Old Splatterhand

ArmyOfOne, don't wanna share your ideas? would be way easier than searching the aussie forums

but a stiff "oil pan" is supposed to work pretty well, i heared

ArmyOfOne

You are on the right track. Use long studs attached to the oil pan bolts and use a .75" aluminum plate bolted to the bottom of the engine. This ensures that the whole engine stays perfectly straight. This eliminates the need for pinning. There are people out there running TONS of boost like this without any reliability problems. Just make sure you cut out holes in the plate for the oil pickup and to drain back to the pan.

GMON

I dont see this doing much of anything. I have seen in person the specific type of failure we are trying to combat. The rotor housings move from just under the top dowel to well under the spark pug holes. Bolting a plate to the bottom of the engine will do nothing to stop that. Combustion pressure is litteraly trying to blow plug side of the engine off. Since there is play between the housing and the bolts the housing pushes out untill it is stoped by the bolts. If there are a few dowels in there this pressure is contained.



If somone trys to tell you that putting a plate on the bottom of your engine is going to stop the above description ask them why mazda put so many bolts over on that side?? Yeah, no offense but it sounds like total bs to me.





Also, for us, "TONS" of boost will start at 30psi.



I cant bealive that none of these people who pay out their *** for these engines have no idea as to how their builder put the dowels in.



Oh well, hopefully, either one of these big spenders or one of our famous engine builders can tell us just how this is done.



The way this thread is going Ill have this engine pinned and back in the car before I get an answer out of this crowd.



p



GregW

ArmyOfOne

From my understanding all pinning does is stop the plates from twisting and cracking.

Pinning aleviates some of the pressure from twisting but it does nothing to control expansion because you are still using the same tension bolts to hold it all together.

Example take a sping and pull the ends apart, now take the same spring and put it inside a pipe... does the spring stretch any less when you pull with the same force? No.



BTW my tons start at 35psi... :lol

j9fd3s

so putting the dowels in there is gonna transfer the force to the iron that breaks anyways better?



strengthening the oil pan area is basically downside free.....

alaskarotorhead

Hey,

So here's one to throw out.What if you had an extra set of factory pins an machined then down on a lathe to fit the other holes?Just something simple to ponder........



Nick

astrochild7

don't fit/ not enough room... with the tension bolt installed you got about 2.5-3mm on the housings and about 1-1.5mm on center iron... not enough or uniform must mill to a larger unifrom size... personally I like the idea, of using the bottom plate and 3 additional dowels and PROPER TUNING for ***** and giggles.... that should be bullet proof.... **** next we can heliarc bracing to the spark plug side of the motor.... what happens when we start blowing the side of the motor out, its only made of aluminum....

1revnrex

Yah there ya go, talk down to the people who are attempting to help you. PM Ito smartass....



Oh yah heres the link for RX7 Club you'd fit right in...

GMON

I dont buy the twisting theory. I have seen this in person and I think once you see one your will agree. You could clearly see where the housings slid against eachother.



Pinning does control the expasion. With no pins the housing can move outward untill it hits the bolts. With pins it cant move.



I guess we can agree to disagree on twisting.

GMON

Putting dowels in there will spread out the force over 4 pins instead of just 1. So divide the force by 4 and you have what each one will deal with. Sure its not as simple as that but its the general idea.



I still think a plate on the bottom of the engine is a waste of time. Again, we agree to disagree.