Mercedes Power Unit Hardware & Software

[Hoffman900]

You can all but throw Franco Nugnes in the bin, he comes up with wild theories spun out of thin air and reports them as factual.

Why would what Nugnes reported Mercedes could do not be possible. A lot of people could throw a lot of others in a bin simply because of disagreement.

Nunges is one of the most unreliable when it comes to reporting on F1, the only reason he gets any attention is because the outlet he works for motorsport.it.

His articles are opinion pieces that get presented as factual reporting. He went on and on for the past few years about Ferrari swapping to a narrow nose which never materialised.

Now, apparently, he knows what Mercedes are doing with their power unit. This from a guy that doesn't attend the races.

Exactly. It's tabloid reporting guised as being technical.

[pursue_one's]

According to FujiTV, Mercedes power unit upgrade(reliability) to apply for FIA.

[zibby43]

FIA declined to pursue RBR/Ferrari’s requests to meddle with Merc’s plenum.

AMuS:

“Red Bull's request to the FIA about the alleged Mercedes cooling trick with the plenum came to nothing.”

"That was shot down,” per the Red Bull camp.

[b2bL44]

FIA declined to pursue RBR/Ferrari’s requests to meddle with Merc’s plenum.

AMuS:

“Red Bull's request to the FIA about the alleged Mercedes cooling trick with the plenum came to nothing.”

"That was shot down,” per the Red Bull camp.

As expected. The reporting on the subject by AMuS and Mark Hughes already indicated that this was a nothing burger.

My understanding is that the 2021 power unit has not had any upgrades on the ERS side. Will Merc introduce these for the 4th power unit for Lewis?

Lot's of testing taking place on Bottas' components. Interestingly for Sochi only the ICU, TC and MGU-H were replaced, because they are matched up with one another of course. So if Merc do have reliability concerns, this is where they lie. Alternatively this is where they could be pushing for reliability vs performance for the coming development freeze.

[pursue_one's]

[godlameroso]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. When this happens the valve seat is no longer contributing towards valve cooling, leaving the valve guide to dissipate all the heat of the exhaust valve. This softens the metal of the guide increasing the bore of the guide. When the guide can no longer guide the valve properly, the valve begins to wobble and begins trashing the valve seat as well as the valve stem seals. This leads to lower compression and massive oil consumption.

[SiLo]

I think Hamilton can take a penalty and not be impacted too much with the remaining circuits bar maybe Saudi and Qatar. The rest should be ok to overtake on with DRS.

[zibby43]

FIA declined to pursue RBR/Ferrari’s requests to meddle with Merc’s plenum.

AMuS:

“Red Bull's request to the FIA about the alleged Mercedes cooling trick with the plenum came to nothing.”

"That was shot down,” per the Red Bull camp.

As expected. The reporting on the subject by AMuS and Mark Hughes already indicated that this was a nothing burger.

My understanding is that the 2021 power unit has not had any upgrades on the ERS side. Will Merc introduce these for the 4th power unit for Lewis?

Lot's of testing taking place on Bottas' components. Interestingly for Sochi only the ICU, TC and MGU-H were replaced, because they are matched up with one another of course. So if Merc do have reliability concerns, this is where they lie. Alternatively this is where they could be pushing for reliability vs performance for the coming development freeze.

Great intel re: the ERS.

Hopefully we get some reliable information on what happened with Bottas’ Monza spec PU.

[gruntguru]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. . . .

You are suggesting that valve clearance is not adjustable. I find that unlikely.

The other consequence of such a high degree of seat erosion is a problematic reduction in gas flow. Again - unlikely that they have seat erosion as bad as that.

[BassVirolla]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. . . .

You are suggesting that valve clearance is not adjustable. I find that unlikely.

The other consequence of such a high degree of seat erosion is a problematic reduction in gas flow. Again - unlikely that they have seat erosion as bad as that.

It's known if the valves are directly pushed by the cams or there are rocker arms?

When Honda tightened a bit the distance between the camshafts, it came nearly clear Honda should be using rocker arms.

I don't know if Merc and / or Renault are using hydraulic or solid tappets / cam followers... Or are also using rocker arms, as some suspect is Honda doing.

In any solid (not hydraulic) layout, I don't find reasons for F1 manufacturing tolerances not being sufficiently accurate to get rid of any adjustment mechanism (and potential failure, and greater moving masses).

If I were designing an engine as "perfect" as those, I would try to avoid it by sufficiently adjusting the dimensions. In road engines, cam lifters adjustment is essentially to account for mechanical wear of the cams and the valve stems and I suspect that also for manufacturing economy reasons (cheaper to have not so perfect rocker arms, but adjustable).

[_cerber1]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. When this happens the valve seat is no longer contributing towards valve cooling, leaving the valve guide to dissipate all the heat of the exhaust valve. This softens the metal of the guide increasing the bore of the guide. When the guide can no longer guide the valve properly, the valve begins to wobble and begins trashing the valve seat as well as the valve stem seals. This leads to lower compression and massive oil consumption.

This has nothing to do with Formula 1 engines, manufacturing precision and a mileage of 5000 km, excludes such a development of events.

[saviour stivala]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. . . .

You are suggesting that valve clearance is not adjustable. I find that unlikely.

The other consequence of such a high degree of seat erosion is a problematic reduction in gas flow. Again - unlikely that they have seat erosion as bad as that.

It's known if the valves are directly pushed by the cams or there are rocker arms?

When Honda tightened a bit the distance between the camshafts, it came nearly clear Honda should be using rocker arms.

I don't know if Merc and / or Renault are using hydraulic or solid tappets / cam followers... Or are also using rocker arms, as some suspect is Honda doing.

In any solid (not hydraulic) layout, I don't find reasons for F1 manufacturing tolerances not being sufficiently accurate to get rid of any adjustment mechanism (and potential failure, and greater moving masses).

If I were designing an engine as "perfect" as those, I would try to avoid it by sufficiently adjusting the dimensions. In road engines, cam lifters adjustment is essentially to account for mechanical wear of the cams and the valve stems and I suspect that also for manufacturing economy reasons (cheaper to have not so perfect rocker arms, but adjustable).

The valves as used by all the present formula one engines are not pushed-on by the camshaft direct, the cam lobe pushes on a finger cam-follower and the cam-follower pushes on the valve lash adjusting cap which sits on top of the valve stem. Cannot contemplate a non-adjustable valve lash design in a formula one engine design. Hydraulic tappets are not compatible with formula one MAX RPM. With a valve adjustable design, formula one engine builds where valve lash noise is no problem, the adjustment facility is used to fine tune the build (equalisation of all cylinders/calibration) of cam-lobe designated specification targets.

[sosic2121]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. . . .

You are suggesting that valve clearance is not adjustable. I find that unlikely.

The other consequence of such a high degree of seat erosion is a problematic reduction in gas flow. Again - unlikely that they have seat erosion as bad as that.

It's known if the valves are directly pushed by the cams or there are rocker arms?

When Honda tightened a bit the distance between the camshafts, it came nearly clear Honda should be using rocker arms.

I don't know if Merc and / or Renault are using hydraulic or solid tappets / cam followers... Or are also using rocker arms, as some suspect is Honda doing.

In any solid (not hydraulic) layout, I don't find reasons for F1 manufacturing tolerances not being sufficiently accurate to get rid of any adjustment mechanism (and potential failure, and greater moving masses).

If I were designing an engine as "perfect" as those, I would try to avoid it by sufficiently adjusting the dimensions. In road engines, cam lifters adjustment is essentially to account for mechanical wear of the cams and the valve stems and I suspect that also for manufacturing economy reasons (cheaper to have not so perfect rocker arms, but adjustable).

I think they adopted rocker arms 15 years ago.

[godlameroso]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. . . .

You are suggesting that valve clearance is not adjustable. I find that unlikely.

The other consequence of such a high degree of seat erosion is a problematic reduction in gas flow. Again - unlikely that they have seat erosion as bad as that.

Depends how you adjust valve lash. I would think they'd have fixed rockers to save weight, why waste time with adjustable set screws that add mass to the rocker arm. You calculate the lash over the engine life based on projected valve seat erosion. Perhaps they had more seat erosion than anticipated, the answer would be to use different seat material or design more lash into the rocker arm. This would have a small almost negligible airflow penalty, while extending proper valve seat contact. If in fact such a thing is happening, it is a common fix in the road car world with engines that have set screw adjustments for valve lash. You make the valve lash one ten-thousandths of an inch looser than spec limit to buy yourself some time.

Obviously this is not an option with these engines, thus the money must be spent on ever more exotic materials for the valve seats.

[BassVirolla]

The hotter you run the CC, the more valve seat erosion happens. When the valve seat erodes the valve stem becomes taller relative to the rocker arm. Eventually the valve seat erodes to the point that the valve no longer fully closes because the clearance to the rocker arm has disappeared. . . .

You are suggesting that valve clearance is not adjustable. I find that unlikely.

The other consequence of such a high degree of seat erosion is a problematic reduction in gas flow. Again - unlikely that they have seat erosion as bad as that.

Depends how you adjust valve lash. I would think they'd have fixed rockers to save weight, why waste time with adjustable set screws that add mass to the rocker arm. You calculate the lash over the engine life based on projected valve seat erosion. Perhaps they had more seat erosion than anticipated, the answer would be to use different seat material or design more lash into the rocker arm. This would have a small almost negligible airflow penalty, while extending proper valve seat contact. If in fact such a thing is happening, it is a common fix in the road car world with engines that have set screw adjustments for valve lash. You make the valve lash one ten-thousandths of an inch looser than spec limit to buy yourself some time.

Obviously this is not an option with these engines, thus the money must be spent on ever more exotic materials for the valve seats.

Or none airflow penalty, if you mate a bigger clearance with a cam with more lift.