Upgrading valve springs

[tsoob]

ahhh what the hell, ill give you some springs that i have leftover from motor we just scrapped, if they don't fit ill also lend you my angle grinder to cut them down

[TRD_ZERO]

Anything to save a couple dollars

[4agtepwr]

Id look for a spring with at least 50 pound seat pressure but 60 would be beter. At the end of the day I know I wouldnt go running 20 pound on stock 20v springs as there junk, but thats up to you. Mine are Performance Springs (brand) from Kelfords and they were 50 pound on the standard installed height and I had to shim them 20 thou to get them to 60 because thats the minumum i would run. $300 bucks for springs seems cheap to me in comparison to a fuc*ked block, pistons and head

[escortman]

Id look for a spring with at least 50 pound seat pressure but 60 would be beter. At the end of the day I know I wouldnt go running 20 pound on stock 20v springs as there junk, but thats up to you. Mine are Performance Springs (brand) from Kelfords and they were 50 pound on the standard installed height and I had to shim them 20 thou to get them to 60 because thats the minumum i would run. $300 bucks for springs seems cheap to me in comparison to a fuc*ked block, pistons and head

they sound like the same springs i got

[4agtepwr]

Yeah i think they were good value for money aye, was a little pissed that I had to shim them cause I was a little worried that they would go coil bind with over 10mm lift but they were still ok and had enough gap.
I think Kelfords can supply a spring for a 20v that can take the same or more lift and will still give a decent amount of on seat pressure.

[Bazda]

Yep same springs as i got for my 20v. Performance springs made in Australia.
The 20v ones come with spacers that have to be used (I think only for blacktop) so it costed a little more than $300 for me..

Thats what happened to me I got valve float, just as well the 20v valves are tiny and soft! didnt really do anything to the piston at all haha but a nice S shaped valve stem.

[MAGN1T]

Id look for a spring with at least 50 pound seat pressure but 60 would be beter. At the end of the day I know I wouldnt go running 20 pound on stock 20v springs as there junk, but thats up to you. Mine are Performance Springs (brand) from Kelfords and they were 50 pound on the standard installed height and I had to shim them 20 thou to get them to 60 because thats the minumum i would run. $300 bucks for springs seems cheap to me in comparison to a fuc*ked block, pistons and head

The manufacturers actually know what they're doing when they fit the factory springs.
Excessive seat load causes increased wear in the valvetrain.

Has anyone looked into part numbers and specs for N/A versus turbo springs for the same motor?

Steve

[Bazda]

Lynn Rodgers actually calculated how much seat pressure I needed and the standard 20v ones were under his calculations. hence why mine got valve float and bent a valve.

[rollaholic]

The manufacturers actually know what they're doing when they fit the factory springs.
Excessive seat load causes increased wear in the valvetrain.

Has anyone looked into part numbers and specs for N/A versus turbo springs for the same motor?

Steve

no doubt they do. they were never intending for the heads to be pushing 200kw + though were they, or any amount of boost. (20vs that is)

you must admit that pretty much any mechanical component has its limits, why is it so hard for you to accept that valve springs ideally need to be upgraded past a certain point?

[TRD_ZERO]

The manufacturers actually know what they're doing when they fit the factory springs.
Excessive seat load causes increased wear in the valvetrain.

Has anyone looked into part numbers and specs for N/A versus turbo springs for the same motor?

Steve

no doubt they do. they were never intending for the heads to be pushing 200kw + though were they, or any amount of boost. (20vs that is)

you must admit that pretty much any mechanical component has its limits, why is it so hard for you to accept that valve springs ideally need to be upgraded past a certain point?

Because members on toyspeed have proven otherwise.
Hey all fair enough this is the kind of input i was looking for to finally make my decision

[rollaholic]

im not saying you specifically need new valve springs. you'll note i said 'past a certain point'. i dont know what that point might be, im only sure that it exists.

bazda for example certainly sounds like he found the limits of stock valve springs on his head.

[MAGN1T]

bazda for example certainly sounds like he found the limits of stock valve springs on his head.

You don't seriously think that valve float caused one and only one valve to bend.
More likely bad workmanship.

I've never had a problem upgrading parts so long as the theory behind it makes sense, the boost thing certainly doesn't.

I've always had a serious distrust for everyone in the trade, no more so than the performance side of things. That's after many years of dealing with many "sharks"

It's easy from their point of view, just upgrade ALL the parts and the customer pays.
When you build your own toys you soon learn that most parts don't need to be upgraded. 90% of failures would be caused by a bad tune, the rest by bad workmanship. Do your own work and get an automatic lifetime warranty.

Steve

[rollaholic]

how do you propose that bad workmanship caused one and only one valve to bend, since the spring itself clearly cant be at fault?

the clearances and tolerances at high revs, as im sure you know, are pretty minimal - you cant imagine a situation where the valve springs are approaching the edge of their effective capacity, and one marginally weaker spring, or one with a minor fault causes said failure?

i wont disagree with you on the sharks front, though i think such people are to be found in all walks of life.

[fivebob]

You don't seriously think that valve float caused one and only one valve to bend.

Why not, there are many things that cause valve loft differences, not least production tolerance in spring pressure, and each valve will have different clearances so it could be quite easy for only one to get bent.

More likely bad workmanship.

How so??? Could you please explain what sort of bad workmanship would cause a valve to bend after running for a length of time. I can accept that bad workmanship might cause one to bend at initial startup, but not once the engine is in service

I've never had a problem upgrading parts so long as the theory behind it makes sense, the boost thing certainly doesn't.

Actually it does, as I posted in my earlier post. It affects valve acceleration and therefore the degree of valve loft. In case you missed, or simply ignored it I'll repeat.

the required seat pressure to move the valve has been reduced, therefore the valve will accelerate faster and you will then get more valve loft.

The higher you rev the engine the greater the valve loft. Which at some point in time will result in valves meeting pistons and the inevitable bent valve.

[MAGN1T]

As soon as the valve is off it's seat, the pressure across it begins to equalise.
When it's fully open, the pressure across it is at it's least and spring load is at it's greatest, significantly more than in the closed position so boost has negligible effect.

Obvious?
That's why it was ignored.

Steve

[pc]

bazda for example certainly sounds like he found the limits of stock valve springs on his head.

You don't seriously think that valve float caused one and only one valve to bend.
More likely bad workmanship.

I'm not going to re-read bazda's build thread but I assume that the lift, duration, and rev limit were all raised at the same time that the boost was increased.

[fivebob]

As soon as the valve is off it's seat, the pressure across it begins to equalise.
When it's fully open, the pressure across it is at it's least and spring load is at it's greatest so boost has negligible effect.

Obvious?

The only obvious thing is that you don't understand the physics involved at all

[MAGN1T]

how do you propose that bad workmanship caused one and only one valve to bend, since the spring itself clearly cant be at fault?

.

Maybe one or more of the valve guides are a bit (too) tight, the hotter the valve the tighter it gets , until it sticks open and bends.
Stronger springs will ...........

I had that with one of my previous V8s after I blew the rad hose off. Bronze valveguide inserts for the loss when overheating.

Steve

[gepsk8]

i think head guy is covering his ass as he had issues in passed with valves having issues so to cover his ass(warrenty, consumer guarantees act) wants u to put new valves springs in.

[4agtepwr]

Its really hard not to get really angry on here sometimes. Im an engine builder by trade, and guess what we dont actully get paid a shitload of cash. There not in there just cause I wanted to spend a bit more money on the bloody thing.
There there because the valve needed that much on seat pressure when the valve is closed and also the correct pressure over the nose of the cam at full lift.
Barrys engine bent a valve because the stock 20v springs arn't up to it. Its that simple. And have seen more than one 20v turbo fail for that exact same reason.