Author Topic: Temp of down-pipes?  (Read 3507 times)

bpossel

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Temp of down-pipes?
« on: May 15, 2007, 18:31:12 »
Hello All!

Does anyone one what the temp of our downpipes are where they connect to the exhaust manifolds?

I made a grave mistake!  I sandblasted and then painted my downpipes with 500 degrees engine paint.  Tonight I started the engine up and the paint bubbled and smoked.  Luckily no fire...

So, now I need to drop the exhaust system again and redo...  what a stupid mistake!

Help, what paint do I need to use on the down pipes?  What temp range for the paint?

As always, thank you!!!

Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

ja17

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Re: Temp of down-pipes?
« Reply #1 on: May 15, 2007, 20:51:17 »
Hello Bob,

You must use manifold paint on these. I believe the temp is well over 1000 degrees at times. The exhaust system must handle the hot combustion gases which are much hotter than the engine coolant.  Try The Eastwood Co.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

hauser

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Re: Temp of down-pipes?
« Reply #2 on: May 15, 2007, 21:27:33 »
Bob, have you given any thought to the jethot coating?

http://www.jet-hot.com/

1969 280sl 5 spd
Gainesville, Fl.

bpossel

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Re: Temp of down-pipes?
« Reply #3 on: May 16, 2007, 06:01:04 »
Hi Joe & Bob,

Thanks for the replies.  This just confirms how valuable this site and group of experts is!  Always do the pre-planing and consult this group 1st.  I thought high temp paint would work.  Paint can has a picture of an engine on it with fire coming out of the exhaust.  Problem is that it is only rated to 500 degrees.  Should have checked on heat output of our manifold to downpipes....  Lesson learned!  Maybe this post can save some time for the next 113 owner...

I did send my manifolds out and had them beed blasted and ceramic coated.  Look nice!

Thought I would save a few $ and sand blast and paint the down-pipes myself.  Well, it all looked great until I ran the engine for a few minutes.  Paint on the downpipes smoked and bubbled.

When I go through the effort to pull the exhaust system down again this time I will have the pros coat it.  My exhaust system is all welded together so rather a booger :evil: to get it down and back up again so its properly connected to the manifolds. Have to order another set of copper nuts again also... Oh well... :(

Thanks again!
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

merrill

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Re: Temp of down-pipes?
« Reply #4 on: May 16, 2007, 19:32:02 »
Bob,
eastwood co has high temp manifold paint in various colors

I painted my exhaust system with 1200 deg spray paint from napa.
I think pep boys has a similar paint.

Matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230
Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

bpossel

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Re: Temp of down-pipes?
« Reply #5 on: May 16, 2007, 20:03:55 »
Hi Matt!

I ordered a can of silver exhaust manifold paint from Eastwood today.  They rate it at 1200 degrees.

Tonight spent a couple of hours and, once again, removed my intake and exhaust manifolds.  Also removed my starter.  This made removing the downpipes and entire exhaust system much easier.  

I will sandblast the downpipes again and then repaint next week.

Regards, Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320
« Last Edit: May 16, 2007, 20:05:11 by bpossel »

66andBlue

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Re: Temp of down-pipes?
« Reply #6 on: May 16, 2007, 20:39:42 »
Bob,
I have used a VHT product (1500 degree rated) for a different project (not a car) and had excellent success.
Make sure that the metal is free of any grease or oil residues - wash the manifolds with brake cleaner or something similar - and bake it in very slowly after each coat. Try to find a gas barbecue large enough for the downpipes and heat them up as described in this procedure recommended by VHT: http://72.10.43.141/high_temp.htm.
Wish you good luck!

Alfred
1966 blue 230SL automatic
« Last Edit: May 16, 2007, 20:40:21 by 66andBlue »
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

Shvegel

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Re: Temp of down-pipes?
« Reply #7 on: May 17, 2007, 04:15:22 »
I have never put a thermocouple on a pagoda but the Caterpillar 3508's that I maintain run about 900f when they are working hard.