I have commishioned a local machine shop to look into pinning our latest engine project. There is a 1 time $600 tooling fee to make the base and cnc program. Which I will most likely be eating. And it is $400 for one engine. However, If I can get more engines to be pinned at the same time both prices go down. The idea is that it takes quite a bit of time to get everything setup.



This is GURU style pinning only it uses a bolt instead of a stud with a nut on the back of the engine. You can do all the bolts or just the combustion side.



Each bolt hole will be reamed out to a tight tolerance fit for the new bolts. The bolt becomes a pin as well as a bolt.



Anyways, Im calling out local folks and others are welcome to get the price a little lower.



Its prolly going to be another couple of weeks before we have the materials (bolts) fully tested so if anyone is interested in getting in on this pm me for details.



Also, these guys really know what they are doing. They are the r&d engine machine shop for a local snomobile manufacuture. Last time I was in they showed me a cyl head with removable combustion chambers they had made. Talk about a quick way to change your comp ratio.



Thanks



GregW

 

What about remachining for the Aussie-Style Studs?

 

isn't a stud better than a bolt? Because as your tighten the nut down on a stud, the resistance (tightness) is not divided between stretching the bolt, fighting the friction of the threads and the friction of the seat. Where as on a nut, you are only really fighting the small number of threads and the small area for the seat of the nut that is against it's mounting surface.



Btw where are these super strong bolt obtained? are they cut on on a lathe from stock? Because cut threads are substanially weaker than rolled threads on a commercial bolt/stud.

 

[quote name='banzaitoyota' date='Apr 7 2005, 10:16 AM']What about remachining for the Aussie-Style Studs?


[/quote]





Not quite following ya here. We are using new bolts taht are thicker than stock. They are cut to length and threaded on a lathe. Threads in front plate stay stock.



We could do studs or bolts I guess, I just like the bolt idea better.

 

The stock torque is 32lbs. Which isnt ****. You DONT need a super strong bolt to hold 32lbs of torque. Yes, thes are quite long. However, You could easily lift a 1/2 ton truck with one of these bolts. Nuff said.

 

GMON: I HIGHLY recommend you go read Carol Smiths triest on cutting threads in CRITICAL fasteners! A CUT THREAD IS NOT AS STRONG AS A ROLLED THREAD!. I admire the work you have put into this project, but all the fancy CNC MAchining is for Naught with the use of a sub-par fastener!

 

[quote name='banzaitoyota' date='Apr 7 2005, 10:30 AM']GMON: I HIGHLY recommend you go read Carol Smiths triest on cutting threads in CRITICAL fasteners! A CUT THREAD IS NOT AS STRONG AS A ROLLED THREAD!. I admire the work you have put into this project, but all the fancy CNC MAchining is for Naught with the use of a sub-par fastener!


[/quote]



banzai, I totally agree with you. That has been taken into consideration. I have been assured that the threads will rip off the cast before they will rip off the cut threads. Keep in mind this starts happening WAY above the envelope for the 29 ftlbs of torque required.



This was one of the first issues we discussed. We have a meeting set up for late next week and I will print this off so we can rehash this issue once again.



Maybe a test is in order for these cut threads on a junk housing. That should put any question to this issue at rest.



Another thing you need to remember, anyone that is doing this mod does not expect their engine to be one that goes 100k. It would be nice but above 400hp you as well as I know rotarys dont last long(relative). Im not saying we are doing anyting half assed. Im just saying the cost should mirror the benifit.



Thanks for all the input, keep it comming.



GregW

 

Update: These are the studs being used.



http://www.xtremerotaries.com/main2/stud.htm



Again, we still need to nail down "exact" pricing. We are just looking for others to help lower per engine cost.





Thanks



GregW

 

I am in with GMON on this project, the guys doign this are incredible, the owner took a snowmobile engine, cut it in half and put it on a go cart.... i was impressed. We have a meeting for next friday and will be bringing my motor up there but would really liek to lower this price.

 

Update: These are the studs being used.



http://www.xtremerotaries.com/main2/stud.htm



Again, we still need to nail down "exact" pricing. We are just looking for others to help lower per engine cost.



For 1 engine and 4 of the above style studs its $400 + bolt price. We are currently looking into the exact price of producing studs with these specs 4140 Chrome Moly, 180.000 psi tensile strength, all heat treated and black oxided.



Yes we are copying Guru, sorry, Aussieland is way too far for me to send my engine. And I dont see a patent anywhere





Thanks



GregW