Topdawgg

Ok, Ill admit it right now, im pretty new to any type of headwork..

Im currently building a 84mm GE Sleeved GT35R setup and shooting for around 500+whp..
I decided i think its time to do some headwork and upgrade the valvetrain.

So i took the head to a very reputable head shop locally for a port/polish and Im just wondering what I should do for valves.
Im almost positive i wanna go with Supertech or Ferrea, but im not sure to get oversized or not, and whether or not to get ones with any Dish.

I plan on running GSR cams for now... Possibly ITR/CTR.... or even eventually down the road going with a more agressive Turbo Cam...

Just lookin for some advice.. thanks..

Monstah

dished valves may help with reducing mass (good when you turn some wicked rpm's), but most of the "race" type valves are made of better, lighter material anyway...and most have the swirl polish with multi angles to help flow around them and create the tulip shaped air cone you want.
As for the oversize, the port/polish job should increase flow enough to produce 500hp on the stock sized valves. Sometimes an increase in valve size can actually be worse off due to shrouding as the valve edge is brought closer to the chamber edge. You could always take a little material out though.

Topdawgg

ok, so im lookin at a set of stock sized...


but they are dished, i guess they are all dished arent they?

good/bad for my setup? does it really matter all that much?

Monstah

I have flat faced stainless valves on my car. It doesn't make a huge difference really wether they are flat or dished. I shift around 7500 (84mm bore, 89mm stroke) If you rev pretty high, look for a lower mass valve anyway. You'll likely find them dished.

Topdawgg

ok, so these dished supertech valves wont hold me back at all...

I wouldnt mind revin to 9-9500 for the track as long as im still makin some power up that high...

cuin9sec

SuperTech

WVTURBOCRX

im run a entire skunk2 valtrain except for crower cams nad i ported and flow tested the head my self. i would recommed the skunk2 stock size valves , they are thinner at the ends and also "tuliped" for better flow.

Monstah

I don't see how they would hold you back. They should help with your airflow.....and would be good with your port/polish job.

Monstah

WV - you mean the undercut stem is thinner than the Supertechs?
IMO that's not always a good thing with aftermarket cams/higher ramp speeds.
I like the tuliped valve faces...I had a set of those once and they worked well.

Topdawgg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Monstah &raquo;</TD></TR><TR><TD CLASS="quote">I don't see how they would hold you back. They should help with your airflow.....and would be good with your port/polish job.</TD></TR></TABLE>

sorry, bad choice of words...

i just meant will they be fine to handle 9500 ish

93supercoupe

so do u think upgrading in valve size would hurt the flow at 500whp and 9500rpms?

Monstah

yeah, they'll be fine.

Monstah

no, it won't hurt, but I was saying that it isn't really necessary to hit 500

WVTURBOCRX

im not saying its thinner but there is plentty of thickness for 9500 rpms. ive never seen the supertech valves to compare. i also agree about not oversizing your valves, you can then run into valve shrouding issues

93supercoupe

so when do u think upgrading valve size Would benefit?

Maybe on an NA setup or something?

Monstah

I'd say upsizing would be good when you get to the point where your head is a cork.

WVTURBOCRX

on a NA setup yea it can help greatly but my experince flow testing dohc vtec heads is that they can flow very well staight from honda. my stock b16 head flowed more air than my friends edelbrock chevy racing heads. he didnt like that.
but when you do a race port job and oversize the valves you take away alot of the velocity in the intake witch is bad at low rpms but good in high rpms when a na engine really needs to breath. correct me if im wrong somtimes what i know and think dont come out very well as words.

Monstah

Along the same lines as what you're saying WV - let's say your intake system is capable of flowing 1000cfm, your exhaust 1000cfm, your head after a good port/polish 750cfm (not real numbers, just for arguement sake) then oversizing would help to increase the flow capacity in volume to reach the 1000 and improve performance on that system... of course, a loss of velocity is possible, but in that type of situation, your cork was the restriction of only 750cfm.

BTW - not surprised about the Honda head outflowing the Chevy race head. That b16 is very efficient.

JDogg

type r valves flow the best of anything out there... but they are dollas, i run ferrea if i dont have itr

Topdawgg

Also, are the supertech valves loud at all?

I know some other valvetrain you can Hear ALOT...

JDogg

if the valve train is loud something is wrong

turbobubble630

stock is fine i have stock in my car and i rev my car to 10,800 all day no problem

whiteef8

Supertech

and about the noise question, the first couple hundred miles on my valvetrain were "clickier" than they are now, now it sounds stock. i guess breaking them in?? anyways, i definately swear by supertech!

Topdawgg

bump


bought supertech valves... nitride coated stainless... stock sized

need some questions answered about springs/retainers
do i want dual springS?

do people stay brand specific? or are springs/retainers all the same basically?

HiProfile

Dual-spring is usually 2 springs with a lower spring rate, rather than 1 with a very high rate. Tyically you want the duals, but it depends on mass & spring rate (brand differences). FYI a 'turbo' cam usually means less duration, more lift. That combo means steeper slopes, which means more susceptability to float - in terms of floating and creating overlap, not floating and contacting piston/other valves. Running heavy-duty springs on a stock cam means a little bit more power needed to turn the cam, but its already moving half crank speed, and very little friction involved.

As for the head flow question, usually higher flow means extending the torque curve for higher rpm's, but usually sacraficing low-range because velocity is less. Experienced porters know how to minimize the bad, and amplify the good.