lancethrustbone

Hey all! Happy holidays!
Just wondering if anyone has seen this before. I was doing an install for cams and valve springs today and was presented with this situation with the stock setup. It seems the timing chain and cam sprockets were both off by 2 teeth in the same direction. I'm fairly certain that the colored links are supposed to be lined up with the arrows on the sprockets. Shouldn't matter now since its going to all be redone and lined up as its supposed to be. Just wondering if this is something that really matters or if it actually managed to jump 2 teeth or if it was just assembled this way from the factory and since the timing was right they figured they wouldn't pull it off again to do it again.

Pics
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Thanks for looking!

hhrfreek

iTrader: (6)

Don't get confused by that. If they skipped or were installed incorrectly the motor would be dead. Basically if you kept turning the engine over they would eventually line back but every rotation doesn't allow them too. Don't forget there are 3 timing notches and links to line up though: intake, exhaust, crank. The angles of the cams and crank is also important, but I am sure you have dug up install info if you're this deep already. It doesn't matter how they are lined up until you are putting it back together. GL If you are unsure come back to the forum. Double check your work before you button it up.

Did you get ZZP cams/springs?

Also you are quite the lurker dude lol first post and you joined more than 2 years ago. Welcome.

574

iTrader: (5)

Im pretty sure youd notice if it was off by two teeth

lancethrustbone

Yeah the cams and springs are from ZZP. Been wanting to do this for a while and pulled the trigger when they were on sale on black friday.
I never noticed anything wrong with it before. I'm finishing up today so when I'm reassembling I'll be looking below at the crank sprocket when I have to ease the tension on the chain to put the sprockets back in. Its then I'll see if the chain down there is off by the same amount. If they were all off by 2 teeth but still timed properly I guess that'll explain why I never noticed it while driving. I wanted to double check with anyone that may have done this before to see if they noticed what I noticed when I first cracked open the valve cover.

Yeah I've been reg'd for a while on here but I'm normally on hpt forum. Usually only doing ecu work not much mechanical. This is why I'm putting a pause here while I find out what was up with the timing chain and the links not quite matching up on the stock setup.

Thanks for checking this out and happy holidays.

hhrfreek

iTrader: (6)

They aren't off by two teeth. After you reset the timing turn the engine over by hand until you see the timing links are back over the cams and you will see what I mean.

Also are you going to have a chance to dyno tune with the cams? If you do please work with the VVT tables for gains. I am sure results would transfer nicely to stock cams as well. A lot of the LE5 tunes I've seen ignore these likely because a lot of the tuning is data logged on the street. I doubt much is there, but a few extra whp would be worth an hour or two on the dyno figuring it out. It'd be good info to share.

noorj

iTrader: (17)

THIS!! I played around with the VVT tables for hours, only to keep second guessing myself as to what my "butt dyno" felt. Can't go by 60-100 times cuz this car's too slow

lancethrustbone

I still haven't checked the link down on the sprocket on the crank but the pictures you see above were all taken with the engine in the same position. The red link in that picture, not shown, should be on the arrow on the sprocket below or possibly off by 2 as well.

On a side note for the tuning. I have a pretty sweet map for the stock cams I hammered out after many data runs from 15 to 80ish all in 2nd gear. It lead me to a map that gives all the torque it can below and then transitions nicely at about 4.5 k rpm for power that seems to lead all the way out to 7k until the shift into 3rd at 78mph. Nice cruising economy but if you get heavy on it it phases the cams around for really great low end torque from around 1.6k on up until the transition. Hammered it out after maybe 3 dozen runs on this nice half mile stretch of road where I live. Someone was even nice enough to paint out start and finish lines a quarter mile apart.
Pretty much ran runs at static cam phasings on intake, exhaust, and mix with overlap and sync and just looked for the areas where I had best power and then framed the whole thing together for a nice workable mapping. It took a fair amount of runs since I was chasing statistically repeatable results. A bit of a pain when only relying on engine logging from sensors without a dyno to give me some direct data back. I only had run times, engine load, delivered torque (measured from pid), and a few other data collections to work from.
I have a pretty large thread over on hpt under the name viceroykarl (I think you payed a visit there iirc). Its been left for a while so its probably 7 pages back in the thread list. I have some of my results posted there but not too much of my final results since I was really aiming at teaching others the theory behind cam vvt tuning for those who wanted to know rather than handing out the answers in hopes that others go out and get working on this too to get some nice results to share. Basically encourage some community learning and contribution.

For the new cams I notice I see almost no info on them. I hear of people getting the new cams but then the thread stops there and they never post again saying how it went or what power they got or anything that can be called a result. Its almost as if the few people that even get cams for the le5 never talk about it.
I'm quite excited to get back into the cam tables again with the new cams in. I will be sharing the results in some form of hard data, no matter how miniscule the gains may turn out to be.
Probably only as hpt log files since I really don't have time to get to a dyno since I only have about another week before I have to head back to school for the next semester.

hhrfreek

iTrader: (6)

ok I do recall your name on the other forum. I wish I would have taken time to tune with the cams. I had them installed after I was boosted and the butt dyno showed me clear gains without even changing my tune. When I was ready to start cam phasing, later in my build, I was having other issues with my engine and eventually got out of it.

noorj

iTrader: (17)

I remember reading thru that thread too! I'll be keeping an eye out on it now Once I get my clutch done I'll be working on the tune more too, trying to always learn!

lancethrustbone

I should have it done tomorrow hopefully. Then all that is left to do is drive back to Philly to get my cable since I left it in my apartment so I can start logging and tuning. I'm not expecting any drastic change out of the cam but I'm hoping that I can at least feel the difference. This is part of the long plan to get an m62 on here. I'll hopefully be posting logs after the weekend after I've had time to digest the results.
I also asked a gm tech about the timing chain and he said he has no idea why or how that would have happened on my stock engine. The important thing is its timed up with the new cams so I won't have to worry about it any longer.

Powell Race Parts

iTrader: (3)

Hold the phone; if you have a VVT ecotec, and you dont have the Kent Moore tool to position the VVT cam gears then you will be screwed. Once these cam gears are held in place, you must align the crank pulley, then install the chain with the appropriate colored links matching onto the exhaust, to the inlet, and to the crank marks. When you do tha,t the crank pulley moves and its easy to think you are off, but trust me without the tool VVT are a struggle to get right.

ZZP make sure their cams are degreed correctly, so providing the correct installation procedure is followed, you will be fine. If you did not use the service tool, and you did not pay attention to the crank pulley, and the marks look like they are off by two teeth, they are. The reason that they do not line up currently as the car is, simply explained: crank is not in position.

\Front cover has to come off to do it right, the aftermath of short cuts is not pretty...

lancethrustbone

Thanks for the tip. I didn't have the tool but the engine was re-timed anyway after matching up the colored links with the marks on the sprockets on the cams and crank.
My mappings I had for my cams carried over nicely to the new cams. Great low end torque gets this thing up hills in overdrive like it is its job.
It goes nicely up to 7k and wants to keep going but my current tune I have set for shifts at 7k due to the stock springs.
I have to check out my injector duty cycle before I start tuning up to 8k rpm. Also do some tweaks around the bottom end to separate the cam overlap a bit more since these new cams come with more overlap so I can unlock some more bottom end.
It has a nice smooth idle since I had adjusted the idle vvt areas before. It revs noticeably harder now though

Preliminary "butt dyno" results are good though. (I love that term now )

newt

iTrader: (2)

All three "teeth" and corresponding coloured links only line up once every 117 full rotations of the motor...so something close to that.

So if you lined them all up, you would have to spin the motor over 360* 117 times for them to all line up again.

Don't worry about that, seems all is well tho....just wanted to pass that info along.

lancethrustbone

Thanks for info. I figured it was something like that due to the tensioners or something. Either way the install went fine and now I'm just finishing up tuning spark timing. The results are exactly what I was looking for. Nothing over the top but it definitely was what I needed to liven the engine up.
It pulls well from 5k rpm all the way as high as I safely feel going up to. I managed to save some of the bottom end torque as well so that means I can still move around traffic on the turnpike without having to get out of overdrive.
I'm being held up by airflow but I won't be doing anything intake related until after the upcoming summer is over. By then I'll have the time to put on the supercharger I've been considering getting.

noorj

iTrader: (17)

how much airflow are you seeing with the cams?

lancethrustbone

I'm seeing a peak of 19 lb/min on the MAF sensor but VE corrected and dynamic airflow readings are peaking at 23.
Before VE and dynamic air was peaking at 18 or 19 tops and the maf sensor would peak at 17.
I'm sure I can eek a bit more out of it if I finish off the exhaust 2.5" all the way from the dp but I'll cross that road later. I'm not going to be doing anything on the intake side since I'll have to rip it off anyway to put on the supercharger. Aiming for 250-ish hp when I'm done. That should be all the pep I need out of it to keep me satisfied.
Should be able to pick that up after summer if I go back to my lab job for my summer internship.

lancethrustbone

Well it looks like I went the right direction with this cam choice and tuning.
Was able to beat down a late model 2.5L Golf manual trans with some aftermarket exhaust modification(it was pretty loud). He had a head start of me because I didn't know he wanted to go but I managed to sweep right by.
Probably isnt really worth mentioning the victory since it looks like, at least on paper, a slower car than the stock 2.4 cobalt. Probably would have been a victory even without the cams.
Sadly he got really mad about it and tailgated me the for another quarter mile with his high beams on blowing the horn.
Just a quick lookup on the net claims that engine as 170 hp so by the margin I beat him by I can only assume I had a noticeable bit more than that.
I didn't dyno it yet but I'm hoping I'll have enough money to justify it after my next break from school comes up.