This isn't a replacement for doweling. It will add more strength to the engine, but not as much as doweling.

 

are you making studs for both 12A and 13B motors, or just for 13B?

 

Hmm...

If these are supposed to fit in the existing holes, most of those tension bolt holes have coolant running through them.
Does this mean by running a larger diameter fastener, you are reducing some of the cooling in the housings?

Most of the stock 13B tension bolts are noticably "necked down" if you look at both under the bolt head and right after the threads.
Could've been easier and cheaper just to keep the same diameter, but the tension bolts look like they have been machined down...for a purpose?

Hmmm...


-Ted

 

I have been saying this for 4 or 5 years now ever since i seen the solid pins
a local builder is using.
my feelings are that mazda made the tension bolts with a set amount of elasticity
which allows for the expansion of the aluminum housings.

with out the give of the mazda tension bolts I would imagine that the
housings will see higher levels of crush damage.

I still think 6 well placed dowels that allow the tension bolts to pass through the
inside of the dowel and thin enough to keep strength in the material that they pass
through is the best way, least that's how i do them.
if you think this isnt enough add dowels to all the tension bolt holes.
matt

 

not to mention the leaking issue the studs have past the nuts around the threads.
matt

 

I have used the studs numerous times (machining required)at 35ft/lbs. There is no need to go anymore than that. I have't had any issues. Use a high temp sealer and you wont need thread loc nor have any leaks.

-S-

 

like a porsche.... its so they can stretch, or maybe like the porsche snap off and be put in the glovebox so i can look at em

 

this stud kits are the real deal ... 12.7 mm... cure my crack steals and spin bearing problem ...making well over 800 hp .....if you need machine work to fit the studs let me know ..my friend bought a mill machine just to do this work on rotaries
los angeles california area...