Old Snapper!?!?

[alwaysFlOoReD]

Now you know what type of person you REALLY are.

I'm wanting input on the feasibility of using copper pipe for exhaust gaskets.

I bought these two old snapper riding lawnmowers a few years ago and finally decided to see if I could get them running. I don't have pics of each side by side but they look the same.

One has an optional electric start, I'm glad I started on the one with a pull starter as the 1st one basically fired right up with new gas and a spark-plug.
There was a problem with the head gasket on the second one;

I also had to make an exhaust gasket.
Remembering from when I took a diesel pre-apprentice course when I took old work hardened FI copper gaskets then heated it to a red-orange color and dropped it into cold water. This anneals the copper so it's soft enough to conform to any rough spots. So I decided to use some copper pipe I had in the scrap pile;

I flattened out the copper and then traced the outline of the gasket;

After drilling and cutting with an air operated cutting tool, [a coping saw or jig saw would work great too] I bolted the old gasket to the new and did the final filing;

I tried using the drill press with a rotary file but that didn't work too well. I think it's because I couldn't get to a high enough rpm. I finally went back to old school hand filing.
After putting it back together and cleaning the carb I got it running. Not that well yet as I didn't think to keep track of how far in the two needles were turned in. I'm guessing that the one is for air/fuel at idle and the other is for at load.
The exhaust gasket seems to be working well but the head gasket is leaking. I don't think I had it torqued down good enough. I have since looked up the applicable torques and will try annealing the head gasket again. A new head gasket is on order if it fails @~C$9.00. I wanted to do this as a proof of concept for exhaust gaskets for my 4.0l off road racing and some other motors I have for drag racing projects. I know this works for brake and fuel lines but; Is copper pipe going to handle the heat? Will it anneal like I remember? Will it work as an exhaust gasket? Head gasket?
Thanks for input,

Richard

 

[85_Ranger4x4]

I do know tractor pullers use copper headgaskets to deal with really high compression... but they are premade (places will custom make about anything) and to my knowlage are not made out of pipe. They also likely have a fresh cut head and surfaced block as well to limit the imperfections. They are not ideal but for some circumstances are about the only option.

The two bolt flange exhaust will bend really easy it you get after it trying to tighten it.

 

[70roadrunner]

to anneal any metal, you heat it up and let cool slowly. dropping it in water hardens it

 

[straycat]

Old Snapper?? Whew!!! I thought you were talking about a girl I knew back in high school...that was her knickname....She would call you over for a make out session and then she would let you to put a hand or a finger here or there and she always had some sharp fangs hiding in places.....lol

 

[alwaysFlOoReD]

I do know tractor pullers use copper headgaskets to deal with really high compression...

Good to know.

to anneal any metal, you heat it up and let cool slowly. dropping it in water hardens it

I agree that dropping steel in water hardens the metal but that doesn't happen with copper. I don't know why though.

Old Snapper?? Whew!!! I thought you were talking about a girl I knew back in high school...that was her knickname....She would call you over for a make out session and then she would let you to put a hand or a finger here or there and she always had some sharp fangs hiding in places.....lol

I'm glad someone caught [snicker] my joke.

Richard

 

[OilPatch197]

Are these the mowers that had the magnesium decks?

 

[saskbill]

I remember reading about (heat and then) quench annealing copper years ago in an article about spin-forming bowl outs of copper sheet on a wood lathe. Sounded funny at the time to anyone used to working with steel, but the general consensus out there is, the key to annealing copper is heat cherry red, then cool fast or slow, as you prefer. Repeat as necessary to fend off work-hardening.

A couple of articles to ruminate on:

http://www.therevcounter.com/mechanics/50128-annealing-copper-head-gaskets.html

http://en.wikipedia.org/wiki/Annealing_(metallurgy)

 

[alwaysFlOoReD]

Are these the mowers that had the magnesium decks?

Not that I'm aware of but now I'll check.

I remember reading about (heat and then) quench annealing copper years ago in an article about spin-forming bowl outs of copper sheet on a wood lathe. Sounded funny at the time to anyone used to working with steel, but the general consensus out there is, the key to annealing copper is heat cherry red, then cool fast or slow, as you prefer. Repeat as necessary to fend off work-hardening.

A couple of articles to ruminate on:

http://www.therevcounter.com/mechanics/50128-annealing-copper-head-gaskets.html

http://en.wikipedia.org/wiki/Annealing_(metallurgy)

Thanks for the links,

Richard

 

[wahlstrom1]

I wanna say AllenD tried a few times to get homemade copper exhaust gaskets to work to try and seal up a shoddy pair of headers but never had long term success with it.