AFAIK, the HKS cams are fine on the stock valve train. I have been runing 272's for over a year, and I am fine. All they really do is increase the duration, not teh lift by a significant ammount. If you increase the lift, then you risk the stock valve train.

 

Just DSM. I definately agree with you that the stock springs and retainers work well together. The entire valvetrain was designed by Mitsu to work together for probably 150,000 miles or more if maintained. My whole reason for starting this thread was that I would be interested in dropping in HKS cams on the stock valvetrain and running it like this for a year or two. I was basically looking for a one-year review from people who have the stock valvetrain with HKS cams to see if any problems have developed now with time and miles. Now the issue has come up with the stock retainer possibly hitting the seal with any upgraded cams. This was exactly the type of information I was after. Many people seem to have gone quite a few miles with this setup with few if any reported problems. They also seem to make quite a bit of power for minimal investment. $550 for cams and if tuned correctly gives like another 25whp. That rocks. Very informative thread thus far. Thanks for the input.

 

The stock spring is not lightweight... the stock retainers are though. Most aftermarket Ti retainers are heavier than the OEM Evo aluminum ones. At Revolver we took a different approach.... we looked at sprung and unsprung weight very much like you would when shopping for wheels or suspension. Our kit has less unsprung weight (including the valvespring) than other performance offerings allowing us to keep spring rate low to decrease parasitic losses in the valvetrain.

Hollow cams are light - and very trick, but unfortunately making aftermarket cams out of hollow cam blanks would make them too expensive for most enthusiasts. Also there is very little gained from making the cams hollow - the polar moment of a spinning cam is not hugely changed by making it hollow. Anyway the extra pound that you add from using solid cams instead is more than made up for by the additional horsepower gained.

 

I have a Revolver set being shipped out Monday. I give my impression of the set when I get them. I have a few customers to get out of the way before I install them, but I'll let you guys know...

 

Notice the (Aftermarket) in that post? I'm well aware that we have different oem spring/retainer setup, however all the aftermarket valvetrain out there, is shelf DSM parts.

 

interesting

 

The EVO stock springs suck. As much as they such at up to 26 psi of boost, 7600 rpm and using the largest HKS cams, 280's, they have worked very well on the RS.

The stock EVO retainer is extremely light, light enough that I don't think any aftermarket retainer is going to be lighter. We have spring sets here also. The retainer is very short as the ones being compared, this will give more clearance for lift and the seal.

There are many spring/retainer options out there. I have tested a bunch of spring kits and weighed a bunch of retainer kits. Our spring and retainer kit sells for $275. These are the same kits we install in all of our Stage 3 heads and the same ones that we use in our 7 and 8 second drag 4g63's. I have run them to 10,000 rpm and ran 46 psi of boost using them.

As I said there are many choices, I will warn you guys that there are a few sets out there that test WORSE than stock.

Here is some information on the stock EVO 8 springs I did.
Stock retainer only weighs .004 grams.

Stock spring seat pressure is 62 pounds
Open pressure is 140 pounds
Coil bind is .490.

Good luck with your choices.

David Buschur
www.buschurracing.com

 

I had ment to say "spring setup" which would include the retainer as well. But my mind often works alot quicker than my fingers. As you can see from some of my posts in this thread, there are often words missing or poor wording, due to me changing the wording mid sentence and not correcting.. Anyway.. I need to proof read.. But thats entirely off topic. Just wanted to clear that up.

 

I'm not sure I follow you. What is it about the stock springs that you find lacking? They are very light and apparently keep the valvetrain out of float in the RPM ranges that the stock bottom end will support, even with HKS 280 cams, so what's wrong with them? Isn't the very low spring pressure a plus if there is no problem with valve float?

(Obviously running a motor well beyond the factory rev limit or using cams with substantially higher than stock lift is a different issue.)

 

(Obviously running a motor well beyond the factory rev limit or using cams with substantially higher than stock lift is a different issue.)

There you have it

David Buschur
www.buschurracing.com

 

It would be interesting to see the seat, and full lift pressures of all the maufacturer's spring offerings. Like I said, I'll be giving the Revolver set a shot (they are already on the way)... If I find them lacking, I'll call up David.

David, are/were you using Eibach springs? I know I remember someone using them... might have been on the Type R though.

 

We'll publish that info for you guys shortly.

We have used the Eibach EVS springs on my personal Evo - although they do not have a set specifically for the 4G63 so we had to machine special retainers and lower spacers. Our spring has some advantages over the Eibach - more lift (spring travel), OEM fit, substantially cheaper, harmonic dampening designed into the spring, and it is an EVO specific application. If you look at valvesprings in a "Spintron Machine" (used to simulate high RPM running conditions) a poorly designed spring will flutter and surge at certain positions and RPM's. We have written software to simulate running conditions and we can build a spring to "self-damp" its own motion. So Zeus.......... you wont find them lacking it is the best spring available for the Evo valvetrain.

 

Hey, no offense... if not anything else, the people here can count on my honest opinion.

 

So ogvm what kind or ringing did you observe with the stock springs? I ran double trw springs on my last application which was a small block chev I reved to 7k with .445 lift. A set of self damping springs would have been sweet then and sound interesting now for my Evo. I plan to limit spin to 8k. Hope this is not too off topic but we seem to be getting some great info here.

 

This is an update to WORKS' findings thus far.

Thanks to Revolvers' nice photo above, you can see the height of both lifters is dramatically different. (observe where the taper begins on both)

In order to determine the actual clearance between the retainer and stem seal, we need to find out how high the hydraulic lifter protrudes while the engine is running.
When we rotate the cam nose onto the roller, we notice the lifter slowly retracting a few mm and then when we rotate the cam back to the base circle, the lifter rises again (similar to the lifter height on the left).

We are trying to understand if there is a relationship between the height of the hydraulic lifter and the valve spring rate while the engine is not running.
We have multiple springs that we are going to test by the end of the week.