SuzukiHayabusa.org
TECHNICAL => MODS => Topic started by: Shamrock on April 16, 2010, 09:21:48 PM
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Tools you'll need
Degree Wheel TDC 0-180 BDC
Standard 1" dial indicator
Indicator stand
Piston stop
Coat hanger
Paper and pen
Calculator
(http://img.photobucket.com/albums/v207/469boy/Cams.jpg?t=1271477585)
Print it and save it :thumb:
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:thumb: :thumb:
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Step 18 is not correct.
For example, the stock Hayabusa's intake cam opening is listed as 32 degrees and the closing as 64 degrees.
32+64 = 96
96/2 = 48
I take the opening number, closing number, add 180, divide by 2, then subtract the smaller of the two numbers.
32+64 = 96
96+180 = 276
276/2 = 138
138-32 = 106
Which of the two #'s seems correct?
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Wonder how many motors I have messed up that way =( LOL :hys:
Are you using a 0-90-0 wheel?
Step 18 is not correct.
For example, the stock Hayabusa's intake cam opening is listed as 32 degrees and the closing as 64 degrees.
32+64 = 96
96/2 = 48
I take the opening number, closing number, add 180, divide by 2, then subtract the smaller of the two numbers.
32+64 = 96
96+180 = 276
276/2 = 138
138-32 = 106
Which of the two #'s seems correct?
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Thanks for posting! :thumb:
I always have to do a search for this info when rebuilding my engine. :D
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minus small # from big # add 180 divide by 2 done
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minus small # from big # add 180 divide by 2 done
I'd use the word subtract instead of minus but other than that that's how I do it. I've never timed cams at maximum lift...that's a first. I have always timed them using the base circle as 0 than .040 or .050 lift from there.
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minus small # from big # add 180 divide by 2 done
I'd use the word subtract instead of minus but other than that that's how I do it. I've never timed cams at maximum lift...that's a first. I have always timed them using the base circle as 0 than .040 or .050 lift from there.
Subtract, minus, take away,!! what you like not what i like..
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minus small # from big # add 180 divide by 2 done
+1
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Dear friends ,what is the differences between 0.40 and 0.50 duration in degreeing valve
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You need to think about when the small numbers cross over TDC. :id:
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Dear friends ,what is the differences between 0.40 and 0.50 duration in degreeing valve
That depends on the ramp shapes of the cam. To give you an idea of what it might be, I've checked a couple of old-school cams, and they had 7.5º and 7º more duration@.040" lift than at .050" lift.
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You need to think about when the small numbers cross over TDC. :id:
This is true. Just running the numbers without paying attention to which side of TDC/BDC they are occuring can give bad results. Typically the intake cam is expected to open before TDC and close after BDC, and the exhaust cam is expected to open before BDC and close after TDC. That's where the 180 figure comes from, going from TDC to BDC or vice versa. However in some situations, such as with a Gen1 Busa stock exhaust cam, it can close before TDC when checking@.050" lift. Therefore in that case we need to *subtract* that small number, because it's not going the full 180º from BDC to TDC.
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The best resource I've found is on Web's page, over in the left column follow the link to degreeing your cams and go to the bottom of that page.... there is a little spreadsheet program that does all the math for you and it never forgets to carry the one!! We just fire up the old smart phone and pull it up while we are doing the job. No muss no fuss correct every time.... Just remember which side of TDC you're on.
http://www.webcamshafts.com/
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http://racetoolz.com/
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I've never timed cams at maximum lift...that's a first. I have always timed them using the base circle as 0 than .040 or .050 lift from there.
this is the way Ive been doing it for a few yrs, taking measurements .040 before and after max lift. seems more intuitive. the numbers are close together, easy math, add up then divide by 2. you can get an idea for roughly where the CL will be by the range that shows max lift when you are setting up the DI. I always check PTV and adjust if i feel its too tight.
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I've always found them with the .040 or .050 lift opening/closing method and ran the math over and over....
But the .040 either side of max is going to be tried when I check the cams on the 1K Busa next week. It makes sense and would be so much easier I think.
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I go to peak lift and then zero it and go .010 on both sides. Same results less turning
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i think i can break in a set of rings degreeing cams :hys:
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i think i can break in a set of rings degreeing cams :hys:
Lmao. I've thought the same
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I go to peak lift and then zero it and go .010 on both sides. Same results less turning
Being a machinist and worrying about every .001 play
I only turn the motor in one direction so lotsa lotsa motor turning
:td:
I consider it the beginning of break in LOL
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You can go backwards but go back well past the checking lift then forward. Will wont have an issue.
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Bump for the Newbies