Then the head studs are tightened. SR20’s often have head sealing problems and the high strength studs with the improved head gasket will help.
Next, the correct valve shims are set to make sure the rocker arms sit straight. This step is often neglected by people when working on SR’s. This makes the rocker arms sit at an angle to the cam lobe which increases wear and can cause the rocker to skid off the valves at high rpm. On the SR, one shim is a guide shim with a groove that holds the rocker arm in place. The other shim is select fit and is used to keep the rocker arm level. Nissan makes this shim in many thicknesses so you can find the right one.
First, the hydraulic lash adjusters and rocker arms must be installed. The hydraulic lash adjusters are keep submerged in oil so they won’t get air in them.
A dial indicator whose rod is welded to the shell of an old lash adjuster is used to determine how thick of a shim is needed. The height of the top of the guide shim groove is measured and subtracted from the height of the valve tip. The difference is the thickness of shim needed.
Here is a new select fit shim in place.
17 comments
Why not OEM main studs?
For competition engines, I prefer not to use them because they are torque to yield and they stretch and take a set. They can only be reused maybe once and it’s a good idea to change them every time on a serious engine.
Mr. Kojima,
How do I get in touch with you on building a Ford V6 motor?
for the mains, did you guys use arp’s torque spec or something else? I always thought it was a bit high
We split the difference. ARP’s torque spec is too high and the threads might pull out.
What does ARP call for and what did you guys end up going with?
ARP states 80 ft/lbs we think that’s too much. We use 65 ft lbs.
No WPC this time?
No not on this engine.
Low Silicone…hehe, I hope those pistons don’t need big boobs.
stupid autocorrect
Are you modifying the upper oil pan to clear the windage tray or did you find/make a spacer? the jet nuts on my tray touch the upper pan and require me to mod my pan.
It’s weird on my FWD engine we did have to mod the pan but on this RWD engine, we didn’t.
Hi!
When would you say the HP limit is for OEM MAIN bolts?
Thanks.
//Daniel
They must be replaced every time but around 500 hp
Thank you. Did you also made an Aline bore after fitting the ARP’s?
Thanks!
We always check and in this case no. For Subarus yes 100% of the time.