ok my dad is a tool and dye maker so he knows his way around a lath so i need some specs on hemi head that runs on 93 pump gas because i got him to watch joeak47s video on the diy hemi head and we wants to make one thanks
hemi squish band head
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I say "Take the bull by the horns" and do it yourself,and have your father help point you in the right direction. This is how you learn. Not by having someone else do it.You will have a much greater appreciation for the work,and the finished product. You will then be able to tell all your buddys..."I did it myself". You will surprised yourself how capable you really are.
Don't take what I said wrong...These are words of encouragement. Treat yourself!
Don't take what I said wrong...These are words of encouragement. Treat yourself!
like kwai chang teaching a new grasshopper to snatch the pebble from his hand !!!!
(youngsters will need to google that)
Whats this MIGHT crap???
Go rip that head off your bike AND....
Go grab the old man...and ask him to show you the ropes on the lathe. Then make the arbor which with basic skills will take about 30 to 45 minutes. I guarantee that this will get your juices flowing.
Then procede to mount the head in the arbor AFTER you make sure the plug threads are clean and in good shape.
Now cut about .130 thousandths off the sealing surface of the head...and yes, the original gasket surface will dissappear,and you will be left with a round, inset machined surface.
Now mark the diameter of your cylinder bore on that "just machined surface" of the head.
From that mark,start cutting your squish band inward toward the spark plug hole using the compond rest. I use 11 degress,and so do most two stroke dirt bikes.
Go with say a squish band width of about .450 (four hundred and fifty thousandths) Which will promote higher revs. Forgot what percentage of the bore this would be.
Now start cutting the combustion chamber using a round nose bit. Start at the inner edge of the squish band and work toward the spark plug hole. Do this a little bit at a time until you get the "hemi" shape that blends right up to the spark plug hole.
Once you have it where it looks good,lightly sand it with your finger,remove it from the arbor and go CC the head.
Go rip that head off your bike AND....
Go grab the old man...and ask him to show you the ropes on the lathe. Then make the arbor which with basic skills will take about 30 to 45 minutes. I guarantee that this will get your juices flowing.
Then procede to mount the head in the arbor AFTER you make sure the plug threads are clean and in good shape.
Now cut about .130 thousandths off the sealing surface of the head...and yes, the original gasket surface will dissappear,and you will be left with a round, inset machined surface.
Now mark the diameter of your cylinder bore on that "just machined surface" of the head.
From that mark,start cutting your squish band inward toward the spark plug hole using the compond rest. I use 11 degress,and so do most two stroke dirt bikes.
Go with say a squish band width of about .450 (four hundred and fifty thousandths) Which will promote higher revs. Forgot what percentage of the bore this would be.
Now start cutting the combustion chamber using a round nose bit. Start at the inner edge of the squish band and work toward the spark plug hole. Do this a little bit at a time until you get the "hemi" shape that blends right up to the spark plug hole.
Once you have it where it looks good,lightly sand it with your finger,remove it from the arbor and go CC the head.
well put man! i have learned stuff myself through the time iv had bikes and quads and iv learnt from them. no one gets through life doing things fantastic from the start everyone learns new things everyday! i surprised myself by being able to do my engine repairs as before i would never attempt it. i always use to put my engine into a shop but since iv done things and learned from my mistakes never once put it into a shop. my grandad learned me alot as well but iv also learned him about a few things he didn't know
^^^I:I
ok i need to get another head first hint hint but i probably will do it my dad doesent wanna do that with the head thats on it now plus i still wanna break in the motor befor i put that head on
PROBABLY???
SHUT THE Front door.
Everything including the arbor can be accomplished well within 4 to 5 hours. You wont need another head. Just go slow. There is enough material in these heads,that you can screw up multiple times,and still make it right.
Now go wash that bike and bust out the 12mm socket and ratchet.
DO NOT use the words "might",probably",maybe",or a combination there of. Now get busy and post some pictures when your done!I:I
SHUT THE Front door.
Everything including the arbor can be accomplished well within 4 to 5 hours. You wont need another head. Just go slow. There is enough material in these heads,that you can screw up multiple times,and still make it right.
Now go wash that bike and bust out the 12mm socket and ratchet.
DO NOT use the words "might",probably",maybe",or a combination there of. Now get busy and post some pictures when your done!I:I
You will not get anything negative from this head unless you go under say 18cc combustion chamber and have poor fuel and improper jetting. If its not spot on you could get detonation. To help avoid problems, get the chamber at 20cc's,and make sure your jetting is good to go.
You WILL notice a difference in power. A smoother delivery,etc. Right off the bat you will notice a high idle,because the combustion is more efficient,and you will also notice that it revs like a dirt bike. ..No more lazy revs.
You WILL notice a difference in power. A smoother delivery,etc. Right off the bat you will notice a high idle,because the combustion is more efficient,and you will also notice that it revs like a dirt bike. ..No more lazy revs.
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Depends on many factors...cylinder condition,how many hourson the top end, fuel to oil ratio,altitude,etc.[
However...don't get stuck on the static compression ratio. Its the chamber SHAPE,SQUISH BAND,and SQUISH CLEARANCE that makes the magic happen. Much more efficient/complete burn of the fuel/air mixture.
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Run, don't walk, RUN to the lathe... Listen to Joe...
A redesigned combustion chamber is the best the best thing you can do for your Blaster.
Widen it out, get rid of that little cone and 60% squish, hemi, toroidal, it doesn't matter.
You could cut it with a 1 and 7/8" drill and the Blaster would work better. Honest.
The first hemi head Neil and I put on pretty much doubled the hp of his Blaster.
That was at 27cc and 2mm squish. I am sure the thing would run on regular 87 octane gas.
Cutting the head back to 23cc and 1mm squish gave a small increase over that, but the real secret is in the chamber shape.
Even messing with the squish, the big gain is to get it somewhere around 1mm. Just get it close!
Get the shape close, get the squish close, get about 50% squish (dia 47mm) and somewhere around low 20ish cc's and you will fly.
Of course if you take it just a little too far, problems will happen...
So if you go right to the edge of the wall, be careful you know what you are doing or you could fall off.
Experiment or buy one off the experts. Ken and others sell their knowledge cheap.
Buy a head off Ebay and have it sent to your favourite guru, whatever.
The rechambered head is the start of more power out of your Blaster.
Steve
A redesigned combustion chamber is the best the best thing you can do for your Blaster.
Widen it out, get rid of that little cone and 60% squish, hemi, toroidal, it doesn't matter.
You could cut it with a 1 and 7/8" drill and the Blaster would work better. Honest.
The first hemi head Neil and I put on pretty much doubled the hp of his Blaster.
That was at 27cc and 2mm squish. I am sure the thing would run on regular 87 octane gas.
Cutting the head back to 23cc and 1mm squish gave a small increase over that, but the real secret is in the chamber shape.
Even messing with the squish, the big gain is to get it somewhere around 1mm. Just get it close!
Get the shape close, get the squish close, get about 50% squish (dia 47mm) and somewhere around low 20ish cc's and you will fly.
Of course if you take it just a little too far, problems will happen...
So if you go right to the edge of the wall, be careful you know what you are doing or you could fall off.
Experiment or buy one off the experts. Ken and others sell their knowledge cheap.
Buy a head off Ebay and have it sent to your favourite guru, whatever.
The rechambered head is the start of more power out of your Blaster.
Steve
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