just curious how much torque and hp you guy's think a S5 Na block can handle.. and i'm also looking for its weaknesses. yes i know I can add dowls but besides that.. Mainly looking for the weak points of the side plates...

thanks in advance....

The block is as strong as a S5 turbo block. I dont know why you would suspect the block to be weaker.

the s5 N/a was designed to be normally aspirated and the port design are different

port design doesnt really justify hwo strogn the block is. i would ownder about dowel pin castign suround and the actual castign of the irons under the working surface especially under where the streess cycles of the engine occur. ihavent looked at the s5 NA and s5 turbo castings. but if as mazdaspeed7 sais they are teh same then i dont see why anyone would want a turbo secondary plate as u can port the NA bigger

I dont have any turbo end plates, but I do have a few n/a end plates, and Ill take a pic of the dowel pin areas tonight. But I assure you, they are the same between tii and n/a end housings. The center housings are the same for n/a and TII(except S4 n/a, which has egr passages the S5 and and all TII centers do not have). And the only difference in the rotor housings is the coolant port on the TII ones(its not drilled on n/a housings), and the exhaust sleeve is different.

yes i think i can get the s5 na side plate to flow better and more that the TII plates.... just getting ready to put my S4TII back together and have some s5 na plates to play with.. that and i just pick ed up a mint s5 gxl still running and might turbo that when i blow it.. mainly just trying to find the weak point on the motors to weldup and dowl.

I was wondering this as well. Good to know.