Valve Gearing (timing)

On EACH camshaft there is only one mark and this must align up exactly with the marks on the camshaft end caps when the engine is at TDC (firing). A small dab of red paint helps to highlight them. Although i have found the plate near the crankshaft to be accurate it is worth checking the engine is at TDC via the spark plug hole and a dial gauge.
Tony

 

Here are the alignment marks...

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Hello, I am running into the exact same issue as Erbe did ... my camshafts have 1 and 2 dots, not a single mark as described in the manual. Can anyone assist with the proper positioning of these apparently aftermarket cams? I believe the "1 dot" mark is used as the mark for the intake cam, and the "2 dots" mark is used for the exhaust cam, but I would rather be certain than speculate! Thanks in advance on any knowledge of these cams.

 

Photo?

There shouldnt be any "dots" see post 3 for the slot mark on the cam and corresponding slot on the cam end cap, when aligned all four cams marks should be aligned exactly.

If you are unsure that these marks are accurate then you will need to degree time the cams using a degree wheel.

A search on this forum will help as its a lengthy process that needs accuracy to get right.

Tony

 

Please see photos with dot markings highlighted. The third photo shows the passenger-side cams in approximately (what I believe to be) the correct positions, with "1-dot" intake marking aligned and "2-dot" exhaust marking aligned.

I found the same or similar camshafts at Dino Parts ... you can see the dot markings in their photos as well:
https://www.dinoparts.com/de/teile-zubehoer/fiat/dino-coupe-spider-2400/motor/zylinderkopf/nockenwellen-mehr/17666/nockenwellen-standard-fiat-dino-2400

My question is: With the intake aligned to 1-dot mark, and the exhaust aligned to 2-dot, do the positions of the cam lobes look correct?
Thank you, John
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Likely made by cam grinder during a repair of the cams. Ferrari did not use dots.

I am certainly not a 246 authority but I do not recognize the hex shapes behind the front cam bearing. Is it possible these are replacements from an aftermarket supplier?

 

Anyhow, you will certainly need a degree wheel and a TDC tool to set the cams correctly and then you will know was the dots refer to. Dots or other marks are always considered guidelines and not "first time" installation setting marks.

Best, Peter

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Your cam bearings look worn / scuffed so you need to check them and cam lobes are in spec before you go any further.

Have these been in this engine before rebuild, is this 246 or Fiat Dino 2.4?

Cams should be marked A Intake & S Exhaust

If so and these are the only marks you have then i would suggest you go with these as the reference marks....FOR NOW.

With crank pulley set to 3-4 on the timing mark, No 3 cylinder should be in the firing phase. I would verify all timing events are as spec using a degree wheel after initial set up.

The 246 manual can be downloaded here, it gives useful data on spec's.

http://www.dinospider.com/manuals.html

tony

 

Peter, can you recall if the timing reference marks were accurate? I did mine many years ago and they were spot on.

 

2009 visual on accuracy for the set up on my car..
I see some variation on mark alignment but cant recall what this was in degrees. Kevin

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That looks pretty good for a production street engine.

 

Thank you all for your valuable input. I'll review and make sure I'm clear before proceeding. I've also shot a note out to Dino Parts since they appear to sell these cams with the dots, hoping they may be able to shed light on the markings. For reference, this is for a FIAT Dino 2.4.

 

Every manual I have seen quotes these reference marks once all aligned as the final assembly. Given the width of the thick cam cap mark and camshaft line, a small tolerance is OK.

 

I’ve set timing on my 246, 308 and 512 using degree wheel each time and always found the marks to be rather close. Most likely close enough to just use the marks for upcoming belt change. But I would never install a new set of cams going by marks only.

Best, Peter

 

Totally agree Peter especially aftermarket cams from a unknown source. I have fitted new cams from superformance on 3 dino engines, degree timed them and all were fine and spot on. There will be one that doesnt though!