hmm...my fren changed his valve springs to HKS....must go ask him again....

So 269 camshafts are specifically designed for our stock valve springs? The WORKS 269 camshafts are engineered precisely to match to the characteristics of the stock valve springs? Just afraid that the valve-floating & coil-bind will be increased with the stock valves, thats y i need to know mate...

I always tot that with the use of high performance cam profiles with greater lift, the valve train dynamics will change thus u need stiffer valve springs to optimise valve movement.

Thanks...

 

What are the symptoms of valve float? If you're tracking to car and spending a lot of time in the 5000 and up engine speed area wouldn't they be recommended?

 

i realli dunno mate..WORKs website said the stock valve-springs can be retained with the 269 but can also changed to their titanium makes...So i'm still waiting for a reply either by WORKs or anyone here...

dunno much in details about the cams & springs though...THis is what i gather from the web...Here it goes:

The camshaft uses lobes that push against the valves to open them as the camshaft rotates; springs on the valves return them to their closed position. This is a critical job, and can have a great impact on an engine's performance at different speeds...

When you increase the RPM like 4,000RPM or more, the valves are opening and closing 2,000 times every minute, or 33 times every second. At these speeds, the piston is moving very quickly, so the air/fuel mixture rushing into the cylinder is moving very quickly as well. Just imagine if the tensile strength of the springs are not strong enuff, it will not return to their closed position promptly, this will have a loss of performance.


When the intake valve opens and the piston starts its intake stroke, the air/fuel mixture in the intake runner starts to accelerate into the cylinder. By the time the piston reaches the bottom of its intake stroke, the air/fuel is moving at a pretty high speed. If we were to slam the intake valve shut, all of that air/fuel would come to a stop and not enter the cylinder. By leaving the intake valve open a little longer, the momentum of the fast-moving air/fuel continues to force air/fuel into the cylinder as the piston starts its compression stroke. So the faster the engine goes, the faster the air/fuel moves, and the longer we want the intake valve to stay open. We also want the valve to open wider at higher speeds -- this parameter, called valve lift, is governed by the cam lobe profile. As you open the valve wider at higer speeds you also wants them to return to their closed position promtply. So i guess that is where the springs come in play.

Any other opinions????

 

So I guess there would be a signifacant loss of power when the floating begins. What it would feel like is the real question, complete power failure, lag, stutter...?? I guess there would be premature wear on the cam lobes and lifters. Any chance of a valve colliding with a piston? I'm ASSuming that the 4G63 is an interference engine.

 

Yep.

 

Yes valve float is noticeable with a sudden loss of power. Like a high RPM bog but it stays bogged. SHIFT!

 

So i guess that it will be advisable to upgrade to WORKS valvetrains to optimize the 269 performance.....& to be on the safe side???

 

If you were going above the standard P* Brain Flash rev-limit, I'd say springs and retainers for sure. However, I would think that Pete and the gang have designed the 269s to be safe using otherwise stock components. If there was fear of valve-float, they'd let you know. That being said, whenever I go with cams, I'll be swapping out the springs and retainers myself

 

You'd have to know much more than the duration of the cams to know that. But if you are going to be reving higher than stock redline (7K) with bigger cams, I would get the springs and retainers. They are a lot cheaper than a new motor/rebuild. Overkill is almost always cheaper than starting over. Look how nice the bulletproof Supra was. A lot better than starting over. Overengineer as much as you can afford is my motto.

 

u r so rite.... :>

i tink i will go by the way of reliability 1st....thank u so much dude.....

cheers.....

 

Just a simple google search with "titanium retainer wear" offered several good articles on valve float, how to fix it (ti-retainers) and why it works.

Works, is a flash required with the cams?

 

Tuning (via a flash) is required with any major mod. They do provide a flash for the cams that goes along with the P2.

 

Cool. I think I'm going to take advantage of this cam package Labor Day sale. Might be a while before I get them installed though. I hope Works can let me do the flash update at a later date.

 

Absolutely.
If you already have the P2, the optimized 269 Power Cam reflash is free!

 

I'd like to get them, but the installation is what is going to kill my wallet! I can't get to works, and local places want like $500 labor for any cam install.