HKS valve spring ( max lift )

[30psi 4agte]

8.2mm is bordering on bind ! but like big worm says you would expect waggot to Know what they are on about.


$112 is my trade price.

ehendrikd: it may pay to question them about the posibility of spring bind with these cams and STD springs as its BAD if it is to happen!!!

[ehendrikd]

thanks 30psi... i was going to go by waggot's recommendation, but better to be safe than sorry! lucky i picked up on this thread before going ahead

[30psi 4agte]

The highest you can go with them springs is 9.9mm


Installed height is 1.345 inch = 34.1mm
they bind at .875 inch = 22.225
clearence before bind of .080 inch = 2.032

so how you work it out is ( in mm )
Add your bind height to the clearence you need to stop bind ( 22.225 + 2.032 = 24.2)

Then you subtract this from your installed height.


so 34.1 - 24.2 = 9.9mm of lift safely!

[ehendrikd]

ah excellent...

i'm thinking now about 264 duration + about 9mm lift + performace springs.

i will have a programmable aftermarket computer before these go in, with this setup do you think it would still be somewhat streetable?

i use my sprinter as a day-to-day, but also mainly dirt club events

cheers
evan

[1JZ-Rolla]

I'll vouch for the Performance springs too... ran their 4AG set in my GTE to solve valve float problems at higher boost with the worn out stock springs. Dirt cheap & excellent value!

[30psi 4agte]

yeah it may be ok for street BUT bear in mind that over 8.5mm of lift you need to do a shimless / shim under bucket conversion or risk poping a shim out and causing major damage !! \

P.s you have a PM

[ehendrikd]

ah yes, i had forgot about that. i think the original 8.2 waggot cams may still be the go, but with some uprated springs.

thanks heaps everyone for the great info

cheers
evan

pm replied

[30psi 4agte]

did ya get ya private message

[kingmick]

yeah it may be ok for street BUT bear in mind that over 8.5mm of lift you need to do a shimless / shim under bucket conversion or risk poping a shim out and causing major damage !! \

P.s you have a PM

you sure do need to! i use 3sg buckets! and i wouldnt go higher than 50-55psi otherwise your sapping to much power for no reason. with most setups you get way with 45psi.

p.s ment i use 3sg buckets in 4ag's

[oldcorollas]

100psi is mental! You'd want a pretty good starter motor to get the whole lot spinning!

To get 60psi seat pressure out of the Performance Springs springs, I'm guessing you'd need around a .080"/2mm shim (just a vague guess, but I doubt the shim vs. preassure increase is going to be linear- I bet Stewie could come up with a formula to work it out exactly ) which would bring the bind height a bit closer to the HKS ones.

How much does a set of HKS springs go for?

F=kX ........

force = spring rate x compression.
easy to work out from their specs, since increase in force is virtually linear..

as for bind.. at least in pushrod motor, the pushrod gives way first would hate to see it in an OHC setup tho

spring specs should be given for just the spring itself, so the installed height etc _should_ be from top to bottom of spring.
where it is given as including retainer etc, take that away from the measurement, as it distorts the f=kX relationship

as for seat pressure, easy to work out.
seat pressure required for NA for the rpm you want to run + ( boost x intake valve head area) = required spring pressure.


so... at what lift do you stop gaining in a FI setup? 8mm? 9mm? 10mm?

256x10?

[kingmick]

shame seat pressures are not that easy to work out
to give you an idea, have a look a an egine that is raced heavly around the world and have a look at how many diffrent spring rates and heights
formulas get you into the ballpark!

[takai]

Oh yeah, and i think you need to do those calcs again there 30psi. The HKS springs certainly dont bind at 8.5mm, if they did i would know about it. I stripped my head down a few months ago and didnt see any evidence of them binding at 9.1mm (.360").

[ed]

fyi:

you should ideally leave a MIN of 0.060" clearance from max lift to coil bind, that is industry gold standard.

[30psi 4agte]

Oh yeah, and i think you need to do those calcs again there 30psi. The HKS springs certainly dont bind at 8.5mm, if they did i would know about it. I stripped my head down a few months ago and didnt see any evidence of them binding at 9.1mm (.360").

Ahhhh are you sure they are deff HKS springs ?????????????
Are your cams deff 9.1 mm ????????????????????????????
Did you work out how much clearence is left till bind?????????


9mm is where im aiming for too but from what i have worked out they dont offer much more lift capability than STD springs


VERY INTERRESTED TO KNOW M8!!!

[takai]

Definately HKS valve springs, this is how they came:
http://gallery2.plebeians.net/d/3548-2/DSCF0002_018.jpg
and in this pic
http://gallery2.plebeians.net/d/3562-2/DSCF0011_008.jpg
The box in the corner is labelled HKS.

I test compressed one to check and i came up with almost 10.5mm lift at bind, and the cams are defiantely 9.1mm lift, they are copies of GrpA cams from the Bates AE92 bathurst car.