Rotary Builder....see This And Give Some Feedback
12-12-2004, 11:07 PM
#3
Senior Member
Join Date: Dec 2003
Location: Minneapolis,MN
Posts: 500
I personally dont think thats going to do jack. If you notice the parts that break on the front and rear housings are from the rotor housing trying to explode outward. I have seen two engines that had this kind of failure and you can see that the housing moved outward about 1mm in the area of the oil filter pedistal. There were visible abrasion marks from the movement on both the rear and center iorn housings. It pushed the dowel out and cracked the iorn hosing allowing oil to leak out.
I have seen cracking on both the front and rear housing on the same engine documented, so in my opinion it throws out the theory that its from the engine trying to spin itself apart.
Its always just before or at TDC which leads me to bealve that its caused by poor tuning as well as crappy materials and design. And of course the mazda engineers never thought we would be running 500+hp through these things.
From what I see in those pics the failure I discribed above will still happen and that crap they welded to that engine will do nothing to stop it. The people who welded that on there obviously dont understand the failure in any way shape or form.
An idea I have had kicking arround for quite some time would be not to use extra dowels but use the same idea they used on transmissions to center them and keep them from spinning.
It would be less costly to make a few of these, mill the hole a little bigger and press them into place. I have no idea what they are called???? I spend 10 min one time trying to wrestle a tranny into place. When I pulled the pos out I realized that it and the engine both had the "centering dowels" in them and the two would not mate. When I pulled them out I thougt it would be a great way to pin an engine. You see the same thing on head bolts.
Anyway...My 2 cents
GregW
I have seen cracking on both the front and rear housing on the same engine documented, so in my opinion it throws out the theory that its from the engine trying to spin itself apart.
Its always just before or at TDC which leads me to bealve that its caused by poor tuning as well as crappy materials and design. And of course the mazda engineers never thought we would be running 500+hp through these things.
From what I see in those pics the failure I discribed above will still happen and that crap they welded to that engine will do nothing to stop it. The people who welded that on there obviously dont understand the failure in any way shape or form.
An idea I have had kicking arround for quite some time would be not to use extra dowels but use the same idea they used on transmissions to center them and keep them from spinning.
It would be less costly to make a few of these, mill the hole a little bigger and press them into place. I have no idea what they are called???? I spend 10 min one time trying to wrestle a tranny into place. When I pulled the pos out I realized that it and the engine both had the "centering dowels" in them and the two would not mate. When I pulled them out I thougt it would be a great way to pin an engine. You see the same thing on head bolts.
Anyway...My 2 cents
GregW
12-13-2004, 12:34 AM
#4
Senior Member
Join Date: Jun 2004
Posts: 524
Originally Posted by GMON' date='Dec 12 2004, 09:07 PM
I have seen cracking on both the front and rear housing on the same engine documented, so in my opinion it throws out the theory that its from the engine trying to spin itself apart.
A few moment's visualization will show that if the engine were trying to spin itself apart, the rear upper dowel would break upwards out of the rear side housing. That is the direction that the rotor forces are thrusting against the engine trying to rotate it against the transmission.
The rear dowel never breaks upwards, however. It breaks downwards, exactly as it would be if the rotor housing were deflecting into a circluar shape.
I believe the "twisting" myth came from the movement of the motor mounts from the front cover, to the center housing, to the rear side housing, as turbo power increased. People must have seen that, and correlated the motor mount relocation to the apparent additional strength in the side housings.
The reason the mount moved from the front cover to the center housing was actually to make room for rack and pinion steering, and the reason the mounts moved from there to the rear housing was to balance the engine/trans assembly on one set of mounts, since the Power Plant Frame doesn't actually support the engine so much as keep it and the differential from rotating in relation to each other along the Y axis.
12-13-2004, 06:55 AM
#6
Junior Member
Thread Starter
Join Date: Dec 2003
Posts: 10
... how do i post more picture ? ....
I check on my account .. that the limit is there ,
Well ... i believe that when you have engine mounts on the rear housing (13b-REW ) that will hold on stronger compare to 13bt 2nd gen ,
The entire housing went twisted when the power or torque transfer from the ecentric shaft to the transmission ,
if you run on the dyno .. they are consider as on free load , the dowel housing normally cracks when you boost or test them on the road ,
The Engine mounts theory that mazda makes .... gives better weight balance on the chassis , but will also helps on prevent it not gets twisted as much as on mounts on the centerhousing , power transfer of the engine are from rear housing to the transmission ,
it was my 2 cents .
I check on my account .. that the limit is there ,
Well ... i believe that when you have engine mounts on the rear housing (13b-REW ) that will hold on stronger compare to 13bt 2nd gen ,
The entire housing went twisted when the power or torque transfer from the ecentric shaft to the transmission ,
if you run on the dyno .. they are consider as on free load , the dowel housing normally cracks when you boost or test them on the road ,
The Engine mounts theory that mazda makes .... gives better weight balance on the chassis , but will also helps on prevent it not gets twisted as much as on mounts on the centerhousing , power transfer of the engine are from rear housing to the transmission ,
it was my 2 cents .
12-13-2004, 01:55 PM
#8
Junior Member
Thread Starter
Join Date: Dec 2003
Posts: 10
well i twisted my 13bt .... 3 times ,
overboosting .... it was like more then 2 bar ( 28psi )
untill i discover that the wastegate didnt discharge the air out ,
i didnt put any turbo gauges so didnt know that i was going that high ... but the car damn fast .
only got the rear housing dowel pin break and oil was pumping out from there .... but all the internal and apexseals .. are still intact ,
overboosting .... it was like more then 2 bar ( 28psi )
untill i discover that the wastegate didnt discharge the air out ,
i didnt put any turbo gauges so didnt know that i was going that high ... but the car damn fast .
only got the rear housing dowel pin break and oil was pumping out from there .... but all the internal and apexseals .. are still intact ,
