Just got off the phone with Port Flow and I was talking to them about how their valve springs react to the Jun 3 cams. He said he knows of like 5 people that have broken the JUNs and when they break, they break into like 4 to 6 pieces and ruin the motor. Any suggestions? Just go with Toda?

 

Mmmm...why not JUN?

 

Run the JUN springs if you want JUN cams. The NC boys might not let the FL crew use JUN products without disowning us.. so beware..

 

**** the Hype JUN

 

If you go Toda I'd say Toda Springs, If you go JUN Go JUN Springs

 

I would use the toda springs either way.

I have seen binding on jun springs with jun cams

 

I run JUN springs with my Spec B's - no problems....so far

 

I am running Type R outer springs, and Portflow inners on JUN cams, i hope theres not a problem

 

I've been running my JUN2's on Portflow/ITR's for like 6 months or so.. Mike M. has seen a little more on his JUN3's. No problems yet.

 

Title says JUN 3, not JUN 2

 

well, I ordered the valve springs from Tom, not the cams/cam gears yet.

 

ti retianers tend to let go around 20-25k miles of binding from my experience

 

I have Jun 3's with JUN Springs= Zero problems thus far.

I think usually when things break, it is because of being improperly installed. Overtorqued, under, etc... Or just not your lucky day

Miguel

 

cant overtorque springs
the problem is that people dont check installed height.

 

So the important thing for higher revving is having the spring capability to return the valve to a closed position, and thus avoid float, right?

My question is, if you put in a beefier inner spring (or even inner and outer), why is it then necessary to put on a titanium retainer? Basically, other than a lighter item being moved, which makes it have a ability to rev a little easier (does that translate to higher??), why would you need to upgrade to ti reatiners, especially if what Steve says is right, and they tend to fail after 25K miles ..... ?

 

JUN2 has more lift on the intake side when compared to the JUN3. I THINK it has a hair more duration, too.. but I'm not 100% sure.

 

because im talking about spring bind.
read the post.

Ti retainers are necessary if you want reliability at high rpms.
You also want a valvespring that closes the valve as soon as possible and
keeps it closed while at the same time accomdating the lift you are throwing
at it WITHOUT BINDING.
Ti retainers also help the springs do their job better.

 

Ramp velocity?

 

from what i remember, the specs are pretty much the same.

I dont think ramp angles are published.

 

There are several of us who have known this for a while... Guess what cams we're running. Nobody has posted because we don't want a toda/ jun flame war going on... And as near as I can tell, the jun cams that broke were all sold about a year ago and through a us distributor. I have heard of nobody breaking cams that came directly from japan. FWIW.....

 

Agreed, but that does make a difference in relation to how the springs react (not to mention the metal the springs are made of). A sharp angle is going to put a LOT more stress on the metal, even with less lift. Unless I'm just thinking crazy or something.

 

I've even cracked Mugen valve springs before my rebuild. Now i just run TODA valve springs and i only use OEM type-r cams. So far so good.

 

But other than being lighter, titanium isn't necessarily STRONGER than the stock R retainers ......

So if you run springs with a higher spring rating that have the ability to close the valves fast and hard and avoid bind/failure at 9,000, why change the retainers?

I guess I am skeptical to the reason people need to get ti retainers. The main thing you need to avoid bind and float is a stiffer set of springs. Having a lighter valvetrain lets the parts move easier, but how does lighter translate to a higher redline? Has anyone actually done a strength test at rpm of a stock R retainer compared to all the aftermarket Ti ones?

Based on 5 years of racing bicycles where the only torque and power come from leg muscles titanium parts are NOT always the shizznit ..... I have broken Ti bottom brackets, stems, axles, etc. etc. ....... the biggest problem with titanium is not that it is an expensive metal, it isn't really, it is that it is expensive to fabricate and engineer. Cycling is always one of the first places they trickle down technology from aeorspace, much like F1 racing ........

 

if you arent going to come close to 9000 then dont bother.
Hell, i ran up to 9300 regularly with stock retainers with no problems.

 

.....fwiw, Ti does seem to be more brittle but stronger than steel. *shrug* I dunno, I'll check my retainers at 15k and let you know how they look.