Valve spring project

[Swordsmith]

Some months back I installed the VT modified turbo, and hit a snag. Although I was registering more power than before the install, I was not getting all the power theoretically available. After looking at the logs, VT said it looked like the problem was valve float; the springs were simply not strong enough to work at these power levels. We capped the tune so it would only try to produce the power the valves were limiting me to, and left it at that until the next step could go forward.

Well it looks like the springs are now available, and I have a set on order.

They have ~27% higher seat pressure (56.6 lbs vs 44.5 lbs stock) and ~29% higher pressure at open (101.6 lbs vs 78.5 lbs stock). These are not too aggressive and should solve the float issue at boost pressures up to ~28+ psi at stock redline, or lower boost at higher redline).

 

[Swordsmith]

reserved for pics

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[cndctrdj]

Sounds fun

 

[Preloader]

If you're gonna get in there to swap springs..... Since the Cams have to come out anyway. Why not upgrade the cams while you're at it.

Or will that void VT's warranty on the springs? hehehe

Web Cam Inc. - Performance and Racing Camshafts / Chevrolet Cruze LLU 16 Turbo Hydraulic DOHC 16v

 

[jonboys66]

Wow, these things have some baby cams in them.

 

[stealth]

If you're gonna get in there to swap springs..... Since the Cams have to come out anyway. Why not upgrade the cams while your at it.

Or will that void VT's warranty on the springs? hehehe

Web Cam Inc. - Performance and Racing Camshafts / Chevrolet Cruze LLU 16 Turbo Hydraulic DOHC 16v

Where is this place that is my area code.
edit. Riverside this place is 30 minutes from me gunna check them out.

 

[stealth]

Some months back I installed the VT modified turbo, and hit a snag. Although I was registering more power than before the install, I was not getting all the power theoretically available. After looking at the logs, VT said it looked like the problem was valve float; the springs were simply not strong enough to work at these power levels. We capped the tune so it would only try to produce the power the valves were limiting me to, and left it at that until the next step could go forward.

Well it looks like the springs are now available, and I have a set on order.

site isn't updated how much are these bad boys

 

[mitdr774]

Wow, these things have some baby cams in them.

That is lift at the lobe. Factor in the rocker ratio and it will be higher lift at the valve.

 

[SONIC1.4]

So if I were to purchase the valve springs, and upgrade to those cams, get tuned for it all, would there be more hp to be gained on stock turbo? If not then could I install these two items with the stock turbo while I await a turbo kit?

 

[Swordsmith]

I had planned to use this approach in order to avoid all the hassle of removing the head

Cams are tempting though.

 

[Preloader]

You won't have to remove the head. You will have to remove the camshafts. i am not sure you can remove just the camshaft, but leave the cam gears and chain installed like the cobalt. The VVT actuators are in the cam gear drums.

I could be wrong, but I don't think you are gonna get to those springs without removing the pulleys, timing cover, timing chain and using a special cam clocking tool to time everything when you put it back together.

If you are gonna go through all that, it seems like a good time to install higher performance cams.

 

[Scot]

site isn't updated how much are these bad boys

Looks like the "hardweld" option is $751 / set - which means you send them a set of cams, they build up the lobes by adding material, and then grind the new profile.

 

[Swordsmith]

Or hopefully they hardweld a set they have on hand, charge you that 751 plus a CORE, you send them your set when you pull them out for the swap and get your CORE back. I wouldn't want to sit around with no car waiting for the mail to get to them, them to do the work, and the parts to get back to me. But that's just me.

SO I haven't looked into cams at all, what exactly should be making me drool about the idea? I kind of hate to be giving anybody but MFab my money at this point (even though this whole thread is about giving money to someone Preloader has already decided not to subsidize any further)

 

[Scot]

Or hopefully they hardweld a set they have on hand, charge you that 751 plus a CORE, you send them your set when you pull them out for the swap and get your CORE back. I wouldn't want to sit around with no car waiting for the mail to get to them, them to do the work, and the parts to get back to me. But that's just me.

SO I haven't looked into cams at all, what exactly should be making me drool about the idea? I kind of hate to be giving anybody but MFab my money at this point (even though this whole thread is about giving money to someone Preloader has already decided not to subsidize any further)

Seems like a bigger cam would help a smaller turbo run lower boost for the same amount of flow. No idea how spool / lag / temperatures would change...

 

[Preloader]

It would really help a bring down the boost threshold of a larger than stock turbo.

But I also believe it would help push past the flow limitations of the stock turbo, especially with the upgraded compressor. And with the better springs and cams, You could raise the rev limiter and actually make horsepower above 6k. That's where things should get exciting.

 

[MPFab]

A proper set of Cams on a 4G63 can yield well over 60hp on a stock head. Without flowing the Sonic head, it would be hard to know how much could be gained from cams alone.
Preloader, send me your head, and I'll have it flowed. I'll cover all cost.

 

[Preloader]

I can do that.... Do you need the cams and valves installed? Or just the bare head?

 

[MPFab]

I can do that.... Do you need the cams and valves installed? Or just the bare head?

I'm checking with my guy now. If the head were to be ported, I'd say just the bare head. Since this is about cams, he may want all of it.

 

[Preloader]

LMK, shipping won't be cheap. I'm skeptical about benefits of porting on a boosted application, but I'm so far out from rebuilding that engine, that it's doing nobody any good sitting on my bench.

 

[cndctrdj]

I just did a little research on cams... Most 4cyl cams don't gain much of anything, without other major mods. Turbo engines don't gain a ton from cams cause most stock cams on turbo cars are don't pretty well from the factory.

Since our engines are tiny. I don't think much will be gained from raw Hp.

The idea would be to think of what most cams do. They move the power band further out. So if we could shift our 5k peak Hp to 7k these cars would pull for days.

A good write-up https://www.amsperformance.com/resources/technical-articles/58-famous-dsm-camshaft-test