Author Topic: Purpose of exhaust pipe wrapping  (Read 1308 times)

Offline Richardonly

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  • 1948 Cadillac Fleetwood
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  • Name: Richard V. Pattison
Purpose of exhaust pipe wrapping
« on: July 18, 2012, 08:22:41 AM »
Gentlemen,

On a 1948 and back, the exhaust pipe in the engine compartment was wrapped in asbestos and secured with metal straps.

What was the purpose of this?  Is it still needed/recommended to keep some heat out of the engine compartment?  If this was it's purpose, it seems kind of fruitless given the fact that the exhaust manifold pipes are right on the top of the engine and equaly hot. Also the engine itself emits great heat and the compartment has poor air flow and has nowhere for the heat to escape from under the hood.

When bought, mine did NOT have this on the pipe.  Should it be installed and why?

Thank you, Richard
1948 Cadillac Fleetwood 60S
1995 Lincoln Towncar, Signature Series
1995 Jaguar XJ6
2001 Chrysler Sebring Convertible
1986 Yamaha 700 Maxim X motorcycle

Online Bill Ingler #7799

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Re: Purpose of exhaust pipe wrapping
« Reply #1 on: July 18, 2012, 08:53:56 AM »
The asbestos wrapping was used to help keep the water pump as cool as possible. As you know the exhaust  pipe is right next to the water pump. I have never seen any figures as how many degrees it helps the pump stay cooler verses if you have no wrapping. Is it needed, yes in my opinion. Anything to help keep that flat head cool is I believe a must have. The wrapping is some what expensive, I think around $90 and can be a bear to install. You will find that after starting to wrap the material around the pipe, it will be two big. So it needs to be trimmed to come around the pipe and have a even seam down the pipe. If you are wrapping the pipe while the pipe is still installed in the car,then you might get some help. An extra set of hands is needed while someone trims, holds and then attaches the 3 clamps. The whole job will become much easier if you can remove that portion of the pipe from the manifold and muffler. Now you can lay the pipe on the work bench and do a very professional looking job by yourself. The two pipes I have wrapped I then let sit in the good old hot Arizona sun to dry. The modern wrapping that is now sold becomes somewhat brittle in places after it is dry so if you do have the pipe off the car, handle the pipe gently when putting it back on the car. This is one job which might require several beers before you are finished.   Bill

Offline kkarrer

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Re: Purpose of exhaust pipe wrapping
« Reply #2 on: July 18, 2012, 10:03:31 AM »
I'd agree that the wrap is necessary.  I installed mine with the pipe connected how ever, but I have a lift in my shop.  I used clear/white zip ties to hold it in place while I positioned it prior to installing the stainless steel bands.  I positioned it so that the seam can't be seen.  If you've not installed one of these you might be surprised to know that they usually come in a plastic bag that is sealed and has water in it.  This keeps the material from drying out.  It can be a bit messy until you squeeze the water out and it will still drip after installation for a few hours.  I clipped the ends off the zip ties and left them in place and they're still there.  I may cut the zip ties off before I formally show the car, but they're almost invisible and will eventually get brittle and fall off due to the heat.  By the way, I put a stainless system on this car and have been very pleased with how it worked out.  When I had my exhaust manifolds re-porcelined the guy who did it coated the inside with a ceramic coating so that they don't heat up as much externally.  Running your carb setting a little on the rich side can also help.  Additionally, your firewall insulator needs to be in good shape and as I re-do the interior I'm putting in some peel and stick sound deadener/heat insulator (foil backed) on the floor prior to putting in the new carpet.  I don't know your location, but having a heater in these cars is really not a necessity so you might consider not hooking it up, storing it and plugging the firewall holes,  or at least close off the flow for summer driving.
Ken Karrer 1941 6227D coupe

Online Bill Ingler #7799

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Re: Purpose of exhaust pipe wrapping
« Reply #3 on: July 18, 2012, 10:43:37 AM »
Richard: Here is a picture of a pan that fits under the frame and directly behind the radiator. I have not found this in my parts book but that is not to say it is not in the book. The purpose of the pan is to help direct the airflow coming through the grill and radiator from going down and under the engine rather than directing as much air over the engine as possible. I bought my pan from someone in Akron Ohio maybe 8 years ago. It bolted right in place using the tread holes already in the frame. How much did this help with airflow I can`t say but anything that helps keep the airflow moving across that big hunk of cast iron I am all for installing on my car. What were the years this pan was used?  Can anyone give me the parts number or what page to look at in the Master Chassis Parts book?  Thanks  Bill

Offline Raymond919

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  • Name: Ray Schuman
Re: Purpose of exhaust pipe wrapping
« Reply #4 on: July 18, 2012, 11:34:42 AM »
Hi Everyone,
I've been reading this thread and have a question. I have a '49 Series 62 with the overhead valve engine. The exhaust manifolds are on the sides and the exhaust pipe runs from the bottom of the passenger side exhaust manifold down between the battery and starter toward the rear.
My exhaust pipe comes nowhere near the water pump but the Authenticity Manual calls for an exhaust pipe wrap for a total length of about 15 inches. This is in an area where wind would constantly blow over the pipe while driving. Could it be for heat radiating toward the battery and starter? If this is a concern, why doesn't the '48 and earlier cars with the flathead engine call for the same wrapping on the exhaust pipe (or does it?).
Ray

Offline kkarrer

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Re: Purpose of exhaust pipe wrapping
« Reply #5 on: July 18, 2012, 12:29:30 PM »
The wrap is called for in the earlier cars.  Anything that can be done to lessen the heat in the engine compartment helps the battery, water pump, all other associated parts... and the driver.  The 15" length is sufficient to get the pipe below the car where it can be blown back and out when the car is moving.  It also protects your hands when your working in that area and the engine has been or is running.
Ken Karrer 1941 6227D coupe

Offline Scott Anderson CLC#26068

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Re: Purpose of exhaust pipe wrapping
« Reply #6 on: July 18, 2012, 02:16:44 PM »
My 41 does not have ithe mud pan but I'm told by Bob LeCoque that it absolutely should and for the reason you described. So at least back to 41 is correct. I've seen it on several other 41s. Agreed anything we can do about cooling them is good.

Also re the exhaust pipe wrap I have wondered in the past about it shielding the starter from heat soak too as the wrapped area of the pipe goes right under/by it, for whatever good it may do. I have removed and replaced mine as it just needed some sprucing and since it was only cosmetic I found that a new coat of white header paint makes a huge appearance impression in there. It broke in going back on but I've clamped and used a little glue to temporarily hold it (im sure it burned off quickly) so it looks whole. Might soak it internally now I know of it next time. Great advice as always from Bill about replacement technique about more than one set of hands and beers.

By copy to Ken, mine also has stainless exhaust. After 12 years in FL and 2 in WA it still looked great in the wrapped area and really good in the rest. I'd love to know how the inside manifold coating works out. I've even seen an aerosol product from Eastwood, possibly there are others too of course.
« Last Edit: July 21, 2012, 08:33:14 AM by Scott Anderson CLC#26068 »
Like I always say sometimes, there's a lot of human nature in everyone...

Offline R Sotardi #11719

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Re: Purpose of exhaust pipe wrapping
« Reply #7 on: July 18, 2012, 06:20:22 PM »
My 1950 also has(had originally) the wrap. It could reduce heat to the starter, but at idle it really reduces heat to my wifes feet, as the heat would radiate to the toe board in the footwell.Ron

Offline The Tassie Devil(le)

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Re: Purpose of exhaust pipe wrapping
« Reply #8 on: July 18, 2012, 06:37:17 PM »
I also believe that it also quietens the exhaust during the initial transition from the solid Manifold to the thin piping.

Anyone who has experienced thin-wall exhaust tubing will attest to the noise that comes as the result of combustion pressures.

Cadillac tried to make their cars as quiet as possible, and the wrapping does help.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'55 Buick Special Post Coupe (LHD)
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Offline Brad Ipsen CLC #737

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Re: Purpose of exhaust pipe wrapping
« Reply #9 on: July 18, 2012, 08:42:31 PM »
I think the group number/part number for the pan you describe Bill is Group 10.1140 Mud Pan Shelf.  It calls it out as front.  The same group number list the V-16 mud pans which are left, right and front so that also is the same sort of part.  This is a part that was probably taken off many cars by mechanics thinking they know better than Cadillac engineers.   
Brad Ipsen
1940 Cadillac 60S
1938 Cadillac 9039
1940 Cadillac 40-6267
1940 LaSalle 40-5227

Online Bill Ingler #7799

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Re: Purpose of exhaust pipe wrapping
« Reply #10 on: July 18, 2012, 09:32:25 PM »
Hi Brad: Thanks for your input. Yes sir, there it is in my Master Parts book called as you said, Shelf, Mud Pan Front. I wonder what they paid the person to came up with all the names for parts. Most of the times the name for the part is straight foreward and other times the names appear to be way out in left field.      Bill

Offline Richardonly

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Re: Purpose of exhaust pipe wrapping
« Reply #11 on: July 19, 2012, 07:03:59 AM »
Gentlemen,

To add insult to injury, as the original photo shows, the car was fitted with A/C from Frigette in 1951.  Frigette made cooling units for cars starting in 1918.  Perhaps it was for some sort of trucking instead of ice?

In any case, as with all A/C units, the radiator is restricked by the condensor(?) in front of it.  This causes a problem with a push electric fan as there is little room left AND little roon for a pull fan, which is better, but unsightly.

Once again, I can see the need for the "wrap" in regards to the water pump, BUT with that overhead exhaust I cannot imagine it making much difference in the engine compartment area.  Other than being unsightly, why didn't they wrap the entire exhaust starting with the manifolds?

Should retitle this " How to Remake a Better 1948 Cadillac."  LOL

Richard
1948 Cadillac Fleetwood 60S
1995 Lincoln Towncar, Signature Series
1995 Jaguar XJ6
2001 Chrysler Sebring Convertible
1986 Yamaha 700 Maxim X motorcycle

Offline Jeff Maltby 4194

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Re: Purpose of exhaust pipe wrapping
« Reply #12 on: July 21, 2012, 06:44:01 AM »
Here's my oem 49 pipe wrap in half's from the factory with aluminum clamps.
« Last Edit: July 21, 2012, 08:11:10 AM by Jeff Maltby 4194 »
Jeffo 49er chapter

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Honda Gold Wing gl1500 Gwrra 353 1978

Offline Raymond919

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  • Name: Ray Schuman
Re: Purpose of exhaust pipe wrapping
« Reply #13 on: July 21, 2012, 08:52:08 AM »
Jeff, be careful in handling that, or better yet, don't handle it. Slide it into a plastic zip-lock bag and seal it. It's most likely asbestos and can be harmful.
Ray

Offline Richardonly

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  • 1948 Cadillac Fleetwood
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Re: Purpose of exhaust pipe wrapping
« Reply #14 on: July 24, 2012, 07:07:31 AM »
I have been told that the wrap also keeps the water pump cooler, thus the water (coolant) at a cooler temperature.

My running temp on the highway averages 200-210, ouside temp at 85-95 degrees.  With the outside air and a 6 blade fan, does the water pump really get the heat or is the wrap more for slow city driving?  Even there, does the fan not blow back the heat?

After reading what you have written, I shall install the wrap, but still have the above questions.  I suppose that it is needed, otherwise why did they originally install it?

There appears to be enough clearance to install it with the pipe on the car on the 1948 Fleetwood.  Not measureing it, I estimate it to be approx 4" of clearance.  What do you think????
1948 Cadillac Fleetwood 60S
1995 Lincoln Towncar, Signature Series
1995 Jaguar XJ6
2001 Chrysler Sebring Convertible
1986 Yamaha 700 Maxim X motorcycle

Offline Richardonly

  • Posts: 531
  • 1948 Cadillac Fleetwood
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  • Name: Richard V. Pattison
Re: Purpose of exhaust pipe wrapping
« Reply #15 on: July 24, 2012, 07:10:04 AM »
Does the wrap start at the bottom of the flange or an inch down?  Perhaps at the bolt ends???
1948 Cadillac Fleetwood 60S
1995 Lincoln Towncar, Signature Series
1995 Jaguar XJ6
2001 Chrysler Sebring Convertible
1986 Yamaha 700 Maxim X motorcycle

 



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