Chevota

Prihad, that is why I know there is little to no overlap. I dont believe my car has overlap under any conditions, but is possible if I force it. The Op's engine might have some under certain conditions, maybe, but not idle.

Chevota

I just checked, because I was curious too. Here's the overlap chart for my M278, because I know you love pix n stuff:
At 2240rpm x 32% load, -8 degrees is as close to overlap as it gets. In idle mode it will override this chart and be -61 degrees, usually.
The other chart is as close as I've come to overlap (-1 deg) which, ironically, was to reduce power in that 1700-2200rpm range.

The M276 no doubt has less negative overlap than I do, but if does have actual overlap I bet it's probably only starts after 2Krpm and I doubt it's more than 10 deg at red line. 10 deg barely registers anyway. At idle it'll be -61 like mine.
My truck on the other hand, with a fixed cam, has 76 deg overlap. Now that is overlap, and way too much imo so I adjust a bunch of it out



Thanks for posting that cam/plate video showing the marks. I've been wondering, and asking if they had any, now I know So happy I made a pix from the vid

S-Prihadi

Thanks for your data table from M278. Too bad I do not know exactly how those numbers come about because I don't know anything about HP Tuners. That is from HP Tuners right ?
However, I want to learn more too


This is M276 3.0 Turbo camshaft VVT advance/retard after 3 minutes of engine already running from a COLD start .
Total 120 seconds logging only by Xentry for this test. Temperature of the day 30 - 32C / 86 - 90F
The VVT angles can be logged nicely at 7.1 data point per second by Xentry.



I am assuming both intake and exhaust camshafts of M276 3.0 Turbo because it has VVT anyway, ....... is of the same duration.
There is no point wasting money making Intake and Exhaust camshaft duration / lobes of a DOHC engine to be different if VVT system is employed.
So I only need to do simple E plus G column




.
This is engine OFF and COLD start to idling. NOTE : Any Xentry VVT special capture is only 120 seconds.

I think this is how MB engineers wants to heat up the CATs as fast as possible from cold start with such huge overlap to 28-30 degrees.


.

Sorry, I need the exhaust and intake "hill" diagram above to help me visualize.
So exhaust camshaft retard makes the valve opening "hill" move to the right, since exhaust event comes first before intake event.
Intake camshaft advance makes the valve opening hill to the left, even making more overlap.






.
8 degrees total overlap at stable idle is very very small overlap. In terms of actual valve opening, its super tiny I am sure, but an open valve nevertheless.


I attached the original files from Xentry and the one I translated to English for you to take a deeper look.
I can't tune ECM like you...so me can only see but no touch.


.
Here is a data of M117 oldie non VVT engine I was trying to understand how in non-VVT days Mercedes camshaft are spec out to.
But the duration of the cam is using 2mm lift as starting point, unlike USA typical 0.05 inch or 1.27mm lift. SAE standard calls for 0.006 inch / 0.15mm lift.
https://www.benzworld.org/attachment...s-jpg.1166953/







..
Wow even 1 degree advance/retard matters for the engineers before VVT days. Look at how Bank 1 and Bank 2 is on purpose by camshaft is 1 degrees difference for its timing.





.

S-Prihadi

Mak,

This is the INTAKE camshaft Bank 1 , HP Fuel Pump fuel lobes positions I need your help with.

When the camshaft position sensors are removed, the tone wheels of BOTH camshaft, its first short rising edge as shown below, will be in the middle of the hole of camshaft position sensors.
For Exhaust camshaft, the ending of the short rising edge is to be in the middle, for intake camshaft, the beginning of the first rising edge is to be in the middle.




.
I shall mark the beginning riding edge of Bank 1 intake camshaft signal wheel as the ZERO. In green target +




Imagine that the image of intake camshaft below, its signal wheel ZERO ............. is where I mark green arrow.



All I need you to do is please measure the red arrow top of fuel lobe to the green zero, how many degrees is that ?
We use clockwise as reference. So the fuel lobe to be measured is the RIGHT side of green/zero of camshaft. Our imaginary zero ...LOL.

If I have this information, when you or anyone has shifted camshaft tone wheel or bad slow fuel quantity control valve activation of HP fuel pump, by scoping we can tell its actual happening.
The timing of quantity control valve activation of HP fuel pump is super critical, wrong timing means as good as a DEAD HP pump.


The tone wheel of camshaft is seen by the M276 engine is as below and attached in PDF.


.

I am on a 4 fuel lobes camshaft, your M276.9 3.5NA is on a 3 fuel lobes.


Scope capture below of intake camshaft tone wheel and crankshaft and HP fuel pump quantity valve, BUT is for my 4 fuel lobes.





1 - 2 - 3 - 4 in red for above and below image is : The camshaft position sensor reading the tone wheel, the sequence of the 4 rising edges seen by the scope.
Scope image/data capture on its presentation screen is from left to right, so most right zone is OLDEST or FIRST data.




Oky doky.... thank you for this favor.

S-Prihadi

Chev,

Please take a look ......
Need to pick your knowledge.





This information below from WIS is both the same for M276 family and M278/M157 family, explaining the LARGE overlap during low rpm and low load.
I am attaching the WIS in PDF too.




I am desperate to know the actual billet camshaft duration , the VVT part is easy, it can add up to 40 degrees of play/freedom, but where is the basic non VVT true START or END of the intake and exhaust valves opening ?

Thanks

Chevota

I wrote a nice fat post just for you Prihadi
HP tuners has a function to compare things in tune, to another tune, to see what exactly is different about them. So, while not really the point of the function, I used it to compare the Int to the Ex and that's the chart it spit out.

So your Int is 33 and Ex -25. The -25 I'd expect, the 32 I didn't. I would've thought yours would be 36. Curious... I don't know why I don't have a copy of your eng data, but I will ask around, and if successful I will post it for you. My guess is it's pretty much the same as mine, just 3deg advanced at idle, but we'll see. Seems odd to me because why bother? Or perhaps your eng was made first, then when they made mine they fixed a flaw. Just kidding, but if I had to guess I'd go with idle emissions.

The US has, for many decades, used .006" lift, .020", .050", and sometimes .100, .200, .300., even .400 but that's pretty rare to have a cam that big. That's lift at the cam, not valve fyi.
The .006 is the common "advertised" duration. Why .006? It was determined long ago, that it typically took ~.006" cam lift before the valve of a hydraulic push rod eng actually moved the valve at all. So basically the .006 is a more real # of seat to seat valve time and you ignore actual because it doesn't do anything. The .050 is similar because there is no flow at .006 and .050 is where flow is finally enough to really matter. So .050 is what matters duration It's also a clue when compared to the .006, to see if the cam is lazy or not. The Benz # of .020" (.5mm) is shy of that, so if you see a few deg of overlap in a Benz, how much does it really count?
Also, you could have two cams with an advertised duration of 270, but the .050 for one is 220 and the other is 240. The 220 version would be an over the counter lazy high performance cam. The 240 would be something you have custom made, and an actual high performance cam. I made one almost identical ages ago; 270 advertised, 244 at .050. An example factory high perf cam from the '60's is for a 350 horse 327 eng that was 282 adv and 222 at .050. It was the second cam I ever bought, and my first Chevy cam. Lazy, and too small, but it seemed cool at the time because it was a factory hi-po cam. It wasn't very cool but certainly better than stock.

A typical cam for a generic V8 is more like 190-195 @ .050. That sheet for the M117 showing 187 @ 2mm would probably be ~195 @ .050? Interesting they changed from 2mm to .5... The advertised at .006 and .050 of that is anyone's guess, but being oem I'd assume the .006 is lazier and more like the 250 you said.
The 220KW M117 is likely 210-215 @ .050. I'd imagine that moves the rpm band up ~800?
That 222 @ .050 for the 327 I mentioned is basically rpm limited because with higher rpm you need stronger valve springs, but stronger springs eat cams, lifters and valve seats. So they draw a line on spring pressure and that cam is about as big as you can use with said spring. I believe it took what the factory called "Z28" springs, typical for a Z28 Camero and a popular spring to have for gear heads. More accurately; it's simply the limit the mfg was willing to go for a production vehicle. There is also lifter pump-up, which limits rpm. The fix for pump-up was the solid lifter, which very very few oem V8's had. I've never actually seen a factory solid cam V8. They were basically race motors the factory was forced to sell to the public in order to qualify for certain race events, now coveted and worth big $. Solids are measured at .020" instead of .006 because the lash took up ~.020. I believe .018 to .028" lash is what I recall. Whatever the story, the .020" rule was made and it stuck, even if it didn't match the lash on your cam at all.
I tried a couple custom solid cams, didn't care for 'em. I won't bore you with why, just that the better option is to use a hydraulic cam with lash. Solid cams need to be cut different so the taking up the lash is gentle. This is a necessary evil for the masses, but not for me, and it hurts idle quality and low end torque. A hydraulic cam has no such ramp. I'm the only person I know that has done this, using a hydraulic cam with lash, but it works really well. Later I switched to hydraulic lifters, with the same lash. No pump-up because they're already pumped. The only real drawback is you have to check the lash more often, be more accurate in your setting, and know what to set it to since there is no precedent. Oem rockers for those engine were more much more difficult to adjust accurately, so much more room for error. It all adds up to making it more risky and Joe Blo would probably screw it up and burn a valve, or bend a push rod, break a rocker etc. Lash is also noisy. I had less lash (,008 In and .010 Ex) but the slack was taken up much more violently, so it ended up just as noisy. My M278 is probably noisier and I may never understand why.
I then switched to bleed down lifters. They bleed down while the valve is open, which shortens the duration. Opening is the same, just closes earlier. The Ex closing earlier was the more important one because it reduced overlap. The Int helped by reducing flow reversion, which becomes a problem with more duration. Since the bleed down is time related, the effect is less and less as rpms increase, which is a match made in heaven.

I started playing with cams when I was 16, with my first car, and of course I had to tinker with everything. There was virtually no information on cams and all the "experts" didn't actually know sht. At 18 I got a job at a speed shop, which is where I discovered they have no clue about cams either. I swear to god they said to me; "The best cam for the customer is the cam we have in stock." No matter what, tell them the cam we have on hand, even if far from ideal, is perfect for them. I learned a valuable lesson in business as well, never trust the guy making a profit from you.

A few years of experimentation later I had a much better feel for cams, but still only commonly available "race" cams, because what else is there? Then I met Danny Crower, of Crower cams. He not only knew his sht, he and I had the same mindset on how a cam should be cut. He was happy to explain what he knew, and more importantly, why things are the way they are. All the pieces of the puzzle I was having trouble with, he had an answer for. First off, he said everyone in the industry is scared to sell people a better cam because A; most people don't really want as big a cam as they think, regardless of what they believe. If you sell them what they think they want, and they're unhappy, they blame you. B; a cam cut to truly work better has a shorter life, and no cam mfg wants the word out that their cams are short lived. After all, the cam mfg doesn't make cams, they make $, so that comes first. As a result, people like me end up getting a smaller and lazier cam than we want >:|
Lazy means the valve opens/closes slowly, for long life. This is exactly what happened to me with my very first cam ever, bought at the same speed shop I later worked for btw, and now I know why I got F'd. I was very disappointed because that cam was barely better than oem, and I mean barely. At 16 a cam was a big purchase for me, and a huge waste of $. The only bennie was the lesson learned in cams, and marketing.

Fast fwd some 10 years, with a brain full of experience and Danny Crower filling in the blanks, I was able to make some real cams. I don't mean they suggest a cam and I agree, I mean I tell them what to make. It would make them nervous because no way they'd sell such a thing to Joe Blo. One of the times, when Danny wasn't there, they didn't do what I asked and tamed the cam down. I was rather upset, who does that? They claimed the cam was too much to work with EFI. I proved it was not. Next year it was in their catalog. It was a tamed version, but not nearly as tame as the one they originally cut for me.
I also have about a dozen of my own personal Crower part #'s. No way those will be in their public catalog, but I/anyone could have one made using that #. Kinda fun to have my own one of a kind cams and part #'s. They also have a secret cam book, which Danny showed me, at the dismay of the other staff. I think it was the manager who glared at Danny and shook his head when he pulled the book out I love it! It wasn't cams, but individual lobe designs. From there you decide your lobe center, and base circle. Base circle is something very few think about, but when you start making the cam more aggressive, it's a real concern. Another concern is stroke and rods, so some, like mine, "they" say I need a smaller base circle. I didn't, not really, but I did because of the lobe shape. Why you ask? If the ramp is too aggressive for the lifter, the edge of the lifter will dig into the ramp. Obviously a bad thing. The fix is to either use bigger diameter lifters, or make the cam base circle smaller. The latter is much easier.

The cam specs for my M278 are 203 Int, 228 Ex. Measured at .5mm. I guess they had to pick a #, and it had to be metric, so .5 it is. Basically equal to .020" for the US, but .020 was only used on solid lifter cams so not easy to compare. Either way, 203 @ .020 is small by any standard, but it's roller which will/should have a better area under the curve since you no longer need to worry about wear from the more aggressive ramp of the lobe. So they can look just like my more aggressive lobes (see pix). That will make it make it act more like a cam I had made, but factory. I suppose it may be equivalent to a cam with 10 more deg at .050? Still too small, but better than an old flat tappet cam with 203 deg.

Then there's the NA vs turbo, which does need to be different regardless of what anyone says. For NA the overlap is a good thing, to a point, and it's not for everyone. Most fixed cams have too much overlap imo. I think once overlap scavenging became a thing for racing, everyone had to have more of it. Whatever sells best it what they make, and more overlap doesn't hurt lifespan so guess what they sell... It's another reason to have them custom made. I ran 8 to 10 degrees more lobe separation than what was considered "ideal" because I actually tried ideal and it was a disaster. The lower the rpm the worse it ran, and by a lot! I lost 20% mpg and no doubt more than that in low end torque. Around 7k is when it seemed to be on par with my wider LC version of the exact same cam, but no better imo. Yes, I made cams just to check lobe center. Like you, **** with data, I was **** with hardware and it was nothing for me to swap out cams just to see how it works. I forget how long it took me to pull a cam out, but it was record time. I think ~30min? Seems extremely optimistic but I was a master at it. I'd also try various degree settings and learned the intake lobe centerline was all that mattered. My engine liked 108 deg on the Int no matter what. Duration, lobe center, nothing mattered, 108 was ideal. The same "experts" claim 100 was my #. Which I never even tried because any deviation from 108, in either direction, was for the worse.

Back to overlap. One problem is it makes emissions a lot worse, HC specifically. This is, imo, why most oem cars today have no overlap, especially at or below normal cruise conditions. If there is a little, like 10deg, the valves are barely open so scavenging is probably zero. Direct Inj eliminates that HC problem, but the EPA also wants EGR, and the more negative overlap, specifically via the Ex cam, the more EGR you have. This is why I/we don't have EGR valves, the cams do it for us, as I'm sure you know. There is also pumping losses to deal with, so there is ideal cam timing to make pumping losses minimal to improve mpg, which are the settings you see at cruise rpm/loads. At idle it's all about emissions, imo, so max negative overlap. At cruise it's all about mpg and emissions. At full power it's all about power, but still limited by emissions. The best thing for our cars, imo, would be bigger cams, or just a bigger Int cam. Not sure why mine has the cam it has, but I'd imagine it has everything to do with profits and Big Brother EPA.
The M157 has the same cams as I do, which surprised me. Maybe they have bigger valves and/or higher ratio rockers, I dunno. The Ex centerline is he same as mine, and same as yours. The Int is positioned 10deg retarded to mine, 13 to yours. As you know, we have 40 deg available, but Ive never seen it all used, nor do I use it because it's simply more than is useful. The M157 only used that extra 10 deg at idle, so I'm guessing it's an emissions thing. It uses about 5 of it at the top end.

The Mercedes cam timing, for the curious: The Ex is the moment the Ex closes, meaning the moment it hits that .5mm mark during closing. So if mine is -25 it means at 25 deg BTDC. A 15 would mean 15 ATDC, which is the max it can go, but mine never goes past 8. So 33 deg used of a possible 40, for my eng.
For the intake it's when the Int opens, so when mine says 36, it opened .5mm at 36 deg ATDC. A -4 would mean it opens 4 BTDC, which is the max mine can go, but 4 is as far is ever does, so 32 deg of a possible 40.
Other brand mfg's measure things differently. I forget which but one starts at TDC on the firing stroke, then counts in degrees from there. I don't recall if it was valve opening lobe centerline, just that the Int had a big # since it was many crank degrees away. The old school US method like that cam card from Comp Cams, typically measures at lobe centerline, not open/close. So you might say 240, 112LC. I take that as 240 @ .050 and 112 lobe centers which is the gist of the info. The open/close is set by the duration and LC so you can figure it out. Now it seems they all mention the open/close @ .050 as well, but may instead use .006. When I'd have a cam made it was more involved than a couple #'s, obviously. My cams were almost flat on top, btw. I didn't want to much lift because you get diminishing returns, and more lift means more stress on everything. So I'd limit to ~.530" at the valve. With the more aggressive ramps and longer duration, that meant a nearly flat top. It was rounded only enough to prevent valve float, which is the valve opening so fast that when it comes to the top of the lobe, and/or on the way down, it doesn't "catch air". Worst case would be the valve not following the closing ramp, and catching air all the way down and slamming closed full force. Plus your push rods can pop out of the socket, which will end badly. A cam mfg will also suggest what spring you need for xx cam/rpm, but they always suggest way too much pressure to be safe. This is bad for your parts but it's butt coverage for the mfg. My springs were very light for the cam, but just enough to work perfectly to my 7800 shift point. Seat pressure was 120 and I think they suggested 180. That's a massive difference... Oem I think was 90? Then the spring rate matched so it wouldn't catch air over the top, which I think I had 300? Without a pointy lobe I didn't need to have as much. I never had a lobe fail and I believe this is why. I'd also use a harder cam material. I believe it was Rockwell 55. Well, I remember the 55 for sure, and assume it's Rockwell.
When I first played with the Benz timing I had to convert it to LC to get a feel, for it, like how I have to do with the metric system
Since the M278 cams are super expensive and a nightmare to change out, I won't be getting replacements. So now it's all about VVT and what settings work best. It's not easy because it doesn't respond to changes as much I would've thought, plus with the turbo it throws off the feel. So I make a change and net more power, then I look at the data and see it had more boost. Hmmm... Does it really matter if it worked? Well, what happens in the same situation but less or no boost?
What happens to the exhaust valve at higher rpm and max load, because one setting may make the same power as another, but one of them makes the valve hotter. How would I know? The M278 has an issue with that so when I tweak the Ex timing am I making it better, worse, no change? I look at the M157 Ex timing and despite the same cam and range of movement, the position at peak power/rpm is quite different, 10deg retarded. Why? I tried the M157 settings and I can't tell the difference, it just sounds different. Then I wonder, are my valves hotter? They should be on the actual exhaust portion, but how much reversion am I getting? Is that why mine close earlier, to prevent reversion? Perhaps the M157 has liquid cooled valves and I don't, and that's the answer to why? Or perhaps it's larger turbo means less back pressure and thus less reversion? Maybe both?

Turbo cars have little to no use for overlap, and oem turbo cars have zero use for it. A blower motor is different, but still has little need for overlap. The turbo is controlled by the exhaust, obviously, but cam timing is a factor. Off idle, the more advanced the Ex cam the quicker the turbo responds, and how much boost it makes. That second chart where I had -1 deg overlap was because the oem timing was making too much boost in that zone, so I retarded the cam in that area to tame it.

In the pix you posted yesterday you can see your Ex changing at idle. Normal idle will be -25, or probably -15 if idle rises too high, or Cat timing kicks in. Then when it goes closer to 0 that's low pumping loss mode for mpg. It doesn't matter much what it does down there, meaning low load, it matters when you floor it. That's where having the Int and Ex adjusted to make max power matters, or to make less if you can't hook up. When I adjusted my Ex timing to make less power it was for two reasons, one was so boost climbs slower and thus better control it, the other was it was making too much boost and tripping a fault, which turns the turbos Off! That kinda defeats the purpose.

And thanks for posting those pix on where the pickups trigger cam position. I wondered about that... Added to my pix collection

In these, the modded lobe and overlap pix, and the gist of the oem M278 cam timing. There are some differences when the eng is cold, but they go by these warm charts when you hit ~120F so imo they can be ignored.

S-Prihadi

Sweet..... Thank you Chev

I swear to god they said to me; "The best cam for the customer is the cam we have in stock."
I like that saying hahahaha

Attached older engines M271 ( non turbo version ) , M272 and M273 with more generous information on their cam/timing.
Uses 2mm valve lift too and new chain and has old chain data too.


M273 - new chain.







If you have in-cylinder pressure transducer a fast one, I bet you can tune your engine better as you can see actual pressure, any delay, turbulence and whatnot inside the cylinder , at least at low RPM.
Given you know so much about camshaft mechanicals...


.

MakUsa

Just an update on the progress:
Yesterday I didn’t had time to remove the cylinder valve cover and inspect the valve lifters but at the end of the day I removed the intake manifold and I was able to see all the intake valves thru the inlet ports so I spin the engine manually and watch the valves on cylinder number one first of all they both open and guess what? One opens more than other and i waited couple minutes and the difference became more noticeable
Also i spit the engine again manually to close the inlet valves and one valve closed faster than the other
I am talking about the both inlet valves on cylinder #1.
i also watched the rest of the inlet valves on all the cylinders and they all opened and closed together at same time and distance.

Chevota

My guess is the "adjuster" is bleeding more oil of the valve that opens less. When the eng is Off, a valve not on a lobe will bleed next to nothing. If on a lobe it will bleed a lot. From there, with no oil pressure to refill it, it will stay bled out (shorter) and unable to open the valve as much as when filled with oil. How long they take to bleed out I don't know, but my old school engines would bleed in a few minutes? The time varied a lot, but bleed they do. The fancy bleed down lifters I mentioned bled out in a few seconds.
This is one reason I used hydraulic lifters in my previous story, because solid lifters don't do that so when the valve is parked on a lobe and sits there all day/night, it fatigues the spring more vs a lifter bleeding out and closing the valve half way.

Unfortunately you can't fire it up with the valve covers off, which was awesome with an old school motor like my truck has. The you can see it all happening live
I guess you could move the lobes to bleed the oil out of the other adjusters, if you were curious. Also, do the cams move up much when turning by hand? I assume you have two little dealies (pix) that hold the cams down so they don't jump out altogether, but there must be some slack in there which would upset the valve openings.
Imo you should do what I suggested earlier, which is to watch the cyl fire via the plug. That will tell you if it fires or not, plain n simple, and watching the spark via the rigged wire, see if it had spark at the same moment.

S-Prihadi

Getting closer and closer to predicted culprit.....nice

Ask : The intake valve which closed FASTER, is that the one with less opening too ?
If YES, check if that valve also open SLOWER ?

MakUsa

Answer:Yes
They seem to open at same speed/time but one goes back slowly after is fully open
Its really hard to see this at first I didn’t notice but after carefully looking and spin the engine couple times and observe the intake valve yes it’s definitely lazy valve
I wonder what the exhaust valves are doing also?

S-Prihadi

Mak,

You can use a camera type boroscope to see the exhaust valve at the same time.
However you need an articulating one, being easier to aim at exhaust valve.

Articulating version




If you use the common dual mode : forward looking and 90 degrees boroscope, the exhaust valve will be too close to spark plug hole, the camera can not focus on the exhaust valve lip.
See below, even the distant intake valves close up region is not far enough to focus well.



Please if you can, take lots of good photos to see the carbon build up on your intake valves.
Since you have good mileage and I am curios how much carbon is building up for your Direct Injection engine.

BTW, when the bank 1 cylinder head was removed, does that means all valves of Bank 1 now is super clean ?

Thanks

Chevota

Nice borescope Prihadi. I paid like $10 for mine so you can imagine how well that works. At work we have a nice one, and while checking valve function in a 3" pipe we actuated the valve. We weren't actually looking at the valve, we were past the valve looking at something we thought was the valve :o So it closed and crushed the borescope... Go ahead and guess what a replacement cost? Not a whole borescope btw, just the probe.... $20K US. Oops...
If yours is a reasonable price I'd be interested in a link or make/model.

S-Prihadi

Ouch !!! US$20K boroscope....

The articulating one is the one needing tablet/smartphone, so no screen.
Choose either 6.2mm or 8.5mm camera head diameter, mine is 8.5mm and 1 meter.
https://www.aliexpress.com/item/4000...21ef1802ote94T

This articulating boroscope has a weakness. Its camera probe "wire" is soft,
Imagine compass heading north as UP and SOUTH as down, EAST/WEST as side way.
It can not erect when used in NORTH or EAST/WEST. It has to slide against a surface, otherwise it will limp. I hope my description make sense.
Using in SOUTH mode for cylinder inspection is OK as the last 2.5inches of its end is the articulating mechanism, so it can easily do 180 degrees bend.

I hope Teslong one is better in terms of camera "wire" stiffness and it has a screen and two way camera too.

Higher resolution screen . Camera is still a 1080p. This is a 180 x 2, so it can articulate to LEFT or RIGHT, some can only articulate to one side.


===================

My dual camera is this one : .
But you can choose this one , newer and better with 360 degrees rotating side camera : .
There are times where I can't spin the camera "wire" to aim at a component in the 90 degree side camera view, hence a 360 degrees rotating camera is the way to go.

Happy shopping

JettaRed

iTrader: (1)

Hmmm, I think that's what my doctor used on my last colonoscopy.

S-Prihadi

So Mak, how is your repair progress ?

S-Prihadi

Yuhuuuuu.... Mak how's progress ???
At the least some courtesy to let us know...