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Chain Tensioner Question (pics)

I have had a suspect left tensioner for a while. Yesterday when I inspected it I thought that it clearly was defective ( piston not fully expended) I noticed that tension on the chain was not fully not what it could be (a little play at the top, to the right of the sprocket, very tight on the bottom, think that is called the ramp on the bottom). There was no metal in the housing that I thought would show evidence of other parts wear.

Feel like I had this all figured out, I wire-tied the sprocket down to the right to maintain tension on the chain, more so than it was upon inspection. I replaced the tensioner. Pulled the grenade pin and the piston snapped out like it should so I clipped the wire ties and thought all was well.

Here is my dilemma. At this point I'm uncomfortable because there is still a little play in the chain to the right of the sprocket. Does the tensioner piston stroke further out when the engine starts? Do I need a new sprocket? Am I being overly concerned (screwing this up is scary). Hopefully all is normal but I sure could use some expert advice.

John


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Old 07-02-2006, 06:03 AM
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Patton,
Looks like your timing chain is stretched out and needs to be replaced.
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DOUG
'76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's.
'85 911 Carrera, stock, just painted, Orient Red
Old 07-02-2006, 07:32 AM
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there are some places in the rotation where the chain is not fully trensioned. If your tensioner snaps out, I would guess that it is ok. The oil pressure from a running engine will also help with the tension.
Old 07-02-2006, 07:32 AM
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2.7RACER
I was thinking chain stretched as well. Oh... seems like maintenance never ends. I'd like to get a few more easy miles on (bad idea?)but now it will always be a thorn in the side. OK, off to read how to replace a timing chain .....eeeek.

Do you think that in the current state I can drive?
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Old 07-02-2006, 08:21 AM
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2.7 racer,how can you tell the timing chain is streched ???? that is borderline irresponsible for someone to throw out unless you have more info than what John posted.
John,
i just did the upgrade to my 79 SC along with cam housing oil restricters and also worried about slack,I worried about the axial play in the idler sprocket arm,I worried about not spending 600+ on new wider idler arms vs using the 10$ spacers,you need for a pre 80's car, I worried about slipping a tooth,etc etc.
I sure as hell did not worry about a stretched chain on a 70 k mi.engine !!!!

To give you a data point and not just a brain fart,
I did prime the tensioner with oil as wayne recommends in his engine re-build book I inspected the seal at the top of the plunger ( not much to inspect) and checked the plug on the side of the tensioner.
Wioth similar anxiety as I suspect you may have, i checked and double checked,I rotated my engine slowly with a ratchet and socket at the fan pulley (cw rotation-plugs out) to ensure the valves were not hitting the pistons, I even borrowed a gauge block from a friend and verified cam timing on both sides.for a 70-80 k mile block I suspect NO chain stretching!!!

Buttoned it up ,fired it up ,and since they were primed there was not a hint of chain rattle as they came to pressure.
I have asked the board how to identify a faulty tensioner and received little feedback except to button it up and if the initial chain noise does not subside quickly when you fire it up then it is faulty. if it quiets down thgen you are fine. Remember it is oil pressured not spring tensioned so withoit the oil lines hooked up it is not going to be as tight as mechanical tensioners would be. Rotate your fan pulley without the cam covers on and observe the tensioners ,mine did appear to take a bit of skack out of the chain after a few manual revs, but not as much as when they are under 3-4 bar of oil pressure.
Remember free advise is worth exaactly what you pay for it.

Oh and yeah, In addition to a new chain (may as well do both) you need a complete valve regrind , new brgs and bump stop rubbers for your shocks too,and new tail lights too !!! (my appology in advance for the sarcasm. Good luck buttoning it back up.
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Old 07-02-2006, 08:35 AM
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hbkramer,
I have already buttoned it up. I did not see the proceedure for primining the tensioner in the technical articles. Can you explain to me how to do it.

In all do respect to 2.7RACER, I believe what he is basing his opinion on is the position of the lever arm (don't know the tech actual part name)that the piston pushes upward on, thus maintaining the tension. From the pic, the lever arm is very close to being at the maximum end of travel without being into the case. In the case of a tighter chain or a bigger spocket, there would be more room between the lever arm and the top on the case.

All in all there is some room for travel if the piston where to further extend with oil pressure. If I need to open her up, I'll do it gradly to prime the tensioner. So, How do I get the tensioner primed?

Thanks,

John
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Old 07-02-2006, 08:55 AM
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Looks like chain stretch too me. Pretty bad actually. I wrote a tech article on changing chains without splitting the case. Its a very wise investment for you at this time. With that much strech its even questionable that you use the same sprockets with a new chain.
Did you check the right side. If that one has the same stretching the chain tensioner wheel will be cutting into the chain housing by now.
A quick check of the cam timing will show you some answers as well. If the cams were set with good chains then they will be very retarded with stretched ones. You will be losing lots of low end power as a result. Could actually gain top end power however.

Lastly it appears that Mr Kramer has his head in the clouds and is actually incorrect when he explains how the tensioners maintain pressure. In fact its a guy like Mr Kramer that will lead you to believe you need nothing and all is well . Then when your chain fails its your problem for listening to such inexperienced free advice.
Kramer for what its worth the reason 2.7racer knows the chain is stretched is because the idler wheel is fully extended or nearly there anyway. You didnt notice that did you ?

Kurt Williams
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72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles
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Last edited by pjv911; 07-02-2006 at 09:17 AM..
Old 07-02-2006, 09:14 AM
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From the technical articles



From this picture, you can see the cap between the lever arm and the case looks to be greater than a half inch with the grenade pin pulled. I'm sure that mine is much less, say 3/16" max. I got a bad feeling on this one.

John
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Old 07-02-2006, 09:15 AM
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Read my above post. Yes you have some work to do. And it needs it asap.

Kurt Williams
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Never drive faster than your gaurdian angel can fly.
82 SC w/965S eng and G50 6:1 hp/w ratio
72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles
65/66 912 1 owner 76k orig
01' Aston Martin DB7 V12 Vantage Coupe 6spd
Old 07-02-2006, 09:18 AM
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I adjusted the valves last week as per 2.7RACER's suggestion from the thead valve adjustment . All the gaps were greater that .003" . Currently, I have awsome low end power at least it feels that way to me. I'll open the right side and post my findings.

Also pjv911, I read your artical but when you refer to the "oil drain pan " , I may be a doof but I don't see on on this 3.2 case?

Oh how I wish I could just have a few beers and go fishing .
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Old 07-02-2006, 09:35 AM
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Patton, no oil drain pan(sump) on your 3.2 case, just the side oil drain.


BTW, Thanks 2.7racer and pjv911. Learned another really cool thing today

Last edited by 89turbocabmike; 07-02-2006 at 09:45 AM..
Old 07-02-2006, 09:43 AM
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OK pjv911, does that mean that I have to open the case to replace the timing chains? I knew that when I hit that deer on Thursday night that this was going to be one of those weekends.
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Old 07-02-2006, 09:46 AM
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hbkramer,
I wasn't firing from the hip when I suggested the timing chain was stretched. If you will look carefully at his picture, you will see the tensioner is almost fully extended. It is almost touching the inside of the chain housing. You will also notice the chain on the idle sprocket is nearly touching the mounting bolt.
Patton posted a second picture showing what a unstretched chain looks like.
I'm sure if you look you will see my advice was very well constructed. Perhaps you will learn what to look for.
Have fun,
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'76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's.
'85 911 Carrera, stock, just painted, Orient Red
Old 07-02-2006, 10:39 AM
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Lets all get along and learn. Hopefully this thread can be used as an example to those like myself that have much more to learn. Fortunately, there is plenty of technical data provided by our host that clued me in on that fact that something wasn't right. Likewise, there are plenty of very very knowledable people here that share their expertise for which I am very grateful, saved my ass more than once. Seems like I'm having a run of bad luck. My girlfried (100% German) says that I'm lucky in bad luck situations. I think she is dead on.

Now, please tell me how to proceed (do I need split the case), er.. engine drop? I woud like to get the parts ordered from our host so I can get this great daily driver purring again. I love this car...

Special thanks to 2.7racer and pjv911,

John
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Last edited by Patton; 07-02-2006 at 11:33 AM..
Old 07-02-2006, 11:14 AM
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The oil sump plate makes it easier to see that the inner chain is on the crank gear properly. It can be done without the sump plate just as easy. But you will need a mirror to see the chain position. Be sure to inspect your gears as closely as possible for noteable wear. Worn gears will prematurely wear a new chain. Also make sure you put the master links in the correct direction. Be sure to buy the chain with the master link because they are sold without links as well.
Let us know what the right side looks like. And if the housing is a little cut up it is most likely still ok and wont need replacement.

Kurt Williams
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Never drive faster than your gaurdian angel can fly.
82 SC w/965S eng and G50 6:1 hp/w ratio
72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles
65/66 912 1 owner 76k orig
01' Aston Martin DB7 V12 Vantage Coupe 6spd
Old 07-02-2006, 07:35 PM
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Doug, I owe you an appolpgy. Humbly as well. My eyes are not as good or experiencedand as yours are..

I now see what you picked out quite readily.

Back into lurk and learn mode. again, my appology.

John , good luck,how many miles on your car
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Old 07-03-2006, 04:43 AM
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The engine is a transplant. The car has around 109K and the engine (supposely) has 35K on it. The PO said the engine was the built by Porsche Sport in California in 2002. I have made contact with them (being very helpful) and they don't have any any records of PO.


Here is the build sheet that I have on the engine on the PO's letterhead. I will be trying to verify as much as I can this week as some is greek to me.
1- 3.4 ???? twinplug fuel injected
2- Ported heads
3- titanium valves ????
4- pinned block ????
5- 11:1 compression ????
6- Balanced
7- 310 degree high lift 7000 rpm cams ???
8- SSI's
9- Huntly air fuel management system



John
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Last edited by Patton; 07-11-2006 at 05:35 AM..
Old 07-03-2006, 05:20 AM
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HB,
No harm, no foul. We all have a bad day sometimes.
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'76 911S 2.7, webers, solex cams, JE pistons, '74 exhaust, 23 & 28 torsion bars, 930 calipers & rotors, Hoosiers on 8's & 9's.
'85 911 Carrera, stock, just painted, Orient Red
Old 07-03-2006, 05:51 AM
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No need to split the case, but it is definitely easier to drop the engine. I never was able to change the chain with the engine in the car (84 carrera).
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Old 07-03-2006, 05:54 AM
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Right Side...EEK

Well, I think I'm very fortunate. The right side is in near disaster state.




As you can see the tensioner is fully extended and the sprocket cut a gouge into the housing.

OK, I'm ready to order parts. Here is my list. Suggestions please.

****Tensioning Sprocket (sold per each, 2 required), 911/911 Turbo (1974-89) PN 901-105-055-00-M260 $44.25
****Pin (sold per each, 2 required), 911/911 Turbo (1974-89)
PN 900-197-010-00-OEM $0.50
****Circlip (sold per each, 2 required), 911/911 Turbo (1974-89)
PN N-012-415-1-OEM $1.00
****Timing Chain (with Master Link), 911/911 Turbo (1974-89)
PN 911-105-529-50-M48 $43.00
****Chain Ramp Kit (all needed ramps), 911/911 Turbo (1974-89)PN C-105-22-KTN $38.75

****PEL-TOL-P202 Cam Socket, with 1/2 Drive
****PEL-TOL-P203 46mm Crows Foot, 1/2 drive
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Last edited by Patton; 07-03-2006 at 10:52 AM..
Old 07-03-2006, 07:40 AM
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