Good News, Broken Chain Ramp

[snbush67]

One might ask; How is that good news? Because its not something else .

Am I safe with the little bits of plastic that might be lingering or should I try to flush the case with somthing?

Shortly after installing my SSI's and M&K 2/2 I started hearing a strange noise ticking and assumed it was the a exhaust either leaking, valve ticking or just a new exhaust sound. Then last week I was out driving around in a "spirited fashion" and it got a bit more noticeable under load. I got under and retourqed all the exhaust nuts etc, definitely no leaks.

So checked all the valves, (they were all dead on) and double checked everything, checked the head-studs, no issues, buttoned it back up and still got the same noise. So I drained the oil again and this time a few small chunks of black plastic came out, took off the chain covers and found out I was short a chain ramp, luckily most of it was still in the chain housing and the rest came out of the sump plate.



This is the first time I have had the tensioner covers off, probably the first time anyone has seen the inside of these in 30 years, original tensioners and no safety collars. I am considering upgrading to new tensioners, but might just go with collars, these things have been in there 30 years whats another thirty?

I am assumming the ramp was just old and brittle, I will replace them all. It was the lower right inboard ramp.

Am I safe with the little bits of plastic that might be lingering or should I try to flush the case with somthing?

[911pcars]

I wasn't aware Porsche still installed rubber chain ramps in engines as late as 1978.

You were fortunate. When these eventually become brittle and break (and they eventually do), one of the broken pieces ends up between the sprocket and the chain resulting in a jumped tooth. All this results in the cam timing going off. The valve(s) then hit the piston(s) which can:

a) bend the valve(s)
b) break the rocker arm(s)
c) crack the piston(s)
d) all the above

The newer plastic replacement chain ramps come in two flavors; black and brown. Follow the suggestions for how many of each.

Ask me how i know?

Sherwood

[village idiot]

Wow, I'm bummed for you Shane. Fortunately you discovered it before it escalated.

You know you may just have to open up the motor just to be safe.(cough, cough bigger cams, tensioner update, cough, cough)

[snbush67]

Sherwood,

Its plastic, just old and worn, at least I think its plastic,

Originally Posted by village idiot

Wow, I'm bummed for you Shane. Fortunately you discovered it before it escalated.

You know you may just have to open up the motor just to be safe.(cough, cough bigger cams, tensioner update, cough, cough)

No reason to be bummed, it could have been a lot worse.

I think I got it all, any piece(s) left hanging around wont be big enough to derail the chain, I have used a mirror and light and have managed to fish out some small pieces, Its been like this about two weeks I guess, but I have only driven it about 40 miles.

If I was opening up the motor I would be going for the 3.2 SS upgrade, I am happy with this motor and the way it performs.

I may just have to do the tensioner upgrade though, $$$ .

[village idiot]

Oh well, this is why we have jobs........to pay for our toys

Even I may have to toss some money into the Carrera as it smokes a little too much for my liking.

[snbush67]

Anyone have any hints, tricks tips etc. on replacing the inboard ramps?

I am assuming that I just loosen the bolts and slide the ramp in holding it in place with stiff wire or something and then feed the bolts through and tighten.

Is it that easy?

[snbush67]

My car obviously has a feminine quality, bought her SSI's, M&K, and PMO's and now she does this for attention, she's spoiled rotten.

Tommy, Your car just smokes because she thinks it's cool, my car smoked a bit on start up with the CIS.

[Aurel]

Originally Posted by snbush67

Anyone have any hints, tricks tips etc. on replacing the inboard ramps?

I am assuming that I just loosen the bolts and slide the ramp in holding it in place with stiff wire or something and then feed the bolts through and tighten.

Is it that easy?

They snap in and out of the bolts that have a groove. No need to remove the bolts if I recall. I did it last year, so my recollection is a bit fading but I did not have to remove those bolts

[Gunter]

With the tensioners keeping the chain tight, I cannot see that the ramps slide in and out of the pins.

IMHO, the tension has to be released for some slack in the chains to make the exchange possible.
You don't want to drop anything into the void.
I would move to Z1 with #1 at compression stroke, tie up the chains, remove the tensioners and proceed from there replacing all ramps because if one is that bad, the others are not far behind.

[Aurel]

I was assuming the chain was not tight anymore on my description...

[village idiot]

Originally Posted by Gunter

...... and proceed from there replacing all ramps because if one is that bad, the others are not far behind.

Listen to this man

[T77911S]

the tensioners may be bad. chain slap may have been the cause of the breakage. if the tensioners are 30 years old, replace them anyway.

can you flush???
remove sump plate and flush? and with what?

pcars,
not sure where you got "rubber chain ramps" from or did i miss it.
my 83 3.0 has plastic ramps too, i dont know when or if they changed them.

[911pcars]

"pcars,
not sure where you got "rubber chain ramps" from or did i miss it.
my 83 3.0 has plastic ramps too, i dont know when or if they changed them."

Apparently, my oversight. I must have had a flashback to a time when the rubber versions broke my engine (valves, rockers). BTW, to my recollection, I haven't seen a broken plastic chain ramp, but I suppose if they can break, they eventually will. If there's no apparent engine damage from the breakage, I'd flush/fish out as many broken pieces as possible, - easier if there is a sump plate, then replace all the ramps as suggested.

Sherwood

[snbush67]

Thanks for the advice, I was going to flush through the chain cover openings down to the bottom of the engine and out the sump hole. I think it would be ok to flush with diesel fuel. Anyone have any better suggestions? I will blow it out with compressed air.

The chains are still tight and the tensioners are doing a great job. I really don't see any reason to change them, you can see in the photos that they are less than 2cm extended.

I think this ramp just gave up, he was probably getting a lot of crap from the other chain ramps and said f this. He was the only brown ramp in there and it was time for him to go.

How sure are you that don't have to remove the bolts on the inboard ramps?

I will be replacing all the ramps and installing safety collars.

[T77911S]

i would guees if the tensioner was bad, the chain could slap it around enough to break it. especcially if he got off the gas then back on it hard.

could he remove the sump plate and flush with water?? i have heard of flushing with kerosene but i am not sure if i would jump on that one or not, but then i have heard of putting water into the intake while the engine is running to clean carbon, its a volvo thing. i guess not much different from using sea foam, which i did do, twice.

[snbush67]

Im only going to be flushing the bottom part of the engine, shouldn't be an issue, any diesel left behind should evaporate and I'll run the old oil and gaskets for a couple minutes and then do fresh oil gaskets and H/W.

Im wondering if maybey the tensioners are weakining. I can't push them down by hand, I'll try leverage and a screwdiver later.

[tobluforu]

If that is all that happened then count your lucky stars. This same thing happened to me, but I was less fortunate as I was accelerating when the ramp broke off. This caused the valves to bend and the pistons in turn ended up with tiny dents. I then went to pressure fed tensioners, etc...

[snbush67]

1..2..3..4..5.. Counting stars makes me sleepy, now I need a nap.

I hope that is all that happened, I will know more after I get it back together. It seemed to be running fine, just making some noises.

[911pcars]

I think diesel oil or kerosene would be fine. Starting from the oil tank, use copious volumes to help flush out the more weighty pieces into a large open pan.

You should only have to back off the ramp bolts, not remove them; at least until you can somehow arrest/latch onto them to extricate from the case. To replace, the new ramps (also temporarily cabled somehow with string or ??) snap into place. A long lever/screwdriver helps this process. Do one at a time and start off with the engine at TDC, no. 1 firing, place marks on chain box, sprockets and chains so you have a reference point to return to.... just in case.

Sherwood

[oldE]

"How sure are you that don't have to remove the bolts on the inboard ramps?"

The retaining bolts come out for the inboard ramps. The outboard ones just snap off/on the studs (as long as it isn't freezing in your garage.

Les