Valve Spring choice/seat pressure ??

[turbotalon1g]

Ok I messaged Kelford about the springs I have.

I have crower titanium retainers and spring set, NOT BC.

Anywho he/they sent me 2 messages.

First he said yeah they will be fine, then he said wait, you will need our beehive spring with shim to get the 110lb seat pressure.

I told him E85, 35psi and about 500whp on a DJ. and limit of 8kish.

Any reason boost level would make him change his mind on spring selection.

[4g63tcrazy]

Just curious.. Is this still going to be on the 16g or are you running a different turbo now?

[Febo]

The force of the boosted air behind the valve body trying to push into the cylinder?

I never thought about it before but I guess there will always be a static 35psi pushing on your intake valves when they are closed.

[Pushit2.0]

What cam shafts?

[turbotalon1g]

Kelford 272s.

[Pushit2.0]

110lbs of seat pressure is A LOT. This is not a truck boat truck V-8 will long push rods and rockers. Stock seat pressure is like 50 some lbs and the crowers should be ~60-65 lbs seat pressure and pending lift ~150-160lbs full open pressure. I ran crower spec springs in my car shimmed for 210lbs full open pressure (.430" intake lift), and my car seemed to like the 47psi it made on the street. So I take it you are worried about the valves on the intake side of the cylinder on the exhaust stroke being pushed open by intake manifold pressure? The exhaust manifold will be under higher pressure but the valves are a little smaller also.

~John

[turbotalon1g]

Basically at first kelford said my spring setup was fine, then he said no because of the boost level that I would need their spring with shim.

[JET]

I run standard Crowers in my car too. I put a small shim under them, but it wasn't much, .025" or something? I run Crower 415's too, which should be much bigger than the 272's. The ramp is one of the big things with springs, but I doubt they would ramp up that extreme for a medium cam. I bet you would be fine with the Crowers.

[turbotalon1g]

Cam specs here:

http://www.camshaftshop.com/camshafts/model/evo-1-3-4g63-vr4/30/

Spring info:

Kelford Racing, High performance valve spring set (with spring base and titanium retainer) to suit 4G63 DOHC engines, EVO1-EVO9. The valve spring is of ovate wire beehive style, the benifit of this is superior valve control therefore allowing more rpm, boost and reliability versus a parallel spring design. Use the factory spring base for Street/ Strip applications up to 8000rpm and 23.5lb(1.6 bar) boost, over that use the supplied spring base to incerase seat pressure to 110lb (50kg)

[Pushit2.0]

Well of course they want you to buy there springs. I think your fine with what you have, they are a proven setup.

~John