if my 03 kia rio 1.6 dohc mi-tech engine was based on the mazda b6 engine, would the mazda b6t fwd engine fit my car? how much modding would need to be done? or if anyone knows of a direct bolt in engine, please let me know. thanx for the help

[renamed, stickyed by Haddy]

oh boy. here goes again. someone make this a sticky...

the B6T drops in physically. yes. kind of.

you'll need the rio front engine mount (the one across the timing belt. next you will have to do something about a clutch. you have to use the Rio flyhweel if you dont plan on changing the transmission. chaning the transmission is harder than it looks. the rio uses a cable clutch tranny, the B6T is for the most part hydraulic, and finding a cable clutch B6T transmission is harder than parting the red sea. trust me. i've tried. on top of that the B6T transmission is cable speedo drive. the rio is electronic. the rio speedo sender SHOULD fit the B6T transmission. next is the axle problem if you swap to the B6T transmission. custom axles arent that hard to have made. finally the transmission mounts are just different enough to screw things up. custom made trans cross member is not that hard to make.

now the hard part of the swap. electronics.

if you keep the rio transmission and flywheel you can still use the rio crank sensor. (be careful installing the flywheel, it has to go on a specific way to insure the trigger wheel on the flywheel is in time with the engine) from here on in it will require a standalone efi system. the rio cam sensor cannot be mounted to the mazda head. so the stock ecu will have no idea whats going on anymore. alternatively you can use the engine harness and ecu from the B6T, however that will require splicing in for power, ground, ignition switch, not that hard. the only downfall with that is it will NOT pass an emission test. the old ecu and the low compression of the B6T just wont be able to meet new car OBD2 standards. on top that the stock B6T ecu is limited by the MAF for power, and max boost.

so sportage to also explain more, which motor is better in the long run?

thats another loaded question.

which one is better in the long run is dependant on what you want to do.

it boils down to this. for short blocks, the rio engine is better suited (much better) to high rpm NA applications. it has longer and lighter connecting rods. it has shorter and lighter pistons. the pistons use thinner and more tightly spaced rings. the big end rod journals are smaller diameter, so less frictional losses. also with the longer rod the resulting higher rod/stroke ratio reduces frictional losses and increases piston dwell at TDC. there is also a whole complicated acceleration thing that is far beyond the scope of this website.

for high boost applications the mazda short block is better. it has infinitely more aftermarket with regards to pistons, connecting rods, etc. maximum engine speed is usually lower in a turbo engine compared to the NA engine, so the slightly heavier weight of the mazda pistons and rods is not such a penalty. make sure you use a 'big nose' mazda engine, as the small nose ones are prone to breaking.

with regards to cylinder heads, that again depends on what yuor intentions are.

if you plan an all out high rpm NA screamer, or a high boost monster the mazda head is the head of choice. it has larger ports, larger valves and a larger combustion chamber. there are oversize valves readily available for it, as well as valve springs, retainers, solid lash adjusters, and many many cam profiles. Be careful which mazda head you use as only very few are compatible with the later generation mazda block (which is the Rio block). now, if you use the Rio cylinder head, its easy to make high compression thanks to its smaller combustion chamber. it has smaller ports that, although lower max port flow, maintain high velocity. so in the end you can make a high torque NA engine, that still pumps out a respectable amount of HP, or a very highly responsive smaller turbo engine with say a max boost of about 10psi. the smaller port rio head makes great flat torque, so its perfect for a street fighter type of engine setup, where maximum thrust at engine speed is required.

This has got to be the most information I have been able to see in one place!!!!!

Thank-you SPORTY!!! Can't believe that I missed this info for so friggen long!!!!! Well worth the read.

I would like to hear about the different combinations of internals more with the above information as well if at all possible. Like what a B6T crank will do for a Rio motor. I understand the strengthening for boost thing involved but what about N/A applications??

Virgo, here's two more threads for reference:

http://www.streetkiaz.com/streetkiazx/modules/newbb/viewtopic.php?topic_id=14927&forum=17&post_id=177308#forumpost177308

http://www.streetkiaz.com/streetkiazx/modules/newbb/viewtopic.php?topic_id=8573

Quote:
MOSES LIVES AMONG US!