I was wondering on peoples thoughts regarding are valvetrain are?

how far can we go in terms of modding our cars before we have to start upgrading these components.

I'm pretty sure that well have to upgrade the springs for sure, but now with tuning available we can start pushing back our rev limiter.

- how far can we push the Rev. limiter before we need to upgrade

- what if you have cams should you upgrade sooner, and how high could you safely push the rev limiter back before upgrading.

 

definantly want to upgrade your springs earlier if you have bigger cams.. thats big duration and lift you need it

 

I guess my real question is am I safe to get a stage1 or a tune with my cams?
these came have a 0.05 duration

 

give me cam specs..

lift/duration @ 50, not advertised

 

I'll post as soon as I get them
but if you were to guess right now am I safe for power adding mods, and hold off on tuning the rev limiter until I replace my springs?

 

Once you have stronger valve springs, Forged pistons, and cams ( a ported head would be smart too), you're good to about 8K. In the build book, they recommended a ~7850 shift point if I remember correctly. Once I have pistons, valve springs, cams and a ported head, I will probably set the rev limiter at 8K.

 

what about valves, retainers, locks? you think they're all ok for an 8K RPM.

I don't know, if I'm going to change out the springs, I might as well swap the whole head, to one that has been ported like the JBP Stage 1, the cost labour would be the same. but again if I do that your right might as well change the pistons too.

but all of that is pretty big $$$

yah I'd definetely have a bullet proof motor then, but I just don't have the money for that right now.

I'm really interested in knowing how much I can safely mod or tune right now before it's a must for a valve train upgrade, if any

 

didn't the 300WHP book replace the springs?

 

yes it did.

 

Are you guys sure that the EatonM62 can handle high revs as high as 8K?

 

I don't see why not, it's no different then putting a smaller pulley

 

I won't advise it IMO. I realize we still make power at 7k but 8k is over doing it and will indefinitly stress the blower too much. I would make it a point not to go past 7k for redline. I would however replace any internals you plan on meeting or exceeding the specifications for.

 

That makes no sense. You realize putting a smaller pulley on stresses the blower more because your making it spin faster and adding another 2k to the redline over stock is making the blower spin even faster over specification that it was given. That is a receipe for destruction.

 

The Eaton M62 that is on the Cobalt SS/SC is working well within is efficient range.
The M62 only starts to lose efficiency and become over stressed at 14000RPM

 

2.7 or lower pulley going at engine speeds of over 7k will make the blower spin way beyond 14,000RPM. That was my point.

 

oh your combining both mods together, then yes I agree with you, you have to find a happy medium with in the two.

that being said, if you build a motor capable of a 8K rpm then your sure to be safe when your car hits 7K-7.5K, for longer periods of time.

now I really don't want to have to build my motor to that point. but by looking at recent dyno charts of people who have been tuning there cars, you can clearly see that the motor itself is still capable of producing more power beyond 7K.
I'm mainly trying to find out if that is a safe situation for me, as I have Cams

 

I won't take it past 7k, the motor making power yes I agree but it's not a honda it's a chevy. Even the drag cobalts don't take things past 7k if you notice on some of the seriously built ones.

 

Damn Hondas! My friend has a k20a2 that revs to 10k! Its a sport bike for god sake!

 

You guys need to keep in mind 2 things. 1) for the Gen V M62, the rpm limit is 16000, not 14000. 2) When you go to forged pistons, your going with higher compression, which means you'll actually have to switch to a BIGGER pulley, which spins the blower less. I plan on going 10:5:1 compression, and probably a 2.8 pulley with water injection. A 2.8" pulley will spin the blower slower than the 2.5" pulley I'm getting ready to put on. With the higher compression, you'll make more power with less boost.

 

I'm not trying to take it past 7K. write now I have stock tune, no stage reflash.
but if I get tuneing or a stage 1 reflash will my valvetrain be able to hold up to the 7K rev limiter, with the cams that I have installed.
my biggest worry is the valve springs, are they going to be able to handle a 7K revlimiter, and Cams

 

Well I guess we will find out once my engine is done. I am going for the 8,000 mark and everything is being planned for that. I won't bother will the pully or injectors until after tuning and seeing right where I am at. I have to say though that it seems odd GM released the build articles showing 7850rpm on the dyno chart if doing so was all wrong, considering they benifit nothing when some does it (because they aren't selling this as a kit)

 

You WILL need stronger valve springs to go with cams and shift past 7K.

 

any idea on what labour should cost in upgrading the valve springs?

also anyone know who makes them? so far I only know of
JBP
Bates
Ferrea

 

It's probably not going to be too cheap. The valve springs on these motor's are a fairly tough job. Plus, with 16 of them, it'll take some time.

 

Didnt JBP put in their HD LSJ springs when they did your Stage 3 cams?? I was under the impression they had...
WOT