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Cam Timing - Printable Version

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Cam Timing - KRAG50 - 01-11-2013

Question to those who have timed their cams using the two dial indicator method. After pressurizing the Verio Cam actuator to 40 psi, how much air leakage did you notice? Not around the air connection point but down around the body itself?

A steady hiss or minimal slight slow leak?



Thanks

Cam Timing - flash - 01-11-2013

it leaks. by the way, if you are rebuilding the engine, reusing the variocam valve (not solenoid, but actually the valve) and everything is dry, that method won't work right. it results in the cam timing being off. you need to pressurize it with oil. basically it's a hydraulic valve, not unlike one in an automatic transmission. if there is no oil in there, then it doesn't seal up right. we saw a 13 degree shift on my motor between pressurized with air versus oil.



the air method works fine though if you are just servicing cams or variocam, and the oil is still in there.

Cam Timing - KRAG50 - 01-11-2013

Oil should be in there, I just removed and reinstalled after head service.



Thanks

Cam Timing - Cloud9...68 - 01-11-2013

[quote name='flash' timestamp='1357927004' post='137303']

by the way, if you are rebuilding the engine, reusing the variocam valve (not solenoid, but actually the valve) and everything is dry, that method won't work right. it results in the cam timing being off. you need to pressurize it with oil. basically it's a hydraulic valve, not unlike one in an automatic transmission. if there is no oil in there, then it doesn't seal up right. we saw a 13 degree shift on my motor between pressurized with air versus oil.

.

[/quote]



WHAT???!!!!!! <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" /> <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" /> <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" />

Cam Timing - flash - 01-11-2013

yup - checked and rechecked. ended up having to degree in the cams like other engines.

Cam Timing - DaveN - 01-11-2013

Good thing it didn't turn over and start eh Cloud? <img src="/forum/images/smilies/968/wink.png" class="smilie" alt="" /> You sound like you may have used air in the timing.

Cam Timing - Cloud9...68 - 01-11-2013

Uh - yeah, like everyone else who has ever timed the cams on these engines. When I did it, I was very pleased to find the final position on the adjustment wheel on the front of the cam to be in a very reasonable spot - close to, but not exactly at, the center of its adjustment. Ran through the whole procedure twice, and ended up in exactly the same spot. Confused, to say the least....

Cam Timing - flash - 01-11-2013

the problem is the wear and how much air slips out. without the oil to make the seal in the valve, it does not move as much as it should, and consequently your cam timing is off. we went round and round with this. it just wasn't coming out right. once we used oil, it all fell into place. if you use a cam degree wheel, you can easily see this.

Cam Timing - willw - 01-11-2013

I happen to be working on mine now, and running more air pressure seems to help. I think I'll add a shim under the upper valve adjuster plate to stop it from dipping slightly between stokes.

Cam Timing - kwikt - 01-12-2013

Does anyone have a drawing of the dial indicator pin extensions used on the cams? I want to make sure I have everything before I tackle this job.

Cam Timing - KRAG50 - 01-12-2013

Here you go.

One other note, It did make a difference to the timing after I add oil to my pressurization tube/ adaptor.

Cam Timing - flash - 01-12-2013

scary isn't it?

Cam Timing - kwikt - 01-12-2013

Thanks Krag50, that'll keep me busy for a while. How long is the bent extension? I can't make out the length.

Cam Timing - Lear35A - 01-13-2013

[quote name='flash' timestamp='1358017704' post='137350']scary isn't it?[/quote]

Nah, with a little practice one can do it in one's sleep.

Cam Timing - flash - 01-13-2013

what i meant was that it is scary that the way everybody has been doing, which is how the manual says to do it, may not give them the result they think it is.

Cam Timing - KRAG50 - 01-13-2013

Kwikt

About 105 mm overall from the major diameter of the Gage, 85 mm to the center of the bend, 20 mm down to the end, 45 degree bend.

Cam Timing - Contadino - 03-11-2013

I'm having new sprockets welded on by the guy that does it for Webcams. I asked how he aligns the new sprocket teeth to the cam and he said it could end up 1 or 2 degrees off. After thinking about this I guess it wouldn't matter as long as they are both off the same amount. But if one is + 2 degrees and one is - 2 degrees I think that would affect performance. Since the car is only used for DEs I don't want to lose any power. There is no way to adjust one cam to the other right? Other that moving it one whole tooth??? Maybe they will come back perfect and I am just worrying too much.

In case you are wondering why I am using Webcam, my local Porsche tuner recommended them and since they are the ones who will bail me out if I run into a snag, I decided to heed their advice.