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Timing chain replacement

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

I previously ran another post called crank nut removal which some of you may have seen? I am onto another stage now for what I am trying to achieve and I have further questions which I did ask in my previous post which I think may have got lost, I mention this because there may information within that post that may help.

Anyway......I am changing my timing chain and I have some questions.

To change the chain only do I line up the scribe marks remove cam sprocket wrap around new chain and put back cam sprocket same way it came off?

I don't have to remove crank sprocket?

Should I change the oil thrower and how does it fit on?

Should I change oil seal, the one installed looks good?

Should I use gasket seal when putting cover back on?

Please see picture....Do the marks I have roughly marked look right?

Many thanks

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bobbylrowland bobby l
cochran, ga., USA   USA
everything looks good in picture,including the slack in timing chain.I don't see an oil slinger, it's supposed to have one. you should always replace gasket and seal.

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

I am getting some chain noise and there is definitely more slack than the recommended amount hence why I am changing the chain.

I removed the oil thrower, should that go back with the cup facing the front of the car or cup towards the engine?

Can I simply take the cam sprocket off wrap around chain and put back in exactly same place?

Thanks

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bobbylrowland bobby l
cochran, ga., USA   USA
Simply put yes and yes.if the gears look good then a new chain should should take up a lot of slack. you might want to check the tensioner to make sure it's not worn

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

For the cost I plan to change the tensioner it's a no brainer!

tmpass Avatar
tmpass Tim P
Medway, MA, USA   USA
1970 Triumph GT6+ (MkII) "Capo"
1970 Triumph GT6+ (MkII) "Blue Oxide"
on a side note these motors were noisy from day 1, hence the goop applied to a lot of our timing covers at the factory. Most goop just fell off over the years... mine was still on there til recently.

Various pics and threads attached.

http://www.triumphexp.com/phorum/read.php?7,1302623


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tapkaJohnD Avatar
tapkaJohnD John Davies
Lancaster, Lancashire, UK   GBR
In reply to # 1501421 by philipheys Thanks

For the cost I plan to change the tensioner it's a no brainer!

Phil,
Many have found that modern copies of the OE tensioners are not up to the job, wear and split quickly. Unless your old tensioner is badly scored, I'd put it back in!
JOhn

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Tonyfixit Avatar
Tonyfixit Tony M
Duncan, British Columbia, Canada   CAN
The check for chain slack is to hold a straight edge to the slack side of the sprokets. There should be no more than 10mm slack in the chain.

In my experiance, most wear occurs at the sprocket teeth.

No keeper on the cam bolts suggets the sprocket has been off before by someone who did not replace it. Do you feel confident they checked the timing when putting thing back together?

The timing chain not only controls your valve timing, the cam also drives the distributor, and can effect ingition scatter (inaccurate ignition timing)

Doug in Vegas Avatar
Doug in Vegas Douglas D
Las Vegas, Nevada, USA   USA
In reply to # 1501444 by tmpass on a side note these motors were noisy from day 1, hence the goop applied to a lot of our timing covers at the factory. Most goop just fell off over the years... mine was still on there til recently.

Not hard to replace.



You have to listen to conspiracy theories,...and haggle.

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tapkaJohnD Avatar
tapkaJohnD John Davies
Lancaster, Lancashire, UK   GBR
In reply to my http://www.triumphexp.com/phorum/read.php?8,1501391,1501445#msg-1501445 teeka56 (Mike Leisner) sent this to me as PM (why not post?)

"On my 1972 car, the only thing on the motor that ever failed was the tensioner- wore thru. At 97,000 miles.

Mike"


I offer in evidence, M'Lud:
http://www.tr-register.co.uk/forums/index.php?/topic/63234-timing-chain-tensioner/#entry544779

Of course OE tensioners wear out, after thousands, nearly 100,000 miles. It's just that people have found new reproductions wearing out after hundreds of miles.

John



Edited 1 time(s). Last edit at 2017-12-06 05:46 AM by tapkaJohnD.

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

Should I keep or replace?

There are no scaring and when I rub my finger across the surface it's nice and smooth.


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laverda1200 Paul LeClair
Calgary, Alberta, Canada   CAN
In reply to # 1501480 by Tonyfixit The check for chain slack is to hold a straight edge to the slack side of the sprokets. There should be no more than 10mm slack in the chain.

In my experiance, most wear occurs at the sprocket teeth.

No keeper on the cam bolts suggets the sprocket has been off before by someone who did not replace it. Do you feel confident they checked the timing when putting thing back together?

The timing chain not only controls your valve timing, the cam also drives the distributor, and can effect ingition scatter (inaccurate ignition timing)

Hi Phil

I agree with Tony's post, quoted above.

Better to start with new sprockets and the best quality new chain you can find.

Then use a degree wheel, piston stop and dial indicator gauge to check actual top dead center, usually the basic factory marks are out a couple of degrees from the factory. Once you know and mark your own true top dead center, then use the degree wheel etc again to time the cam properly.

these engines will run with the cam timing out even several degrees, they just do not run as well as they can and should. Also, as Tony pointed out, basic cam timing then drives your distributor, which also needs to be set properly once true top dead center is actually found. Doing it right does not costs anything more other than spending the time to acquire the necessary knowledge, then acquiring some inexpensive tools like a cheap dial indicator and magnetic base, you can print off and make your own degree wheel or just buy an inexpensive one, and you can make your own piston stop from an old sparkplug.

getting the basic details right WILL make a big difference in how well the engine runs. You have no guarantee that whoever did the job last did it right, and just copying the marks from the last guy does not mean they are right. My two cents.......

CraigL Avatar
CraigL Gold Member Craig Larsen
Santa Clara, CA, USA   USA
I agree with Tony and Paul. How many miles on the engine and sprockets? You may find it best to replace both sprockets. I replaced sprockets, chain, seals, tensioner etc. a few months ago. At the same time I replaced the rockers with bushed rockers and new shaft. The new sprockets did not have the timing marks. I used the degree wheel and dial indicator to set the valve timing just right. Take the time to ensure you have it right! It is too much work to have to do it over again. Once complete and after re-setting the ignition timing, the engine runs great! Pay for the more expensive timing chain - noise will be reduced.

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