Making thinner head gaskets

[Grunter215]

Whats the best stuff to use.Need more compression on my PE400. Do non standard ones blow out easier?

[suzuki27]

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.

[vandy010]

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.

[Doc]

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??

[oldfart]

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 

[Grunter215]

Thanks guys.I'll hunt around for copper sheet or RM gasket.

[LWC82PE]

make sure you check your squish band clearance after.

[Grunter215]

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

[Maicojames]

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.

[mainline]

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. "

[Lozza]

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

[Doc]

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.

[Doc]

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?

[gorby]

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 and it was interesting to see how much a motor can move around with just two mounting bolts holding it in.

[lukeb1961]

http://encyclopedia2.thefreedictionary.com/quench