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Crank nut removal

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mkivmarty Avatar
mkivmarty Marty Yanik
N.E.Ohio, USA   USA
Notice the dimple and scribed line on the cam gear? That looks original. It should align with the woodruff key on the crank pulley to indicate TDC compression stroke. Rotate your engine to align them BEFORE you remove them and DON'T move them while installing the new ones. If you don't you will be getting a degree wheel and starting over. Pay attention to the orientation of the oil flingers. Its easy to get them on backwards. Doing so and you will be replacing your chain again soon!!

Marty

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Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
Assume you already removed the tensioner.

philipheys Avatar
philipheys Phil Heys
Accrington, Lancashire, UK   GBR
Thanks guys,

I have always struggled with the theory side of information and that is great feedback you have provided but honestly I don't understand any of it, maybe a British thing!
I need practical step by step information or better still video guidance.

Thanks
Phil

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Tonyfixit Avatar
Tonyfixit Tony M
Duncan, British Columbia, Canada   CAN
My bet is the new prockets will be un-marked, so here is the procedure from the Triumph manual. They state it better than I could, I hope the print is visible from the picture.

The first pic shows the maximum slack in the chain as 10mm, I think you are 'way' beyond that.



Edited 1 time(s). Last edit at 2017-12-02 06:17 PM by Tonyfixit.


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clshore Carter Shore
Beverly Hills, Florida, USA   USA
When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

GottaSpit Avatar
GottaSpit Duncan A
Folsom, California, USA   USA
I like Elin Yakov;s u tube videos about restoring a '68 spit, a '73 TR6 and a '72 GT6. He has several videos about cam timing.

Try

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1501000 by clshore When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

It's not really all that difficult. You can be off a tooth and all it will do is change where your #1 plug wire fires. You just have to make sure the vacuum advance doesn't hit the block.

The Spit is a great car if you like to pull the dizzy. For a lot of cars the drive gear is mounted to the shaft. The Spit has an indexing slot that only goes on one way. Set the crank to TDC on the compression stroke and set the gear so the rotor is where you want it and fine tune with a timing light.

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spitfire50 Avatar
spitfire50 Paul Mugford
Rochester, N.H., USA   USA
In reply to # 1501021 by Doug in Vegas
In reply to # 1501000 by clshore When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

It's not really all that difficult. You can be off a tooth and all it will do is change where your #1 plug wire fires. You just have to make sure the vacuum advance doesn't hit the block.

The Spit is a great car if you like to pull the dizzy. For a lot of cars the drive gear is mounted to the shaft. The Spit has an indexing slot that only goes on one way. Set the crank to TDC on the compression stroke and set the gear so the rotor is where you want it and fine tune with a timing light.
Uh, Doug, This is cam timing being discussed, not ignition timing, BIG difference. Cam timing is much fussier and missing by a tooth makes quite a difference to how the engine performs.
All the best,
Paul

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1501047 by spitfire50
In reply to # 1501021 by Doug in Vegas
In reply to # 1501000 by clshore When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

It's not really all that difficult. You can be off a tooth and all it will do is change where your #1 plug wire fires. You just have to make sure the vacuum advance doesn't hit the block.

The Spit is a great car if you like to pull the dizzy. For a lot of cars the drive gear is mounted to the shaft. The Spit has an indexing slot that only goes on one way. Set the crank to TDC on the compression stroke and set the gear so the rotor is where you want it and fine tune with a timing light.
Uh, Doug, This is cam timing being discussed, not ignition timing, BIG difference. Cam timing is much fussier and missing by a tooth makes quite a difference to how the engine performs.
All the best,
Paul

Oh. I mark before disassembly. Last time I think I used white out followed by a fine sharpie to draw the line.

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clshore Carter Shore
Beverly Hills, Florida, USA   USA
In reply to # 1501050 by Doug in Vegas
In reply to # 1501047 by spitfire50
In reply to # 1501021 by Doug in Vegas
In reply to # 1501000 by clshore When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

It's not really all that difficult. You can be off a tooth and all it will do is change where your #1 plug wire fires. You just have to make sure the vacuum advance doesn't hit the block.

The Spit is a great car if you like to pull the dizzy. For a lot of cars the drive gear is mounted to the shaft. The Spit has an indexing slot that only goes on one way. Set the crank to TDC on the compression stroke and set the gear so the rotor is where you want it and fine tune with a timing light.
Uh, Doug, This is cam timing being discussed, not ignition timing, BIG difference. Cam timing is much fussier and missing by a tooth makes quite a difference to how the engine performs.
All the best,
Paul

Oh. I mark before disassembly. Last time I think I used white out followed by a fine sharpie to draw the line.

When you CHANGE the cam sprocket, your marks and lines wind up in the trash can.

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, British Columbia, Canada   CAN
Changing the chain and re-using the old sprockets will lead to rapid wear.

It really is not a big deal to set the cam timing with a stock type cam (both valves equally open at TDC)

Just follow instructions and rotate the engine (clockwise) and double check when you think you have it.

If a job is worth doing, it is worth doing well!

I noticed that the cam sprocket was not fitted with a bolt keeper plate (bendable tabs) on your car?
I have never seen those bolts come loose, but it might be a precaution to fit one.

philipheys Avatar
philipheys Phil Heys
Accrington, Lancashire, UK   GBR
Hi guys,

I have lined up the marks which I think are correct?
Does this look right to you guys?
I am planning just changing the chain do I take off the large sprocket wrap around chain and put back on the in the same position?
Is it as simple as that?

Thanks


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Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1501065 by clshore
In reply to # 1501050 by Doug in Vegas
In reply to # 1501047 by spitfire50
In reply to # 1501021 by Doug in Vegas
In reply to # 1501000 by clshore When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

It's not really all that difficult. You can be off a tooth and all it will do is change where your #1 plug wire fires. You just have to make sure the vacuum advance doesn't hit the block.

The Spit is a great car if you like to pull the dizzy. For a lot of cars the drive gear is mounted to the shaft. The Spit has an indexing slot that only goes on one way. Set the crank to TDC on the compression stroke and set the gear so the rotor is where you want it and fine tune with a timing light.
Uh, Doug, This is cam timing being discussed, not ignition timing, BIG difference. Cam timing is much fussier and missing by a tooth makes quite a difference to how the engine performs.
All the best,
Paul

Oh. I mark before disassembly. Last time I think I used white out followed by a fine sharpie to draw the line.

When you CHANGE the cam sprocket, your marks and lines wind up in the trash can.

Most have their own marks.

If they don't it's not that hard to lay the old one next to the new one and figure out where the mark goes.

clshore Carter Shore
Beverly Hills, Florida, USA   USA
In reply to # 1501109 by Doug in Vegas
In reply to # 1501065 by clshore
In reply to # 1501050 by Doug in Vegas
In reply to # 1501047 by spitfire50
In reply to # 1501021 by Doug in Vegas
In reply to # 1501000 by clshore When you remove the large sprocket, you will lose the cam timing.

I recommend leaving it alone, and changing all the rest.

Unless you WANT to go through re-timing the cam.
It's not difficult, just finicky, and hard to get timing just right.

Search this site for postings on how to do it, and special tools and equipment required.

It's not really all that difficult. You can be off a tooth and all it will do is change where your #1 plug wire fires. You just have to make sure the vacuum advance doesn't hit the block.

The Spit is a great car if you like to pull the dizzy. For a lot of cars the drive gear is mounted to the shaft. The Spit has an indexing slot that only goes on one way. Set the crank to TDC on the compression stroke and set the gear so the rotor is where you want it and fine tune with a timing light.
Uh, Doug, This is cam timing being discussed, not ignition timing, BIG difference. Cam timing is much fussier and missing by a tooth makes quite a difference to how the engine performs.
All the best,
Paul

Oh. I mark before disassembly. Last time I think I used white out followed by a fine sharpie to draw the line.

When you CHANGE the cam sprocket, your marks and lines wind up in the trash can.

Most have their own marks.

If they don't it's not that hard to lay the old one next to the new one and figure out where the mark goes.

Sorry Doug, you are just not getting it.
The marks you see on Spitfire OEM sprockets were SCRIBED BY HAND when each of the motors were built, by the worker, AFTER the cams were timed.
If you see marks on a replacement sprocket, they are sure to be wrong.

Timing the cam requires resolution to at least 1 degree, and 1/2 degree is even better.
The method you describe, are your naked eyeballs capable of discerning 1 degree of arc without any scale or reference?
It is challenging enough to time the cam using dial indicators that can resolve to 0.001", and a degree wheel that can resolve to 1/2 degree.

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, British Columbia, Canada   CAN
[/quote]

Sorry Doug, you are just not getting it.
The marks you see on Spitfire OEM sprockets were SCRIBED BY HAND when each of the motors were built, by the worker, AFTER the cams were timed.
If you see marks on a replacement sprocket, they are sure to be wrong.
[/quote]

Agree!
If you wish to play 'wheel of fortune' with your cam timing, so be it.

But setting it to spec, correctly, is NOT difficult.

It looks to me like the cam sprocket has been off before. Who knows if it was put back right?

Set the crank to TDC.

Take of the cover pull the cam sprocket and chain.

Set the cam to have #1 valves equally open (see instructions )

Re-install the chain and sprocket (with the chain tight on the right side) DO NOT MOVE CRANK OR CAM.

Rotate the crank two turns and check the valves are again equally open at TDC.

As stated, your cam sprocket has 4 holes, by rotating or turning the sprocket you can set the timing within 1/2 a tooth

The stock US 1500 cam is often considered a peice of 70's emission control garbage. Perhaps 'one tooth out' makes little differance. Others may feel it needs all the help it can get.

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