Hello all
I am going to do the timing belt early in the new year and want to
introduce the Porken cam timing adjustment capability. Am buying the
new sprockets to fit the new round toothed cam belt (including S4
cam sprockets).

Question, or two questions:
1 has anyone got an old 16 valve Porken cam timing tool that
they no longer want and would sell?
2 Assuming no answer on the above, the 32 valve Porken tool is
available. How hard would it be to recalibrate this to use on a 16 valve motor?

Thanks in advance.
Andrew K
81 manual, Brisbane Australia

 

I have a 16V tool that I could lend you. I am in Honolulu so shipping back and forth might not be as bad.

 

I think there is a thread talking about some of this, I've been thinking about doing the same, and there is an adapter part you need, but I forget exactly what it is.

Any special reason you are doing it this way as opposed to using, I think, the Mercedes cam keys with offsets?

 

I think it's time for Ken to make another batch

https://rennlist.com/forums/928-foru...sion-kits.html
https://rennlist.com/forums/928-foru...installed.html


Ken's thread on the Mercedes keys:

https://rennlist.com/forums/928-foru...ce-retard.html


Another idea would be convincing Lindsey Racing to make a set of adjustable cam gears for the 16V (I've e-mailed Mike and Dave Lindsey)
http://www.lindseyracing.com/LR/Parts/944CAMGEAR.html

EDIT - I just received a response from David Lindsey - I'm sending him a set of 16V cam gears for them to look over and estimate cost for a 928 version. Looking at a possible group buy for 10 sets or more.

-

 

Good summary post, thanks!

 

For simple adjustments, Carl makes offset cam keys for 80-84.

http://www.928motorsports.com/parts/...aft_keyset.php

 

To all above:
Thanks for responses.
• Karl, JP in Melb has one which I can borrow (if I'm super carefull!) but I am
aiming to get one in Brisbane
• The Porken system is good and simple although if it wasn't around I'd use
the Merc offset keys
• Cracklin Rosie: thanks for info on the Lindsey Racing 944 product- interesting
to see what they come up with
Ken: can your 32 valve tool be adjusted to work on a 16 valve?
Andrew K 81 man, Brisbane

 

What has me scratching my head is that any "interesting" cam will be custom ground, why not order it how you want it? If using a stock cam, why the fuss?

 

Because changing the offset of the keyway to the profile of the tooth is not possible.

So you need the adjustability to be able to set the cams where you want/need them.

 

The Merc keys only work on '78-'79 cams which use half-moon/Woodruff keys. (Carl at 928 Motorsports makes some that fit '80-'84, which use parallel keys.)

No. The 16V tool goes through the cam gear and up to the marks on the head to show the timing. The 32V tool goes over the top of the cam gear to a different spot.

 

Hello all
I am about to start on this. As a matter of interest, did you get a reply from David Lindsey re a group buy price?

Rgds
Andrew K
81 manual
Brisbane, Australia

Another idea would be convincing Lindsey Racing to make a set of adjustable cam gears for the 16V (I've e-mailed Mike and Dave Lindsey)
http://www.lindseyracing.com/LR/Parts/944CAMGEAR.html

EDIT - I just received a response from David Lindsey - I'm sending him a set of 16V cam gears for them to look over and estimate cost for a 928 version. Looking at a possible group buy for 10 sets or more.

-[/QUOTE]

 

Andrew,
Let me know what your timing is.....not quite ready myself, but nearly all the parts assembled.

jp 83 Euro S AT 53k

 

My 84 Euro has 32V cam gears installed for use with the 16V adjustment kit.

Is that not an option, Andrew?

 

John
I will probably start in three to four wks so will get it done and then send you an SOS for the Porken 16 valve tool. How about you?

Landseer, I've got the 32 valve sprockets. The only problem I've got is that John has the only Porken 16 valve tool in Australia and he is in Melbourne. It would be easier to have one in Brisbane too. So if any US-based 928-ers have moved up to a 32 valve and no longer need their Porken 16 valve tool, there is a buyer in Brisbane Australia!

I thought the adjustable cam gears mentioned on this thread looked like a pretty elegant solution.

Rgds
Andrew

 

and what is the goal for trying to better optimise the stock 16 valve cams? the problem is that the exhaust lobes are tied to the intake lobes, so advance the intake and you advance the exhaust, which might be opposite of what you want. same thing is true on the 32 valvers, but i guess you could advance or retard one cam from the other by 15 degrees if you wanted too and then adjust both from there.

I went through this with the tool, it is convenient, but i kind of like the old fashion way. we did an adjustment which retarded the cams 8 degrees, to better match the GT (like) cams i had on the original Holbert engine. i ended up gaining 5 hp and losing 20ftlbs of torque, which was exactly what i wanted to do for being optimized for racing. (more hp-seconds! )

i woud be curiious to see the effects on the 2 valvers with a change from stock timing, euro or US.

The tool is pretty nice to be able to adjust or set cam timing without having to remove the cam covers on the 32valver.