Doing cam timing

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14 May 2018 11:21 #783346 by Dr. Gamma
Replied by Dr. Gamma on topic Doing cam timing
The bigger the degree wheel, the better!!!


This one works great, but can be a bitch to mount on some motors.

Works great on Kz900/1000 motors!!!

1972 H2 750 Cafe Racer built in 1974.
1976 KH400 Production Road Racer.
1979 Kz1000 MK. II Old AMA/WERA Superbike.
1986 RG500G 2 stroke terror.
1986 GSXR750RG The one with the clutch that rattles!

Up in the hills near Prescott, Az.
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14 May 2018 15:50 - 14 May 2018 16:17 #783359 by VTEC
Replied by VTEC on topic Doing cam timing
Can't figure this one out. Go the dial indicator set up perfectly. Perpendicular with the bucket in the shim removal cutout. Goes back to zero on the base circle every time. The timing specs on exhaust is opening 54.5 BBDC and closing 17.5 ATDC. Got opening at 54 BBDC, but closing is at 11 ATDC. They are APE 410s made by Webcam. Specs are at .050". Doesn't make sense?

Correction. Got it dead on at 54.5 but still 11 at .050" on the downslope. 6.5 degrees off.

KZ1000-K2
ZRX1100
XR400R
Last edit: 14 May 2018 16:17 by VTEC.

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14 May 2018 17:29 #783373 by loudhvx
Replied by loudhvx on topic Doing cam timing
I realize this is a discussion on the larger motors, but on the 550's, I have never seen the TDC mark off by more than about 1/2or 3/4 of a degree.

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15 May 2018 06:59 - 15 May 2018 07:17 #783401 by zed1015
Replied by zed1015 on topic Doing cam timing

VTEC wrote: Can't figure this one out. Go the dial indicator set up perfectly. Perpendicular with the bucket in the shim removal cutout. Goes back to zero on the base circle every time. The timing specs on exhaust is opening 54.5 BBDC and closing 17.5 ATDC. Got opening at 54 BBDC, but closing is at 11 ATDC. They are APE 410s made by Webcam. Specs are at .050". Doesn't make sense?

Correction. Got it dead on at 54.5 but still 11 at .050" on the downslope. 6.5 degrees off.

Spec for APE 410's are 59 - 27 @ .030" lift.
There must be something throwing off the calcs , possibly the valve clearance.
Are you running close to zero for degreeing purposes as APE don't seem to clearly specify that figure but unless specified it should be done with next to no clearance.
They do mention .004" cold but whether they mean for running or timing is unclear.
.004" is on the tight side for running though and I prefer going to the .006" end once built.
The wider the clearance the less duration it will show and you would need to compensate by splitting the difference.
If you still have problem it may be better to use the lobe center method and set them at 108 to 110 .

AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
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Last edit: 15 May 2018 07:17 by zed1015.

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15 May 2018 09:12 #783407 by VTEC
Replied by VTEC on topic Doing cam timing

zed1015 wrote:

VTEC wrote: Can't figure this one out. Go the dial indicator set up perfectly. Perpendicular with the bucket in the shim removal cutout. Goes back to zero on the base circle every time. The timing specs on exhaust is opening 54.5 BBDC and closing 17.5 ATDC. Got opening at 54 BBDC, but closing is at 11 ATDC. They are APE 410s made by Webcam. Specs are at .050". Doesn't make sense?

Correction. Got it dead on at 54.5 but still 11 at .050" on the downslope. 6.5 degrees off.

Spec for APE 410's are 59 - 27 @ .030" lift.
There must be something throwing off the calcs , possibly the valve clearance.
Are you running close to zero for degreeing purposes as APE don't seem to clearly specify that figure but unless specified it should be done with next to no clearance.
They do mention .004" cold but whether they mean for running or timing is unclear.
.004" is on the tight side for running though and I prefer going to the .006" end once built.
The wider the clearance the less duration it will show and you would need to compensate by splitting the difference.
If you still have problem it may be better to use the lobe center method and set them at 108 to 110 .



Hey Zed. Thanks for checking. The online 410 specs aren't close to the cam card that came with the cams. I'll send a pic after work.

I'll double check with APE. And yes, I'm as close as possible to zero lash.

KZ1000-K2
ZRX1100
XR400R

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15 May 2018 09:57 #783410 by zed1015
Replied by zed1015 on topic Doing cam timing

VTEC wrote: Hey Zed. Thanks for checking. The online 410 specs aren't close to the cam card that came with the cams. I'll send a pic after work.

I'll double check with APE. And yes, I'm as close as possible to zero lash.


Using a higher lift for reading will reduce the degree figure so the card you got is probably correct.
Maybe the online specs of .030 lift put the cam too close to the base circle to get easily readable lift to degree figures.

AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-





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15 May 2018 10:31 #783412 by VTEC
Replied by VTEC on topic Doing cam timing
Do the specs I have above come out to 107.5 lobe center?

KZ1000-K2
ZRX1100
XR400R

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15 May 2018 11:19 #783416 by zed1015
Replied by zed1015 on topic Doing cam timing
Online specs give.
Inlet open = 27
Inlet close = 59
27 + 59 +180 = 266
divide by 2 = 133 and deduct 27 = 106.

Your card specs.
inlet open = 17.5
inlet close = 54.5
17.5 + 54.5 +180 = 252
Divide by 2 = 126 and deduct 17.5 = 108.5

Online specs give 106 centres and the card specs give 108.5 centres.

AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-





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15 May 2018 11:50 #783418 by VTEC
Replied by VTEC on topic Doing cam timing
The specs I gave were exhaust. Still doesn't seem like the card matches.

KZ1000-K2
ZRX1100
XR400R

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15 May 2018 13:10 #783422 by zed1015
Replied by zed1015 on topic Doing cam timing

VTEC wrote: The specs I gave were exhaust. .

Doesn't matter as long as they are the same cams
The online specs are=
Inlet is 27 - 59 and the exhaust is 59 -27.
Centres work out the same for both.
If yours are the same cams then the inlet timing will be a mirror image of the exhaust.
Is your inlet figure not 17.5 -54.5 and the exhaust 54.5 - 17.5 ?

AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-





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15 May 2018 15:36 - 15 May 2018 15:37 #783429 by VTEC
Replied by VTEC on topic Doing cam timing
Nope. Different animal. Clearance too.



KZ1000-K2
ZRX1100
XR400R
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Last edit: 15 May 2018 15:37 by VTEC.

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15 May 2018 15:52 - 15 May 2018 16:17 #783430 by VTEC
Replied by VTEC on topic Doing cam timing
Spoke with APE, and they said website specs are old, use cam card. Told him I'm getting 11 on the close side (should be 17.5) with 54.5 on the open side going by the card. He's calling Webcam to get the story.

I redid it at .030" lift and get bigger numbers but still low on the close side. I'm guessing this means the specs are for a cam with a different duration?

KZ1000-K2
ZRX1100
XR400R
Last edit: 15 May 2018 16:17 by VTEC.

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