What is so good about getting taller or shorter valves?

 

I am assuming you mean oversized valves? A larger diameter is more airflow, and in some cases higher RPMs can benefit from lighter valves like titanium.

 

So what kind of valves for what setup?
For Fi would larger be better or smaller?
And the same for NA?

Prices?

 

You always want more air, so for FI you would want oversized valves.

 

So what about the prices and where to get them. If it would yield more gains why nobody is selling them yet?

 

Probably due to the high cost of production combined with the rather small amount of people interested.

 

You would be hard pressed to find oversized valves for our cars, or titanium valves, or both. Reason being, there is not much of a markert for our cars here locally. I might have the handle on some, but I am not sure myself. Just like us Miragers when we were looking for ARP head studs, it would take a mix and match from another vehicle and see if it would work.

Nonetheless, like bahamut always says, we are not like some of the other car groups out there with tons of disposable income.

 

first cross refrence our valves with other mitsus and see if you can find that might have larger valves produced or maybe another mistu with slightly larger valves would work... YOur best bet however would to contact dave at rpw and find out what they know. just shoot him a pm... he is VERY good at getting back on those usually with in 48 hrs.

 

I'll ask this DSM guy around here.... He knows his DSM and I didnt think he would know much about the 4G93 but he pulled some Clevite 77 bearings out of a hat for me. Much cheaper and much better than the stealership. He was the one who was telling me get some oversized valves, titanium retainers blah blah blah.

Will see what he can do.

 

BTW, I was going to ask about ARP head studs on the Mirage forums, but I guess that answers my question. So I'm gonna see if we have any real interest in getting those made and see what ARP requires for a kit. Could be beneficial, especially considering both Lancer and 1.8l Mirage guys would benefit.

 

And what's the deal with ARP head studs??? Just stronger bolts?

I have sent a PM to Dave about the valves. It would be pretty cool to have titanium oversized valves. Higher RPM and more air!!! With a camshaft it would be a great combination.

 

Yeah, stronger bolts to handle the higher engine forces that will be placed on them. Not really necessary but recommended. One less part to break .

Nonetheless, us Miragers have been running with the MR2 turbo head studs. They fit perfectly and so far, no one has any complaints about them. I am not sure if there is a difference in the length of the 4G94 and the 4G93, but that is what we have been using.

As far as valves, nothing so far... will check with the shop today and see.

 

RPW is offering ARP head bolts for our car. Their price list has them at a direct replacement. Listed as $188 USD.

 

According to their availablity screen, there is none yet for the Mirage, and no mention of the Lancer, even though they do list a price on there.

 

Well, I'm going straight off the price list. I don't think the site is updated (ever).

But I'm going to stop talking now, since my feelings towards RPW are more than clear enough.