Looking for help re: my chains and more
 

Hi!

A couple of weeks ago, I posted that I need to fix some oil "faucets". A major source of oil is coming from between the cam boxes and engine. Today I spent 5.5 hrs. dropping the engine a tranny and taking off the muffler and cracking the chain covers.

Lots of pics to follow. I am not sure how to diagnose my chains. From what I have read and seen, it looks like the left chain might be stretched, but the right looks OK. Input would be greatly appreciated!

Also, I plan on adjusting the valves and don't know If I should do that before the chains and cam box come off or can it be done on reassembly? I really don't plan on timing the engine by myself - I have never done this, but would like to have a heads up.

Gratuitous self portrait, where's the engine?? Here you go 84porsche!
http://forums.pelicanparts.com/uploa...1187580584.jpg

Left cam/chain box.
http://forums.pelicanparts.com/uploa...1187580506.jpg

Left tensioner...
http://forums.pelicanparts.com/uploa...1187580532.jpg

Left cam gear.
http://forums.pelicanparts.com/uploa...1187580668.jpg

Left sprocket that attaches to tensioner.
http://forums.pelicanparts.com/uploa...1187580707.jpg

Left chain ramp.
http://forums.pelicanparts.com/uploa...1187580752.jpg

Top of left tensioner.
http://forums.pelicanparts.com/uploa...1187580786.jpg

More pics
 

Right cam/chain box.
http://forums.pelicanparts.com/uploa...1187580851.jpg

Right tensioner
http://forums.pelicanparts.com/uploa...1187580887.jpg

Top of right tensioner.
http://forums.pelicanparts.com/uploa...1187580920.jpg

Right chain ramp.
http://forums.pelicanparts.com/uploa...1187580964.jpg

Right cam gear.
http://forums.pelicanparts.com/uploa...1187581053.jpg
http://forums.pelicanparts.com/uploa...1187581085.jpg

Sprocket at top of right tensioner.
http://forums.pelicanparts.com/uploa...1187581123.jpg

Both sides look ok to me. Replace if you don't plan on being in the motor in the next 4 or 5 years.
http://forums.pelicanparts.com/uploa...1187582493.jpg
This is a pic of a new chain.

Thanks! I should add, that this is the first time these chains have seen the light of day since leaving the factory! 227,000 miles. This adventure, is only to buy me a little more time. I can't afford to rebuild the engine right now, but other than the external leaks, the engine is strong. It *should* be torn down for a complete rebuild.

Dave

Nice shot, Dave! Impressive work your are taking on there.

That looks like a pile of Danish beer boxes in the back ??? :eek: :D

Thank you Markus! I can assure you, that, there are no Danish beer boxes back there! If anything, you'd see German or, more likely, Jamaican 'Red Stripe' boxes ;)

As far as my work, I have no idea what I am doing! :rolleyes:, but I will prevail!

Dave

Your ambition far exceeds my own. Impressive! Good luck getting it all back together. See you on Mul when I actually get back there.

Thank you Derek. I have no doubt that I will get everything back together and running.... I _need_ it to be running by Sept 8.

My only other option, is to put it up on blocks and I can't do that!

You are more than welcome to come out and get the engine back in ;)

Dave

Dave,

Before putting the covers back on, run the engine to see the chain tensioner show.

There will be no leak from the left side and just a small one from the right.

At the same time you can hear what the engine sounds like without a muffler.

wow. exciting and ambitious. I don't know anything (unless it has one chain, two wheels and no motor) but I will help put it back in if you need a hand.

There is a "master link" chain you can install without splitting the case. I might consider it if I were you. I'm no expert, but the way you evaluate motorcycle chains and sprockets is to look at the valleys between the sprocket teeth. They start out symmetrical. When they're worn, they start to take on a teardrop shape. Like your right side sprocket.

I see what you are talking about with the worn sprocket.

If I can live with the chains and sprockets for a couple more years, it would help with $$ issue right now. If I didn't have the leaks behind the cam boxes, I would not have taken the covers off and probably never known the condition, until I plan on tearing down the engine - in 2-3 years (I hope).

Quite frankly, I'm doubtful that anything bad is going to happen. These engines are SOOOOO robust. I suppose valves could touch pistons if the cam timing is off due to the chain wear, but how often do we hear about that? Or any other chain problem other than people worried about their chains. In fact, we rarely hear about engine failures at all. And.....your plan is to freshen the engine anyway.

Candidly, I probably will never rebuild another 3-liter. When I need another engine, I'm likely to be in 3.6 territory. Sell my engine for whatever its value is.....add the rebuild budget to that.....and pony up just a few more bucks for a V-Ram 3.6. Or 3.8 or whatever.

Engine Test Run......
 

Ned,

I have a spare motor that has some strange noise coming from chain box. Don't know whether it's the chain or ramps causing the strange noise at this point. My plan is to run the motor without the chain housing covers but I'm not certain it is SAFE and that's holding me back. So any feedback or comment is much appreciated.


http://forums.pelicanparts.com/uploa...1187657622.jpg

Slodave,

Sorry for piggybacking on your thread. I was reading your post with intererest and saw Ned's reply. I wanted to perform Ned's suggestion of running without chain covers last month but decided to postpone it until I could confirm it's advisable. Thanks.

Tony

Ned, I think I am going to pass on your suggestion. Sounds interesting, but I don't think I want to take a chance. Maybe before I tear the engine apart in a couple of years.

Tony, now you have me thinking. I have a slight noise on startup, but only the first time the car is started on a given day. Does not matter if it is in the morning or afternoon. Maybe I should just go with the master link route and change the chains and sprockets.

Dave

Just a thought - once warmed up, the engine should get wider at a faster rate than the cam chain gets longer (engine is aluminum, chain is steel). So the present condition (which I am not smart or experienced enough to evaluate) should be worst case, and anytime after startup it ought to be better.

QUOTE:"Maybe I should just go with the master link route and change the chains and sprockets."
_____________________
Dave,
Remember that you will need to 're-time' the cams if you do this.

I am also with the group that suggests leaving it alone till complete re-build time. You rarely read of the chains failing.

When I changed my ramps and tensioners, I wondered the same thing. Should I replace the chains and perhaps the sprockets? (You see, the sprockets should be changed at the same time since old sprockets will stress new chains) Commentors reported that chains are replaced at rebuild time, but not in between. Don't worry about it, they said. Indeed, what I found when I rebuilt the engine at 183,000 miles was exhaust valves that were a bit worn, and rings that were at the edge of spec. Bottom end bearings were still serviceable, but showing wear. Especially the layshaft bearing and the rear main. So....if you knew the condition of the other parts in your engine, you would know that many of them match the degree of wear you're seeing in the chains and sprockets. You never know when something bad might happen in an engine, but odds are that your engine is not ready to start throwing parts. Indeed, your Carrera engine probably has more valve guide wear than anything. That's probably your engine's biggest enemy right now anyway. Worn valve guides.

The point of this is to just be careful what you worry about. Lots to choose from. One good option is to button her up and drive. These engines are not finicky, short-life engines. It'd probably enjoy a track weekend more than a chain replacement.

I have to take the chains off to get the cam boxes off. I am re-timing the the cams anyway.

OK, I'll live with the existing chains and sprockets. Now I just need to find someone with the right tool around here so I can get the cam gears off.

Thanks for the answers so far!

Dave

Unless you use new chain sprockets on the I-shaft, don't feed a new chain on old sprockets, go here:

http://forums.pelicanparts.com/porsche-911-technical-forum/200267-new-chains-without-new-sprockets-read.html

New chain sprockets on the I-shaft are much more important than new cam sprockets and idler sprockets with a new chain.

if your pulling the chain box, you may as well replace what ever you pull off. The parts are not that expensive and if you have it off anyhow...................................

I am taking my chances and leaving them alone. The cam boxes still need to come off in order to address some oil leaks.

Dave

Your chains looks perfectly fine, bolt it up and drive it.

Thank you to everybody that says I should keep the old chains. But I must stress this point: I DO NOT have the money to replace every part, just because I am in there. I honestly cannot even really afford to to buy the gaskets and rubber o-rings I need, but if I do not fix the oil leaks, my other option is to put my car on blocks, cancel insurance and not re-register the car in two months. The oil leaks are coming from BEHIND the cam boxes. The only way I can fix them, is by taking the cam boxes out and replace the gaskets.

That said, I am picking Wayne's 911 engine rebuild book on Thursday, so that I can read about timing, chains, tensioners, etc. If anyone has advice on how to accomplish my tasks, or can point out any good threads, it would be much appreciated.

When I have the financial means (money) to rebuild my engine, I will replace everything that that is worn out or beyond tolerances. I hope this makes sense. I enjoy driving my car and do not want to put it away and not be able to drive it. The rest of the engine is in great shape, despite having 227,000 miles.

Thank you so much for taking the time and responding to the initial post :)

Dave

I had substantial leaking behind the chain housings. I think I've finally got it fixed now, but it took a couple of tries. As it turns out, that area is hard to seal. It is probably the gasket, rather than the rubber o-ring. Coat the rubber o-ring with silicon grease like Dow Corning 111 or 112. I used copper gasket dressing on the semi-triangular thrust plate gasket, but JW has stopped using that because it can cause the gasket to squeeze out under the pressure. I used the dressing and did not tighten the bolts greatly. I used blue loctite to try to ensure they don't back out. There is nowhere they can go anyway.

Dave,
If you need to save a few bucks you can borrow my Wayne's book. It will help offset the gasket kit cost. Let me know and I can drop it off or if the group is meeting this week I can bring it with me.

By the way those chains do not look bad for the miles on your motor. I have seen some that look like throwing stars with 2/3 the miles you have.

Goes to show guys oil IS CHEAP!!! AND GET SOME GM EOS IN IT.
KEITH EPPERLY
87 SLANT NOSE TURBO LOOK CARRERA CABRIOLET

Hi Jeff,

Thanks for the offer, but I actually bought that today and will pick it up on Thursday. Books are one thing I don't mind buying. I will read the thing over and over and then use it when I tear the engine down in later, you now, 300,000 miles - that was my goal at one time.

I could use a cam bar that fits my 84. That's one thing I'd rather not spend $$ on and use it 4 times, then put it away.

Fortunately, I had bought some of the gaskets for the easier leaks a while ago. I don't think this will get too out of hand. I was not looking forward in spending $400.00+ for chains and sprockets.

Dave

Another side project while the engine is out, is to replace the intake gaskets. I bought those a few months ago, when I found that a lot of the barrel nuts were loose. Nows the time to see how many (I hope none) have been sucked in. I'll remove that tomorrow and see if the bake-a-lite insulators are serviceable.

Dave

Hey Keith, if you are suggesting that this 911 has had regular oil changes, you'd be right. Dad was on the ball while he owned the car and I have been changing it too frequently, but with good reasons :). I have easy access to the Shell Rotella T and at $38.00 a case, I'd say it's very inexpensive.

Dave, call me. You've got my number.

Don't worry ... you'll get through this. :eek:

All,

There is no particular risk in running the engine with the chain covers off. It will leak a little from the right side but thats no big deal.

The noise of a loose chain is quite unforgettable, like a chain being rattled around in a metal garbage can, and you would probably see the chain hitting with the covers off.

The real advantage is when you have someone blip the throttle to unload the driving side of the chains. This should show the tensioner taking up the resulting slack.

The unmuffled engine noise is a little threathening so you could bolt up the muffler for the tensioner show. Use earmuffs if you run it unmuffled as the noise will be down there.

Ned

Progress
 

Tonight, a few friends stopped by and the cam boxes are off. Tomorrow, I send in a big list of parts to PP and while waiting, start cleaning and truing up critical mating surfaces. A big thank you to Chris (porcupine911), Marco and Marc (mkaraoglan)! Everything came apart with ease. With some expert eyes, it's been determined that chains, sprockets etc... are just fine and will last a few more years (knock on wood).

I found a Euro pre-muffler and hope to be installing that as well.

Here's the engine as it stands tonight.
http://forums.pelicanparts.com/uploa...1187852256.jpg

Nothing like coming home and smelling like jet fuel, oil, gas and beer!

Dave

Ned: Working at an airport gives me access to all sorts of un-muffled engines and jets. Personally, it does not excite me to run my 911 engine without a muffler :D

Way to go. Let me know if you need help when putting it back together. I will be back from Japan on Friday August 31st around lunch time.....

Thanks Ingo! We'll see how things go.

For those that are interested:
Here's how the engine looked before removing the cam boxes and covers.
http://forums.pelicanparts.com/uploa...1187856949.jpg

Fun stuff!

Dave, when you and I talked on the phone and I mentioned the improvement I got by replacing the Cat with a Euro bypass (not to mention the better sound), I didn't think you were going to look for one. I'm glad you did. You'll definitely notice an improvement in both power and sound quality. Good job.

Heh, heh, what the hay, it's only money ;) and I'm only in debt, not ready to file bankruptcy - yet. I searched the "For sale" forum, but things were very dry. Posted a "WTB" and found someone I actually have talked with before and he has one he is willing to part with.

I have a nice IT project coming up and it will last a few months, so, I will have some money coming in and well, Porsche's are very addictive!

Dave

I just did that. Bursch bypass with an M&K. :eek:

Do it!

If you can find someone with a CAT that has failed, you can easily break up the innards with a broom handle, and they make a nice-sounding baffle chamber, except there would be no baffling. Same as a test pipe, only with a deep resonance. Pretty cool, actually.

Were your cam housings leaking at the connection to the case? That'd be unusual. My problem was leaking down the back of the housings, between the housings and the heads. Serious leak. Again, that problem is probably the semi-triangular gasket thingie. Be very detail-oriented when you install those gaskets.

And finally, I work at an airport too. Love the smell of kerosene in the mornings, and the sound of jet engines. Those darned MD-80's are the loudest things that fly out of here, by far. And I am continually marvelling at 747's. What made us think that a large building could fly?

I know about the cat trick, but wanted to go with a more proven Porsche route :).

The cam boxes were most likely leaking (severely) from the back, but with 23+ years of crud, who knows where some of the other leaks are from. I did not do a dye/blacklight test.

I actually do not work at an airport, I just have access to my dads hanger certain times of the year. The hanger is located at the North/West end of KVNY.
http://forums.pelicanparts.com/uploa...1187937359.jpg

Tomorrow I go and clean dirty parts!
SmileWavy

Cam boxes and covers are clean, as are the valve covers.
http://forums.pelicanparts.com/uploa...1188010083.jpg
http://forums.pelicanparts.com/uploa...1188010100.jpg

I will scrape the rest of the brown stuff visible on the backside of each cam box and apply some JB weld, per Wayne's engine rebuild book.

Tomorrow I will make sure all surfaces are flat and I still need to take a razor blade and make sure all of the old gaskets and sealer is removed from the cam boxes. I will also gently compress the tensioners in a vise and insert the grenade pin that'll keep them compressed until they are reinstalled. I'll make the pins from a coat hanger that is extra thick.

SmileWavy