Costom tension bolts or studs
 

there is a local bolt manufacture in my area. they can make any style of fastener in any size and thread pitch.
i was thinking of having some custome studs made up.
has anyone else gone this route?

Why? There's commercially available stud kits, both stock sized and oversized.

why? i want to eliminate the middle man!

Its going to be FAR more expensive to have one set made, if its going to be a decent product. The only way I can even offer them is by making them in bulk, same goes for Rohan...

Heat treatments, straightening etc is expensive...

you make these? how much do they cost from you? what do you think about using studs vs doweling
they are about 450 from mazda trix and i can get my engine doweled for 600
but thew say i cant use them with the stock flywheel

Are you talking the oversized guru stud kit? The oversized kit requires the complete block to machined and re-threaded to use them. The machine work alone for a 2 rotor engine will be close to $750.00 and more for a 3 rotor. Add the cost of the Guru kit and you are talking about $1200.00.. about double what it cost to simply pin a 13b motor.. For you 13b guys I am not sure how worth it it is but for people like myself currently building a 20B it is needed on the longer 20b engine when you have plans of making HP above 500..

They have 2 sizes. One which requires machining and one that doesn't.

I had mine 13rew studded with the oversize ones. I only put 3 stud on the spark plug area. All the PR running 4 on their 7's 13B. If you have a drill press and know how you can do it yourself. I was quoted $600 from the machine shop and it cost around $250ish for the drill press at Harbor Freight. It's not as hard as people make it to be but hey I'm a rotaryhead on a budget :D

Yes there are many people only using 3, 4 or 5 studs.. And you can probally get away with using a standard drill press.. but when doing the entire motor..all 18 studs, that needs to be done on a CNC machine with each part secured into a fixture to insure each hole is correct. The benefit from the oversized studs is the increased clamping tension achieved when using all of them. Only using 3, 4 or 5 absolutely defeats the purpose of this modification.

My 20b is completely studded all 18..

There's probably too much slop in a drill press to accurately drill the holes (besides, you should be drilling them under sized, then reaming anyway). You could do it on a manual mill with enough time and patience. For instance, you could make a fixture to locate the pieces by the stock dowel pins, then do one hole at a time on all the plates and housings while keeping the mill in the same place, then reset for a new hole and start over. This will take a lot more time from having to keep changing the plates and housings, but if you've got your own mill and the time to do it, why not right?