WP/TB change question
12-21-2014, 07:09 PM
#1
Banned
Thread Starter
WP/TB change question
Just started on the WP job and drained the coolant, removed hoses on the 82.
I rotated the engine to get TDC on the harmonic balancer and cam gears before locking the flywheel.
My left cam gear is not perfectly lined up with the notch and V pointer, it is about a 1/2 tooth off to the right as you are looking at the gear from the front.
Prior to this, the engine ran great with no misses. Should I try to rotate the cam assembly once I remove the belt to get perfect alignment or leave well enough alone? Haven't removed the right cover yet to see where the right gear is at.
Thanks!
I rotated the engine to get TDC on the harmonic balancer and cam gears before locking the flywheel.
My left cam gear is not perfectly lined up with the notch and V pointer, it is about a 1/2 tooth off to the right as you are looking at the gear from the front.
Prior to this, the engine ran great with no misses. Should I try to rotate the cam assembly once I remove the belt to get perfect alignment or leave well enough alone? Haven't removed the right cover yet to see where the right gear is at.
Thanks!
12-21-2014, 07:29 PM
#2
Intermediate
JetDriver,
I am in the middle of the TB/WP on my 86. My Passenger side cam is also about 1/2 a tooth off. I am new at this, but I think when you go to install the new TB you will likely need to rotate the PS cam to get it into the new timing belt notch. I'm sure others with extensive experience in tis will chime in here as well.
Gman
I am in the middle of the TB/WP on my 86. My Passenger side cam is also about 1/2 a tooth off. I am new at this, but I think when you go to install the new TB you will likely need to rotate the PS cam to get it into the new timing belt notch. I'm sure others with extensive experience in tis will chime in here as well.
Gman
12-21-2014, 07:31 PM
#3
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They never line up perfectly...too many pieces can be moved slightly either way (like the cover that the mark is cast into.
As long as you can't move the gear one tooth and make it any better.....you've got it in the correct place.
Your cam gears are not adjustable, like the 1985 and later gears. Tighten them down, set them so that the notch in the gear is as close to the pointer as possible....and forget it.
As long as you can't move the gear one tooth and make it any better.....you've got it in the correct place.
Your cam gears are not adjustable, like the 1985 and later gears. Tighten them down, set them so that the notch in the gear is as close to the pointer as possible....and forget it.
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greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
12-21-2014, 07:35 PM
#4
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JetDriver,
I am in the middle of the TB/WP on my 86. My Passenger side cam is also about 1/2 a tooth off. I am new at this, but I think when you go to install the new TB you will likely need to rotate the PS cam to get it into the new timing belt notch. I'm sure others with extensive experience in tis will chime in here as well.
Gman
I am in the middle of the TB/WP on my 86. My Passenger side cam is also about 1/2 a tooth off. I am new at this, but I think when you go to install the new TB you will likely need to rotate the PS cam to get it into the new timing belt notch. I'm sure others with extensive experience in tis will chime in here as well.
Gman
You will need to set your cam timing correctly.
Do not simply line the marks up....this will not work!
Porken makes a clever tool to do this....which eliminates the necessity of removing the valve covers to do this job.
Liftbars.com is his Website, I believe.
12-21-2014, 07:43 PM
#5
Out of curiosity...how many miles are on the belt?
And, I would think…if your tension was somewhat out of adjustment…it could let the belt be off that much. A new belt, properly tensioned will probably bring he marks closer.
And, I would think…if your tension was somewhat out of adjustment…it could let the belt be off that much. A new belt, properly tensioned will probably bring he marks closer.
12-21-2014, 07:47 PM
#6
Intermediate
Greg,
Thanks for chiming in. So when I install my new belt, if the belt is off on the Passenger side cam gear by 1/2 tooth, I should not rotate that cam gear the 1/2 tooth to make the gear mark line up with the notch in the back of the cam cover housing and slip into the new belt? If the belt won't line up perfectly without moving the cam gear that little bit, do I need to do something else like you mention above?
Thanks, Gman
Thanks for chiming in. So when I install my new belt, if the belt is off on the Passenger side cam gear by 1/2 tooth, I should not rotate that cam gear the 1/2 tooth to make the gear mark line up with the notch in the back of the cam cover housing and slip into the new belt? If the belt won't line up perfectly without moving the cam gear that little bit, do I need to do something else like you mention above?
Thanks, Gman
12-21-2014, 07:58 PM
#7
Greg - for clarification - if you mark where your belt came off, (gear to cover) you can just keep the gear in that spot (even if it springs one way or the other, move it back as you put the new belt on) and you will be ok. The timing set is only if you have NOT preserved your original marks... right?
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12-21-2014, 08:16 PM
#8
Banned
Thread Starter
Thanks Greg!
My belt only has about 3000 miles and about 14 months.
The rebuilt metal impeller WP that was about 4 years old and 3000 miles was reused after an engine rebuild.
Yeah I know, should of got a new Laso pump while I had everything apart. Now the old pump is leaking, so out it comes. Penny wise and pound foolish I guess....
My old worn alloy cam gears have really started to fray the new TB. I scored a nice set of steel gears that will be installed with the WP job.
Everything will be dismantled tomorrow and hopefully WP installed. Let the RTV cure 24 hrs, install and tension the belt and reassemble on Tuesday.
Hopefully all will go well so I can make the Xmas gathering 28 Dec.
My belt only has about 3000 miles and about 14 months.
The rebuilt metal impeller WP that was about 4 years old and 3000 miles was reused after an engine rebuild.
Yeah I know, should of got a new Laso pump while I had everything apart. Now the old pump is leaking, so out it comes. Penny wise and pound foolish I guess....
My old worn alloy cam gears have really started to fray the new TB. I scored a nice set of steel gears that will be installed with the WP job.
Everything will be dismantled tomorrow and hopefully WP installed. Let the RTV cure 24 hrs, install and tension the belt and reassemble on Tuesday.
Hopefully all will go well so I can make the Xmas gathering 28 Dec.
12-22-2014, 01:39 PM
#9
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Just started on the WP job and drained the coolant, removed hoses on the 82.
I rotated the engine to get TDC on the harmonic balancer and cam gears before locking the flywheel.
My left cam gear is not perfectly lined up with the notch and V pointer, it is about a 1/2 tooth off to the right as you are looking at the gear from the front.
Prior to this, the engine ran great with no misses. Should I try to rotate the cam assembly once I remove the belt to get perfect alignment or leave well enough alone? Haven't removed the right cover yet to see where the right gear is at.
Thanks!
I rotated the engine to get TDC on the harmonic balancer and cam gears before locking the flywheel.
My left cam gear is not perfectly lined up with the notch and V pointer, it is about a 1/2 tooth off to the right as you are looking at the gear from the front.
Prior to this, the engine ran great with no misses. Should I try to rotate the cam assembly once I remove the belt to get perfect alignment or leave well enough alone? Haven't removed the right cover yet to see where the right gear is at.
Thanks!
12-22-2014, 01:52 PM
#10
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Greg - for clarification - if you mark where your belt came off, (gear to cover) you can just keep the gear in that spot (even if it springs one way or the other, move it back as you put the new belt on) and you will be ok. The timing set is only if you have NOT preserved your original marks... right?
12-22-2014, 02:25 PM
#11
Rennlist Member
I presume with the earlier motors such as yours you do not have the issue of interference so setting the flywheel at 45 degrees as we do with the interference [32 valve?] motors is not required.
Just a point of observation for clarity.
Regards
Fred
Just a point of observation for clarity.
Regards
Fred
12-22-2014, 04:38 PM
#12
Rennlist Member
the marks are always off a bit.. adjustment of the cams is independent of this phenom, as its a function of the belt and the mechanical bits all involved.
best to get it close, and this should be obvious, and then adjust the cams... pretty hard to not pick the right spot with the cam gears. one way will be closer than the other, so it will be obvious. usually, you will never be more than a 1/4 tooth off the cover or head marks, again, which is fine.
best to get it close, and this should be obvious, and then adjust the cams... pretty hard to not pick the right spot with the cam gears. one way will be closer than the other, so it will be obvious. usually, you will never be more than a 1/4 tooth off the cover or head marks, again, which is fine.