OzVMX Forum
Marque Remarks => Suzuki => Topic started by: Grunter215 on September 13, 2008, 07:45:04 am
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Whats the best stuff to use.Need more compression on my PE400. Do non standard ones blow out easier?
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Maybe consider getting 10 thou of an inch shaved off the head-any decent aotomotive machine shop can do it. I know the RM250N/T came with optioal head gaskets(Copper) in 0.9mm and 1.2 mm,with the 0.9 giving slightly more compression-check for same on RM/PE for yours.
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i made one up years ago when i was at school for my then new RM125t from a sheet of thin copper i flogged from the metalworking dept of my school. as a then 14yr old, i can't even say i noticed a difference but went back to the stock one just to play it safe.
have fun cutting it out. copper is the go.
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why not simply run a copper RM400N/T gasket? From memory they're thinner and fit straight on :-\ oldfart, can you confirm or dismiss this comment??
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Rm 400 head gaket = .5mm and do fit . I have a template and make my own out of sheet copper .5mm
takes about 10 minutes with a hole punch a set of snips , tidy up with die grinder and then anneal :)
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Thanks guys.I'll hunt around for copper sheet or RM gasket.
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make sure you check your squish band clearance after.
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Oldfart said to anneal...whats that???. Would like to have a go making gasket but dead end on copper sheets....any leads on where to buy?? Can get brass sheets whats the difference
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To anneal is to make a metal softer. Heat it up with a propane torch until it just starts to glow-then quench in water( use tongs or something to handle it will be hot). Copper sheet is available in small amounts in the hardware/home improvement stores-and also in hobby/craft stores here in US. I think you may find the same in NZ-even if it requires a bit more looking.
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I pinched this info off a gasket companies website. There seems to be some difference of opinion out there about whether the quenching part of the process is actually necessary.
"After the gasket has been worked to proper size it is ready for use. It may be necessary to re-anneal the gasket if it has work hardened. Annealing is a heat treatment that softens copper. The gasket may work harden somewhat if you have worked with it but it still should be soft enough for use.
Since there is oxygen within the copper it can only be annealed (using flame heat) a few times before it becomes somewhat brittle. I don't rec. reannealing more than three times.
OXY/ACETYLENE TORCHES may give TOO MUCH HEAT. We do NOT REC. this method.
Heat the metal until it appears just dark red while in a dark location. More red or orange is not necessary. Ideally, a temperature of about 900d F is optimal. Let air cool. Once cool (in about five - ten minutes) brush with the"Scotch-Bright" pad on a flat hard surface to clean and flatten. A flaky post annealing residue is normal after annealing in air. Bright annealing in an inert gas oven is optimal and prevents this oxidation. "
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Not anywhere ever have I seen a reference to rapid cooling for annealing.Rapid cooling is the way to harden materials.
http://au.youtube.com/watch?v=3jSz11lz8MA
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errr..I'm no expert but I think you'll find copper has quite different properties to other metals in this regard.. I have always quelched the head gaskets in cold water after heating them and never have I had a problem but I don't think it makes any difference.Never do I need to scotch bright them either as the quelching removes the residue leaving clean copper. I'll find where this cooling method for copper is mentioned but I've definately read and heard of it since I was a kid and I've always followed it. It's quite possible my 400 still uses the original hi-comp head gasket as I've annealed it over and over again due to the fact the dealers always supplied the low comp gasket. ;)
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well Loz you are correct..I can't find it written anywhere either that dunking in cold water is the method. I still stick by my thoughts as to the differing properties of copper in the fact that no matter what you do to cool it the only way it will work harden is from being repeatedly bent and re-straightened. My guess is my dad or one of his mates once told me the quelching 'secret' and I've done it ever since..old school theories maybe? :-\
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the instructions with my newly made copper gaskets from the good old USA,recommends heating with a propane torch til dull orange and quenching in room temparature water.
it also goes on to say how you torque it down cold,then warm up motor and torque whist warm,then let it cool and retorque again.
with the XL350 that means pulling the motor back out of the frame and pulling the rocker cover off.
boy,that exhaust pipe was hot :o and it was interesting to see how much a motor can move around with just two mounting bolts holding it in.
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http://encyclopedia2.thefreedictionary.com/quench
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I looked in the definitive tome 'Machinery's Handbook' today and it does in fact say to quench after heating.Heat was nowhere near red just light to medium blue.I may perform an experiment with 2 strips of copper sheet, 1 quenched and 1 air cooled.Put in vice and count the number of bends until fracture. ???
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I think you're right Lozza, I'm a fitter and turner by trade and I remember when I was an apprentice, and doing a lot of mainteince fitting, I was always told that when you wanted to reuse a copper washer, you heated it to dull red and quenched it in water to anneal (soften) it so it can be used again.
Work hardening is a broad term used to express the change of character a material exhibites after being used, with copper being so soft, a few applications of compression and heat are enough to work harden it and change its charictistics.
The charasticts of copper in a head gasket application is to provide minimal sqeeze or loss of dimension and yet make a good seal. If it's used too many times, you should also make sure it has not deformed and formed ridges or lips that could cause leaks or has compressed below standard thickness. For example, check out the copper washers under the M10 socket head bolts that hold nearly all Japanese forks together, they nearly always deform to the extent that they're sometimes difficult to get out of the slider. I always file them flat and sometimes reduce the OD so they can once again fit in the counter-bore then re-anneal before refitting.
Like with everything where you're using / rebuilding old machinery, best result are achieved is in the fitting detail adopted in reassembly.
Peter
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After some more reaserch I found this from a bonsai website that was cut and pasted to which I promptly cut and pasted
The copper will maintain it's soft crystal structure after annealing at any realistic cooling rate (from very slow like letting fire die down to fast like throwing it in a bucket of water). Generally, I would suggest water cooling to prevent excessive oxidation of the surface. Steel (iron + carbon) on the other hand will change it's properties dramatically upon rapid cooling . However, it is possible to cool copper fast enough to make it into a brittle material. This normally involves cooling rates of greater than 10 million degrees C per second which can only be obtained by spraying a very thin film on to a very cold surface (this equipment is very expensive
So it can be annealed either way and the water is merely to prevent oxidisation. I still learn everyday ;D
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thanks Lozza, I never why I dunked them I just did..part of the process I was explained :D I'll just have to rememeber not to cool it at rates greater than 10 million degrees C per second :o brrrr!!! phark I never knew it could get that cold but then I suppose it would be an infinate scale like heat and speed..terminal velocity..where does it stop? does it stop at all? is it as relevant to money as they say? :P :D yes because when 1 runs out of money so does the speed and heat :D babbling as usual...
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im the same as a few other guys. i have always heated copper head gaskets and then quenched them and never had an issue, especially when combining with the blue hylomer gasket sealant, but my preference is to use a new gasket when ever possible