Yay, I get to be a noob and ask noobly questions.

Long story short, I pulled the head on my 8 to replace the head gasket, and the machine shop found a crack in the head. Since trying to buy car parts from people these days is like pulling teeth, my best option appears to be an Evo 7 motor that I have available to me, taking the head, and parting out the rest (don't ask about it here, look for a thread mid-week or so).

Well, as far as I can tell from my research, the cam pickup is the same, and at the very least the gasket for the t-stat housing is the same, meaning both of those bolt up. Manifolds are obviously not an issue, and I can't think of anything else that'll be getting bolted back up that is possibly different.

However, I'm finding that the springs and retainers are different, something about square seat vs tapered. This means, for obvious reasons, that I cannot put my SI valve springs (Dynotech, MAP Beehive, whatever you want to claim them sold as) in under the Evo 7 retainers, and would need aftermarket retainers, as they are listed to work with Evo 8/9 retainers only.

However, and I'm probably missing something blatantly obvious, if they work in an Evo 7 head with 8/9 titanium retainers, those retainers are basically factory replacement units for stock 8/9 retainers, are they not? So could I not use the factory 8/9 retainers I already have instead of upgrading to something I wouldn't otherwise need? As I said, I'm probably missing something obvious, but if the springs work in 7 heads with 8/9 aftermarket retainers, I'd assume they'd work with 8/9 stock retainers as well.

 

I know the springs i got fit my head and the company said they work in all 4g63's back to the 80/90s 6 bolts... Idk if the sales guy is retarded or if he was right... But piper race cams is the comapny... And i'm certain if theirs fit everyone elses will as well... Maybe the steel seat that sitts under the spring is what is different and so its causing confusion...

 

Well, it's been confirmed (and MAP's page for those springs specifically states) that aftermarket 8/9 springs do not fit Evo 7 heads without 8/9 aftermarket retainers.

So basically, my question boils down to this: Is there anything special about aftermarket 8/9 retainers that would allow them to work in this instance that is not also an attribute of the factory 8/9 retainers?

 

After some googling i think i'm on the wrong emd of the spring... The only thing i can find in the relm of reference to square valve anything is the keepers... In which case your evo 8 valves would except the evo 8 harware inside the evo 7 head... Or vice versa the 7 keeper will work with 7 valves and retainers and you can still run 8 springs...

Hope that helps... For reference
http://www.hotrod.com/techarticles/e...s/viewall.html

The info is toward the bottom

 

you are way over researching. evo 8 stock springs/retainers are being used in the 1990 4g63 engines. they will certainly drop into the evo 7 head.

 

If he is right and the valve stem is square groove it wont... Or it will and after a few miles the keepers will strip off.., its best to keep the parts that belong together... Together...

Clear this all up... Get the head... A 3/4 socket... A rag... And a hammer.., put the head on a table, place the rag under te head in the combustion chamber of 1 cylinder. Take the socket and place it over the spring retainer... Smack it woth the hammer until the keepers pop off... Take picks off the spring, under side of the retainer, and concave side (inside) of the keepers... Everything should be able to be cleared up

 

I have installed BC springs on various Evo generations (3/6/7/8) with no issues.
I think that coolant grove design is slightly different between 7 & 8 heads, but that won't prevent you from installing the 7's head.

 

mitsubishi never made square groove keepers.
I have interchanged valve train parts from heads from 1990-2006. I know every single change that was made on all the years.

and that removal method should not be used if parts are going to be reused. the keepers sometimes bounce and get wedged sideways. scarring both the keeper and valve stem groove.