JakeS2

So, we are at stage to get cams in order. Everything else went fine, but 5-8 exhaust cam does not have one sharp marker, but something that has two corners, pfft.

Can someone say if the timing is off or not.

Apprecite the help, I was supposed to get adjudtment cauges but no luck so far

FredR

Model, year of manufacture, cam number and some photos of what you are seeing might help the diagnosis a little

Rgds

Fred

JakeS2

for some reason dem pics did not get attached:

JakeS2

take two:

cams are from '86 and modded to run on s4 head

JakeS2

this tapatalk client drives me nuts!

FredR

Kind of figured that just may be the case given your description and the fact that I have a set of those cams [currently unmodified].

Not sure your photo will help anyone who may be able to answer your query but I look forward to reading about such.

The manual advises use of tool 9226 to reference the cams correctly. To time them initially the engine should be at exactly 45 degrees on No1 cylinder with the noses [index marks] pointing upwards. The distance between the noses should measure 113mm. Presumably you are already at this position?

Timing on No 1 cylinder for this cam set is correct when the lift at 20 degrees after TDC is 1.6mm on No1 cylinder inlet and 2.0 mm on No6 cylinder inlet. The specific details for the timing procedure are in the wsm- you need to follow this carefully.

It would be interesting to know if these cams can be timed with the 32VR tool.

Rgds

Fred

JakeS2

on the last pic i counted seven links from the chain.. reason i am asking these is that my lst xyz bolt snapped so I cannot risk opening them many times anymore :/

yes, i have counted the 113mm from the markers.

Rob Edwards

S4 cams have a pyramidal alignment nub, S3 have the little rectangular nub

(EDIT- Wrong, Edwards, shoulda actually looked at a set of S3 cams.... I have one set here where the 1-4 intake & exhaust, and the 5-8 intake have pyramidal humps, while the 5-8 exhaust has a rectangular hump. For whatever that's worth...

I _think_ the measurement should be from the peak of the pyramid to the farther edge of the rectangle, but in any case you want the nubs aligned with 7 cam chain plates between the teeth (plate #1 being the one that 'covers' the tooth that's perpendicular to the chain, and plate #7 covering the tooth on the other cam)

From the '85 Service Info Tech booklet: (42 links is confusing nomenclature- there are 42 pins, linked by 21 plates...)



Here's a pic of a pair of Colin's cams, 1 must have been modeled off an S4 cam and one modeled off an S3 cam (?). I zeroed the ruler on the middle of the rectangular plate to get 110 mm- If I'd measured from the outer edge it would have been 113, which I'm 99% sure is the same spec for both S3 and S4 cams.

GregBBRD

The workshop manual clearly spells out the opening and closing events of both the intake and exhaust cams.

If there is doubt, put a degree wheel on the end of the crank, a dial indicator on the lifters, and degree in the cams....it's a pretty basic engine assembly requirement.

JakeS2

rotated cams full circle and now i have the seven links as spec'd.

JakeS2

and the pic

john gill

Listen to what GB says , the only way to measure where the cams are is to use the dial measurement as the manual. Once this base line is created , Porkens tool is then very useful for future adjustment.
If you do not base line the cams you are then only guessing, the original position, and they can vary a lot .

JakeS2

tnx guys, i am for sure going to get dem dials

GeorgeM

This may help. I must have watched it 10 times while retiming the cams in my GT.

Vilhuer

Problem is that cam itself or more specifically how Porsche marked correct position. Its so badly done on some S3 cams that its difficult to know which of the two possible positions to use. Only sure way seems to be to use dial indicator. Preferably with angled tip factory special tool. I've been saying this to Jarko several times already.