Bacon

iTrader: (12)

So my motors out and re-assemble will be occurring shortly after a few choices.
I wanted to look a little further into what available on the market as I see prices all over the board. And then you have those that do all 16, some just 5, some list real specs, some list nearly nothing but come from renowned racers/shops. So here’s a list of what I see right now, and would like to see what all the rest of the guys making power on what studs…. Simple as that, so try and keep it in your pants

TurbloBlown www.turblown.net
$390.00
• These studs feature hot rolled threads and allen head tips.
• Rated at 195000 PSI tensile strength.
• No machining is required for installation.
• Studs are compatible with OEM or aftermarket flywheels.
• Our kit replaces all 16 inner tension bolts.

Goopy www.goopyperformance.com
$195.00
• Replaces 5/6? Of the Studs
• Bolt head is same size as stock (stock flywheel ok)
• Machining is required for installation. (60$ for their kit) or figure machine shop$
• 12mm oversized shank, no tensile strengths listed
If you have to buy 3 kits to do all the motor (they better throw one in for free) $585 + install

Xtreme Rotaries www.xtremerotaries.co
Looks like both kits cover all 16 bolts
13b 12.7 mm kit $434.00 (machining required)
13b 10mm kit $434.00 (no machining required??)
NO other data given

Gabby Skern http://skernracing.com
Looks like both kits come wilth
13b 10mm kit 380
13b 12.7mm kit 395 (machining required)

Mazdatrix www.mazdatrix.com
Stock DIamater $513.00
High quality 12-point nuts rated at 180,000 PSI tensile strength. Studs manufactured from 4140 chrome moly, heat treated, centreless ground and black oxided. Note the standard factory manual flywheel cannot be used with the Stud Kit. Includes 16 studs and 16 nuts.

Oversized kit 513 (machining required)
High quality 12-point nuts rated at 180,000 PSI tensile strength. Studs manufactured from 4140 chrome moly, heat treated, centreless ground and black oxided. Engine must be accurately drilled, reamed and tapped to give 0.2mm clearance. Includes 16 studs, nuts and sealing washers. Does NOT include/need the two at the bottom of the "legs" closest to the oil pan.

*Note: The standard factory manual flywheel cannot be used with the Stud Kit.
Rotary Works www.Rotaryworks.com
Titanium is cool but I see thensile strengths in the 128,000-138,000 tensile strength range , even with aerospace grade annealed.
$475.00 (stock Size)
Fits 13B rotary engines from 72-95.
- Titanium stud kit for street application
- 10.5mm diameter with stock thread, Titanium nuts and washers included. 16 Studs kit.
- Supports higher boost applications for street and race
- Half the weight of conventional steel, strong tensile strength.

Titanium stud kit for Race application Also $475

- (12 studs)10.5mm diameter combined with(6 studs)12.5mm with stock thread , Titanium nuts and washers included. Total of 18 studs in Race kit.
- Supports higher boost applications for street and race.
- Drilling Required for 12.5mm studs (3/4 of engine)
- No drilling required on front primary plate(threaded plate)
- Half the weight of conventional steel, strong tensile strength.

Titanium stud kit Extreme race/Comp Also $475

- Titanium studs come in (12 studs)10.5mm(6studs)12.5mm , Titanium nuts and washers included. Total of 16 studs in extreme kit.
- Supports higher boost applications for maximum horsepower.
- Drilling Required for 12.5mm studs
- Drilling and taping of primary front plate
Does machining for the larger thread on the front cover make sense opposed to the other options. 12.7 vs 10,
I wasn’t planning on needing a new flywheel either lol

So what do you run (studs / Hp) and any issues

864angel112

iTrader: (7)

+1

13B-RX3

iTrader: (2)

I prefer doweling over studding. I have used A-Spec studs in the past and they were very high quality. Honestly i think the machining of the parts is more important than who makes the studs.

killahrx7

if not tuned properly they will all break. i've had pinned and turblown kit together and ripped plates apart. just my 2 cents

MANSU_V36

what a good thread, i'm wondering the same too.

bigdv519

iTrader: (3)

How do you feel about a combination of the two....say 4 extra stock dowels per rotor housing and stocksized studs not needing machining? I'm leaning toward going that route on my next setup. Dowels for torsional strenght/housing stretch, studs for even torqing of the engine.

Bacon

iTrader: (12)

Agreed, in a perfect world/ with proper tuning. Any advantage? Did the studs hold? Just the plates cracked?

just startn

iTrader: (33)

What dowels are you running allen?


ps. Good thread

RXTASY57

iTrader: (2)

How much HP can you run if you are properly tuned WITHOUT any pinning, studding or doweling?
Guess what I'm asking is, can you get away with nothing and still run lots of HP?

864angel112

iTrader: (7)

I started similar thread like this about two or three month back. I'll bump so you can get more feedback on the subject.

13B-RX3

iTrader: (2)

I don't think that's a bad idea but i do think it's unnecessary. I use 3 extra factory dowels. I feel that the biggest problem with oversized studs is the amount of material removes, especially from a rear iron that is already thin.

I have seen over 700 with no studs or doweling on a FD motor.


Both sets of plates cracked in a way that lead me to believe the machining for the studs weakened them.

vmarx7@yahoo.com

iTrader: (37)

[QUOTE=13B-RX3;10739537]I use 3 extra factory dowels.[QUOTE]

where are the dowels located/placement?

bigdv519

iTrader: (3)

To clarify, the unnecessary part is the studs non requiring machining? Their only advantage is more even torqueing of the engine, since the stock tension bolts do pop alot under torqing?

And when you say 3 extra dowels, I would assume that is 3 per housing correct?

Thanks a bunch.

vosko

iTrader: (4)

i have the goopy bolts in my engine, goopy did the machining. they are $200 for all of them. not x 3. my engine has not seen high boost though yet

13B-RX3

iTrader: (2)

Yes, 3 extra dowels per rotor housing (6 total plus the factory 4). I think doweling and aftermarket stock sized studs are a bit overkill, i have never seen a bolt failure that wasn't due to sustained high RPM harmonics or overtorquing. When the chamber is at peak pressure there is a very small area of the irons that are exposed to combustion pressure, the majority of the load is trying to push the rotor and rotor housing away from each other not push the irons apart. As for the "twisting" load of the motor it all depends on how you have your engine mounted. Mazda moved the mounting points for the engine back as the power level went up for a reason. IMO unless you are planning to make more than 800-900hp i wouldn't worry about that at all.


Of all the aftermarket fasteners i have seen i do like the Goopy bolts the most. I will have to give them a shot one of these days.

sk8world

iTrader: (5)

Looking into all this now. I dont like the idea of drilling the irons. I know it has been done time and time again and proven. Seems like the biggest issue is the amount of space around the stock bolts allowing the movement. I am guessing the clearence is much tighter when larger studs are used and when you add extra dowels? I wonder if some type of sleeve over the stock tension bolts or stock size studs would work?

RXTASY57

iTrader: (2)

I am not using anything and am running 650+ RWHP @ 30 PSI.
Have done this hundreds of times without anything happening.
Makes me believe, it's all in the tune.
My next engine will be balanced, clearenced, and I will add two pins for ***** and giggles.

sk8world

iTrader: (5)

Yeah, I ran for 5yrs in the area as soon as I went over 700 w/480tq I found the limit. But from what I have found that is right in the area when the twist happens. Its the torque. 650-700hp 500tq area.

RXTASY57

iTrader: (2)

Guess I will keep the boost down to avoid "The Twist"!

C. Ludwig

iTrader: (27)

I've always thought and external girdle would be a great option. We used to girdle the heads on 2-strokes to keep the engine together. But, even if you keep the block together, the stock e-shaft is going to do all kinds of silly things.

RXTASY57

iTrader: (2)

I have thought about that as well. A really stiff oil pan brace for starters. Wondering what you could bolt it to externally on the sides and top of the block? Hum?
Good E shafts are very expensive. Started thinking about building a bullet proof engine and the cost gets up there pretty quick! Guess you could build a pretty good one for under $15k.

C. Ludwig

iTrader: (27)

And suddenly that Coyote crate motor starts looking like a really good option.

RXTASY57

iTrader: (2)

LOL! Yeah... where do you stop?
Guess you could just buy J-specs and run them till they die!

Turblown

iTrader: (12)

This is completely accurate. Nothing will stop an engine from breaking under heavy detonation, or pre-ignition. It wouldn't matter if the block was a solid billet piece, etc etc. Tuning and fuel used is by far the most important piece to preventing an engine from breaking. I have two customers making over 950rwhp using just our stock "sized" stud kit. Their engines will not last one quarter mile pass without our kit( one blew 7 engines in one year to figure this out). The most important thing our stud kit does it stop the engine from expanding. The stock tension bolts allow the engine to expand a few thousands, and our studs allow zero expansion. This was measured on an engine dyno using a strain gauge. On a side note our kits are the only ones that have an allen head embossed into the tip, making installation easier, and our kit fits the OEM flywheels.

KNONFS

iTrader: (14)

Could you share specific data on the strain test? Would love to see real life results/data