Cam Timing Help

[Naloos13]

Hi All - I've got a '77 2.7L with a set of Crane 296 Cams. I was able to get the lift specs for jleutjen's chart, however am completely lost on setting these up. I've got 3.72mm of lift on cylinder 1 at crossover, but with all my searching and wayne's book I'm lost as to where to go from here.

thanks!

[A horse with no name]

This may be of help??

https://youtu.be/RPGGtiAeGAs

[Naloos13]

Thanks I watched that last night as well. My assumption is that the cylinder 1 movement referenced at 2:50 in the video is a number that should be associated with the crane P296 cams I have. So i guess is the 3.72mm correct for this cam or any suggestions on moving forward without this?

[Naloos13]

I was able to get the following info from Crane re: the P296 cam:

Intake opens at 31degrees before TDC and closes at 51 BDC. Intake centerline is 100 degrees after TDC.

Let the confusion continue...

[Flat6pac]

Sounds like degree wheel time now

[Naloos13]

So I've determined that these webcam grind shaft are virtually idential, so I'm going w/ 5.2mm w/ .10mm valve lash. Am i missing anything? Camgrinder?

Web Cam Inc. - Performance and Racing Camshafts / Porsche 911 SOHC 12v Timing Card

thanks!

[gereed75]

The only number you need is the "lift at TDC with 1.0 mm lash" number.

The video is helpful and makes complete sense if you understand the concepts, but I find it more logical to set the crank at Z1 and then rotate the cam to get the desired lift number. Same result, slightly different thought process.

The cam nut torque now mentioned in Waynes book is 100 ft lbs, not the 100 NM used in the video. It is a bit hard to pull this amount of torque and requires some physical strength. Two guys can do it, one holding the cam, one torqueing but that can be difficult to coordinate also. Always recheck the lift value after torqueing because it can change.

Read the book, think about it until you understand the concept and what the hardware does and it will become very clear to you. I find it VERY beneficial to set up two gauges (one on cylinder #1 and one on #4). This allows you to quickly verify each side successively and takes all uncertainty out of the game.

Short of using a digital angle indicator, I find the best way to check the Z1 mark at the pulley is to put an exacto blade in the case parting line, set a cell phone above the exacto blade with the flashlight shining down on the blade. Move the flashlight until the shadow cast by the blade is perfectly vertical (if you have a pulley with a hole in it the shadow will bisect the hole when it is vertical and the pulley is at Z1). Sighting down the shadow cast by the blade onto the pulley can be used to take all of the parrellax out of the sight line. Try it, works great.

Good luck, not that hard once you understand it.

[A horse with no name]

Good info!..I somehow thought think that you may have an Aztec heritage 😇 as only they were brilliant enough to be able to work out degrees by means of light shining through a hole ay😎

[Naloos13]

Thanks - I understand the mechanics and concept if i have the lift @ TDC w/ .1mm lash. My main issue is that I don't have that information from Crane. I found a Webcam grind that is almost identical (link above) and set it up last night w/ those specs at 5.2mm, but not sure if there is another verification i can do to ensure this is the correct setup?

[A horse with no name]

I understand what you mean - Confirmation. Being that Crane doesn't seem to be able to do this maybe you should trying phoning one of the many racing rebuilders that are on Pelican such as: John Walker in Seattle, Steve Weiner at Rennsport in Or., or say someone like Patrick Motor Sports in Az. KTL is often on BBS - I would also try sending a private message to him.

I do think that you have it, but having a 'Pro' confirm it, will certainly let you get a good nights sleep ay.😊