sharkb8
Squamish, BC, Canada
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I am the owner of a 1991 Beaver Marquis diesel pusher coach with a 3176 Catepillar engine with 88,000 miles.
Recently I had to have some major repair work done to the engine – new exhaust manifold, a new turbo charger and repair to the electrical harness. The turbo had a hole in it on the hot side and when it was removed the mechanic found the manifold needed replacing as well as it had seized and cracked. The Cat mechanic told me there was insulation wrapped around both of these components and that the insulation likely caused the problem to occur because, the components over heated. He checked into it further and found that that this was something done by the RV manufacturer. Apparently it was regularly done by Beaver and Monaco, possibly in an effort to keep the bedroom cooler and quieter?
After repairing the coach, the mechanic put insulation back on the manifold and turbo charger but, he warned me that the parts would likely fail again due to excessive heat generated.
What I would like to know is, has anyone else out there heard of this before or has the same wrap on their unit. If so, has anyone taken the insulation off the manifold and turbo and what effect it's had.
Personally, I’m inclined to remove the insulation because, I don’t want to get hit with another $8,000 repair bill.
Any input in this regard would be appreciated.
Jack
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gunny357
North Carolina
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Your mechanic is right.
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ThurstonAndLovey
Formerly of Gilligans Island
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Maybe you can insulate the compartment walls rather than the turbo and manifold?
Some pretty good stuff to do either job at www.designengineering.com
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Sully2
Cincinnati
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gunny357 wrote:Your mechanic is right.
Without a doubt!
2000 Country Coach Allure; Cummins ISC 330 HP; 71/2 - 8 MPG regardless
2002 Jeep Liberty
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Sully2
Cincinnati
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Remove the insulation from the engine direct...and if you wish to insulate the bed's dog house...attach insulation from the engine side of the compartment with a "stand off" ( clearance" between the insulation and the doghouse framing itself.
If you want to get really hairy...make some "spools" of hardwood ( like sewing thread spools) and thin sheet aluminum... Screw thru the AL and thru the hole in the spool into the framing. Get some muffin fans and blow air between the aluminum and the framing ( 12V muffin fans are cheap)
I dont care how hot the engine gets...the wood framing of the bed's doghouse will never see it.
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sharkb8
Squamish, BC, Canada
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Thanks for the reply guys. I was thinking the same thing as in insulatating the under side of the bed platform which covers the engine. Something along the lines of the insulation under the hood of your car.
I wonder why the RV manufacturer would have taken the route of insulating the manifold and the turbo given the amount of heat they generate and how important it is to expel that heat?
I mean insulation like under the hood of your car has been around for some time.
Cheers
Jack
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wolfe10
Texas
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Gillig did that, NOT Caterpillar.
Where they ran the wiring (engine wiring)was close enough to the manifold and turbo that it could melt the wiring.
BEST answer-- remove insulation from turbo and manifold BUT, MAKE SURE TO INSULATE ENGINE WIRING FROM THE HIGH HEAT.
And, yes, you can insulate the bed area very easily.
Brett Wolfe
1993 Foretravel 36' U-240
Cat 3116, Allison 3060
Caterpillar RV Engine Owner's Club: www.catrvclub.org
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sharkb8
Squamish, BC, Canada
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I have done a bit more searching and have found wrapping the exhaust and turbo is not an uncommon practice. I found this on another site where I posted this very concern. Thanks to LargeCarPilot from iRv2 for the following. Still curious as to what caused the failure though if it wasn't due to the thermal wrapping.
"The exhaust from a diesel engine is still burning when in exits the exhaust manifold and feed into the turbo. The turbo housing is made of cast iron while the turbo impeller blades (on the hot side) are made of titanium or inkenol. As as diesel engine is truly a heat pump holding the exhaust heat in the manifold turbo, and exhaust pipe is a good thing. It also creates a scavenging effect, thus moving the burned fuel mix out of the exhaust pipe. I.E. Heat travels to cold.
The insulation serves two purposes. One is keep high heat out of your coach and to provide sound deadening. A diesel engine exhaust operates in the range of 600-1200 degrees. The surface of the exhaust manifold if viewed in the dark after pulling a long mountain grade would be a dull red color from the exhaust temperature. "
Here's a couple of sites regarding thermal wrap if interested.
http://www.atpwrap.com/
http://www.designengineering.com/
Cheers
Jack
Jack and Jan Roberts
2006 Wildcat 5th wheel
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Sully2
Cincinnati
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sharkb8 wrote:
"The exhaust from a diesel engine is still burning when in exits the exhaust manifold and feed into the turbo. The turbo housing is made of cast iron while the turbo impeller blades (on the hot side) are made of titanium or inkenol. As as diesel engine is truly a heat pump holding the exhaust heat in the manifold turbo, and exhaust pipe is a good thing. It also creates a scavenging effect, thus moving the burned fuel mix out of the exhaust pipe. I.E. Heat travels to cold.
The insulation serves two purposes. One is keep high heat out of your coach and to provide sound deadening. A diesel engine exhaust operates in the range of 600-1200 degrees. The surface of the exhaust manifold if viewed in the dark after pulling a long mountain grade would be a dull red color from the exhaust temperature. "
Jack
Thats INCONEL and Ive got news for ya...the exhaust manifolds on 90% of gasser coaches will glow cherry red pulling the crazy loads people expect them to haul up long grades!
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sjholt
Henderson, NV
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I wrapped my old gasser exhaust pipe(by the oil filter)to stop the heat from going into it. After a long trip and just getting home I heard an exhaust leak. The exhaust tube broke completely off where I wrapped it.
It may be good for racing- but it is not good for long term use.
JMHO
Skip
1996 32' Monaco Windsor DP
Cummins 5.9L 230+ HP
5 Airbags in front- 4 in back
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