LostMarine

Educate me. Im having them do a fresh block with all the bells and whistles, but i dont know what is really required for the head. What "stages" are you all running? My goal is just to max out the 6466 and be done ( ~850-900rwhp).

If i can do just the normal $500 valves/guides ( like my current head), why should I drop $2-3k?

Thanks

umair

There is no need for a built head on a s2000. All i would do it freshen it up and get a good intake manifold/throttle body.

staylor725

I'm running the standard size ferrea comp plus valves with ferrea bronze guides, bc dual springs, keepers, and steel retainers. Not sure of the power limit of my setup but I only plan on pushing it to 700whp, I think it should be reliable at that power level. I don't know why people are always saying no need to build the head, I know more than a few people who have dropped valves and not because ap1 retainers failed. They just break off at the bottom and trash your motor. The problem is the 5.5 mm valve stems, with your power goals I would get the over sized 6.6mm on the exhaust side. Both sides would be best but at least do the exhaust side because It will take more heat before failing.

LostMarine

so, im a newb, whats the equivalent IP "stage" of that?

Mijae007

At least stronger springs would be ideal at that power level to prevent any valve float.

Spoolin

I have the 2.5x head build much like Redstar and I believe Bales. That was recommended to me by John at IP.

staylor725

2.5x is the 6.6mm exhaust side and 5.5 intake side. 3IX is intake and exhaust 6.6mm.

InlinePRO - InlinePRO Race Spec Cylinder Heads

Jaspah

A 6466 pushes 30psi of air onto your intake valves easy, which makes it harder for the valvesprings to close them. Therefore, use upgraded springs and retainers on the intake at least.
If your valves still look pretty and shut 100%... no need to upgrade them IMO.

I just did build my head because the guides were waaaay out of spec. Read the workshop manual. The clearance between the valve and guide should only be 0.11mm max. Mine were more like 1mm+ after 100k miles. So please do check! This will lead to better valve cooling and less oil consumption.

mys2k3

Inline pro no longer uses the 6.6mm stem on the intake side. The only difference between the two seems to be the port and polish. I'm leaning more towards the 2.5x even though they recommended the 3IX.