how-to on cam timing...

Not an expert, more of a novice. But wanted to contribute, and I didn't see any detailed threads on here as to how-to do cam timing... I read as many as I could, and tried to compile them, with pics...

If anyone notices errors, please share! I hope this helps folks down the road:

Needed:

Dial indicator ($100 for a good one...)
Cam timing wheel, $25, summit
10 magnets, $10, Home depot
2 large cinder blocks... free
Couple zip ties
Straight metal rod
feeler gauges
One oil filter remover, large, Pep Boys, $10
3 coffees, 2 heaters to heat the garage in Wisconsin
An inquisitive wife
A family member who is a mechanic in case you screw up...

Ok

This is the method where you use the dial indicator... The WSM talks about a different method, where the cam clearance is set to 0.5... This method with the dial indicator was mentioned by several pro's on this board... so it must work .

STEP 1 measure the valve clearance for the cylinder 1 and cylinder 7. Should be 0.2-0.25 intake, 0.35-0.4 exhaust

STEP 2 Look at the flywheel, set it at TDC for cylinders 1-6 (Marked as PM 1-6). Use your handy dandy rubber strap pipe wrench - works great!

STEP 3 goto starbucks... its still cold outside...

STEP 4 get your magnets and place them on the crank pulley... Take the aluminum degree wheel, and attach using magents on the other side... The magnets hold it on VERY firmly... MArk the wheel with the correct timing for intake and exhaust opening/closing... Intake 13 degrees, 126 degrees for exhaust opens (erroneously labelled on my wheel as exhuast closes...was corrected!)

STEP 5, use a wire attached to a nut, to mark off zero degrees...
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

I started with the passenger side, cylinder #1...

STEP 6 Dial indicator is sitting on two cinder blocks, with a metal sheet on top for the magnet to attach to... With the block being aluminum, there wasn't much to stick to...

STEP 7 The dial indicator has a straight tig welding rod attached to it (any metal rod will do), held on with 2 zip ties..

STEP 8 Spin the crankshaft you are going to measure until it looks like its just about ready to touch the valve shim...

STEP 9 Place the dial indicator on the valve seat. IT MUST BE PARRALEL TO VALVE TRAVEL, it its off, it effects the readings...

STEP 10 ... SLOWLY SPIN THE CRANK, one tiny grunt at a time until the dial indicator JUST starts to move...
Image Unavailable, Please Login

 

Now here comes the key part... the WSM does the camshaft measurements at a clearance of 0.5... WHICH IS NOT what your car is set too, assuming its set correctly.

Now, if you happen to have shims available where you can set the clearance to 0.5 temporarily, you are really lucky (or, more likley a pro!).

Option two is to use the dial indicator to compensate for the difference by allowing it to "over rotate."

For example, your intake lash is set at 0.25 mm. You need 0.5mm... So, when you are spinning the crank, and the valve shim JUST starts to move... you need to add another 0.25mm or travel before you call that the "opening" and read it on the wheel...

Well, heres a fun fact! Dial indicators are read in thousands of an inch, NOT mm... At least not the ones I have...

So, for a properly set intake you have a lash of 0.25mm, but need 0.5, or an additional 0.25. The good news is, thats about 10/1000's!

On a properly set exhaust you should have a lash of 0.35-0.4, and need 0.5 or an additional 0.1 to 0.15 mm. The good news is, thats about an additional 5/1000's...

STEP 11 So, to recap, rotate the crank until the intake shim just starts to move, and go an additional 9-10 thousands...

STEP 12 For the exhaust, do the same, but go an additional 5/1000's...

Make sense?

Now, some folks will want to be even more accurate... Honestly, I don't think its possible...

Keep in mind you will NEVER BE absolute TDC. You will NEVER be able to exactly determine when the valve opens at the dial indicator has an error rate of 2-3 thousands, etc... But this should get you to within a degree or two...

More PICS to follow...

 

Ok, intake valve, cylinder #1...

Overstate the crank by 9/1000's past opening... and its SPOT ON... woo hoo!

Step 13... Thank God that worked...
Image Unavailable, Please Login
Image Unavailable, Please Login

 

STEP 14, same thing... Exhaust valve...

Over rotate by 5/1000's and read the wheel...

WOO HOO spot on... so far, so good...

STEP 15, go check daughters math home work. Help wife take down the christmas tree...
Image Unavailable, Please Login
Image Unavailable, Please Login

 

thank you bo for the info what is correct

here again my question from an other thread:

did someone ever have been on a dyno with exact timings and with timings only at the original marks? and what difference had been?

and have a coffee or a beer


you also may check then the closings of the valves. then you see how good you worked

 

STEP 16, repeat on the other side..., and wouldn't you know it... ITS OFF just the slightest amount...

Intake, when checked over rotated 9/1000 is 2 dgrees off...

Exhaust is 4-5 degree's off...

Step 17... doubt that you did it right, and check again... recheck TDC...

STEP 18 ... argh, still off... Check one more time... same result...

Guess I will be adjusting some cam timing and rotating the cams a slight amount... (anyone have a tutorial on that?)
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Intake reading about 2.5 degrees off...
Image Unavailable, Please Login

 

learning by doing and much practice

 

Well, I hope that helps the next person down the line. I really appreciate all the threads about doing your own major, and replacing water pumps, etc.

Lessons learned:

1) The first folks that did this back in 2006 when ferrarichat started were barve son of a guns - pioneers! (Jeff/Carguy comes to mind).
2) The input form the pro's was awesome (Brian, Steve, Verrell, Dave, etc). Thanks guys!!!
3) Anyone attempting to do a major without owning a lift/ and arsenal of tools, and access to ferrarichat is really beyond brave...

Questions for the pro's...

1) How close can you measure the timing? To within a degree or two?
2) Given variation of measurement, at what point do you adjust the cams? 2 degrees off? 3 degrees off? 4?
3) Can someone verify that the flywheel TDC marks are spot on (I would assume they have to be... but I hate to assume)

Happy Holidays guys!

 

Honestly, I don't know if there is much value to do this on a car that runs great and passes emissions... But I wanted to do it right, so I checked...

The pics above are with the old belts. Plan to do this again once the water pump and new belts are on... Perhaps that one exhaust valve will magically correct itself . If I have to move it a couple degrees I can...

The odd thing is, when measuring the cams clearance, the feeler you slide in come in thousandths...

And there is some variation in terms of how folks read what the largest feeler is that fits... The difference between and 0.36 is tiny, as is 0.201 and 0.245 or what ever it is. Well, the difference in degrees on the fly wheel is probably 2+ degrees from one feeler to another...

I really question whether there really is enough precision in the measuring process to get to within 1 degree... I think Ferrari specs a measurement plus/ minus 1 degree....

I wonder if getting a cylinder stop is more accurate, I will probably do that too on the next go round... Reading off the flywheel marks likely easily adds a couple degrees of error...

 

Bo,

This goes back to a post you made earlier about buying the special tool to depress the valve bucket to slide shims in and out. You see you don't need that tool at all. I always measure and remove the shafts and I always loosen the cam cog bolts at various times during the major. Removing a shaft makes for easy shim change. If a shim wasn't flipped over the size is written on the other side. Do some math with your measure and you can buy the right shim. For where you are now you need a loose cambolt so you can slide the lock pin out of the cog and advance or retard the 2 degree off shaft. You can see the holes in the shaft overlap the holes in the cog. Moving one indexing position is very small and could be that 2 degrees. Play with it and you will see.

 

Thanks, appreciate it...

Doing this the first time takes forever... The second time takes 5 minutes...

I truly applaud folks who have done this before on their own... I wouldn't even attempt it without the help of folks on here...

More pics to come...

 

Bo! well done buddy; kudo's to you

as a comparison on the 2.5 deg off, was the lash on that particular valve slightly more than the 0,25mm upper limit? as the late open could show a 2.5deg early close if you rotate it round more (the 244deg duration) if so, it just means the shim has just a little too much wear and the timing is set correct. No reason to index the timing gear if that is the case.

Pete K
Perth, WA

 

Great documentation!

Many thanks - I'll be reading it several more times for sure....

Was the small strap wrench adequate? Did you wish for more?

Once again - great job - I'll be following you, but a few weeks behind. Your work wiil be greatly appreciated!

rgds,
Vincenzo

 

Strap wrench worked fine... A torque bar with a huge nut would have been nice, but couldn't find one that big in my garage...

The magnets I thought were a neat trick...

Also, I couldn't really find a rationale for checking when the valves close... If opening timing is correct, and closing is off... Then what? Usually that's camshaft wear... These cars don't have that at 15,000 miles... And if it did? You can only set opening or closing degree spot on... Can't do both.

 

Good point, plan to recheck...

Motor runs great... I almost hate to mess with it...

 

Oh, and even though I did the best I could to describe what I did, and collate prior threads on this, I should add the disclaimer that I am not a Ferrari mechanic, so if I outlined anything incorrectly I apologize.... As the lawyers on this board might say, follow the steps above at your own risk. Don't want anyone crunching their valves by doing it wrong... If your unsure, goto an expert .

Hopefully one of the pros can chime in and verify this is correct based on prior threads. Seemed to work for me... Nice method to at least verify the valves are really close...

 

to go excatly to 1° is nearly impossible, plus minus 2 degrees are ok

the PM 1-6 and PM 7-12 are correct. the other I never checked 100 %. but because the distance between the flywheel marks and the pin is not so little there are of course measuring or reading errors

 

OK... made my own shim removal tools for $1.99

Worked great!!!

http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/509550-make-your-own-cam-shim-removal-tools-%241-99-a.html#post144414528

 

good idea
and cheaper you will never get it

 

keep in mind that your tools are made of a relatively hard material compared to the valve train.

scratching cams is more of a possability when compared to a soft brass...

likely not an issue (the cam is also hardened) but perhaps some extra care may be in order.

rgds,
Vincenzo
Image Unavailable, Please Login

 

Your dial indicator is set at a very incorrect angle so you will get a very incorrect idea of the amount of valve movement.


I only looked at the pictures. I have no idea if there are other mistakes in your write up but without reading it I suggest not reinventing the wheel. Just follow the book. If done the way described it minimizes screw ups.

 

I thought about that... But according to the description of the ferrari tool it is made from "hardened vanadium steel and chromed and then colored black... So, it seems the ferrari tool is of a harder material than untreated steel I am using?

 

Ok, you just made my heart skip a couple beats...

I did catch some errors:

The degree wheel does have a marking error on it that was mentioned in the text: I said exhaust closes at 54 degrees, but meant to say exhaust opens (i.e. I wrote exhaust closes twice by error...).

Is that what you meant? If not, please let me know. 3 of the 4 markings were pretty accurate based on the thread below:

Otherwise, all the markings were as described by Steve Magnusson and corrected in the WSM in this thread post #17:

http://www.ferrarichat.com/forum/boxers-tr-m/355626-cam-timing-testarossa.html

I think you posted/added to this thread...

The dial indicator should be parallel to valve travel, perhaps that was what you meant? Plan to finesse further during the real valve check when the new belts are put on. Round one was just practice... Will post more pics when that happens in a week or so.

As always, help appreciated.