3.3 piston ring change. hopefully.
 

Hi guys.SmileWavy

Just wanted to show some progress pics and maby ask some questions if you don`t mind. I`m hoping to just go in and change #3 piston rings and patch it up again.
Engine out.
http://forums.pelicanparts.com/uploa...1338752598.jpg

http://forums.pelicanparts.com/uploa...1338752622.jpg

http://forums.pelicanparts.com/uploa...1338752635.jpg

How much of a stripdown will i have to do to get access to the sylinder? i want to mess as little as possible :)

Oheggem

I just did this recently. You can remove the heads, cam towers, cams and chain housings as a single unit. You'll need to remove the chain tensioner stud on the left chain housing to allow the chain to exit the chain housing. It was easy except the unit is heavy. Doing this saved me alot of work by not having to remove all the rocker shafts and cleaning/sealing the cam towers to the heads.

-Andy

was hoping for something like that. Thanks for that tip dude. Will defenatly go for that. Don`t have to split the tranny/engine or strip the top of the engine down?

Just hope i get this back together because the nearest Porsche mechanic is about 600 km away :(

I`ll give an update on the progress :)

I think you'll have to remove the intake system and the fan shroud, don't see any way around that.

-Andy

Well i think i fubared up a bit. I forgot to set the cams/crank to TDC. can i fix this after reassembly?
http://forums.pelicanparts.com/uploa...1338931315.jpg
http://forums.pelicanparts.com/uploa...1338931339.jpg

Also i found a locking clip like below:
http://www.heliwholesaler.com/images/0447-1.jpg


Found this just below the highest pin here. Can`t remember what it`s called.
http://forums.pelicanparts.com/uploa...1338931293.jpg


I feel like this is never gonna be in one peice again. I feel like this is too big a task! I so hope i can do it!

Not sure what that clip is off - it is external to the engine tho - must be off some linkage bit or similar. have a good look around before installing - while you can get to everything.
If you are pulling a cylinder you will ave to pull all the cam gear and that head at least, which will mean really pulling the shroud/CIS stuff off. It is not a biggie since engine out - a few simple bolts/nuts. Trying to do less is not worth it.
You can cam time it anytime - but preferably with engine out. If you have put engine back in, you can still do it, but it is 5 x harder. You need to pull the cam chain case off (only doing one side -right?). This means pulling the rear engine tin off. You will need the I/C and manifold off to get at the LHS inlets for the timing. Then need to mount a dial gauge as best you can on the inlet side - preferably #1. You may need to make up a steel plate that will bolt down on the inlet side to mount a magnetic base too - mounting the dial gauge in here is a bit tricky/tight. You don't need to use #1 if it is easier to use #2 or 3.
Not sure if you actually doing this in engine or not, so will post more details if you need them.
Alan

look like the accelerator linkage clips on the throttle body.
Bruce

I`ll be at work for most of the 2 upcoming weeks so no work done but will just continue taking apart the left head and change those piston rings, then do the camtiming later.

Alan, the engine is out and the CIS and stuff is off along with the fan cover:) Can you not see the pictures? hmm

Thx so far guys :)

Think Bruce is correct in the clip.
It will work out great.

Regarding TDC, no problem. You need to time the cams anyway.


OHeggem, du kan ringe meg, 90884590, om du trenger litt hjelp.
Overhalt noen av disse motorene

I thought i`d order the P202 claw thingy for the cam gear when i realized that i don`t have the same as seen with others. I have one nut and nowhere to mount that tool as it mounts off a big bolt head. I thought i`d just airgun it off. Torquing it back on might be an issue as i can`lock it off.
I`m taking the head of without touching the rockers and valves so i don`t have to do valve clearance and stuff like that. I can just throw the head back on, time the cams and be on my way. I need to modify the dizzy though.

Is there any tools i absolutely haveto buy? I will order them at once if there is. have have none of the porsche tools now.
Also ordered the MSD 6424 with a new coil. Will be exiting to say the least.

At work so nothing happens for about a week and a half.

Totle, lagra nr ditt. Forvent en telefon :) Takker!!

You'd better show us a pic of your cam end. You can't just rattle gun the bolt back on - or I certainly wouldn't try. Not sure why your cam end would be different.
And I would be resetting the valve clearances while I had the engine out -easier than when the engine is in.
Alan

Pics of the cam end:
http://forums.pelicanparts.com/uploa...1339351618.jpg

http://forums.pelicanparts.com/uploa...1339351633.jpg

Used air pressure gun to get it off. Worked fine but torquing it might be a hassle.

All i had time to do really today because of work :)

OHeggem

When assemble again you Can fasten the pressure plate side and torque according to spec

I'm not sure what is different about your cam end. You have a bolt into the cam and a retaining washer. You need to torque the bolt to 88 ft lb.
The difficulty with doing it via the flywheel/crank is that you are putting all the torque load thru the timing chains. Not a good idea really. Best to lock the cam as per original plan.
The other thing you could do is check the timing on the other side first, then synchronise the 1-3 side. While there is a range/tolerance, you want to get both sides the same, ideally. This means checking/setting valve clearnces on 1&4 , so you may as well do the others at same time.
Alan

Well, the difference is that there`s nowhere to use the special tool at torquing the bolt. I will just have to use the crank to hold back. Can`t wait to get the head off.

I will need a special tool to check valve clearance yes? I might just hope to avoid this. Will update when things happen again :)

Totle, is that where there oil pump to the turbo is mounted? That might work actually! Thx :)

You just need 4 thou or 0.1 mm shim for checking the valve.
Your bolt is no different to anyone elses. The tool is designed to work around it specifically to do that job.
At a guess if you use the chain tension to torque the bolt you are applying about 10X the stress the chain was designed to work at. You could verify that once you pull the heads off. It looks like you are going to pull the heads with cam box intact. In which case you can put the lot on your bench and measure the torque it takes to rotate the cam against the valves. My guess would be 5-10 ft/lb. You want to apply 88 ft lb to the chain that drives your engine.
You can imagine the stress on the links, and the possibility of stretching one side of your chain, while the other side is not stretched.
You may get away with it. Others may have done so. All I am saying is it is not good practise and these engines deserve the utmost respect when working on them - ie best practise , if you don't want issues after.
The oil pump is the turbo scavenge pump and drives off the end of that cam - by a drive pin. Not sure if you can lock the cam from there (can't think of how you would do it). I think he was referring to locking the flywheel.
Alan

As Alan said, I was referring to locking the flywheel, not the cam at the scavenge pump side.
Oheggem, Give me a call and I will explain the procedure for piston to valve clearance

Oheggem , I am traveling now but will be back in Norway on the weekend. I have the correct cam holding tool, you could borrow it for the short time you need it to time cams. If you dont have Waynes book, it is very helpful. Also search this forum for "cam timing" and spend an evening reading posts

Ring meg lordag 92021588

Regards,

Wade

Been super busy at work but removed the head today. Also the sylinder to check those piston rings. They are intact but the gaps where right next to eachother. On the picture i had moved the top ring a bit.

http://postimage.org/image/lrsnhlovt/

Can that cause smoking? What`s next to check?

The piston doesnt look like it has a problem with blow by the rings.
Bruce

Remind us again why you are pulling #3.
You have a smoke issue. How did you get to conclude #3 is the problem, and how did you conclude it was the cylinder/piston?
Have you checked the valve/valve guides(s). #3 and others.
Regards
Alan

It smoked blue on acceleration and when i removed the headers the #3 exhaust outlet (probably the wrong name) was wet with oil. Others where dry.
Here`s a picture of #3

Imageshack - 06092011031.jpg

Ofcourse i should`ve done a leakdown and/or compression test first... but i didn`t. Kinda regret it now when the rings seem ok. Maby the rings are just worn out on that sylinder...

You can measure the ring gap by inserting the rings (removed from piston) in the TOP of the cylinder - the very fraction that does not suffer piston wear. This is the true original bore size. Any wear on the rings will show as an increase in gap between the ends. Measure with a feeler gauge the gap.
Check the oil ring is OK - not broken.
If you intend re- using the rings - ie they check out OK - take note which ring comes from where. And there is a top and bottom edge to each ring - ie do not flip them upside down if putting back in.
regards
Alan

You never mentioned the mileage on the motor in any of your posts. The single photo you posted of the #3 exhaust port is not very telling. However, having said all that, these 911 motors are usually good for about 200k miles for bearings and rings. But, the valve guides are usually only good for a life of about half that. When your valve guides wear, olil will leak down the valves stems into the exhaust port and create the blue smoke of which you spoke.

So, my suggestion is that you consider inspection of valve guides and not rings as the potential source of your smoking. If the motor does, in fact, have around 100k miles since new (or the last rebuild), then consider doing a complete valve job on the engine including inspection and/or replacement of worn valve guides. It is relatively easy to pull the heads now that you have the motor out of the car and partially disassembled.

Have you removed the valves on #3. Apart from wear they can also crack or break.
Check the rings as per mentioned above - including the oil ring - there is a special orientation for each part of that ring. And check the guides for wear or damage.
Alan

Will try check the guides and do some more research on the rings. i have new rings for that sylinder though so i think i`ll replace them. i should maby change on all but i`ll see.

The engine has run 194k km so it has stretched it`s legs quite a bit. not sure on history on the engine so i have no idea what if anything has been done to it.

Thank so far and i`ll give an update in the weekend as i`m working now. Much apprech!!!SmileWavy