512 TR cams ?

I have seen cams with about 8° camshaft difference to a degreewheel

 

Are those numbers shown on the cams themselves? One problem is that manufacturers sometime assign a part number to the raw cast/forged part and then a different part number to the machined part (so the part number for the raw cast/forged part are only used internally at the manufacturer). Those part numbers don't seem to match anything in any F SPC available online, and the machined 512TR exhaust cams have other part numbers in the 512TR SPC.

Per romano's point, how much is "way out of line"?

 

Cam marks are only for assembly.... not timing.

Don’t worry about wrong cams. Extremely unlikely they are wrong for your engine.

Get out the degree wheel and set them per factory spec. Ignore the cam markings. All will be fine.

 

If one of my employees ignored cam markings I'd fire him.

About the worst advice I have ever seen given.


They are a reality check. Every single human ever born makes mistakes. If the marks are off by more than a couple of degrees its time to go back and redo the work.

 

https://www.ferrarichat.com/forum/threads/512-tr-cams.635553/

 

And how does that quote change anything?

 

You described it as way out of line. There is no way we can judge what that is. Good close up photos can be a big help. Typically if I see more than 2 mark widths misalignment I question the accuracy of the timing job and want it rechecked.
Its not so much the marks are incorrect, its just that they were haphazardly marked and especially a good 4 valve design a few degrees can make a big difference depending on the combination of inaccurate setting of both cams.

Also since the cams are the same world wide, they are just set differently for different applications even if the marks were perfect they would be in different spots depending on what set of specifications they are set to. And that takes place on the exhaust.

 

Still curious where you got the 140485 and 140486 part numbers from? If they are shown on the cams themselves, you might send pics of them to F part vendors who have the 140098 and 141425 cams in stock for comparison -- just a thought.

 

An even and odd number is typical for a right and left part but in every data base I have access to I cannot find those numbers on anything.

 

Still think those could be internal manufacturing part numbers for the raw, unground state of each cam (but only guessing that) -- now we just need someone with a known set of ground 140098 and 141425 512TR exhaust cams to see what's shown on them. If it does turn out that they are not standard 512TR exhaust cams, then we have something very interesting to investigate (as, like Brian, just don't see those numbers appearing anywhere in the F SPC documentation).

 

I think a more important picture would be of the timing marks at TDC.

But it sure looks like how Ferrari numbers cams. And I cannot think of why at the raw stage they would feel the need to mark them as exhaust cams.

I also do not recall ever seeing one with 2 numbers on it.

If this was my job I'd be asking someone to run the number in the Ferrari parts system computer and see if anything came up. The number range is too early for a TR and I have published 512 part numbers preceding 512 production so its not like early superseded cams.

 

In the 91 512 parts book which preceeded the cars there is not even a 1404xx part number. It skips from 140360 to 140594.

 

karl, you may check please the crankshaft degrees form opening exhaust valve until closing exhaust valve with 0,5 mm gap, then you know if these camshafts are original with open degrees or something special.
what about the inlet cams? what number is on?

 

Many diverse ideas out there on ‘how’ to set cams.

Check out post #25 and ensure that you understand what is happening. I found this nuance to be a big issue.

This info may help:
https://www.ferrarichat.com/forum/threads/83958-major-2016-cam-timing.513496/

 

nothing unusual, on my BB carb it is even a little more

with what valve play you adjust the cams with degree wheel?

you also checked the closing times?

again my post and question from before:
you may check please the crankshaft degrees form opening exhaust valve until closing exhaust valve with 0,5 mm gap, then you know if these camshafts are original with open degrees or something special.
what about the inlet cams? what number is on?

 

thank you for the photos, but also those numbers I cannot find anywhere
could you please post the complete VIN

ok with this 0,5 mm clearance.

why cylinder 1 and 9?
when you not check when exhaust will open how can you then adjust the timing???
I really wonder - what has the inlet opening to do with exhaust closing?
could you please explain this. never have heard about this to do

 

that is why I told you to meassure both to see what camshaft you have.

yes, when the camshaft has different complete degrees. and because of the strange numbers I think it could be so, but of course not sure

right, but you can average it out

the marks I use only for approximately adjustment to turn the engine without getting trouble that a piston will hit a valve. then I turn the crankshaft with degree wheel to this position when inlet will open. then I adjust the inlet cam. same I do with the outlet cam. I never until now adjusted by closing valve. when I finished I check always the complete degrees where the valves are open. sure, then I also can read the degrees for closing and often it is up to 6 degrees beside. I once checked how the degrees will change when there is a valve clearance from not 0,5 rather 0,48 or 0,52 ( you can not meassure this with a feeler gauge, you only can feel it with much experience but up to 3/100 mm you not can feel ) but have not my writings with me here in thailand. so you may check by yourself when you change the valve clearance by 0,05 mm. you will be surprised how much the difference will be. when I remember right ( but really not sure ) for 0,05 mm it is 2 degrees crankshaft each way, so together 4 °. but not sure if I remember right. check this please.

 

Guys... you can never achieve o,5mm clearance. Our shim selection is limited. Without 0,5mm EXACTLY, setting your timing per factory spec is wrong.

Chart out your valve movement by each degree of wheel movement. Then observe how far off your overall duration actually is. Then, recalculate the actual point (degrees) at which your cam should start to move the valve.... based on the duration you actually achieve.

Your cam profiles are correct. Your cams are symmetric. If your opening is right..... it will close at the right time.

Test it yourself.... if you get the opening correct (per spec) without recalculating, your closing will ALWAYS be off.

You will chase your own tail around and around and never get it right.

This is an actual sample:
If it were set per factory spec (13 deg BTDC opening), it would have actually been 0.95 degrees advanced at opening. It would appear to be correct while opening at 13degBTDC.... but actually wrong.

On closing, it would ‘appear’ to be closing at 13 deg BTDC + 242.1 = 49.1 deg ABDC some 1.9 degrees off factory spec. Seemingly way off.

It ‘appears’ to now open at the right time, but close way out of spec.

The cam is not wrong... the measurement technique is wrong.

This example is based on actual clearance of 0,507 mm rather than the spec of 0,5 mm. The closest to 0,5mm that was available to me with my shim selection.

Bottom line: set this particular cam example to actually open at 12.05 BTDC and expect it to close at 50.05 ABDC.

Image Unavailable, Please Login