Rotary7s

Whats the thread pitch for the a/c brakets?>

I pulled the studs out and need to get some bolts to hold my engine to my stand..

Rotary7s

RotorMotorDriver

iTrader: (1)

Take the studs to the hardware store, find a nut that fits, then youll know the thread pitch.

~T.J.

MikeLMR

it'll be a metric course size , measure the overall diameter of the thread and then go to the hardware store and ask for a Metric course in the approximate size ... from memory I think its an M10

Mike

Rotary7s

The studs were gone when the a/c got threw out abotu 3 yrs ago..

I know I could of took it there to match

djmickyg

if there M10 which im pretty sure they are then the pitch is 1.75 mm
if there M8 then the pitch is 1.5mm

Jeff20B

iTrader: (13)

I figured out a way to mount all four arms of my engine stand to a rotary (front plate). Two 10mm x 1.25 bolts and two 12mm x 1.5 (they're from an FB Watts link I believe). I've got one of them here so I can measure it for you guys. The bolt head is 17mm, the shaft is 65mm long, the threaded section is aprox 22mm in length. I top it off with a washer that is 1/16" thick with a 1/2" hole. It fits well on the 12mm bolt.

The only downside to using bolts is that you have to remove the two studs in the front plate. The upside is the arms have built-in stand-offs that allow easy access to the 'plug side' of the engine. That's why such long bolts must be used.

Note: This has been tested so far on a '73 and '83 front plates. I'm pretty sure Mazda kept this suff unchanged throughout the 13BREWs. I bet the Renesis is the same too.

Rotary7s

Hey if you have a front cover/plate mounted show me the set up..

Its been a couple days and I still didnt get this done,I might just have to carry my dam plate in the dam store to get a fit

Jeff20B

iTrader: (13)

I'm rebuilding an engine soon. We finished the porting last night and now the metal pieces need to be cleaned. After that, I'll mount it to the engine stand and take a pic or too (film camera so it may take a while).

To find the correct bolts, bring one of the arms and the plate into the store and find some bolts that will fit. I mentioned the thread pitches above. Next, screw them into the engine all the way finger tight (don't tighten with a wrench or anything because the threads deep inside the plate will damaged the bolt tips). Compare them to the arm from the engine stand. Get bolts that are a little too long and just use washers. Do not get bolts that are too short. Too little thread into the plate will cause the engine to break the bolts and crush your feet. Get grade 8.8 bolts or something decent like that. I can lean on my plate when it's attatched with all four arms. It's pretty solid