Mr. LV

I just broke a seal on my 13b re and have a machined and doweled motor. Is there any one in sothern california that can machine my new housing for the added dowels?

c00lduke

I'm not sure where mazdatrix is in relation to you but i think they can do it.

Mr. LV

Thank you, they are very close. I believe that is where my original builder had the motor done to begin with! I suppose I should call them.

Goopy

"Mr. LV"
I would like to give you some advice from years of rotary drag racaing with collaboration fron the top inovators in the sport today..

Dowel Machining is not neccisary...if the engine streesses and twist the housing and intermidiates you have a problem with either side-seal lubricity/tollerance or perhaps flaten rotor bearing...

The theary that the crank acually distorts under severe HP/tourq is still unproven to me since my backround in metalurgy/engineeering does not allow me to belive that a crankshaft with as much tensil would bend and not break.

Mr. LV

When I originally bought my motor from Redline in So Cal, they recommended the dowelling for housings "twisting" not for shaft bending. Anyway the motor is allready dowelled so I have to match the new housing so it all matches.

kenn_chan

I asked pan speed when they rebuilt my 3 rotor, and I also asked Amamiya bout it a while back (at there chiba shop) and they flat out said that they don't even pin the motors they put a T-88 on, let alone anything smaller. (not that I could afford what they were proposing at the time anyways!)

Kenn_chan

RICE RACING

No the motor will twist itself apart at anything above 2psi boost running modified twins :P

680RWHP12A

motor pinning helps alot , especially at higher boost levels.... the motor only has 2 dowel pin points(opposite each other) used to locate the housings and those have excessive clearence, meaning the motore flexes alittle bit.... when the motor is pinned, there is almost no motor flex, thus making the motor stronger.... remember the tolerences inside these motors is close so even with small amounts of motor flexing, it can cause internal motor damage(most commonly rotors contacting the rotor housings, or housing breakage around the dowel area...

however, guys are make lots of power on the newer motors because the factory saw a problem and fixed it by making the housings stronger around the dowel area...

p.s. i know mike from redline, he builds great motors!!

now

iTrader: (1)

pinning also reduces harmonics, if you take apart a high boosted motor which has some
miles put on it, you can see scuffing between the rotor housing and the iron housing on the spark plug
side, this shows how much movement there is.
I believe that pinning not only adds strength against twisting but it also stops the scuffing which i feel
contributes to coolant o ring failure, something seen widely in the 3rd gens.
pinning cant hurt if its done right,
which means using a pin that allows the tension bolts to do the job they were engineered to do!
allowing for expansion as the motor is heated and cooled.
which = not using studs as dowel pins!
matt