Apex944

iTrader: (10)

So, I purchased a stud kit the other day.
It seems they are 1 short and only have 15 in stock and may not be able to get another one for 6 weeks.

Would it be wise to just use 15 studs and 1 stock tension bolt?

Were would the best location for the stock tension bolt be at?
Maybe the lower part of the engine where there are a few to help hold it and a less stress area?

I know that I dont want to place it on the combustion chamber side, and the exhaust/intake side may be under a good bit of stress from the combustion forces going on across the shaft. Which kind of rules it out as well.

Maybe the top half in the center of the block?

I cant think of the best spot to place it at if I do get the kit.

Please help me out with this, kind of hoping to get the car running in about 4 weeks.

Thanks

SpecFC

I wouldn't advise it, considering the stock tension bolts are torque to yield. You won't be able to match the torque between it and the other studs.

Apex944

iTrader: (10)

Yeah, I was just thinking about that when I was out in the garage looking at where the studs go.

Anybody have any experience with mazdatrix engine studs?
Good/Bad etc... ?

I may just spend that extra $100 and get the kit from mazdatrix for $441 that has all of the studs.

No offense to the company that I was trying to buy the kit from originally though, just that I need to get my engine together asap. Ive had it for 9 months now and have not driven it or heard it run 1 time

Aaron Cake

iTrader: (1)

The stock tension bolts are not torque to yield.

However they are not regular steel, but spring steel. This is necessary to maintain even tension over the engine as it lengthens and shrinks with temperature changes.

The benefits of using studs is another one of those things open for debate. Generally though they will only be required in a high HP engine that is operated at high RPM.

SpecFC

My mistake, once again your knowledge is superior aaron, haha.

Apex944

iTrader: (10)

I searched for info on the studs quite a few times and only a few good threads talk about them. Not really much info on them other than what the company's selling them tell you in the little description.

What do you think about them Aaron?

Would they be a worthwhile investment and help strengthen the block?
Or would they screw up the expansion's and contraction's of the plates/housings when they get hot to cold and vice versa and maybe cause a plate to crack?

And how about the tension bolts?
Do they have any strength at all to be able to hold about 300-350 whp constantly? Would I be able to use the stock bolts in a 400-420 whp setup later on when I decide to change up the setup on the car?

Can the original one's be re-used?


Just trying to collect info to decide whether or not it's worth it to have studs, now that Aaron brought up the expansion and contraction of the plates since the plates are iron and the housings are aluminum....

Turblown

iTrader: (12)

I have never seen any evidence that spring steel should be used in this application. Even running higher than OEM recommend torque specs causes no harm to the rotor housings, or plates. Both the Falken Rx-8 and Rx-7 run our studs @ 50 ft lbs of torque. I do not recommend that high of a torque spec for street use as other components do wear out quicker. I believe the factory went to the cheapest bidder to save a buck. Mazda designed the engine around factory power levels. This is very evident in the rest of the engine, not just the tension bolts.

These studs do indeed strengthen the block. Its pretty simple physics. If you choose to reuse the factory tension bolts, I would at least buy new ones.

Aaron is correct though, studs are not very prevalent in the rotary community, they are however a basic mod on piston engines. Even a lot of OEM piston motors comes with studs from the factory, you don't see any head bolts in the Countach..

Apex944

iTrader: (10)

Cool, thank you for the info on the studs.

What torque rating for the studs do you recommend for street use?
Should I just do the factory torque spec like if I was using tension bolts?

Im waiting to hear back from you guy's on monday to see if you'll be able to get a full set in stock in about a week.

Crossing my fingers because I believe your guys' studs are better than the mazdatrix studs seeing as you guys have put alot of effort into them.
For one, they can be used with or without a factory flywheel unlike the mazdatrix, theyre realisticly priced, and you actually help out the customer with more info about them.

Please get another batch in for me

bigdv519

iTrader: (3)

What is the OD of the studs you want to buy? Any machining to the irons/aluminums? If not then, your just going to have some stronger fasteners that will not stop the motor from twisting and breaking an iron.

As for the original question of whether or not to use just 15 studs and one tension bolt. I don't think it would matter. The motors problem is twisting and breaking a dowel pin casting area. Unless the bolts are bigger and act as an added dowel, the motor is still going to twist.

Hope that helps.

Aaron Cake

iTrader: (1)

I don't remember where I originally found out they were spring steel, but I do remember that it was a from a very reputable source. It was either directly from Mazda itself, from an SAE paper or from one of the rotary books (perhaps it was the biography of Felix Wankel?).