ALFAGTV6.COM

[patzo_3l]

does anyone here use these valve springs from iap?

http://www.international-auto.com/index ... sid=857345

and if so what revs are you running to and what sort of lift cam are you using?

[Murray]

I have run the "performance" springs from IAP for 3 years on my 86 GTV6 with S cams.Car is regularly tracked and I see 7200 or so rpm on a regular basis.No problems.My understanding is that these springs are essentially "blueprinted" versions of the stock springs.

[Duk]

Good to know they are available for a good price

Can someone explain that to me . How can a valve spring effect emissions unless it's not closing the valve properly?

"USA Note: not legal in the USA on pollution-controlled motor vehicles."

[MR2 Zig]

To the People's republic of California ANYTHING that isn't stock is illegal including valve springs, pushrods, the kind of hose on your radiator, your aluminum coolant tank, JK's con rods. The state has a testing procedure to approve various parts as smog legal that very few are able to afford, nevermind that many of those parts have no effect on emmissions or, if used, would result in lower emissions. For example ... I can't upgrade my fuel injection legally. If I wanted to do that I would have to "hide" the new injection (make it look stock) even though it would release fewer emmisions than the L-jet.


zig

[Mats]

It's the same here in Sweden (depending a little on MY, before -76 anything goes).
But the guys checking the cars are usually cool about it, they aren't doing anything unless you are seriously pushing it.
The guy checking my race car (!) last time actually thought it was great, usually when cars come in with race seats they are too narrow for him.

[Zamani]

Really? In Sweden? The land of 1000 bhp BMWs and Volvos???

DO yo have a yearly emissions test?

Wow, seriously off topic now.

About valve springs, I've used stock springs on my 12V for the longest time. I guess if the rpms are set to a limit of 7K with non-aggressive cam ramps, it should be ok. I'm not sure if the ramps are worse for the rockers or springs....especially old style V6 rockers.

[Mats]

Emission tests? We have government monopoly shops that go through the whole car and will fail you randomly for any stupid stuff you can think of. Not having windscreen washers for instance, or if they think the car is too loud or too low. No measurements needed, judge, jury and executioner.

On the other hand you have some cool dudes in there too, guys that will let you roll through without even looking at the obviously not standard suspension on a race car because he knows the car only sees the street when you drive it to and from the checkup.
Or the guys that manage to lock the emission test equipment exactly on the only spot in the range where it is legal, just because it is an old and well kept car and he knows that it will run like crap if you adjust it to suit the test.

Anyay, sorry for the OT.

[Jarle]

Hi- patzo

Did some research when I innstalled these springs in my race heads.

The IAP springs are about 5mm longer ,free lenght, than stock once (one of the reasons these were brought to the workshop).

Std valvespring
Spring force valve at seat (35mm): 70lbs
lift 10mm(25mm): 150lbs

IAP
Springforce at seat : 110lbs
lift 10mm : 195lbs

Sperry valve springs:
(not sold anymore) : 80lbs
: 165lbs

Jim K. made a thread about performance valve springs and I think the spring-pressures he recomended for a high performace engine was in the area:

Seated : 80-100lbs
At 10mm lift; 170-180lbs

To get acceptable values I lowered the spring base 2mm on both intake and exhaust witch also gave rom for more valve-lift (with the right pistons).


I would not use these springs on a relatively "standard" engine.

Jarle