Gonna build this spare 2.6 I have. Got most of the parts, NJV head, valves, heavy springs, lifters etc etc. Can a guy do like a .020 over bore, slap a header and free flow exhaust, and a Weber 38 on it and see any increases? Or is that a waste of time?
Or is there a little more that should be done. Trying to keep it as close to stock as I can, and find a nice balance of improvement to budget ratio.
Skip the heavy valve springs... No gain and all you get is more friction.
Have the piston skirts coated with a dry film lube.
Run a wider gap on the second ring. Run the top gap in spec.
Lightly port the head, short side radius cleanup and remove casting imperfections and flash.
Try and get a 9:1 CR. Most aftermarket pistons are "decked" to reduce the CR by 1/4 to 1/2 a point. Pretty much the wrong direction for a non turbo motor.
Find a good shop to bore and hone the block. One that understands how to hone a performance motor. A plateau hone seems to be the best thats readily available.
web page You might find a difference in how well this works compared to say a motor done with a hone from Harbor Freight. A good shop will match the honing abrasive grit to the type of rings you run. Whatever you do, avoid using plain cast iron faced rings.
Fit the piston clearance before you have them coated.
Once you have the head on shim the timing chain tensioner for minimal clearance.
Verify your cam timing. My gut feel is the 2.6 is a bit over cammed for a truck. You can look for a smaller cam (the stock one from a 2.0 would be a good experiment), or try advancing the stock cam 4?. A crazy future idea I have had is a simple RPM sensitive cam advance for the 2.6. Dial in 4-8? advance at low RPM, and 4? retard above 4000 RPM.
Remove the ears in the #3 cylinder bay ( bottom of the block).
MAG check the block for cracks in the deck before you have it bored and honed.
