Spring height on 3.0 heads

[JohnJL]

I had a set of heads ported, new guides, valves, and larger intake valves. I have a new set of eibach springs and stock retainers, seats and caps.

Eibach lists seat pressures of 90 lbs at 36mm and 277 at I think 15mm from memory.

I brought the heads to a local shop who is new to me but recommended by some race guys and he seemed to know what he was talking about from the look of the shop and various aircooled stuff they were working on.

The machinist called today to ask what height to set the springs. THey tested the springs and measure those spring pressures at the given heights, but he noted its "going to take a bunch of shims."

Is there a separate height spec, aside from the spring pressures? I have only a rudimentary understanding of heads which is why I sent them to a shop, but I thought the height was irrelevant, since its determined by the valve stem?

Thanks for any help, hes due to start assembly in the morning as I need to pick them up in the afternoon.

[cgarr]

So your saying at 36mm he is not showing 90#?

[bh912e]

Given that you have good springs you set them for your desired seat pressure, then check pressure at full lift and finally check for any coil bind at full lift.

[JohnJL]

Originally Posted by cgarr

So your saying at 36mm he is not showing 90#?

I wasn't clear on that from our short discussion.

Originally Posted by bh912e

Given that you have good springs you set them for your desired seat pressure, then check pressure at full lift and finally check for any coil bind at full lift.

That sounds right to me, I was hoping he'd know what to do since he's the expert..

[PFM]

John,

If lots of shims are required it sounds like you may have another problem. New valves, new size, new seats. Is the valve length correct? It should not take a "bunch" of shims. This may be why the shop is questioning.

My 2 cents,

[Mark Henry]

I'll be doing the exact same job on my 3.0 heads at the end of the month.

Are these the light or heavy (race) Eibech springs? I'll have the race.

[JohnJL]

Heavy, the ones ending in .444

[Mark Henry]

Cool, could you post or PM me the final shim results...mine might work out different, but at least we'd know if we're in the same ballpark.