I havent seen someone do a proper anaylsis of the loads in a 13BT and how exactly additional dowelling will fix things. GURU sell a stud kit as an alternative to dowels.



There was production changes to Mazda through S4/S5/S6 engines to rectify problems and Ive been advised the S6 end plates are supposed to be the most meaty in this area.

 

You are correct in saying that S6 rear plates are the strongest of the lot, I have seen several S4 rear housing cracked but never kept them around for the photo OP you are now requesting. As for dowels it is just one builder/tuners way to help improve block strength and integrity, but as BDC says proper tuning seems to alleviate the problems we seek answers for. And sorry I would not be getting any cracked housings anytime soon as I have fully mastered the tuning art bit.

 

This is the bit Im interested in. Im thinking, has anyone actually looked at the loads inside the motor from the factory? Is there a fatigue limit and associated failure from this "problem"? Does additional dowels "fix" it, or is not a real fix. Like Ive seen photos of guys who have cracked through the additional dowels. I know that hearsay and it isnt scientific, but you guys see what Im getting at.



I honestly dont know and it would be great if someone was able to nail down the specific loads and the specific benefit / drawback of additional dowels.

 

i hope that i can clear this up for you cracked dowel pins guys.ill be honest here i make over 700 horse power to the wheels on gas in a s6 car.and i never once have broken a dowel pin or cracked a housing.the reason you ask? lets take this one step at a time.its true that older engines don't have the meat around the pin area.but the real reason for breaking is the mounting of the engine.think about where your motor is mounted from,the s5 is from the center,the sa22c is from the front cover.the s6 from the rear engine plate ok.when you apply tourqe through via transmission,clutch and futher drive train,what happens to the engine.the tourqe is transfered through the plates.hmmm what hold the plates together the pins.when you mount from the rear plate the tourqe can olny transfer throught that plate to the motor mounts only!

 

yah i think that has a lot to do with it

 

its not new news by any means,mazda fugured that out through the years and thats why its mounted at the rear now.another tip that i have,i don't solid mount any rotary down for that reason too.

 

i wanna see everyoens pics of broken dowels, please post

 

So anyone got any info on where the dowels go when you do this.



GregW