Remove cams mystery 70 911

[blackbird225]

Hello again folks. I've been sick with a repiratory thing for 3 weeks. My engine has been on the dolly for 2 months now with no work being done .

I have the hefty tools and my trusty books from Wayne. I also have my rockers out to Competition Engineering and new reground E-cams from camgrinder.
I am now looking at the end of the cam, the sprocket and the whole mess tensioner assembly. In Wayne's Engine book, he is removing the com towers to r/r the cams. Please tell me that I don't have to pull all of that away to just replace the cams?
Or do I? Remember, I am just replacing the cams and rockers. The engine has good compression and leakdown, just an insane annoying tick. My P mechanic and others here have suggested that this is a cam lobe/rocker face tick.

How to just pull and replace the cams once inside the chain housing?

michael

[Grady Clay]

e-mail from Michael:

Hello Grady,
You have helped me in the past. I need a tip on a critical step in my project. I searched, posted, etc with no luck. If you remember, I have a 70T, engine out. I have pulled the rockers and sent them to Competition Engineering for regrind, etc. I have a pair or reground E-Cams from Camgrinder on this list.
I have the tools to remove the cams.
SO-- I have pulled the chain housing away and now I am looking at the cam sprocket and tensioner assembly. What is my next step? Do I just put the crowfoot on the nut, cam holder on the end of the cam and unscrew that huge nut? Should I release the chain somehow first?
I really appreciate any suggestions you might have. Don't want to screw this up!
Michael

Grady’s reply:

Michael,
OK, you have all 12 rocker arms out of the engine so there is no risk of bending a valve when turning the engine and the cams are out of time (or from turning just the cam.)

When you say: "I have pulled the chain housing away and now I am looking at the cam sprocket and tensioner assembly." I assume you mean you have removed the chain covers but the chain housings are still attached to the case.

The next step is to remove the tensioner and idler sprocket assembly.

Remove the six chain ramps. Note the position and color. Each has a long and short end.

Next is to use the crow's foot and cam wrench and undo the large 46 mm nuts. You must pull the two tools against each other. Be sure to keep them straight on the nut and cam.

Once the nut is off the big washer will just fall off.

Next, remove the cam timing adjusting pin. At this point you should be able to just wiggle the sprocket and get the sprocket and pin off.

There is a multi-prong flange on the end of the cam. VERY carefully work that off the cam (don't damage the prongs.) It is attached to the cam with a key, remove the key. There are some shims under the flange, keep them with the flange and sprocket for that side.

There is a 3-bolt sealing flange, rubber O-ring, and gasket next.

Now the cam is able to be removed. As you withdraw the cam, support it with your fingers through the cam housing openings so the lobes don't damage the aluminum bearing surfaces.


Does this engine have or has had MFI? If so, you must remove the MFI pump drive sprocket from the front of the left cam.

If you find yourself with any difficulty, STOP.

Best,
Grady

[blackbird225]

Grady ...
I have MAJOR difficulty. I have 2 big 1/2 inch breaker bars and the correct cam holder and crowfoot wrench, but neither side will even BUDGE. I actualy could easily stand and bounce on the bar and nothing!
Any suggetions?

michael

[Grady Clay]

Michael,

If you absolutely can’t get it off, your recourse is a high performance impact wrench with a proper 46 mm 6-point socket. There is a risk of breaking the end off the cam. Keep the socket aligned with the can and use only a short burst with the impact wrench but at high air pressure and sudden full throttle. Since the cam is now free to rotate, that will limit the impact, just don’t spin the cam. One shot with an impact wrench should do it.

Best,
Grady

[obrut]

i did this last weekend. it wouldn't budge with a big breaker bar and the proper porsche cam nut tool. one buzz with the impact wrench and it came strainght off.

[blackbird225]

I was thinking this same thing...

[914/6]

Do the piston valve releifs need to be deepened with the cam swap ?
T to E ?

[blackbird225]

from what camgrinder says , there is only .08 mm more valve lift. That is not even 1 /10th of a mm! I am not to worried about that kind of lift. But I'll be the guy on here talking about bent valves next week !
LOL

Ask camgrinder. Not only did he say it will work, but he used the word popular.

Michael

[blackbird225]

I would love to upgrade the whole engine to a 2.4, but I don't have that kind of $$ right now. THe cams are $300 and the rockers refaced are $250ish so this is a sub $1000 refresh. Besides, my 2.2 was rebuilt 2000 miles ago. They just left the worn out tired cams and rockers in it.
I am finishing the job. Oh yeah... Competion Engineering told me that 4 out the 12 rockers I sent him were garbage. See, I am right about my tick! Now I'm getting 4 new rockers and 8 revived from CE.

We'll see. I'll be a REAL shadetree mechanic after this.

MIchael

[BK911]

You can pick up a 2.4 crank and rods for a couple of hundred bucks. That's chump change if you consider how much the total car is going to cost. Now's the time to do it!

Let me know if you need some help. I can swing by for a little while after work one day.

[blackbird225]

yeah crank and rods, then I need an engine seal kit, pistons, cylinders engine holder, engine holder adapter, specific rebuild tools.... etc, etc

My engine is on that cart you suggested I build. IT works perfectly for r/r of the cams, but no way to rebuild whole engine. I thought about a 2.4 upgrade now, but I don't have the $$$ really. I mean if I could get all of the parts and machine work for $1000 it might be worth it. But the engine has new pistons and cylinders in it now. I would actually rather buy a used 2.4 and take it apart and rebuild it, slowly, on the weekends. I just want to get this car on the road, to get some more seat time. I would love for you to come by after work one night and give me your opinion about my new roller and look at my engine while its on the floor. I think you will be pleasantly surprised as to how nice my roller is. The paint is shot, but the body is mint, save a little front pan rust, that does not go through anywhere.

What about tonight or tomorrow? I live right off I-4 and Lee rd
Michael

[echrisconnor]

Are you still having problems removing the cam nuts? Mine came off quickly and easily after doing the following

1. heat the nuts lightly and squirt PB blaster in them when they're hot. Do this a few times.

2. Heat nuts and dab a small block of beeswax on the threads so that it melts.

3. Wedge the breaker bar with cam holder so that it is secured between two of the mounting studs on the front of the engine. Have a helper just hold it in place. Turn the big crowsfoot wrench and give it good thrust to get it going and break things loose. Watch your fingers an knuckles.

[blackbird225]

I am going to try heating, liquid wrench and an impact wrench. I figured out the stablizing wrench trick last night. I could actually stand on the other bar and bounce a little, Nothing.... I thing the heat and impact will spin it off. I'll repor back tonight with the results.
michael

[blackbird225]

Ok, I tried the imapct wrench first. bad move for me... I ate 6 teeth off the little sprocket behind the big front sprocket. Now I will need to find someone who can sell me a spare one of those. Oh yeah, and Im not even sure the impact wrench helped. I heated that thing up for like 10 minutes with a butane torch and after if cooled off, the nut easily came off with my two bars. But I sheared off the teeth of that little sprocket back there. THen the damn cam would NOT easily come out of the tower. A friend from the list and I worked in unison to twist, turn and pry the cam off finally. THEN I found severe SEVERE gouging of the bearing surface and heat damage on the cam lobed from the area where the ticking was bad and the rockers were shot. My cams were atually not too bad. Looks like I was right. The squirter failed at one point in its life and the cam ran dry in the #2 area. BK911 was shocked to see this much damage. Pictures in the morning....

MIchael