need help with my new head & spring pressure at the seat*
Turbo Mini Forums

I have these springs in my head, the springs heights were set within the heights instructed in the leaflet that came with them from Minispares.

They are the Minispares 200lb springs, set to standard height iirc http://www.minispares.com/Product.aspx?ty=...id=33655&title=

now im putting a new cam in my car & i have been told by the person grinding the cam that i need to know

approximate seat pressure of the spring of the head ''At the seat'' I was told to ask.


i recollected on teh phone (graham Russel) grinding my cam said a minimum of 75 pressure at the seat.

as this is a Modern high lift, short duration camshafts & a very radical new design.

i really need that info can some one please help.

Unfortunatly I thi nk you may have a problem finding the info, I doubt anyone has measured it,

Is your head off? If so I'd say whack it under a pillar drill on top of a set of bathroom scales and see what they say with the valve just lifted off the seat.

This is actually pretty interesting to me at the moment, asI've just put in an RE13t, I may check what my spring are and decide if i need to up them while my head is still off,

you can buy fairly cheap testers from the US to measure this

http://www.summitracing.com/parts/PRO-66835/

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

they must have some sort of seat pressure if set to the instructions.

i have no idea how to test this & the head is on the car but the engine is out.

i dont want just to do the cam change shit loads of things.

Found this

http://www.minispares.com/Articles.aspx?ty=ad&aid=367

Looks line they may be a bit under 75, but I'm guessing your lift isnt massive sou you can probably up it with some shims.

he said 65 is on the limit for his cams.

im running 1.3 rollers, my mechanic is doing this so im walking in the dark asking questions.

is this a easy thing to add shims?

I've got you some info Nick.
At 1.40" fitted height those springs will give you a seat load of approximately 82.08psi. This is dependent on lift, but is for valve lifts in the region of 0.400".

WWW.TURBO-MINI.COM

Legend. Looks like I'm good to go then..

When you say lift are talkin about the rocker lift?

Edited by NickG on 9th Apr, 2011.