Posted By: Sportege_Panicmech
New .50 over pistons. (warning. long late night tired rant) - 04/01/12 12:19 PM
my new .50 over pistons with matching rings. motor is getting the appropriate bore to accommodate these plus I asked the machinist to consider this motor being converted to turbo. He said he'd make the clearance a taste looser to compensate for the added heat in the cylinders. in a nutshell, your piston rings have a gap where the end of the rings meet (ring end gap) while cold. theres a stock specification of how much gap you should have and that gap will decrease as your engine warms up to operating temperature. What you DON'T want is that gap closing entirely and the rings not being finished with their expansion due to hotter than expected cylinder temps. This means the rings start to bind up on the cylinders and scuff them and ruin your rings. Think thats what happened with my current engine from all the high rpm aggressive driving cause it burns a good deal of oil. Anyway, it's coming together very slowly guys, but it IS happening. Also getting the crank polished for new bearings. If they are beyond polishing, then we'll regrind them. I've slightly ported and polished the intake and exhaust ports to match the gaskets. I still need to port and polish the intake manifold but it looks like Kia's version of an intake is a thin one. I will have to be careful not to get overzealous with the porting of the intake manifold. Think I'm going to take a drill and 'slot' the holes of the exhaust cam position sensor. Since the original mazda motor was FWD setup as opposed to RWD, The engine's distributor wouldn't be able to fit in the Sportage cause of teh firewall. So Kia removed it and installed a magnetic pickup sensor in its place that informs the ECU of Exhaust Cam's each rotational pass. This sensor is basically what the ecu uses for a timing reference and then instead of the distributor sending the spark to each cylinder, the ECU releases the ground that releases the spark out of each coil pack. interesting note.. the coil packs have two wires.. one is constant hot (once ignition is on) and the other is constant ground except for the instant when the coil is supposed to fire the 2 plugs simultaneously. the releasing ground signal is the instant the plugs are to fire. Yes, both spark plugs, one is fired on a waste cycle. It's a smart design to save Kia from putting an additional 2 coils on each sportage they sold without really any drawbacks. One exception though is if one signal wire goes bad (got the tshirt) you end up with 2 misfires instead of 1 misfire, but surprisingly my sportage not only kept running, but limped me and my family all the way home 10 miles down the highway.
Anyway, I think imma slow the mount holes on that sensor to trick the ECU ignition timing.. only problem is is that when I tap into the ecu and watch the timing I will have to guestimate my adjustment to what the computer thinks its timing is.. The ECU changes timing advance dramatically between idle, accel, and decel I've noticed. I have an app on my android phone that can monitor my ECU specs. Monitor only, no alterations other than clean CEL's. Anyway, the timing will be near 0 during idle, spike to 14-18 degrees advance under accel and roughly 8 advance on decel. Being turbo, I may want to pull timing back a few degrees to prevent Knocking, but I think the ECU will be able to do that on it's on being they are already equipped with a knock sensor (imagine that on an N/A motor.. hmm.. lol). Plus, the underside of the pistons are constantly being cooled with a jet of oil by the piston oil squirters.. another turbo motor trait... weird. lol. Noticing this motor was meant for a turbo. I'd add an oil cooler to the setup but, well.. They have one already too.. lol. If any of you didn't know this (as I didn't for years) the engine has a water cooled oil cooler. Next time you replace your oil filter notice the housing the filter sits on sticks out of the engine a ways.. that housing has two coolant lines running to it and cools your oil with your rad fluid. I'm not sure that they had this feature on the original mazda FE3 motor or if KIA did that one but I like it. Being that the motor was FWD which would put the filter on the 'back' side of the motor, I don't think that oil filter cooler housing would've fit with and have enough room to replace the filter. anyway.. it's like 5 in the morning and i'm exhausted. peace! End rant!