I’m sure this is probably a repeat thread but I figured it’s best to get everyone’s input as today versus what was said a few years ago. so I picked up another motor to play around with, I’m looking to build it, it’s the 99 1.8 non vvt. Build details/questions. I come from the Toyota world so this is all new to me! I’ve built motors in the past so I’m just curious what different components can handle.




I’m shooting for 250-300whp, will be using a t25 I think as they are cheap to come by and rebuilt. I will be removing the egr and doing the coolant reroute. Fuel system is still to be determined. Currently has the exhintake mod (so I was told). I have a megasquirt pnp gen 2 for the tuning portion.




main, rod and thrust bearings I am going to use ACL race bearings.




ARP head, main and rod hardware




Reusing Oem valves, springs, retainers and guides. I will be replacing guides if worn and new valve seals regardless.




My questions are;




What power level is the oem head gasket good to?




Are there large benefits compared to the price to have the head port and polished, larger valves or dual valve springs?

 

1) allofit
2) nope

 

https://www.miataturbo.net/engine-pe...g-ideas-83443/

 

OEM head gasket isn't known to go so no worries, and no need for thicker either. Just run lower CR pistons, lower the better to reach your goals (miat motor makes power from timing).

Large benefits? Sure but not needed for 250-300whp. I'd just refresh the head with supertech single springs. Check valves and guides like mentioned. If they're good, run em.

The rest of your list sounds ok so far. Just add a megasquirt and pair with flow force 640cc injectors or injector dynamic 725/1000cc. Maybe a DW200 pump. FMII kit with no electronics you're set.

 

https://www.miataturbo.net/diy-turbo...k-links-56507/