need help with valve selection
 

Hey guys first and foremost I appreciate any input I get back..I have done alot of searching the past few days and have not come to a real definite answer, not to mention alot of the posts on it are really old. I was having some misfire codes for cylinder 4, turns out the compression is low and Honda is stating its a burnt or bent valve. Im having a friend of mine that works for a Honda dealer on s2ks pull my head so i can take it to a well known local machine shop. I was thinking I would go ahead and replace all my valves, retainers, and springs with aftermarket more durable parts so i wont have to be paranoid about this happening again. Im just trying to figure out if it would be worth it to go with oversized valves, but Im having trouble finding out if one-there are any gains from it and two-if I would have to do any type of tuning/fuel management once installed. Also, I have heard something about 1mm size valves not working do to clearance issues of some sort, if anyone could clear some of this up Id be greatly appreciative, thanks guys :thumbup:

No, they make no power even tuned without tuning you might lose power. In general this motor wants velocity not size.

Sources: Alaniz, Church Automotive and Endyn.

so excuse my ignorance but would my best bet then just be to go oem size but maybe go for strength and just go with like a supertech valve-retainer spring set?I would assume they would all be lighter but more durable. Also could I still get the head port and polished and see any improvement and just stay with regular size valves etc.

Personally for a mostly stock setup I would use OEM everything -- just make sure you get the AP2 retainers and not the the AP1. Not even sure they sell the old retainers any more but just in case order them for a 2004 or up.

The key is to have your retainers checked every 30k miles give or take a lot depending on how hard you drive the car. Or if you know you over revved have them checked immediately.

Source: Me

The Supertech valvetrain is good, but you will have to check that often too because the Ti wears out quicker. You could get the stainless steel supertech retainers instead of the Ti but I haven't heard much about those and I'm not sure it's worth it.

If you are driving the car really hard as in going to the track a lot then go with the Supertech stuff.

Source: Endyn

I would not touch the head. There are 2 shops now in the country that for sure know how to do the right head work on this car. These are very tricky heads to get to flow better and somewhat counter-intuitive. Like I said before this car doesn't like anything bigger. In fact, smaller exhaust ports would be better but then you need a custom header. The reason they are larger from the factory is emissions. The CFM gains are very small even spending thousands. I have one, I know.

Sources: Hytech Exhaust, Endyn, Portflow and Me

If you want to do something while you are in there install a Spoon HG which will boost your CR a tad.

Sources: Me

Man that was a lot of info that was great. So my decision is leaning towards supertech valves standard size..springs and supertech steel retainers not ti. Also spoon head gasket. Thanks for the info

Anything else I should consider?

Yep. It may not be the valves. Pull the head and work out what the problem really is, and then start planning and plotting.

Honda tends to throw out the "bent valves from over revs diagnosis" pretty quickly.

It could also be due to problems in the bottom end.

Yeah my friend that is pulling the head is going to look it over and do a leakdown test
...all other cylinders have ok compression but 4 the one throwing
misfire codes is 170. And I already changed coil and plugs too...hope its just a valve...

Good move. The leakdown will quickly show if there is any leakage past the valves or rings.

thanks for your help. yeah I was hoping to spin this into a positive and take advantage of the head being off..but it just doesnt sound like there are alot of options. I mean it sounds like oversized valves arent the way to go and neither is port and polish..so I guess..just the head gasket..does the spoon head gasket really make a difference? I mean is it something I will notice?