Author Topic: Gaskets  (Read 5645 times)

Offline Mosey

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Gaskets
« on: December 19, 2014, 02:57:42 PM »
Anyone have suggestions for exhaust gasket materials?
Copper?
Store-bought sheet fiber?
Mosey  :headscratch:

Offline Brian Rupnow

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Re: Gaskets
« Reply #1 on: December 19, 2014, 05:04:52 PM »
Mosey--I purchased a sheet of hi temperature gasket material for making head gaskets and exhaust gaskets thru McMaster Carr. It was wretchedly expensive, but then again, there is probably enough material to do about 10 more engines. You can find a picture of it and see the name of it if you search thru my side valve engine thread.---Brian

Offline GailinNM

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Re: Gaskets
« Reply #2 on: December 19, 2014, 05:24:37 PM »
Mosey,
I use PTFE (Teflon) film 0.015 thick or sometimes 0.032 thick.  Unless you are building a high performance engine, the manifold to engine block or head temperature will never reach any where near the max temperature for it.  It is easy to cut with a knife and sharpened brass tubing punches. It only costs a few dollars for a square foot of it which is near a life time supply.  It also cuts very well on a laser cutter using the MIT recommendations so no unpleasant gases are released. I also use it for head gaskets on my hit and miss engines.
Gail in NM
I would like to be the kind of person my dog thinks I am.

Offline Mosey

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Re: Gaskets
« Reply #3 on: December 19, 2014, 08:12:38 PM »
I have a head gasket now of .060" Teflon, and a grey, fiber gasket material from the local auto parts for exhaust gasketing. They both seem too thick but work, so I am hoping to find something better, maybe .030" might be better, if I can find something.
I wonder if I can find a Teflon tape that is about .015" thick?
All of these materials are also quite expensive.
Mosey

Offline Brian Rupnow

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Re: Gaskets
« Reply #4 on: December 19, 2014, 08:24:15 PM »
Mosey--You don't REALLY need exhaust gaskets. The engine will run fine without them. However--Do you have room either on the manifold side or the cylinder side to machine a small round pocket around the exhaust passage and use a viton o-ring. they are very inexpensive and will take the exhaust temperature with no trouble. The pocket should be about .015" shallower than the cross sectional thickness of the o-ring to put a bit of squeeze on it when the bolts are tightened down.---Brian

Offline tvoght

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Re: Gaskets
« Reply #5 on: December 19, 2014, 08:28:00 PM »
I use teflon film from McMaster-Carr. Many thicknesses down to 002". The cost doesn't seem prohibitive.

http://www.mcmaster.com/#film-%28made-with-teflon-ptfe%29/=v3f930

--Tim

Offline stevehuckss396

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Re: Gaskets
« Reply #6 on: December 19, 2014, 11:23:29 PM »
Like tvoght I use the teflon film for gaskets. .020 for head gaskets and .010 for all other gaskets.

As Brian said you don't need exhaust gaskets. I don't use them.
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline Myrickman

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Re: Gaskets
« Reply #7 on: December 20, 2014, 10:36:15 AM »
I like the idea of Teflon as a gasket material and will have to try it on my current build. Guessing the 0.020" stuff should work fine. Making the occasional jump into modeling from working on the full-sized hit and miss engines has been a learning experience and this board is full of clever solutions.. I'm used to making head gaskets from 1/8 sheet material I cut with a scroll saw. Being able to use scissors and a razor knife will be nice...

Offline Roger B

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Re: Gaskets
« Reply #8 on: December 20, 2014, 12:21:37 PM »
I used this for the head gasket on my vertical engine and will use the same on the current build.

http://www.conrad.com/ce/en/product/234783/?insert=62&insertNoDeeplink&productname=Reely-Sealing-material-for-combustion-motors-05-mm-X7288

Best regards

Roger

Offline Mosey

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Re: Gaskets
« Reply #9 on: December 20, 2014, 12:56:33 PM »
Like tvoght I use the teflon film for gaskets. .020 for head gaskets and .010 for all other gaskets.

As Brian said you don't need exhaust gaskets. I don't use them.
Steve, Tim,  and Brian,
I will follow your recommendations.
Mosey

Offline Mosey

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Re: Gaskets
« Reply #10 on: January 26, 2015, 03:29:06 PM »
Mosey--You don't REALLY need exhaust gaskets. The engine will run fine without them. However--Do you have room either on the manifold side or the cylinder side to machine a small round pocket around the exhaust passage and use a viton o-ring. they are very inexpensive and will take the exhaust temperature with no trouble. The pocket should be about .015" shallower than the cross sectional thickness of the o-ring to put a bit of squeeze on it when the bolts are tightened down.---Brian
I still have a tiny leak in the manifold, so I will flatten & polish it's surface and try again, or maybe give the O-ring a shot.
Mosey

Offline Mosey

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Re: Gaskets
« Reply #11 on: January 26, 2015, 06:48:11 PM »
I want to see what the O Ring solution to sealing the exhaust manifold is like.
First I finished my head repairs by crossdrilling the intake and exhaust passages into the new cages. The mirror is so I can see when the drill breaks through into the cage.


Then centered up on the exhaust ports to mill a recess for the O Rings.

Mill the recesses for the O Rings.

Now test the ports for leaks in mineral spirits.

Using a household syringe for vacuum shows seal at the ports, but leaks at 1 of the valves.

So, I have to lap 2 of the valves for a seal.
It is snowing like mad here, expecting 1-2', and I'm in my shop having a good time.
Nothing more need be said.
Thanks for looking.   :whoohoo:
Mosey

Offline Jasonb

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Re: Gaskets
« Reply #12 on: January 26, 2015, 07:10:45 PM »
I just use a liquid gasket, smear a little onto the surface and the excess will squeeze out so it takes up zero height. Once dry you can just rub off the excess to leave a nice clean joint and no cutting to worry about. Seems OK at our sort of temperatures.

You can just see a hint of the blue sealant on the edge of the flange that did not get cleaned off

 

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