Degreeing cams

Got ya covered !

Image Unavailable, Please Login

 

I definitely recommend replacing the stock cam pulleys with a nice updated version. The oem dowel type pulleys were difficult for me to use. I purchased a very nice pulley set from Dino parts Germany. I also purchased their ignition system. The ignition system purchase was a huge upgrade to drivability and performance.

 

Yes, I got mine from Superperformance. Very well made and drilled all round for dowels, just like the cams (Catcams ) they also supplied, and threaded dowels.

 

Well all the cylinder head repairs are complete on my '78 GTS, and the block/gearbox are all assembled, with a new bearings and a set of hi-comp pistons. I've checked the TDC marks for both banks, and they are marked exactly correct. So now I'm ready to refit the heads and time the cams.

On all I've read here it seems the alignment marks on the cams are used to initially set them up in a ball park position, and then the dial gauge and degree wheel used to get the adjustment exactly correct.

My problem is the new set of Catcam hi-lift cams do not have any alignment marks. They do have wrenching flats. I could check the front lobe max lift position with a dial gauge, and mark this on the cams.

I have 40 years experience setting up Lotus -Ford Twincams, where to get into the ball-park the crank is set at TDC, and the cams are fitted with the inlet & exhaust lobes on No. 1 cylinder pointing out, and then fine adjusted with the dial gauge and degree wheel.

Because the 308 has the cams sets are 90 degs apart, I was thinking of fitting one head first and getting this adjusted. Then I could set the second bank at TDC and fit the second head/cams and then get these right.

What do people think ?

 

You don't have your old cams to look at so you could put approximate assembly marks on your new cams in about the same places?

 

Like Steve says, look at the old cams and mark the new ones in approximate positions... good enough to start with.

 

That's good thinking !

Am I correct in thinking ALL 4 cam marks should be lined up when No. 1 cylinder is on TDC compression, not just the rear bank ?

 

All four.

 

Image Unavailable, Please Login

The translation is starting to make sense now !

 

After some more searching , I found this, co-incidently, fromCatcams, the company which manufactured my new cams. They don't mark the cams, but on enquiring, they supplied data sheets for the cams which include figures for lifts at TDC.

Problem solved !

http://www.catcams.co.uk/acatalog/Cam_Timing.html

 

Getting ready to set the cam timing. I had cut out the centre of a degree wheel to stick it on the front face of the crankshaft damper when I had a better idea. As the damper is a nice cylinder, I thought why not mark it off in degrees ? One dressmaker's measuring tape later, when fitting it was 445mm, but with the tiger glue it came out as exactly 450mm ! One degree = 0.8mm
Image Unavailable, Please Login

 

Do it right.... printable timing tape. Just need to know the diameter. https://www.blocklayer.com/timing-tape.aspx

 

The math would drive me nuts....

 

That's a good one alright, never knew about it before !

 

I am now ready to start assembling the heads and cams on my 1978 308. I plan to fit one head first, and degree the cams by setting the specified lifts @ TDC. I plan to do this one side first, fit and set the belt on that side, and then fit the other head and cams.

Have people here used this method ? Does anyone see any problems with this method ?

 

FWIW I’ve always installed both heads, then the cams on assy marks. Set cam degree from there.

 

My new cams are from Catcams, and do not have assembly marks.

However I have found their degreeing instructions, which involve setting the valve lifts at TDC with the cam pulleys loose, and then fitting the locating dowels. The pulley flanges have dowel drillings the full circumference of the pulley flanges.

 

Again you can probably Mark the cams by comparing with the old ones