From what I've been reading from NASIOC about the swap from a WRX shortblock to the STI shortblock, there are a couple of questions I have.. 1. Will the stock WRX heads work on the STI shortblock without other physical modifications to the heads or the block? 2. If it does work, will it be stable? 3. What should be done if it will not be stable? Thanks for the help!!!
The CR will be 8.7:1, not where the motor really wants to be. You could use a thicker headgasket but this is really not the way to go as you will loose the squish area. I am doing a hybrid the same as yours but I will be removing material from the combustion chamber to move the CR back to 8.0:1
correct me if i'm wrong but from my research, looks like cams don't need to change unless you plan on bigger power +400whp in the future... the bigger issue is compression ratio... is crawford the only vendor to make 8:1 compression pistons for hybrid swaps? http://www.crawfordperformance.com/products/db_part_info.cgi?id=111
I'm sure axis would be able to help you with some of that stuff. http://www.axispowerracing.net/index.html
Re-iterating what was said about Axis. Email Ron at Axis and ask him if he has anything that would help. Judging from the thread that is going on Nasioc, I don't think you will want pistons from Quirt right now.
I've read a couple of threads about Crawford on NASIOC too... I've already emailed Axis about their pistons... I'm awaiting email back from them...
the response from axis: Pretty much screwed about getting forged pistons from them for the hybrid... Are there other vendors? i might just have to go with the gasket, but like matt said, i'll lose the squish area... or is the cometics gaskets pretty reliable? i've only heard of them, but haven't heard of their reliability... :?:
Noper, you're not wrong. Most hybrids I've read about have kept the stockers. I've just heard some people suggest changing cause they'll limit the power, but like you said, maybe that's just if your going really high numbers.
Yeah, isn't that nuts? I check on it every couple days to see what happens. It has kinda died now since they have decided to handle it privately. But a few others have come forward. I cannot believe that Quirt was just slapping these motors together without checking measurements on the pistons.
Well the CP pistons are in all likelihood just fine, that's what Axis uses too...but yeah just throwing pistons into a built motor without measuring....*speechless* Sounds like plenty of other people are coming out of the woodwork with the same problems. The ugliest part of it all was how Quirt deflected the blame onto everyone but himself. For shame.
I will be doing nothing to the pistons or heads but clean them and use .051 cometic gaskets with a little bore work... any other suggestions?
