Standard turbo valve springs
Turbo Mini Forums

Does anyone know what the poundage / spring rate of the standard turbo valve springs is ?

And if its higher than 180 lb if increasing the length of the pre load would be advantagous ?

I only ask as I have been adviced to 180lb springs and nothing else, and my valve seats are 2mm further in to the head than normal as I have milled the roof out of the chamber.

Although I do need to pack up the rocker pedistals 2mm to maintain the good rocker angle...do I just pack the springs 2mm as well and use 180's

BTW - I took my buddy VTEC Pete out for a spin this weekend, and even though I am running her in, he gave it a name, the "Brocket"...cause I'm a brocket maaannn, nah nah nah nah nah nah nah nah nah nah nah....

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you have gone this far with the head 2mm in the chambers to lower the CR

i suspect you will be going to be using a modern turbo camshaft?

maybe a phase 2 from AVONBAR?
which IMHO is an excellent cam

upping the spring seat pressure, serves no purpose on our turbo motors as they dont rev that hard

on the inlet and exhausts you machine the spring seats or pack the seats acordingley to bring this back to the original spring deck height which you would find on the mg turbo cam,


thats if your sticking with this cam.


OTHER CAMS!
in a perfect world you need to subtract the valve lift which is EXTRA! in that cam you use from a standard turbo cam (ie) phase 2 cam on both inlet & ex by machining the valve spring seat pockets as mentioned as these are wildly diffrent

if this is not correct and your serious about your engine,
which i presume you are!


with a ......"modern cam you will QUICKLEY KILL your whole valve train"

i have some calcs i will dig out for you

Minispares springs are an excellent choice.

sorry dont know the poundage of the original springs

this is only a guide I hope others may comment!

TURBO DAVE is doing some calcs on the subject at the moment
but he is a busy guy

i hope he can comment

Edited by BENROSS on 23rd Nov, 2005.

So, just to confirm,

I intend to use a NA MG cam or similar ie a modern turbo cam.

Hypothetically, If my turbo head were standard with standard springs are you saying if I use a higher lift cam I would have to drop the spring seat height to avoid binding of the springs at full lift due to the increased lift ?

and is the amount you drop them by the difference in the lift between the standard cam and modern cam ?

In my case, effectively my spring seats are 2mm lower already because of the repositioning of my valve seats 2mm further into the roof of the chamber to allow removal of material to reduce the CR, which means I will have to shim the rocker pedestals up 2mm to keep good rocker geometry.

So to check I have understood

1). I need to find the difference in lift between the standard and higher lift cam

2). See if this is more or less than 2mm

3). Machine or shim spring seat to corrected hieght

Does this make sense or do I have the wrong end of the stick ?

Also do cam kits just come with taylored spring specs to avoid having to do any spring seat alterations ?

Cheers Brocky.

Edited by Brocky on 17th Nov, 2005.

BTW - I took my buddy VTEC Pete out for a spin this weekend, and even though I am running her in, he gave it a name, the "Brocket"...cause I'm a brocket maaannn, nah nah nah nah nah nah nah nah nah nah nah....

Build thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=7483

Katy Mini Owners Club Thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=505552

Let's make sure you embarrass at least one VTEC MINI today !

https://www.facebook.com/groups/17557298589...096464253807802

brocky spot on!

Also do cam kits just come with taylored spring specs to avoid having to do any spring seat alterations ?

Answer is NO!

imho use the minispares springs there excellent

Where the fook has the answer i posted gone???

Question?

How may serealist does it take to change a light bulb

Answer

A fish....a fishy fishy fish...

Anyway thanks for the advise on the springs guys,

Dave I did read your reply and did wonder where t had gone !!!

I wish I'd just started with a na mg head and just changed the exhaust guides to take sodium cooled ex valves....before I milled the chambers on my turbo head, then the springs and everything would have suited the na mg cam... + the larger inlet valve ...although I have throated out the turbo inlet to put in the na mg inlet.

also apparently the na casting walls are thicker so more material could have been removed round the edges, but then is the turbo casting thinner to promote cooling as well as the sodium ex valves

So on balance using the turbo head with sunken valve seats and debeaked may be the best comprimes in terms of cooling?

I got some picks, how do I get them uploaded ?

Cheers guys

BTW - I took my buddy VTEC Pete out for a spin this weekend, and even though I am running her in, he gave it a name, the "Brocket"...cause I'm a brocket maaannn, nah nah nah nah nah nah nah nah nah nah nah....

Build thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=7483

Katy Mini Owners Club Thread - http://www.turbominis.co.uk/forums/index.php?p=vt&tid=505552

Let's make sure you embarrass at least one VTEC MINI today !

https://www.facebook.com/groups/17557298589...096464253807802

go to photobucket

http://photobucket.com/login.php

make member free!

upload your pics one by one

then cut & paste the IMAGE to the forum

good luck