When building an engine of any type balance between intake cams compression and exhaust are keyDaniel,
Would you then say that increasing intake and exhaust valve diameter and increasing compression by going to 4mm domed piston while using the stock cams is not going to gain me much?
Trying to understand........
if you go to big on one side and not the other the power band may suffer greatly . So lets say you
wanted 3 engines all 124 spider 2000 cc but each to have a different amount of power and power band
we will start with the lowest and work our way up .
Engine 1
Slightly Modified over stock
Port Head, Exhaust manifold and intake
Drill Holes in Air Box ( as Casaba suggested )
Maybe use a 1800 Head to increase CR (almost 1 point to around 9 to 1 with stock pistons )
replace mufflers
Change Coil, Wires and Plugs
If you can find a K&N Air Filter great if not no biggy not much of a improvement in stock air filter box
Tune everything just right and as wikkid suggested go through what you have like fuel injectors etc
and clean check test what you have .
Power maybe 115 to 120 HP Power band good to 6k RPM Cost depends on how much you can do yourself
i would say lowest $1200 to about $2500 .
Engine 2 Mild Modified Build
Port Head Intake and exhaust
Replace ECU with Mega which allows you to remove the air flow meter (the bottle neck of the system flow wise)
Drill Holes in Air Box ( as Casaba suggested )
Maybe use a 1800 Head to increase CR (almost 1 point to around 9 to 1 with stock pistons )
replace mufflers
Change Coil, Wires and Plugs
Replace Cam or Cam Shafts for a Mid Power band boost just Intake is Needed something close to the 40/80
I wouldn't use the 40/80's on the market carefully choose a regrind .
2 Inch Exhaust from manifold or header back
If you can find a K&N Air Filter great if not no biggy not much of a improvement in stock air filter box
Tune everything just right and as wikkid suggested go through what you have like fuel injectors etc
and clean check test what you have .
Power some where with in 120 to 145 HP depends on how well you choose your work and parts power band
2k to 7000 RPM Cost once again up to you how much you can do yourself $2000 to $4500 .
Engine 3
2L Head Port and polish Large Valve Larger Cams ( you'll need after market valve springs with lift over 9.8 mm )
Megasquirt ECU Replace stock air filter box with performance air filter round type
Change Coil, Wires and Plugs
4 mm Dome Pistons 85 mm over size
Header and 2 to 2 1/4 inch pipping back
Injectors will need to be replaced with the next size or 2 up
Balance engine parts since engine is out might as well lighten flywheel 5lb to 7 lbs can come off
increase Oil Pump Pressure can be done by replacing spring inside oil pump to a stiffer spring
Tune Engine Adjust Cam Timing 3 Deg advance on Intake 1 Deg retard on Exhaust
Power some where between 150 to 175 HP Power Band 2500 to 7500 Cost $3500 to $7000
Yet we haven't touched full race so thats far more extreme
Does this help ?