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[GMCnet] Sound proof your engine [message #237364] Fri, 24 January 2014 21:32 Go to next message
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
Karma: 10
Senior Member
I used the Silent Running that Armand pointed out (Chuck Botts original post) on the underside of the deck in our Royale. It works and we did experience a drop in engine noise. However, when we put in the new S & J engine we did not have a real HEI air cleaner. The previous air cleaner was cobbled to make it sorta fit the HEI requirement. For break-in we purchased an aftermarket chrome open-all-the-way around air cleaner and a stub in the hole breather "filter". We heard a lot of noise from those. At the Coos Bay rally we purchased a real HEI air cleaner from John Ruff and that made a significant difference in noise (thanks John) and gave us back the proper PCV system. That said, we could, and can now, still hear the noise of the headers. Our Clasco has cast iron manifolds and it is lots quieter. At our sub-3000 RPM range I doubt if there is any difference in performance, but we hear a significant difference in noise level between the two. I am thinking that this a
dditional sound proofing layer will be beneficial.

What I really like is the fact that they offer a ceiling panel product, a rug/snap floor underlayment product, and a wall/roof insulation product that combined look to me like it would dramatically reduce both the heat and sound issues in a GMC. Time will tell.

Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
Visitors always welcome!
glwork@mac.com
http://jerrywork.com




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Jerry & Sharon Work
78 Royale
Kerby, OR
Re: [GMCnet] Sound proof your engine [message #237401 is a reply to message #237364] Sat, 25 January 2014 02:11 Go to previous messageGo to next message
Dan Borlase is currently offline  Dan Borlase   United States
Messages: 743
Registered: May 2008
Location: Kelowna B.C. Canada
Karma: 0
Senior Member
Jerry, I "painted" Silent Running on Eng. the access door of my 26. That and a relocation of the air intake via a piping system
through to the front of the coach, (just back of the front bumper), has made a hugh Eng. sound difference...Judi and I can actually have a "clean and clear" conversation...kinda cool.
Re: [GMCnet] Sound proof your engine [message #237462 is a reply to message #237364] Sat, 25 January 2014 16:13 Go to previous messageGo to next message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
glwgmc wrote on Fri, 24 January 2014 20:32

I used the Silent Running that Armand pointed out (Chuck Botts original post) on the underside of the deck in our Royale. It works and we did experience a drop in engine noise. However, when we put in the new S & J engine we did not have a real HEI air cleaner. The previous air cleaner was cobbled to make it sorta fit the HEI requirement. For break-in we purchased an aftermarket chrome open-all-the-way around air cleaner and a stub in the hole breather "filter". We heard a lot of noise from those. At the Coos Bay rally we purchased a real HEI air cleaner from John Ruff and that made a significant difference in noise (thanks John) and gave us back the proper PCV system. That said, we could, and can now, still hear the noise of the headers. Our Clasco has cast iron manifolds and it is lots quieter. At our sub-3000 RPM range I doubt if there is any difference in performance, but we hear a significant difference in noise level between the two. I am thinking that this a
dditional sound proofing layer will be beneficial.

What I really like is the fact that they offer a ceiling panel product, a rug/snap floor underlayment product, and a wall/roof insulation product that combined look to me like it would dramatically reduce both the heat and sound issues in a GMC. Time will tell.

Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
Visitors always welcome!
glwork@mac.com
http://jerrywork.com




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Most people don't realize that the intake system is one of the main sources of engine noise. Even going to a low restriction filter in the stock aircleaner will significantly increase engine noise. The same goes for the exhaust manifolds. I recall when we first started going to tubular manifolds in production--noise was a major issue. Personally I don't like noise and try to keep things stock.


Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: [GMCnet] Sound proof your engine [message #237467 is a reply to message #237462] Sat, 25 January 2014 17:04 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Bob,

This reminds me of the '56 Chevy that my high school buddy and I built for him. It had 6 two barrel carbs mounted on a ram log
manifold. We tried to fit progressive linkage on the carbs but it hit the manifold so we just hooked them up to run all 12 barrels
at once. It was a BITCH to tune but once we got it right it screamed - literally! The car had a louvered hood and glass packs, when
you punched it the intake made as much if not more noise than the glass packs!

As was the "style" at the time the suspension was set up in a serious rake and when you punched it there wasn't enough weight
transfer to keep it going straight, it was squirrelly. We fixed that (kinda) when we installed a posi-traction rear end.

Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

-----Original Message-----
From: Bob de Kruyff

Most people don't realize that the intake system is one of the main sources of engine noise. Even going to a low restriction filter
in the stock aircleaner will significantly increase engine noise. The same goes for the exhaust manifolds. I recall when we first
started going to tubular manifolds in production--noise was a major issue. Personally I don't like noise and try to keep things
stock.
--
Bob

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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
Re: [GMCnet] Sound proof your engine [message #237505 is a reply to message #237467] Sun, 26 January 2014 11:28 Go to previous messageGo to next message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
""Bob,

This reminds me of the '56 Chevy that my high school buddy and I built for him. It had 6 two barrel carbs mounted on a ram log
manifold. We tried to fit progressive linkage on the carbs but it hit the manifold so we just hooked them up to run all 12 barrels
at once. It was a BITCH to tune but once we got it right it screamed - literally! The car had a louvered hood and glass packs, when
you punched it the intake made as much if not more noise than the glass packs!

As was the "style" at the time the suspension was set up in a serious rake and when you punched it there wasn't enough weight
transfer to keep it going straight, it was squirrelly. We fixed that (kinda) when we installed a posi-traction rear end.

Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426""

Ah the good old days. I think the next/current generation will be twisting dials and burning new chips.


Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: [GMCnet] Sound proof your engine [message #237508 is a reply to message #237364] Sun, 26 January 2014 11:39 Go to previous message
WD0AFQ is currently offline  WD0AFQ   United States
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
Senior Member
What Bob de K said. I moved the intake from top of tbi to the grille. You can't believe the difference. Also headers with one muffler in rear helps a tremendous amount. I am not concerned about who might be out near the exhaust pipe, they can move. Very Happy
Dan


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