is not a Racing engine, most shops ever deal with the "shorter chain"
as it takes too much time to order.
On Thu, May 16, 2019 at 6:56 AM Bob Dunahugh via Gmclist <
gmclist@list.gmcnet.org> wrote:
>
> I read some GM papers on the aluminum/plastic cam gear when it first
> came out in the 60's. The idea was that the chain would last longer. And
> run quieter then an iron gear. Because the plastic would be less abrasive
> on the chain then a cast iron gear. That the aluminum/plastic gear cost
> about 22% more to make. The iron gear was simpler to make. A casting that
> got machined. The aluminum/plastic used more expensive materials. And a
> more complicated process to produce.. They've held up extremely well. The
> problem now is. That gear was an improvement back then. That gear is now up
> to 41 years old. 40 plus years wasn't in their design paramotors. The term
> up grade is an intreating term. Some are just using a produce that has some
> different characteristics. Sound good. But have limited value in the
> application. EFI. Now that is a true up grade that wasn't available back
> then. Bob Dunahugh
> ________________________________
> From: Bob Dunahugh
> Sent: Wednesday, May 15, 2019 11:56 PM
> To: gmclist@list.gmcnet.org
> Subject: RE: Harnomic balancer/timing chain
>
> Skip. ( If your interested. I have a new one on hand cheeper then you can
> get one anywhere. )
> That part is mostly an harmonic dampener. As about all internal
> combustion engine have RPM points. That cause damaging harmonics to build
> up in the crankshaft. And can break the crankshaft if unchecked. That's why
> the outside part is riding on rubber. I've made modifications to engine
> that change the original harmonic levels. And the RPM points. That's part
> of the reason some people break their crank.
> And it's also a part of the balancing system. That's why it has an
> unusual shape.
> The double roller will last a long time. ( But so will the stock
> chain. ) They where developed for higher RPMs, and heavier loads brought on
> by more aggressive cam lob profiles. As then with the more aggressive cam
> lobes. You then need higher valve spring pressures. Then it comes down to
> the fact that we don't have any of these conditions that the double roller
> chain was designed for to start with. Kind of negates the reason to install
> one. I replaced the original chain in a friends 78 Royale. That had about
> 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was the
> issue. Stuck with GM stock. Some builds put in the roller chains, High
> volume oil pumps, high strength rod bolts, and some Mondello high
> performance parts. Sounds like great upgrades. So if these items are great
> improvements. Why didn't the GM engineering department put these parts in
> to start with? GM built these engines to do a task. And we use them just as
> GM meant for them to be used as. And put a warranty on. I've built GMC
> engines just as GM did. I've build some GM engines that can run at 8,000
> RPM's all day. Put out more then double the HP/torque that GM ever even
> dreamed of. These engines must have upgrades because of these extreme
> demands. This is in upgrade territory. Not in, as built for designed
> operation. Face it. GM knows more about their engines then anyone. If these
> so called upgrades were needed. GM would have used them in their build. I
> know enough to know that I'm NOT smarter then the GM engine engineering
> department. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,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: [GMCnet] Harnomic balancer/timing chain [message #343373 is a reply to message #343371] |
Thu, 16 May 2019 09:58 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
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My take on this subject is a bit different. It is NOT HOW LONG THE TIMING
CHAIN SET WILL LAST, BUT, HOW LONG WILL IT DO IT'S JOB WELL. Conventional
"Hyvo, or CYLENT" Chains will reliably last 80,000 miles, more or less.
BUT, they only stay in EXACT time for 20,000 miles or so, then chain
stretch combined with gear tooth wear retards the cam timing enough to
adjust the torque curve.
What the "TRU ROLLER" DOUBLE ROW TIMING CHAIN SETS EXCELL AT, is
spreading out the wear onto the rolling elements. They stay in time for a
very long time in comparison.
I always go to the trouble to "degree in" the camshafts in any engine
that I build. I have seen stock parts off by two sprocket teeth plus 6 or
8° more, particularly on big block Chevrolet engines.
If you remove your stock fuel pump and gain access to the timing
chain to check for slack wear, and you find 3/8" or more slack, I
gur-an-tee that you have at least 8° retard in your CAM TIMING. If you can
live with that, the chain should last for much longer before it gets so
sloppy that it jumps timing half way across Wyoming. It's your money, spend
it how you wish.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On Thu, May 16, 2019, 7:24 AM Jim Kanomata via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Double chain is an overkill unless you feel the engine will last over
> 200,000 miles.
> There are more important issues to address than the double chain.
> Did you know that you can order the chain in different diameters to take up
> the slack that is created when the block is line honed?
> This is not a Racing engine, most shops ever deal with the "shorter chain"
> as it takes too much time to order.
>
> On Thu, May 16, 2019 at 6:56 AM Bob Dunahugh via Gmclist gmclist@list.gmcnet.org> wrote:
>
>>
>> I read some GM papers on the aluminum/plastic cam gear when it first
>> came out in the 60's. The idea was that the chain would last longer. And
>> run quieter then an iron gear. Because the plastic would be less abrasive
>> on the chain then a cast iron gear. That the aluminum/plastic gear cost
>> about 22% more to make. The iron gear was simpler to make. A casting that
>> got machined. The aluminum/plastic used more expensive materials. And a
>> more complicated process to produce.. They've held up extremely well.
> The
>> problem now is. That gear was an improvement back then. That gear is now
> up
>> to 41 years old. 40 plus years wasn't in their design paramotors. The
> term
>> up grade is an intreating term. Some are just using a produce that has
> some
>> different characteristics. Sound good. But have limited value in the
>> application. EFI. Now that is a true up grade that wasn't available back
>> then. Bob Dunahugh
>> ________________________________
>> From: Bob Dunahugh
>> Sent: Wednesday, May 15, 2019 11:56 PM
>> To: gmclist@list.gmcnet.org
>> Subject: RE: Harnomic balancer/timing chain
>>
>> Skip. ( If your interested. I have a new one on hand cheeper then you
> can
>> get one anywhere. )
>> That part is mostly an harmonic dampener. As about all internal
>> combustion engine have RPM points. That cause damaging harmonics to build
>> up in the crankshaft. And can break the crankshaft if unchecked. That's
> why
>> the outside part is riding on rubber. I've made modifications to engine
>> that change the original harmonic levels. And the RPM points. That's part
>> of the reason some people break their crank.
>> And it's also a part of the balancing system. That's why it has an
>> unusual shape.
>> The double roller will last a long time. ( But so will the stock
>> chain. ) They where developed for higher RPMs, and heavier loads brought
> on
>> by more aggressive cam lob profiles. As then with the more aggressive
> cam
>> lobes. You then need higher valve spring pressures. Then it comes down to
>> the fact that we don't have any of these conditions that the double
> roller
>> chain was designed for to start with. Kind of negates the reason to
> install
>> one. I replaced the original chain in a friends 78 Royale. That had about
>> 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was
> the
>> issue. Stuck with GM stock. Some builds put in the roller chains, High
>> volume oil pumps, high strength rod bolts, and some Mondello high
>> performance parts. Sounds like great upgrades. So if these items are
> great
>> improvements. Why didn't the GM engineering department put these parts in
>> to start with? GM built these engines to do a task. And we use them just
> as
>> GM meant for them to be used as. And put a warranty on. I've built GMC
>> engines just as GM did. I've build some GM engines that can run at 8,000
>> RPM's all day. Put out more then double the HP/torque that GM ever even
>> dreamed of. These engines must have upgrades because of these extreme
>> demands. This is in upgrade territory. Not in, as built for designed
>> operation. Face it. GM knows more about their engines then anyone. If
> these
>> so called upgrades were needed. GM would have used them in their build.
> I
>> know enough to know that I'm NOT smarter then the GM engine engineering
>> department. Bob Dunahugh
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
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| Re: [GMCnet] Harnomic balancer/timing chain [message #343375 is a reply to message #343363] |
Thu, 16 May 2019 10:52 |
skip2
Messages: 544
Registered: September 2011
Location: Winter Haven,FL (center o...
Karma: 3
|
Senior Member |
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The PO built this motor up with all the goodies he could from Eldelbrock, probably why it has the double roller setup. There's a many a time I wish it was stock, like when I go to fill it up, have to run premium fuel. From the parts installed I think it worked out 10.5/1 compression. I described the setup to Mr. Patterson and he said that motor has hair on it.
Skip Hartline
74 Canyon Lands, FiTech,
3.7 FD LSD, Manny Tranny,
Springfield Distributor,
2001 Chevy Tracker Ragtop Towd
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| Re: [GMCnet] Harnomic balancer/timing chain [message #343379 is a reply to message #343373] |
Thu, 16 May 2019 12:40 |
Mike Kelley
Messages: 467
Registered: February 2017
Karma: -2
|
Senior Member |
|
|
Jim Hupy:
Are you still rebuilding GMC engines? Need to know for a fellow GMCer!
Thanks,
Mike/The Corvair a holic
76 Eleganza II 26’
76 Glenbrook 28’ stretch
Sent from my iPhone
> On May 16, 2019, at 9:58 AM, James Hupy via Gmclist wrote:
>
> My take on this subject is a bit different. It is NOT HOW LONG THE TIMING
> CHAIN SET WILL LAST, BUT, HOW LONG WILL IT DO IT'S JOB WELL. Conventional
> "Hyvo, or CYLENT" Chains will reliably last 80,000 miles, more or less.
> BUT, they only stay in EXACT time for 20,000 miles or so, then chain
> stretch combined with gear tooth wear retards the cam timing enough to
> adjust the torque curve.
> What the "TRU ROLLER" DOUBLE ROW TIMING CHAIN SETS EXCELL AT, is
> spreading out the wear onto the rolling elements. They stay in time for a
> very long time in comparison.
> I always go to the trouble to "degree in" the camshafts in any engine
> that I build. I have seen stock parts off by two sprocket teeth plus 6 or
> 8° more, particularly on big block Chevrolet engines.
> If you remove your stock fuel pump and gain access to the timing
> chain to check for slack wear, and you find 3/8" or more slack, I
> gur-an-tee that you have at least 8° retard in your CAM TIMING. If you can
> live with that, the chain should last for much longer before it gets so
> sloppy that it jumps timing half way across Wyoming. It's your money, spend
> it how you wish.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
> On Thu, May 16, 2019, 7:24 AM Jim Kanomata via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> Double chain is an overkill unless you feel the engine will last over
>> 200,000 miles.
>> There are more important issues to address than the double chain.
>> Did you know that you can order the chain in different diameters to take up
>> the slack that is created when the block is line honed?
>> This is not a Racing engine, most shops ever deal with the "shorter chain"
>> as it takes too much time to order.
>>
>> On Thu, May 16, 2019 at 6:56 AM Bob Dunahugh via Gmclist > gmclist@list.gmcnet.org> wrote:
>>
>>>
>>> I read some GM papers on the aluminum/plastic cam gear when it first
>>> came out in the 60's. The idea was that the chain would last longer. And
>>> run quieter then an iron gear. Because the plastic would be less abrasive
>>> on the chain then a cast iron gear. That the aluminum/plastic gear cost
>>> about 22% more to make. The iron gear was simpler to make. A casting that
>>> got machined. The aluminum/plastic used more expensive materials. And a
>>> more complicated process to produce.. They've held up extremely well.
>> The
>>> problem now is. That gear was an improvement back then. That gear is now
>> up
>>> to 41 years old. 40 plus years wasn't in their design paramotors. The
>> term
>>> up grade is an intreating term. Some are just using a produce that has
>> some
>>> different characteristics. Sound good. But have limited value in the
>>> application. EFI. Now that is a true up grade that wasn't available back
>>> then. Bob Dunahugh
>>> ________________________________
>>> From: Bob Dunahugh
>>> Sent: Wednesday, May 15, 2019 11:56 PM
>>> To: gmclist@list.gmcnet.org
>>> Subject: RE: Harnomic balancer/timing chain
>>>
>>> Skip. ( If your interested. I have a new one on hand cheeper then you
>> can
>>> get one anywhere. )
>>> That part is mostly an harmonic dampener. As about all internal
>>> combustion engine have RPM points. That cause damaging harmonics to build
>>> up in the crankshaft. And can break the crankshaft if unchecked. That's
>> why
>>> the outside part is riding on rubber. I've made modifications to engine
>>> that change the original harmonic levels. And the RPM points. That's part
>>> of the reason some people break their crank.
>>> And it's also a part of the balancing system. That's why it has an
>>> unusual shape.
>>> The double roller will last a long time. ( But so will the stock
>>> chain. ) They where developed for higher RPMs, and heavier loads brought
>> on
>>> by more aggressive cam lob profiles. As then with the more aggressive
>> cam
>>> lobes. You then need higher valve spring pressures. Then it comes down to
>>> the fact that we don't have any of these conditions that the double
>> roller
>>> chain was designed for to start with. Kind of negates the reason to
>> install
>>> one. I replaced the original chain in a friends 78 Royale. That had about
>>> 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was
>> the
>>> issue. Stuck with GM stock. Some builds put in the roller chains, High
>>> volume oil pumps, high strength rod bolts, and some Mondello high
>>> performance parts. Sounds like great upgrades. So if these items are
>> great
>>> improvements. Why didn't the GM engineering department put these parts in
>>> to start with? GM built these engines to do a task. And we use them just
>> as
>>> GM meant for them to be used as. And put a warranty on. I've built GMC
>>> engines just as GM did. I've build some GM engines that can run at 8,000
>>> RPM's all day. Put out more then double the HP/torque that GM ever even
>>> dreamed of. These engines must have upgrades because of these extreme
>>> demands. This is in upgrade territory. Not in, as built for designed
>>> operation. Face it. GM knows more about their engines then anyone. If
>> these
>>> so called upgrades were needed. GM would have used them in their build.
>> I
>>> know enough to know that I'm NOT smarter then the GM engine engineering
>>> department. Bob Dunahugh
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>>
>>
>> --
>> Jim Kanomata
>> Applied/GMC, Newark,CA
>> jimk@appliedairfilters.com
>> http://www.appliedgmc.com
>> 1-800-752-7502
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> 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: [GMCnet] Harnomic balancer/timing chain [message #343380 is a reply to message #343379] |
Thu, 16 May 2019 12:53 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
|
|
Short answer is no. I cannot build an equal engine for the amount of money
that S and J Engines in Spokane, Washington will. But, I still do my
personal stuff. For twice the cost.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
On Thu, May 16, 2019, 10:41 AM Mike Kelley via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Jim Hupy:
> Are you still rebuilding GMC engines? Need to know for a fellow GMCer!
> Thanks,
> Mike/The Corvair a holic
> 76 Eleganza II 26’
> 76 Glenbrook 28’ stretch
>
> Sent from my iPhone
>
>> On May 16, 2019, at 9:58 AM, James Hupy via Gmclist gmclist@list.gmcnet.org> wrote:
>>
>> My take on this subject is a bit different. It is NOT HOW LONG THE TIMING
>> CHAIN SET WILL LAST, BUT, HOW LONG WILL IT DO IT'S JOB WELL. Conventional
>> "Hyvo, or CYLENT" Chains will reliably last 80,000 miles, more or less.
>> BUT, they only stay in EXACT time for 20,000 miles or so, then chain
>> stretch combined with gear tooth wear retards the cam timing enough to
>> adjust the torque curve.
>> What the "TRU ROLLER" DOUBLE ROW TIMING CHAIN SETS EXCELL AT, is
>> spreading out the wear onto the rolling elements. They stay in time for a
>> very long time in comparison.
>> I always go to the trouble to "degree in" the camshafts in any engine
>> that I build. I have seen stock parts off by two sprocket teeth plus 6 or
>> 8° more, particularly on big block Chevrolet engines.
>> If you remove your stock fuel pump and gain access to the timing
>> chain to check for slack wear, and you find 3/8" or more slack, I
>> gur-an-tee that you have at least 8° retard in your CAM TIMING. If you
> can
>> live with that, the chain should last for much longer before it gets so
>> sloppy that it jumps timing half way across Wyoming. It's your money,
> spend
>> it how you wish.
>> Jim Hupy
>> Salem, Or
>> 78 GMC ROYALE 403
>>
>> On Thu, May 16, 2019, 7:24 AM Jim Kanomata via Gmclist > gmclist@list.gmcnet.org> wrote:
>>
>>> Double chain is an overkill unless you feel the engine will last over
>>> 200,000 miles.
>>> There are more important issues to address than the double chain.
>>> Did you know that you can order the chain in different diameters to
> take up
>>> the slack that is created when the block is line honed?
>>> This is not a Racing engine, most shops ever deal with the "shorter
> chain"
>>> as it takes too much time to order.
>>>
>>> On Thu, May 16, 2019 at 6:56 AM Bob Dunahugh via Gmclist >> gmclist@list.gmcnet.org> wrote:
>>>
>>>>
>>>> I read some GM papers on the aluminum/plastic cam gear when it first
>>>> came out in the 60's. The idea was that the chain would last longer.
> And
>>>> run quieter then an iron gear. Because the plastic would be less
> abrasive
>>>> on the chain then a cast iron gear. That the aluminum/plastic gear
> cost
>>>> about 22% more to make. The iron gear was simpler to make. A casting
> that
>>>> got machined. The aluminum/plastic used more expensive materials. And
> a
>>>> more complicated process to produce.. They've held up extremely well.
>>> The
>>>> problem now is. That gear was an improvement back then. That gear is
> now
>>> up
>>>> to 41 years old. 40 plus years wasn't in their design paramotors. The
>>> term
>>>> up grade is an intreating term. Some are just using a produce that has
>>> some
>>>> different characteristics. Sound good. But have limited value in the
>>>> application. EFI. Now that is a true up grade that wasn't available
> back
>>>> then. Bob Dunahugh
>>>> ________________________________
>>>> From: Bob Dunahugh
>>>> Sent: Wednesday, May 15, 2019 11:56 PM
>>>> To: gmclist@list.gmcnet.org
>>>> Subject: RE: Harnomic balancer/timing chain
>>>>
>>>> Skip. ( If your interested. I have a new one on hand cheeper then you
>>> can
>>>> get one anywhere. )
>>>> That part is mostly an harmonic dampener. As about all internal
>>>> combustion engine have RPM points. That cause damaging harmonics to
> build
>>>> up in the crankshaft. And can break the crankshaft if unchecked. That's
>>> why
>>>> the outside part is riding on rubber. I've made modifications to
> engine
>>>> that change the original harmonic levels. And the RPM points. That's
> part
>>>> of the reason some people break their crank.
>>>> And it's also a part of the balancing system. That's why it has an
>>>> unusual shape.
>>>> The double roller will last a long time. ( But so will the stock
>>>> chain. ) They where developed for higher RPMs, and heavier loads
> brought
>>> on
>>>> by more aggressive cam lob profiles. As then with the more aggressive
>>> cam
>>>> lobes. You then need higher valve spring pressures. Then it comes down
> to
>>>> the fact that we don't have any of these conditions that the double
>>> roller
>>>> chain was designed for to start with. Kind of negates the reason to
>>> install
>>>> one. I replaced the original chain in a friends 78 Royale. That had
> about
>>>> 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was
>>> the
>>>> issue. Stuck with GM stock. Some builds put in the roller chains, High
>>>> volume oil pumps, high strength rod bolts, and some Mondello high
>>>> performance parts. Sounds like great upgrades. So if these items are
>>> great
>>>> improvements. Why didn't the GM engineering department put these parts
> in
>>>> to start with? GM built these engines to do a task. And we use them
> just
>>> as
>>>> GM meant for them to be used as. And put a warranty on. I've built GMC
>>>> engines just as GM did. I've build some GM engines that can run at
> 8,000
>>>> RPM's all day. Put out more then double the HP/torque that GM ever even
>>>> dreamed of. These engines must have upgrades because of these extreme
>>>> demands. This is in upgrade territory. Not in, as built for designed
>>>> operation. Face it. GM knows more about their engines then anyone. If
>>> these
>>>> so called upgrades were needed. GM would have used them in their build.
>>> I
>>>> know enough to know that I'm NOT smarter then the GM engine
> engineering
>>>> department. Bob Dunahugh
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>>
>>>
>>> --
>>> Jim Kanomata
>>> Applied/GMC, Newark,CA
>>> jimk@appliedairfilters.com
>>> http://www.appliedgmc.com
>>> 1-800-752-7502
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
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|
| Re: [GMCnet] Harnomic balancer/timing chain [message #343384 is a reply to message #343363] |
Thu, 16 May 2019 14:05 |
skip2
Messages: 544
Registered: September 2011
Location: Winter Haven,FL (center o...
Karma: 3
|
Senior Member |
|
|
Mr. Dunahugh just PM me with what you want for it and we'll work out getting it to me.
Thanks,
Skip Hartline
74 Canyon Lands, FiTech,
3.7 FD LSD, Manny Tranny,
Springfield Distributor,
2001 Chevy Tracker Ragtop Towd
|
|
|
|
| Re: [GMCnet] Harnomic balancer/timing chain [message #343386 is a reply to message #343380] |
Thu, 16 May 2019 15:34 |
Mike Kelley
Messages: 467
Registered: February 2017
Karma: -2
|
Senior Member |
|
|
Thanks Jim H.:
The info is much appreciated. Trying to help a fellow GMCer who needs an engine rebuild in Oklahoma City, Ok.
Mike/The Corvair a holic
Sent from my iPhone
> On May 16, 2019, at 12:53 PM, James Hupy via Gmclist wrote:
>
> Short answer is no. I cannot build an equal engine for the amount of money
> that S and J Engines in Spokane, Washington will. But, I still do my
> personal stuff. For twice the cost.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
> On Thu, May 16, 2019, 10:41 AM Mike Kelley via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> Jim Hupy:
>> Are you still rebuilding GMC engines? Need to know for a fellow GMCer!
>> Thanks,
>> Mike/The Corvair a holic
>> 76 Eleganza II 26’
>> 76 Glenbrook 28’ stretch
>>
>> Sent from my iPhone
>>
>>> On May 16, 2019, at 9:58 AM, James Hupy via Gmclist > gmclist@list.gmcnet.org> wrote:
>>>
>>> My take on this subject is a bit different. It is NOT HOW LONG THE TIMING
>>> CHAIN SET WILL LAST, BUT, HOW LONG WILL IT DO IT'S JOB WELL. Conventional
>>> "Hyvo, or CYLENT" Chains will reliably last 80,000 miles, more or less.
>>> BUT, they only stay in EXACT time for 20,000 miles or so, then chain
>>> stretch combined with gear tooth wear retards the cam timing enough to
>>> adjust the torque curve.
>>> What the "TRU ROLLER" DOUBLE ROW TIMING CHAIN SETS EXCELL AT, is
>>> spreading out the wear onto the rolling elements. They stay in time for a
>>> very long time in comparison.
>>> I always go to the trouble to "degree in" the camshafts in any engine
>>> that I build. I have seen stock parts off by two sprocket teeth plus 6 or
>>> 8° more, particularly on big block Chevrolet engines.
>>> If you remove your stock fuel pump and gain access to the timing
>>> chain to check for slack wear, and you find 3/8" or more slack, I
>>> gur-an-tee that you have at least 8° retard in your CAM TIMING. If you
>> can
>>> live with that, the chain should last for much longer before it gets so
>>> sloppy that it jumps timing half way across Wyoming. It's your money,
>> spend
>>> it how you wish.
>>> Jim Hupy
>>> Salem, Or
>>> 78 GMC ROYALE 403
>>>
>>> On Thu, May 16, 2019, 7:24 AM Jim Kanomata via Gmclist >> gmclist@list.gmcnet.org> wrote:
>>>
>>>> Double chain is an overkill unless you feel the engine will last over
>>>> 200,000 miles.
>>>> There are more important issues to address than the double chain.
>>>> Did you know that you can order the chain in different diameters to
>> take up
>>>> the slack that is created when the block is line honed?
>>>> This is not a Racing engine, most shops ever deal with the "shorter
>> chain"
>>>> as it takes too much time to order.
>>>>
>>>> On Thu, May 16, 2019 at 6:56 AM Bob Dunahugh via Gmclist >>> gmclist@list.gmcnet.org> wrote:
>>>>
>>>> >
>>>> > I read some GM papers on the aluminum/plastic cam gear when it first
>>>> > came out in the 60's. The idea was that the chain would last longer.
>> And
>>>> > run quieter then an iron gear. Because the plastic would be less
>> abrasive
>>>> > on the chain then a cast iron gear. That the aluminum/plastic gear
>> cost
>>>> > about 22% more to make. The iron gear was simpler to make. A casting
>> that
>>>> > got machined. The aluminum/plastic used more expensive materials. And
>> a
>>>> > more complicated process to produce.. They've held up extremely well.
>>>> The
>>>> > problem now is. That gear was an improvement back then. That gear is
>> now
>>>> up
>>>> > to 41 years old. 40 plus years wasn't in their design paramotors. The
>>>> term
>>>> > up grade is an intreating term. Some are just using a produce that has
>>>> some
>>>> > different characteristics. Sound good. But have limited value in the
>>>> > application. EFI. Now that is a true up grade that wasn't available
>> back
>>>> > then. Bob Dunahugh
>>>> > ________________________________
>>>> > From: Bob Dunahugh
>>>> > Sent: Wednesday, May 15, 2019 11:56 PM
>>>> > To: gmclist@list.gmcnet.org
>>>> > Subject: RE: Harnomic balancer/timing chain
>>>> >
>>>> > Skip. ( If your interested. I have a new one on hand cheeper then you
>>>> can
>>>> > get one anywhere. )
>>>> > That part is mostly an harmonic dampener. As about all internal
>>>> > combustion engine have RPM points. That cause damaging harmonics to
>> build
>>>> > up in the crankshaft. And can break the crankshaft if unchecked. That's
>>>> why
>>>> > the outside part is riding on rubber. I've made modifications to
>> engine
>>>> > that change the original harmonic levels. And the RPM points. That's
>> part
>>>> > of the reason some people break their crank.
>>>> > And it's also a part of the balancing system. That's why it has an
>>>> > unusual shape.
>>>> > The double roller will last a long time. ( But so will the stock
>>>> > chain. ) They where developed for higher RPMs, and heavier loads
>> brought
>>>> on
>>>> > by more aggressive cam lob profiles. As then with the more aggressive
>>>> cam
>>>> > lobes. You then need higher valve spring pressures. Then it comes down
>> to
>>>> > the fact that we don't have any of these conditions that the double
>>>> roller
>>>> > chain was designed for to start with. Kind of negates the reason to
>>>> install
>>>> > one. I replaced the original chain in a friends 78 Royale. That had
>> about
>>>> > 150,000 miles on it. Chain was fine. The aluminum/plastic cam gear was
>>>> the
>>>> > issue. Stuck with GM stock. Some builds put in the roller chains, High
>>>> > volume oil pumps, high strength rod bolts, and some Mondello high
>>>> > performance parts. Sounds like great upgrades. So if these items are
>>>> great
>>>> > improvements. Why didn't the GM engineering department put these parts
>> in
>>>> > to start with? GM built these engines to do a task. And we use them
>> just
>>>> as
>>>> > GM meant for them to be used as. And put a warranty on. I've built GMC
>>>> > engines just as GM did. I've build some GM engines that can run at
>> 8,000
>>>> > RPM's all day. Put out more then double the HP/torque that GM ever even
>>>> > dreamed of. These engines must have upgrades because of these extreme
>>>> > demands. This is in upgrade territory. Not in, as built for designed
>>>> > operation. Face it. GM knows more about their engines then anyone. If
>>>> these
>>>> > so called upgrades were needed. GM would have used them in their build.
>>>> I
>>>> > know enough to know that I'm NOT smarter then the GM engine
>> engineering
>>>> > department. Bob Dunahugh
>>>> > _______________________________________________
>>>> > GMCnet mailing list
>>>> > Unsubscribe or Change List Options:
>>>> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>> >
>>>>
>>>>
>>>> --
>>>> Jim Kanomata
>>>> Applied/GMC, Newark,CA
>>>> jimk@appliedairfilters.com
>>>> http://www.appliedgmc.com
>>>> 1-800-752-7502
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
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