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.