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Camshaft Specs
Hi Guys, does anyone have the specs on the Porsche cams with the following part numbers:
993 105 246 70 993 105 247 70 I am looking for the normal information including the settings were they should be dialed in. Thanks, Richard. |
Those numbers are not in PET and I'd guess the last two numbers got inverted. :)
The 07 cam are the standard 993 hydraulic ones. One needs either the factory tools and fixtures or use a solid rocker and manual adjuster on #1 & #4 to set timing. You can use the 964 spec if you use the latter method. |
You are right Steve - I re-checked the part numbers and I had mixed up the last two digits. Correct numbers are:
993 105 246 07 993 105 247 07 I should have also explained, I am planning on installing these in a 930 engine with solid rockers. Thanks, Richard |
Also - as I haven't been able to find any specs, I measured the lobe profile in the engine with a degree wheel. Listed are the results:
Total lift (zero clearance) = Intake 0.485" / Exhaust 0.446" Duration @ 0.05" = Intake 242^ / Exhaust 225^ Lobe Centerline = Intake 114^ / Exhaust 110^ Intake valve timing (zero lash) @ 0.05" = Opens 7^ BTDC / Closes 55^ ABDC Exhaust valve timing (zero lash) @ 0.05" = Opens 42^ BBDC / Closes 3^ ATDC To get the "Intake Valve Stroke in Overlapping TDC with 0.1.. clearance" I then checked the WebCam and Dougherty sites for cams cams with similar specs and found the following: 964 = 1.26mm (as Steve suggested) WebCam 20/21 = 2.1mm Dougherty DC19 = 1.9mm I could not find the actual lift / duration / centerline information for the 964 cams, so I do not have a good comparison to know if they should be set at the lower end (1.26mm) or if I should dial them in at the higher end (~2 mm)? Richard |
I have the 993 247-07 listed as a 1995 993 hyd rocker cam.
Your specs look closer to the 3.8 super cup cam, number 993 247-70 I have ground a few 993 cams to the super cup profile. |
I just checked the actual part number stamped into the front of the cams and they definitely end in "70" and not "07". This answers a lot of my questions as I really wanted to know where to dial these in. I checked your website and the recommendation is 2.0mm.
I need to get a set of rocker arms rebuilt - I will contact you separately to arrange. Thanks, Richard. |
Quote:
I believe the factory setting is 1.5mm for these cams. This puts them in the engine on a 114 intake centerline, or 2 degrees retarded from straight up. The 2.0mm setting puts the camshaft straight up on a 112 intake centerline. |
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