valvetrain on sr20 det.

[muin2112]

Hey guys, I'm new here and just started a build on my first car (my silvia s15) i bought a bunch of parts from Brian Crower and found out that my valveguides for the intake side are actually too big for the new valves that they provided. has anyone came across this situation and how did you solve it?

[ultimateirving]

Return those parts and buy the correct ones

[muin2112]

I've contacted Brian Crower and hope I get a reply soon. what size are the standard valveguides? 6mm right?

[Tom N]

Sr20de uses a 6mm exhaust stem ( not sodium filled )
Sr20det uses a 7mm exhaust stem. ( sodium filled )

I don't think Brian crower makes stainless 6mm non turbo valves.
Supertech makes 6mm stem Inconel exhaust valves and matching bronze guides but only in 1mm over.

Intake valves are the same in both motors.

[muin2112]

thanks i didn't know that the non turbo had a smaller exhaust stem, I'm going to collect my head from engineering and measure them. I got a reply from Brian Crower to double check them, if not they would replace the wrong ones. I just hope that the engineering shop made a mistake. You guys got any tips for a first timer in engine rebuild and mods?

[Tom N]

thanks i didn't know that the non turbo had a smaller exhaust stem, I'm going to collect my head from engineering and measure them. I got a reply from Brian Crower to double check them, if not they would replace the wrong ones. I just hope that the engineering shop made a mistake. You guys got any tips for a first timer in engine rebuild and mods?


Turbo head had sodium filled exhaust vakves which are 7mm.
A non turbo doesn't need a sodium filled vakve so the valve stem is thinner.

Switching a turbo head to using a 6mm valve is a performance upgrade. They just need to be stainless or better yet Inconel to counter the heat of a turbo motor.

You will need to get new factory DE exhaust valves or Supertech 1mm over DE valves. Brian crower only listed stainless vakves in 7mm stem for a turbo head.
You can switch go a 7mm stem valve if you swap guides also but I wouldn't do that.

[muin2112]

ahhh ok, I havent heard of Inconel but I will do my research into them sounds pretty awesome. Im not doing a head convert since my s15 is a spec r, but i was mainly upgrading most stock components to stronger aftermarket options to hold just a bit more horsepower.

[Tom N]

So you have a sr20det then?

[muin2112]

yeahp! haha thats why in the title of the forum page I wrote sr20 det. thanks for helping me out though guys! any other tips?