Checking cam timing
05-31-2019, 10:24 PM
#31
Registered User
Thread Starter
Originally Posted by Charlie
Jerry, when you get the cams timed and variocam working you are really going to love the performance. Without the spring I assume you have not ever experienced the variocam working. I need to do the cam timing and check my variocam. I had a 968 years ago and I believe it had much better pick up than my current 968. When I put my engine together I just set the cam timing in the middle not having the tools to do it properly.
06-01-2019, 09:11 AM
#32
Instructor
Hey thanks so much for this thread, will be putting the cams back in my 968 soon and will make a base like you described! One question. The Porsche workshop manual suggests a bent stem dial gauge extension is needed. Is a standard mag based gauge with straight probe suitable for use with your base?
Steve
Steve
06-01-2019, 09:32 AM
#33
Registered User
Thread Starter
Originally Posted by ste1999
Hey thanks so much for this thread, will be putting the cams back in my 968 soon and will make a base like you described! One question. The Porsche workshop manual suggests a bent stem dial gauge extension is needed. Is a standard mag based gauge with straight probe suitable for use with your base?
Steve
Steve
Lifter and you need to come in at an angle or your probe would probably be hitting the cam lobe while it's turning.
I got this one.
https://www.928gt.com/ps-26013-30-to...ion-85-95.aspx
06-01-2019, 10:03 AM
#34
Instructor
Thanks so much for the input I’ll get one. I’m trying to work out in my head how linear movement of the lifter is converted to movement on the dial stem accurately going around an angle. Guess it will be clearer when I play with the tools!
Steve
Steve
06-01-2019, 10:57 AM
#35
Registered User
Thread Starter
Originally Posted by ste1999
Thanks so much for the input I’ll get one. I’m trying to work out in my head how linear movement of the lifter is converted to movement on the dial stem accurately going around an angle. Guess it will be clearer when I play with the tools!
Steve
Steve
06-01-2019, 09:32 PM
#38
Registered User
Thread Starter
Originally Posted by Charlie
Hey Jerry, why don't you do us a video? It would be nice to have a 968 timing video for others to follow.
Last edited by Boeing 717; 06-01-2019 at 11:12 PM.
06-02-2019, 01:04 AM
#39
Instructor
Agreed on that one. 968 somehow gets translated into 944 even though there are often big differences. Then it’s a game of guess if it’s the same. If you get even a still photo of the gauge set up it would be wonderful to see it! I’m going to put my refurbished head on in a few weeks time after a vacation and am getting close to belt gear and cam reassembly. Finalising the rather lengthy parts collection as we speak
06-04-2019, 11:30 AM
#40
Agreed on that one. 968 somehow gets translated into 944 even though there are often big differences. Then it’s a game of guess if it’s the same. If you get even a still photo of the gauge set up it would be wonderful to see it! I’m going to put my refurbished head on in a few weeks time after a vacation and am getting close to belt gear and cam reassembly. Finalising the rather lengthy parts collection as we speak
06-04-2019, 02:31 PM
#41
Registered User
Thread Starter
Can you guys answer a couple questions for me?
1) When I reinstall the cams is it ok for the engine to be at top dead center instead of the 45 degrees before TDC like the manual states??
2) what's the best way to apply the loctite 574 to the saddle? Do I put it on the saddle and the engine case or just the saddle? Do I make a bead or do I spread it on like a thin film over the whole peice?
3) I did some trial runs today installing the cam shaft seal and that black cam hole cover. The manual says to install after the saddle has been tightened down. Can I do that without the special tools? If so what's the best way? I reinstalled the old ones for practice and honestly I could just press them in with my fingers. Or should I use a socket to press them in?
4) anyone have a picture of the coat hanger wire used to squeeze the chain tensioner together when your reinstalling the cams?
1) When I reinstall the cams is it ok for the engine to be at top dead center instead of the 45 degrees before TDC like the manual states??
2) what's the best way to apply the loctite 574 to the saddle? Do I put it on the saddle and the engine case or just the saddle? Do I make a bead or do I spread it on like a thin film over the whole peice?
3) I did some trial runs today installing the cam shaft seal and that black cam hole cover. The manual says to install after the saddle has been tightened down. Can I do that without the special tools? If so what's the best way? I reinstalled the old ones for practice and honestly I could just press them in with my fingers. Or should I use a socket to press them in?
4) anyone have a picture of the coat hanger wire used to squeeze the chain tensioner together when your reinstalling the cams?
06-04-2019, 04:15 PM
#42
Rennlist Member
Can you guys answer a couple questions for me?
1) When I reinstall the cams is it ok for the engine to be at top dead center instead of the 45 degrees before TDC like the manual states??
2) what's the best way to apply the loctite 574 to the saddle? Do I put it on the saddle and the engine case or just the saddle? Do I make a bead or do I spread it on like a thin film over the whole peice?
3) I did some trial runs today installing the cam shaft seal and that black cam hole cover. The manual says to install after the saddle has been tightened down. Can I do that without the special tools? If so what's the best way? I reinstalled the old ones for practice and honestly I could just press them in with my fingers. Or should I use a socket to press them in?
4) anyone have a picture of the coat hanger wire used to squeeze the chain tensioner together when your reinstalling the cams?
1) When I reinstall the cams is it ok for the engine to be at top dead center instead of the 45 degrees before TDC like the manual states??
2) what's the best way to apply the loctite 574 to the saddle? Do I put it on the saddle and the engine case or just the saddle? Do I make a bead or do I spread it on like a thin film over the whole peice?
3) I did some trial runs today installing the cam shaft seal and that black cam hole cover. The manual says to install after the saddle has been tightened down. Can I do that without the special tools? If so what's the best way? I reinstalled the old ones for practice and honestly I could just press them in with my fingers. Or should I use a socket to press them in?
4) anyone have a picture of the coat hanger wire used to squeeze the chain tensioner together when your reinstalling the cams?
2. There's no need to coat both surfaces with 574. Just do the cam cap(s).
3. It's a little easier to install the seal and black cap before your caps are torqued. Just make sure they are all the way in place before you torque. No need for any tool if done this way.
4. It's Porsche tool 9530, and yes, you can make one from a coat hanger. Sorry, no pic.
06-04-2019, 05:01 PM
#43
Registered User
Thread Starter
Thanks for the response Michael.
If I already have the engine at top dead center and If put the cams in the same way they came out wouldn't that ensure that nothing would hit?
Also, I can't really turn the crank to get the engine at 45 dbtc because the pistons will be going up and down and the valves won't be moving. Wouldn't that pretty much guarantee that the valves are going to hit the pistons?
If I already have the engine at top dead center and If put the cams in the same way they came out wouldn't that ensure that nothing would hit?
Also, I can't really turn the crank to get the engine at 45 dbtc because the pistons will be going up and down and the valves won't be moving. Wouldn't that pretty much guarantee that the valves are going to hit the pistons?
06-04-2019, 06:08 PM
#44
Instructor
1. The reason to have the engine at (anywhere around) 45 deg. BTDC is so the pistons are down in the bore. You want them down so there's no chance of any valves hitting the piston when installing the cams prior to finalizing your cam timing. Install the cams in the position shown in the factory manual, then slowly turn the crank (and pistons) up to TDC without the belt attached to the cam. Once there, attach the belt and follow the factory procedure.
2. There's no need to coat both surfaces with 574. Just do the cam cap(s).
3. It's a little easier to install the seal and black cap before your caps are torqued. Just make sure they are all the way in place before you torque. No need for any tool if done this way.
4. It's Porsche tool 9530, and yes, you can make one from a coat hanger. Sorry, no pic.
2. There's no need to coat both surfaces with 574. Just do the cam cap(s).
3. It's a little easier to install the seal and black cap before your caps are torqued. Just make sure they are all the way in place before you torque. No need for any tool if done this way.
4. It's Porsche tool 9530, and yes, you can make one from a coat hanger. Sorry, no pic.
Steve
06-05-2019, 02:05 AM
#45
Rennlist Member
Hope you don’t mind an additional question 😀. If the cams are first installed and the engine later turned to TDC, that inevitably involves going a touch past TDC if using a dial gauge to detect TDC. Is it ok to then turn the engine backwards and position again at exact TDC if using the dial gauge method?
Steve
Steve