How To Set Porsche Cam Timing. Rebuilding your air-cooled Porsche engine
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- Опубліковано 6 вер 2024
- This may be the video lesson you were looking for! How to simply set the cam timing. You need to know the cam you have, for the engine you have, and you need a few special tools. Beg to borrow or buy the tools you will need to make the job easy.
Z-block, amzn.to/3tBAKTk
Metric Dial Gauge, amzn.to/2PCm8o4
Crows foot, amzn.to/2Qo9wkD
Camshaft Socket, amzn.to/3dCSyYA
Valve adjust tool, amzn.to/3dG0NDy
Straight edge and holder, www.stomskirac...
Depth gauge, amzn.to/3szKOeg
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Very impressed with this fountain of informative videos for us garage hacks. Back in 2003 I installed my RSR seals with the engine still in the car on my 3.0 ! Yes had to be a contortionist. and I was 20 years younger. Made my own tools due to the tight access. In the video I paid particular attention to how he was setting the tappet valve clearance and watching how much drag was on gauge once tightened and set. When using the screwdriver and open end wrench it is very easy to over tighten or get the .004 spec too loose. I see he can easily spin the gauge without it binding and removes easily. I would guess he is more at .005-6 then at .004 but just nit picking. Great presentations and thank you. It's about time someone posted this kind of very democratic and informative procedure. On a side note, getting kind of tired of watching all the gold card porschettes out there installing independent throttle bodies on their 3.0 and then wondering why when dyno'd they only get perhaps a 10-hp gain and not 30 hp + as promised but only after spending 6 or 7 grand on overpriced assemblies and installs etc ....
zzzz,
Its hard to show a valve adjustment, because it's a feeling not a visually thing. When I worked for Porsche we were not allowed to do a valve adjustment without it being checked by another mechanic for about a year. 34 years later I think I got it now and can do them pretty quickly and know that I'm hitting my tolerances. Yes I agree with the bolt on stuff is usually not very well thought out and most often will take the car backwards in drivability.
Thanks for you comment
Kurt
I have watched a few other videos about setting cam timing, and this was the first one that actually made logical sense to me. You do such a nice job explaining everything and the camera work is tremendous, also. At some point I'll have to do my 3.2, and this is another piece of valuable info in my pocket. Thank you!
Yes cam timing does not have to be complicated. Just take your time and work your way though it.
Kurt
When roughing in the cams, wouldn't you want the 1-2-3 cam dot up and the 4-5-6 cam dot down. Having a hard time getting my head around that. I would think you'd want them set at 360 degrees of crank opposed to each other, 180 degrees on the cam.
You always start with dots up on both cams.
Kurt
Very very nice job,LOVE to see how meticulously you rebuild It
Only thing to say : when you Torque the cam nuts, the correct way to use the open key Whit the Torque wrench is turning It 90grade of the Torque wrench.... (nice nice job ofcourse!)
Yes you are correct. to get an accurate torque the crows foot socket should be 90 degrees to the torque wrench.
Thanks for watching
@@klassikats however, LOVE your work,im looking to Buy a classic 911 and looking for ovehaul the engine if its necesary 😅
Great video Kurt and Sarah! You guys make it look so easy!
Thanks Kav.
I would like to thank you for explaining cam timing so easy. I’ve watched several videos but, you explain it so easy. Though, I would like to ask; what should be the valve lift for a 3.2 engine? Thank you! 🙏
Glad it was helpful!
The Valve timing on the 3.2L is 1.1mm to 1.4 mm with optimal setting of 1.25 mm
Thanks
Kurt
I own a 1984 Porsche 911 Cabriolet European version. Back in 2015, I decided to repair the engine cause it had several broken studs. After the rebuild, everything was fine but thereafter, it was producing a knocking sound. I checked the oil pressure and it had none! I was told that because the car was seating for so long the chain tensioners were jammed! Now I’m looking to tear down the engine again to see what got damage and replace the chain tensioners. So frustrated!
Perfekt instructions once again. That engine is so insanely clean...
Thanks Remco,
Cleanliness is the key to success in any engine work that you do.
thanks for watching
I'm up to this video and they have been so helpful so far so thank you! I started the left side cam timing and learning the hard way. It looks like when I torque the cam bolt on my carrera 3.2 I'm adding .05mm of valve lift at tdc after it's set. I guess I'll attempt to reduce the initial setting by that amount before torque down, but I'm going to take a break tonight and start again in the morning. So far a fun engine to work on and a challenge for sure. You're a master without a doubt.
Vic,
What is happening is the gear is moving slightly against the timing pin as your tighten the bolt, which is normal. You can slightly preload the pin in a different hole and see if that helps. Also 0.05mm is not a huge change as long as the timing is still within the specifications.
Kurt
I think I figured it out. If I come down to spec at TDC by turning the 1-3 bank cam clockwise I can expect a .135mm reduction in lift due to the pin moving into position when torquing down the big cam bolt. So I'm going to go back in the garage and try adding that to my spec and then tighten it down and see if I'm close to my 1.26mm target.
All done and both sides are a match. Once again thank you so much for making these videos. It's really helped me develop my skill set.
Special tools such as old spark plugs to remove timing pins :) haha. Very cool video thanks for sharing the knowledge!
You bet!
Thanks for watching
Very good source of information. First class!! Love to watch your videos. I would like to know what could be expectetd from engine running setting the timing to the end of the tolerance.
I own a 930.16 that was professionel overhauled and i found the cam timing one side set to 1,7 and the other side to 1,72. I checked this because the engine feels a little different than before the overhaul.
Regards Michael
Changes in cam timing will affect the power band. Advancing the cams will cause the power band to move lower in the RPM range while retarding the cams will move the power band higher in the RPM range. Setting the cam timing to either side of the of the specification range will make very slight differences that 99.9% of drivers will not notice any difference.
Kurt
Learning lots! Was hoping to see your technique for torquing the rocker shafts. Do you position all 5mm bolt faces to the flywheel side and work your way out 1>3, 4>6 ?
We show the rocker arm assembly in another video. The position on the rocker shaft is very important, and it is one of the things that I see installed incorrectly all the time. The 5 mm Allen head needs to be positioned so that it can be accessed at all times, as rocker shaft torques are a service item. I will usually install them in the firing order as I need the Camshaft to be in compression and I can set the valve clearance as well.
Kurt
What did you set the valve gap to? And when you torqued the large cam nuts, shouldn't the crowfoot be 90 degrees to the torque wrench.
Valve clearance is 0.100 mm (0.004"). Yes in a perfect world the crows foot should be at 90 degrees to the wrench and yes I usually try to keep it there but sometimes it ends off being off. So looking at the video it looks like the crows foot is about 45 degrees to the inside of the torque wrench. That is going to result in a torque reading that is 3.4 Nm higher than the desired torque. Just the drag alone on the wave washer is probably worth more than that so I am not to worried about it.
Thanks for watching
Kurt
I have watch your video on engine assembly and they are super iam all done and have the engine in the car , I start the engine and when I let go of the key it shuts down I have to have wire on the wrong plug it's starts and the minute I let go of key it shuts down
There are two possible issues here. Firstly it may be running on the cold start injector which only runs during cranking. Then when you let go of the key there is no fuel flow and the engine dies. The other issue is power to the CDI ignition system, is dropping out as soon as you let go of the key. Could be a bad ignition switch.
both are easy to check. If you put your volt meter on the CDI power input and have someone crank the engine while you watch the +15 circuit. If power drops out when the key is in the run position, look at the ignition switch.
Also for the fuel system look at the roll over switch on the sensor plate and make sure everything is adjusted correctly there.
Kurt
There are 2 connecters 1 on each side of the intake and 4 connecters behind the trouble body 1 I no only can go I place it has 3 prongs the other 3 are they to go special places they are 2 prong thank you...john
On the 4 rocker, do you have a special 8 mm hex wrench? If so, can you provide a link? I have a standard hex set with 90-degree bend. There is not enough clearance between the cam box end and the rocker shaft to use it. Thanks for the great videos and replies.
Yes, I made my own as an apprentice while working for Porsche. Mine is made using an old head stud with a small piece of 8 mm hex welded to it
Kurt
Loving the tips!
Much respect.
Appreciate it!
Great video series! I have watched and enjoyed every one. Can’t wait to tackle my 2.7L
Thanks Andy,
Glad that you have enjoyed them and good luck on your own 2.7L project
@@klassikats is the settings for the cams the same for all engine sizers or does 2.7 have different settings!..cheers!
@@john2ndname Mike, each camshaft has its own timing specifications. All Engines have multiple camshaft choices. You need to identify the camshaft using the number stamped into the front of the camshaft. Then refer to the shop manual for the correct timing specifications.
Kurt
@@klassikats cheers Kurt!
@@klassikats Kurt!..can you suggest a good workshop manual for the 1977 2.7 ltre engine!..thanks
Hi Kurt,
Is it possible to replace the chain without splitting the case? I see there are chains with master links available. A complete rebuild is out of my budget, but I have a stretched bank 1 chain so it probably prudent to chainge to gain some time before a complete rebuild. Tensioner is not hitting case yet but it has some play (1mm). Thanks this vid was awesome as they all are!
Yes you can change the chains without splitting the case. You just cut the existing chain and join the new split link chain to the old chain and wind it in.
Kurt
Great video's... those video's will help me a lot to remount my '66 motor! Thanks
Glad to help
Kurt
Hi Kurt. Is it unusual to use fewer shims? On the right side, my measurements left me with 2 shims (.5 mm each).
My rocker shafts didn't install as easily as yours. It took a socket extension and a small hammer to tap them in. Is that indicative of something is not right? I'm using the RSR seals if it matters.
Yes it is normal for the shim count to be different on the cam gears. There are a couple of things that can cause the rocker shafts to be tight. First would be damage in the cam box bores causing an interference with the shaft. If you are using used rocker shafts they may taken a set and the shaft may be slightly belled at each end. Lastly make sure you are lubing the RSR seal well enough as it can drag if you try to install them dry.
Kurt
Kurt i email a while back. Iam working on a 1980 porsche 911sc .i had to replace the head studs as they wer broking off so i replace all the head studs with new and put the engine in the car , and it would start and theminute i let go of the key it would shut off ther are 2 wires that go to each.side of the motor that are mabe fuel regulaters, and 4 wires that go to the back of the fuel and air.box the plug ends are color coded maybe any chace there is a digram for these lugs ,, the car will. Run now but will not idle if disconect the plugs once i connect the plugs the car shuts off once the key goes from start to run passions any help ;;;; Also i understand u make a wire.harness for the top of the engine thank you john
John,
As I said in my email to you there can be a number of items that can cause this. It sounds like it starts and runs on the cold start injector only and that the fuel pump is not continuing to run. I would look at the roll over switch on the sensor plate as well as the fuel pump relay to see that it is getting the trigger signals it needs.
Kurt
Super clear video, thank you
You're welcome!
thanks for watching
Kurt really enjoyed your video on the cam timing and it gave me a better insight on understanding that.
I have a question to ask you on setting the cam timing. I have a relative that is an auto mechanic and he doesn’t think that he needs to use a dial caliper or a digital gauge to set the cam timing he thinks he can use a degree wheel to do that. he has no experienced with working on Porsche engines at all he rebuilt one Volkswagon engine once. Thank you
Marion fisk
Marion,
Even when using a degree wheel you still need to use a dial gauge to know where the cam is. Accurate measurement is the key to precision, unfortunately to many mechanics do not have these skills. When working on many of the domestic and imported cars out there, they mark the timing positions with dots or dashes. This is so the production line assemblers can literally throw it together. A mechanic that just works on those cars can go their entire career without using a dial gauge to set timing. The unfortunate thing about that is they never really have a true idea what is actually happening.
Thanks
Kurt
Hello Kurt. What cams part# do you have here? Your spec is 2.5mm overlap at TDC. Im working on a 2.7 CIS carrera and specs show 0.47mm
Could not tell you as I did this job to long ago to remember. However, if the engine type and the cams you are using call for 0.47 mm then that is what you should set you timing too.
Kurt
THANK YOU FOR THIS!!!
Your welcome....
I'm curious what that gear pin removal tool is and where can I get one?
Trade secret. 🤫It is a spark plug.
LOL, couldn't really tell watching on a small screen.
Thanks Kurt great video if i'm just putting back the cams and they are good without any work done to them can i just put back the same amount of shims for each cam that came off before unesembly. i would measure just to be shore though.
I always measure the chain depth. It doesn't take long and I cant tell you how many times I find that the last guy got it wrong.
Kurt
@@klassikats Thanks Kurt..your tips are a life saver.
Thanks!
Thank you Steve. Glad to help
Whats the size of the nut holding the cam sprocket. Need to remove mine
46 mm crows foot is what you need there.
Kurt
What are the 8 mm and 5 mm torque values for the rocker shafts?
12 nm on those
Top👍 Grazie
Your welcome
Kurt
My right bank camshaft does not turn freely, the left bank one turns ok with fingers but makes a scraping sound. My engine is on a stand much like in this video. I have not put the chain boxes on but was test fitting the cams. When I took the engine apart the cams turned freely. I have had the camboxes vapor blasted some months ago. The camshafts have been polished (although the shop didn't so a great job) but I know how to polish them further. Should I start with the box bearing surfaces? Cams have been sitting covered and protected for about a year. Any tips?
Trenton,
It sounds like a couple of things may be happening. Firstly it sounds like the cam boxes have not been cleaned well enough after the vapor blasting. That is most likely the cause of the scraping sound. For the Camshaft that wont turn it is possible that the bearing surfaces in the cam box where over blasted and have a rougher than normal surface finish. We have a video on cleaning and rebuilding the cam box that you should check out ua-cam.com/video/r8qzvnoSEog/v-deo.html
@@klassikats Thanks. I did take a bit of 800, 1000 and then 3000 grit wet sanding to the box. It helped a bit for the right bank cam box. However I went ahead and ordered a new one from Porsche. The dealer emailed me back and said that my cambox (part number#9931051117R) was a "racing housing". I have never heard of that have you? It looks like a standard box for the 94-98 993s.
Kurt, how much did you preload the dial gauge on the valve retainer ?
Kevin,
1.00 mm approximately
Kurt
Thank you.
Can timing improperly set prevent an engine from starting?
It would have to be off a long way to prevent the engine from starting. The other issue is that if it was off far enough that the engine wont start you most likely have valves hitting pistons.
Kurt
@@klassikats Thanks Kurt..Keep those videos coming. I always learn something useful.
@@klassikats Kurt, I have noticed from watching so many videos on cam timing that everyone always set the gauges up with the foot riding on the valve. Why is it necessary to install the rockers and set the lash to .1mm for intake valves 1 and 4. Since the gauge's foot is riding on the valve, is it necessary to install the rocker? What's the purpose?
What the orientation of the porsche ring compressor..do I rob a bank
Sergio,
The band side without the step in the handle faces the barrel. And no its not expensive, here is a link to it on amazon amzn.to/3ZUqa9e its $128.00 there.
Kurt
Does chain depth measurement apply to all engine type?
Jesse,
Yes and no. The design dimensions of the intermediate shaft stay the same. The difference is in the way that you measure the chain depths. In late 1983 Porsche discontinued the access bore in the case to be able to measure from the outer part of the case to the chain gear. Instead Porsche gives us the dimension from the intermediate shaft thrust surface to the gear, (43.27 mm). Other than that the procedure is the same with the only real difference being now you have to do a little math on both chain wheel depths instead of just one.
Thanks for watching and I hope that answers your question
Kurt
@@klassikats thank you Kurt and sharing your videos. Your videos are very detailed and always helpful. Keep up the good work. Any 930 in your future videos?
@@jesse818 Your welcome Jesse,. We sold our 930 about two years ago and we do have some turbo stuff on the channel. But you never know, a lot of the videos are of customers' cars so if we get a 930 into the shop then we will have more videos on the turbos.
Thanks for watching