port and polish

My port and polish job is complete, and it was fun to do . I got very good results more torque and more power "mad power". It's like the motor pulls with torque all the way through to about 6500 rpm and the power band is there on the pedal as soon as you punch it. This weekend i am putting a Fidanza flywheel to get some quick revs and more power, You know the less mass enertia thing. Well if you want to see any pics just go to Google and type Plaza240. If you do any porting and have any ? holla.

cool how much did it cost?

Dyno?

how is it done???

"dyno?"


you're looking at about a 20hp gain from a good DIY port n polish job. it's a pretty generalized amount to gain. i've seen more and i've seen less. more air = better flow = more hp.

check out this link for a how to:

http://www.sa-motorsports.com/diyport.htm

did u diy? i have been interested in doing this for a while and was wondering if you had any tips?

Keep in mind that the 19 hp estimate in that article is for an engine with large displacement and a relative low volumetric efficiency at peak power rpm. Most engines reach 95% VE around peak torque rpm but the common 2 valve per cylinder OHV engines normally fall to about 80% by the time they reach peak power. This is where sport or race heads increase the flow, its not much (if any) greater in the low-to-mid revs. Some heads have +90% VE at peak hp right off the showroom floor; our

KA24DE has about 86.3%. With a good port job and port match you should be able to reach 91% VE at 5600 rpm as well as holding the VE closer to redline. Gains in the lower rpm are just from improved combustion efficiency. In any case, a dead stock KA24DE should make around 164 SAE net hp @ 5600 rpm with the afformentioned head work. Now say that you have a KA24DE with short intake, sport cams & gears, headers, test pipe, unbaffled exhaust, piggy-back ECU mods, no engine fan and excellent tuning. You make 220 SAE net hp @ 6100 rpm; with the afformentioned head work your power could jump to around 232 SAE net hp. But in either case its safer to bet on around 10 hp gains For a NA KADE. This sounds dissapionting at first but ie really just means your KADE head is pretty good to begin with.

Just some extra tech info, SAE net hp is measure at the output shaft of the gearbox in the gear that is closest to a 1:1 ratio (4th for our 240s as well as most car's MTs) and with all accessories running. In 4th gear your gearbox should be transfering over 99% of the power to the output shaft (beacause the layshaft is free-wheeling and there is no mechanical loading of the gears) but the KA's stock 155 SAE net rating is measured with the AC compressor engaged. So the actual crank hp may be as much as 165.