Bigfoot928

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Tom. M

Something from Vol 1 Issue 2 of the "928 Forum" we put together has specs on the 85/86 32v and S4 cams ... Article on Phil Threshie (928 Developments) and his work back in the day.. I'm sure Rob has these issues hosted somewhere .

Darien

Ask Louie Ott

jetson8859

Here's the information on Colin's cams. I will be installing them in my 93 GTS in next month or so

​Stage 2 w/ Tri-Flow
Intake lift .437" duration @.050" 230
Exhaust lift .437" duration @.050" 228
LSA 114. ​​​​​​

SwayBar

They are nice beefy cams for the street.

Do you plan on doing before-and-after dyno runs to track the changes?

What do you have for an exhaust?

Rob Edwards

Sterling, here are some factory cam specs I measured back in 2015. The bottom row are the cams currently in the new Zombie motor (which is a priority to get running this year). Mark had a bunch of sets of race cams but they're all in this ballpark lift and duration-wise. Note the difference between the quoted factory GTS specs and what I actually measured. I think I'm right.....

jetson8859

unfortunately no before dyno, the original cams were heavily pitted and had low compression in two cylinders (80 nd 100). Will definitely be doing dyno for tuning as will also be installing new injectors and PEMs for sharktuning.

Strosek Ultra

Porsche 928S4 32V stock cams vs. hot street cams vs. full race cams. According to my measuring and hand made diagrams.
Åke

Strosek Ultra

I do not know why one cam diagram became black. Here it is again.
Åke

Strosek Ultra

It is a great advantage to have adjustable camshafts. This is my solution.
Åke

Kevin in Atlanta

Back in the day I was able dial in my 1978 Honda 750's cam shafts using adjustable cam sprockets after determining TDC using a dial indicator and degree wheel on the crankshaft. What a difference that made.

But, I digress. My stroker will have the B1 cams from WebCam, Their specifics are detailed in another thread.

SwayBar

Did you have to rebuild the engine for the low compression?

SwayBar

Ake, did you ever install and get this huge cam up and running?
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And being so big, wouldn't it require ITB's?

Louie928

I'd suggest one of Colin's offerings depending on the ultimate use you intend for the car. You'll have a bucket of low/midrange torque so work on enhancing to top end. Your ITBs will help take care of that. The Ford 4.6 DOHC valve springs will work fine. They are of the "beehive" design. Tuomo has a lot of data on those.

Bigfoot928

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