I have b18c1, and Im putting in JUN valve springs and retainers and skunk2 stage 2 cams (whose specs are almost exact same as JUN Stage 3). I was just curious if these springs are going to be too stiff for the cam lift ???

 

No, they will be fine, there are people on the board (SGT) who are not big fans of the JUN springs

 

I've never used a JUN valvetrain with non JUN cams but I have done vise versa and had bad results... For SK2 cams I just use Portflow springs... They have always held up fine for me... Just watch for binding springs as they can snap cams... JUN springs are linear progressive and I see no reason why they wouldn't work... Peace

 

alright cool...I just didn't want to have the spring be too stiff....but I can't imagine them not working......the specs on JUN st 3 and skunk2 st2 are alomst identical...

 

JUN springs bind at 12mm. make sure you have them installed by a machinist and
the install height set properly or else you may have problems

 

What will happend if I use stiffer springs than JUN springs with JUN cams, would over stiff springs cause the cams snap???

 

Yup, that's exactly what happened to my friend's old CRVTEC motor running JUN3's in the Portflow head... Spring bottomed out and the IN cam snapped... Blew the entire motor... Cracked the sleeves, bent rods, and destroyed the cylinder head... That was only at ~5000rpm too... Peace

 

skunk2 just emailed me back. they said it should be fine? go figure

 

What kind of materials do they use to made the cams, so many bad story about JUN cams.

 

What exactly do you mean by the spring being too stiff?
How is that bad?

 

Stiff is good but only to a point... It reduces the risk of float, etc... On an F/I motor you need a stiff spring to counter the extra pressure from boost... Think of if this way... You're trying to rotate the cam when it's lobe begings to push down the rocker which in turn is then transfered into the valve spring itself.. The extra pressure that is exerted by the spring is just then turned into shear over the cam... (The timing belt is rotating the cam while the lobe is "basically" getting jammed due to the excessive pressure).... This is how cams break... It also comes from spring binding... The spring basically bottoms out so it can give no more while the cam still wants to push down... I hope I didn't make this sound complicated because it really isn't... Latez

 

I got my springs and retainers in. Just want to know if i should take it to a machine shop and make sure they are spec height or not ?

Maybe its fine, as is, installed. But I think maybe I need to double check the height first for my skunk2 stage 2 cams??

 

JUN springs will coil bind with those cams if installed by JUn specs.

Best advice:

Box those springs up, put them under bed, call Portflow:

http://www.portflow.com

Talk to Tom, give CC, ship springs and retainers to you overnite.

Problem solved.

Jeff

 

why would it bind, those are almost the same spec cams as the JUN stage 3 ??? Almost exactly similar

 

I guess I am wrong then.

(joke)

Call Tom, order springs, save hassle. I have nothing to gain.

And who told you they are almost exact same size? They are not? And maybe you didn't know JUN springs are like 7k from bind with jun 3's.

Now you know.

Jeff

 

Skunk2 Stage 2 12.3 mm(intake lift) 266 @ 1mm 11.8 mm (exhaust lift)

JUN Springs

12mm 195lbs
12.5mm bind
**1.340 installed height

This won't work ???

 

Go to importreview.com and look around for a spring test.It tells you everything you need to know.I already upgraded to toda springs and im glad i did.

 

ok.. so here's a question, mainly for knowledge. If you run a JUN spring with a portflow retainer, what will the installed height be? I'm guessing the retainers are going to be different thickness, and will thusly alter the installed height.

 

i see all these threads and id love to believe that jeff and stephen know what they are talkin about. ive had my JUN 3 cams and valvetrain for around 2 yrs now. they have been installed in 2 different heads and have had no problems. while in my 99 coupe i revved the motor to 8700 (ITR redline) and now i rev the motor to 9200 every pass down the strip. so with all this negative attention am i just lucky??? the install height was never checked on either head cause i had never heard of such a thing when i installed them. so whats the deal????

 

I bring the question up because the lift is different on the skunk2 stage 2 cams then JUN 3s

 

I just picked up some portflow inner valve springs, along with ITR outer springs, Ok once and for all.

Will this spring setup work fine for SKunk2 stage 2 cams, and not coil bind ?

Can I use ITR outer and portflow inners with JUN retainer ??


Modified by ScottFern at 6:05 PM 5/5/2003