Does anyone know if the 2009 and newer engines have the same exhaust manifold studs as the older renesis's renesies renesie? I assume they are the same, but atkins rotary only lists 04-08 studs.

Also, is there an alternative to the stock studs. Wanted something with a spline or hex or something to put a tool on.

Unnecessary background. I pulled the 6 port engine from my 2008 because its burning coolant and blowing oil. I picked up a used 6 port from a nice kid on Facebook, fingers crossed it's in decent shape. The new engine doesn't have any exhaust manifold studs at all. Threads look clean and there are not signs of a fight to get a broken stud out. I'll start pulling the old studs soon as I have, but figured since I have to wait I'd ask here.

Thanks for reading.

 

same, 9985-10-850A STUD, also same as FD3 RX7. I recall back in the early RX8 days it was listed as a “turbocharger stud”. Which led to some wild speculation.

M10x1.5 both sides, and by the coincidence of a bachelor life, overall length based on the FD3 stud sitting on my living room coffee table is 53mm, short threaded end into rotor housing is 14mm, long threaded end for manifold is 23mm with a 16mm long blank section at the engine flange face.


.

internet forum lore is that they’re Inconel material, but given the stud only costs about $5 each MSRP from Mazda they’re more likely a 10.9 or similar high strength steel alloy imo

I’d recommend nickel anti-seize on the threads; the copper type at most auto parts stores will just melt away. Which is possibly why they’re missing; either broke off due to the nut seizing or the stud unthreaded itself from the housing instead for the same reason. Which it requires a lot of force to get them to unthread from the housing. The factory really jams then in to the point the housing threads cut into the bare section. I used a stud tool to remove this one and it flattened all the external threads before it finally broke free from the housing.

probably way more info than you ever expected, lolz … been around the block a time or two with these studs.
.

 

More than I expected, but everything I hoped for. Thanks a ton.

 

they’re long, you can likely get away with 40-45mm total length by shortening the long threaded side if ordering them from a fastener company. Belmetric has them in a 10.9 x 40mm length, or 50mm too if that’s what you want

https://belmetric.com/m10-double-end...ku=SH10X40DBLK
.