Crane P314 specifications..

[Jozef Schumann]

Hello gentlemen..
Perhaps one of you may have the timing specification and lift duration values for Crane Cam Part # 520P000006..The grind # on the box reads: 520-P-314-P288-99R..Serial # 520-21-89

I purchased these many years ago after a technical brain session with the now deceased (I was told) , yet extremely knowledgable Harold Broughton (of Ritchie Ginther fame).. He originally assembled the 2.7 to competition specification in a '72 911 which I had purchased..At that time the motor utilized P-306 camshafts, 46 IDA 3C weber carburetors, twin plug heads 11.3-1 compression with dual electromotive HPV coil packs crank triggered.. and when I had querried him as to further modifications, he was rather hush hush about certain components i.e, camshafts, I/E port sizes etc, commenting on "how people just don't know what they're talking about" This was in reference to port sizing and carburation..I was stunned to measure 41mm Inlet ports in conjunction with 39mm exhaust when I dissassembled the motor..I CAN vouch however for the fact that the motor was spellbinding from a performance standpoint.. EASILY outpacing my 2.7 MFI RS Carrera in EVERY conceivable way, indeed even outrunning my modified 3.0 '76 930 at will.. But..I must digress

That was back in 1989..when he finally relented to my inquiry..he simply stated that he'll contact me when he receives the various components I'd require..Approx. 6 months later I was called to come collect my parts..I collected these cams..and a box of valve springs/retainers which I subsequently learned came from Carl at Vasek...With these cams..Harold quipped "you just wont come across a stronger 2.7...anywhere"..I've contacted Crane about the cam profile values to no avail..When the representitive there heard the boxes had a Serial # along with the series of numbers I've mentioned above, he remarked the possibility of special purpose proprietary profiles and couldn't elaborate any further..If anyone can provide any beneficial information, I'd be sincerely grateful..

[camgrinder]

Hi Jozef,
That was a custom grind. The intake specs are similar to my DC80 intake lobe, the exhaust specs are similar to my DC60 exhaust lobe , set to a 99 degree lobe separation. I would time them to 6.2-6.4mm using the standard Porsche method.
I am not surprised they ran well.

[Jozef Schumann]

Mr Dougherty,
I very much appreciate your response..I briefly visited your site to peruse lift/duration values based on the information you've provided..May I ask to what degree of certainty you are of the specifications regarding my particular camshafts since I was ready to ship them to Dema Elgin for specification verification as he's been a most delightful resource for camshaft related issues in the past. Again, your reply is highly anticipated as well as valued...

Best Regards

[camgrinder]

Hi Jozef,
I have checked a number of the Crane 911 cams over the years. The part numbering system you refered to describes the intake first, (P 314) the exhaust second (P 288) and the lobe separation angle last (99R). The P314 is usually mated to a P296 exhaust, so the set you have were custom made with the P288 exhaust profile.
Harold Broughton might have called Crane Cams wanting something slightly hotter than the P306, but not as wild as the normal P314, and your set was made to be an in between profile. Based on your port sizes I think it was an excellent idea.

It might be wise to have them "Cam doctored" to verify the numbers match the cams and how well they were manufactured.

[Jozef Schumann]

John..
Wonderful information! Makes complete sense this numbering system which you have described..I look forward to patronizing your business on other 911 projects in the not too distant future.

Sincerely with gratitude

[camgrinder]

Good luck with your project. If you ever dyno the engine I would love to see a graph or printout.

[Henry Schmidt]

I agree with John on the numbering but what John isn't telling you is that the Crane cams were susceptible to failure in Porsche engine. Lobes went flat. This is so common that Webcam will not repair or regrind Crane cams for Porsches.

If this engine belonged to my customer I would not install Crane cams.

[camgrinder]

Henry is right. I have also seen some worn out used cams.
I have reground the Crane cams with geat results, but I nitride (heat treat) them after grinding.

[Jozef Schumann]

John...Henry...
I see where this type of catastrophic failure would indeed put a most unpleasant damper on ones day upon discovery..I'm under the assumption that perhaps the surface hardness of the failed camshafts would be in question..What value +/- on the 'C' scale should I find if you could be so kind John/Henry as I cannot see metallurgic incompatibility beyond material hardness of the camshaft lobes as being the offending culprit... Have you or anyone else attempted to isolate the cause as I found my 306's to be pristine after many, many cycles of severe duty service..John, I have heeded your recommendation and contacted my old friend Doug Engle which has graciously offered his "cam doctor" for me to plot the symmetry... or lack of... lobe values from cam to cam.

Again, my sincere thanks for the time required of you both to respond.

[camgrinder]

You should have at least 55 or 56 C scale. After nitriding they are about 58.
I have seen some look great after years of abuse, and some fail quickly. Ask Doug Engle about nitriding them. I use a short cycle of about 12 hours.