Moppie: The cam is a street grind - lumpy but not as bad as the race spec R2 or R3 (R3 made its power at 7000-8000rpm). It would have added approx 10bhp to a stock motor with a webber downdraft or RS1200 carb setup. The RS1200 spec engine as a unit was 22bhp over the original 55bhp EB3 despite the fact it was an 1170, not a 1225cc engine.
The best all-motor 1G engine I built totaled out at 98bhp @ the front wheels (in a 680kg car).
Engine specs were EB3 block and head (better than the EB2 - it ran bigger valves and domed pistons with better combustion chambers). The head was decked almost to the manifold studs bumping compression to 10.5:1 and required adjustable cam wheels.
73mm Goldwing pistons were added as well as an EN1 crankshaft and conrods taking the motor out to just over 1400cc.
Induction was the Dell Orto 35mm carbs (look like mini webbers) choked to 32mm - using twin 40mm Webbers is a bitch as the manifold blocks the distributor requiring a 90 degree adaptor to offset the dizzy (likewise with the Mugen Quad-Keihin setup). Exhaust was initially a 4-1 collector, replaced with the Jackson Racing/Bassini 4-1 tuned extractors that ran out of the front of the car and then under it - that robbed torque and I'd built the car to make peak power at 6000, not at the 7500 the Jacksons were designed for (basically because the engine was stroked). I eventually used a set of RS1200 pattern 4-2-1 extractors and a 1 and 3/4 inch exhaust. Ignition was EN1 electronic ignition.
Head work requires cleaning up the ports and valve seats and matching to the intake and exhaust runners. Getting a Mugen head is better, but they don't run thermostats which is a bitch. The bonus is that the exhaust valves are bigger than the stock EB3 intake valves. Mugen intakes are even bigger.
A good street package would be RS1200 spec 4-2-1 exhaust, R1 cam and single/twin sidedraft carbs. Without other tuning you will find the engine will prolly pump 75-80 bhp at the flywheel (the engines are more receptive to mods than any other Honda - basically they are an under-utilised engine).
The engines are also simplicity themselves to work on - just don't over-torque the head as I did the first time... all-alloy blocks tend not to like that
Yes, yes I do love the 1G SBC Civic
