Changing The Valve Springs

[Adam]

I think you'll find the Ford tool is for the Boss engine. It will do the job but is still a PITA to use.

[IH8TOADS]

Thinks that's what ford used for mine and said it was a PITA also. Seems like my issue is induction noise not springs afterall.

[ebxmple]

The main sets of springs I have fitted are the Crow set which comes with the retainers aswell so they are meant for the xr6t and also have fitted sets from Herrod which dont come with spec sheet either. I understand what you mean bout only taking one dud spring or measurement to fail but even factory springs fail. I havent asked for specs etc as I beleived them to be replacement springs and no dramas with measurements etc. How long do you reckon it would take per spring to measure,shim and fit correctly? I am not against what you are saying in any way, I am just keen to learn more.

[RIP85]

I sell valve springs once a week at least (for diesel engine's) out of all my customer 80% of the customers use the different height shims

[01txr]

  ebxmple said:

The main sets of springs I have fitted are the Crow set which comes with the retainers aswell so they are meant for the xr6t and also have fitted sets from Herrod which dont come with spec sheet either. I understand what you mean bout only taking one dud spring or measurement to fail but even factory springs fail. I havent asked for specs etc as I beleived them to be replacement springs and no dramas with measurements etc. How long do you reckon it would take per spring to measure,shim and fit correctly? I am not against what you are saying in any way, I am just keen to learn more.

To check heights is as easy as sliding the Valve Micrometer on, sitting the retainer on, wind the mic out till the collects hold the retainer

in position firmly and read the measurement, remove mic then add whatever shim/shims required and install valve spring making sure

installed height is acheived, I also like to make a note of the exact installed height for each spring.

When installing a large lift cam shaft you should use a light spring that you can fit by hand and measure compressed height

and check valve spring presure at that height to make sure it is making sufficant pressure to suit the camshaft.

You will find quality valve spring manufactures will have specs at certain lifts, they may not be able to provide the pressure

at what your camshafts lift has so if its not a matched kit it is best to have the spring pressure checked for your valve lift.

Eg say 280pounds at 12mm compression from installed height, in one case on 1 valve installed height is 1mm greater

giving 1mm less compression resulting in say 250pounds at full lift.

this is why if installed height length is greater than recommended it will also affect open spring pressure.

if your valve spring isn't making the required pressure for the rpm range of your cam as well boost you are running

it will float and in turn lead to terminal failure. As I said it only takes 1 soft spring to destroy a engine.

I'm not a expert on valve train and have never siad I was, please consult with the manufacturer of whatever product you

use and search for all available info to guide you.

I have based all my comments on what I have learnt over the years.

If I am wrong in any thing please say as all feedback good or negative helps everyone to learn.

There is so much to learn about valve spring dynamics that it would require a book to explain completly.

What would make it harder is not having the hands on experience to fully understand.

Race teams put a lot of money into researching valve train components as it is the differance between winning

or DNF. hence the secret valve train no engineer will disclose.

[bluprinturbo]

"It is a time comsuming process to measure and check all, there would be a lot of mechanics out there that

will charge you for the labour but may skip in doing the process of checking everything and just fit

the springs, they take the risks if it does fail.

They can always argue the point that you have over reved it, not warmed engine before giving it a

workout, run to much boost etc etc".

guarentee you my nizpro valve springs werent installed in this way.maybe that's whats wrong with my car.also,can you pick a nizpro valve spring from a stocker?whats different about them.

Edited 21/05/09 12:44 PM by bluprinturbo

[PHANTMXR6]

Well put, 01txr.

That sounds pretty much on the money to me.

It should help a few more people to understand how things work.

[toxik]

hey guys very interesting reading. I have an 05 bf and was contemplating about putting atomic springs in from a blown ba motor.

the manufacturer should be able to give out the specs for these shouldnt they?

and from what ive read it would be easier to take the motor and my car to the mech rather than pull them out first?

[Adam]

Shouldn't need to do it on a BF.

[typhoon_freak]

mine cut out at 370rwkw, doesnt hurt to do them