I asked Frank down at SFP if running a little over 400hp on stock gsr valves would be safe, and his reply was yes. I was wondering if any of you guys on here have surpassed 400hp on stock valves. Curious because i'm goin to tune my gsr some time next week and i want to break a bit over 400! Y'all think the valves are capable??

 

Yes, as long as you don't plan on going past the stock redline.

Those valves are great up to 8100 and then your taking your chances. If your planning on keeping it under that then your golden.

 

I revved mine way past 10,000 on a track car with no problems.

 

yeah i accidentally revved mine past 10 grand a few times, i forgot to put in the msd chip

 

So 16-18psi would be safe just for high boost, and say about 10 for daily driving?

 

OEM Valves are very strong...I believe Erick's Racing Drag Civic uses OEM GSR Valves and revs to 11kRPM...

 

I was also under the impression that stock valves can easily rev much higher than stock. Some new springs and retainers and your good to go. Putting a Hp level on valves is kinda weird though. they just need to open and close and lose heat into the head.

 

There a re a few guys on here that make over 500hp on stock valves. Rpm isnt to big of an issue 9-10k should be fine.. the thing that you need to worry about is heat. From what Ive heard stock B-series exhaust valves are sodium filled.. is thats the case they should be able to take a good bit of heat. Can anyone confim ?

 

alot of people will tell you to put springs, retainers if your going for that much power at least

 

any thoughts on this in the modern age? What would someone say to using stock ITR valves with high boost?

 

very general question. the rest of the setup and purpose need to be given 1st. A PSI number means nothing so , try not to use that as a method of comparison.

For most street car purposes, yes, OEM valves are fine. If something is wrong in which head flow is real concern for a specific purpose, or a good rebuild, then you can change. Otherwise, they fine.. Even 12 years later..

 

The exhaust valves are the same as other B series, only the intakes are special.
They have a reduced-diameter stem so that they could be lighter, for the higher expected rpm range of the ITR.
I don't know which valve breaks most often, in. or ex., but the thing to consider with your used valves is, as posted above, the heat and how many times those babies have been slammed into the valve seats over the years. Heat will be higher than an all-motor build with a turbo, obviously.
As the valve guides wear, the valve is less-well controlled and doesn't smack perfectly concentrically onto the seat. They endure a kind of side-to side bending, if you will, that will one day cause the head to snap off.
So we ask ourselves, "I wonder how much longer they can take it?"
Weigh the estimate against your ability to buy new ones, and the risk you're willing to assume with your head and block if an old one lets go.
Current spring pressure on your old springs is also very important.
If you have R springs too, remember, ITR intake springs are weaker than GSR/B16, because the valves they were designed to control were lighter.
So, pairing them with heavier valves than an ITR intake lessens their ability to control valve motion.
Some of my ITR springs were exerting less than 30lbs. seat pressure when I checked during head rebuild.
Also, condition of retainers and keepers (locks.)

 

My old GSR is still running around with a totally stock head (built LS shortblock). Its just a shade over 400whp and redlines at 8600rpm. In fact it just clicked 100k yesterday - my buddy sent me a picture of it. Its been boosted since ~63k in 2007

 

yup, mine were boosted for 7 yrs.....and 18 N/A in their prior life in the '90 PR-3 head, lol...
I went ahead and replaced while it was apart.