Steigemeier Stage V Torque Plate Issues

[IronTerp]

As many of you may know, a member of SVTP had an unfortunate breakage of the torque plate on the bottom of his Steigemeier Stage V ported Eaton. While it has been documented previously that a certain number of early edition Stage V's have had issues with cracked welds along the torque plate to blower junction, there has never been a case, (that I know of....), of the aluminum actually failing, or of the plate coming loose to the point that engine damage occured. However, this is a potentially serious situation and am wondering what the metallurgical implications of this design flaw may be. JMD0346 has previously posted some excellent observations on the proporties of aluminum which I will copy on Post #2 of this thread.

Would be great to get some good technical discussion from you folks on why this occurred and the best repair solution so that is does not reoccur.

Below are pictures of the Stage V Eaton in question showing the chunk of aluminum that broke completely off the torque plate.

 

[IronTerp]

JMD0346's professional appraisal of the damage in the above post:

Thats not Aluminum stock that one would buy at a metal supplier. It honestly looks like someting they found and cut a plate out of. The ridges or lines or whatever in it tells me that. Looks like they cut it out of an aluminum awning or some shit. LOL Its junk.

There is no telling what alloy it is. I can tell you this though. 6061 or 6063 or T-6 Aluminum will not break like that. You would not see a chunk fall out of it. That Aluminum in that pic is junk aluminum with a high/low content of alloying elements. Manganese, silicon, copper, nickel etc..

Id like to add. I own/operate a steel fab business. Im one of the few shops in my area that work with aluminum. Ive been doing it for 17 years. I hae quite a bit of experience with it. Ive never seen quality aluminum break like that and ive never seen aluminum welded to cast aluminum that held up under stress.

You wont see that happen with stock aluminum. That plate in the pic is something they salvaged from something that didnt require a 6061/6063/t6... alloy. Aircraft grade. Proper aluminum alloy is stronger than steel. That hole and the crack are from heat coupled with vibration.

Steig knew this. He's far from stupid. Thus the change to a thicker higher quality plate.

HERES the problem with that as I see it. The HQ plate has, imo, solved the material weakness. However. The problem of welding aluminum to cast aluminum is still there.

The ONLY way I could see this work is full-pen welds along the entire perimeter of the plate. With a 1/4-1/2" break in the bead every 2"s or so. This method only because if the vibration causes a crack it will eventually run all the way around it if the bead is continuous.

At this point however my profesional opinion is to remove the plate. R&R'ing a blower is easier than an engine.

 

[Black Talon]

Stieg needs to get in this thread and get this issue squared away. I don't know why Bob has not done so already.

 

[Zak Attack]

The welds on my trucks plate broke also, both sides, all the way down. The plate as I remember it was fairly thick, I sent my midplate back in and they welded it up (a lot better) and I haven't had a problem since (I haven't checked it since then either though.

 

[IronTerp]

The awning comment was meant to convey my opinion that the material used is not auminum stock. I dont know where it came from. Those ridges imo were not "put" in there by steig. That piece of material, where ever it may have come from is , imo, a piece that was manufactured for a certain product/purpose. NOT WELDING TO SUPERCHARGERS. Those ridges look like they are mechanically folded into the other pieces. I bet if you could see the underside of that plate youd see just that. The strips have a peak in the center and are discolored from the other material. Telling me its a manufactured piece for some purpose other than fabrication.

However the new material he is using IS what you would use if you wanted to do this.

So JMD, there is aluminum stock whose properties are designed for being welded and then there is aluminum stock which should not be welded? The purpose of the torque plate in the first place is I assume to smooth out air flow inconsistencies and initially if looked like Bob felt that a thinner, lower grade aluminum/weld would work fine with the stresses/heat that would occur in that area of the motor.

Just can't figure out how that chunk came out.....

 

[ttk53]

in before delete

 

[5spd07gt]

interesting...

 

[latemodelracer2]

It apears from the crack the plate was put under pressure when it was welded in there in that area along the side where it contacts the base of the s/c. It then probley started to fracture and eventually cracked off. Just my guess.

 

[IronTerp]

in before delete

Nah, no reason to fear deletion if there can be some good, legitimate discussion of this issue and how to make it right.

 

[SID297]

in before delete

That would be odd, considering I told Dwight to start this thread.




Anyone else that has had issues with broken welds on their blowers should post up pics too. I larger sampling size of failed weld could help shed some more light on where the problem is originating from.

Could it be that the cast case, welds, and plate all have different coefficients of expansion and what we are seeing here it the result of thermal stress on the various components (basically the case pulling away from the plate, or vice versa, as it expands)? Any opinions on that?

 

[Tifosi2003GT]

in before delete

Now quick question if the metal cracks It would run through the blower & land on the top of the I/C correct or would it make it past that ?




Edited by SID2297, keep the insults limited to Smack Down.

 

[VirtualSVT]

I was told the only thing different about "aircraft grade aluminum" and normal is that aircraft grade has a sheet with all info from inception shipped with it to the final destination.

That's the only difference between aircraft grade 6061 and non aircraft grade 6061.

 

[mustangtw]

Great thread, subscribing... Let's see if we can finally get to the bottom of this stage 5/torque plate fiasco. Hopefully Steig will chime in soon....

 

[03 TOPLESSSVT]

I will check my computer when I get to work Monday morning to see if I saved the pics of mine. I may have got rid of them. Great thead idea Sid and thanks to Dwight for starting it up!

 

[JMD0346]

So JMD, there is aluminum stock whose properties are designed for being welded and then there is aluminum stock which should not be welded? The purpose of the torque plate in the first place is I assume to smooth out air flow inconsistencies and initially if looked like Bob felt that a thinner, lower grade aluminum/weld would work fine with the stresses/heat that would occur in that area of the motor.

Just can't figure out how that chunk came out.....

Yes thats correct. Aluminum stock that the general public/fabricators would buy is primarily T6061/6063 aluminum. Welding supply companys(ie.National/airgas welding supply) stock, primarily, gases and filler rods/wire for welding these particular alloys.

IMO the plate in said pics is NOT either one of these alloys. Judging by the way it basically fell apart. HQ aluminum simply does not do that.

There are levels of quality of aluminum just like any other metal used for fab/manufacture. The metal in the pic imo is on the lower end of quality. Which is not to say thats a bad thing. For its intended purpose it was probably just fine. For this application it was not. Im telling you right now that piece of plate was salvaged from somewhere/something. It was not stock and was not meant to be used in fab work. It was meant to do whatever it was manufactured for.


I know you guys have heard the term "pot metal". Thats what that plate in the pic equates to. Cheap/low quality. With out putting my hands on it I cant say exactly what it is but I can judge by the pics its not stock aluminum.



For the welding side of the discussion, imo, the welding interaction between hq aluminum and cast aluminum is not strong enough to handle the heat/stress/vibration of an Eaton blower. Especially with some of us turning 6.3 million rpm with them. LOL!

Yes it can be done. Ive done it many times. However I didnt require the same amount of strength you would need inside a blower turning 20k+ rpm.






I posted in the other thread how think it MAY work. I would weld full penetration along the perimeter of the plate. Stopping every 1/4-1/2". In other words it would look like a stitch. This will give you greater strength and spread the load out over the entire peice. The spaces would keep a crack from running is one does occur.

 

[IronTerp]

Now quick question if the metal cracks It would run through the blower & land on the top of the I/C correct or would it make it past that ?

No, it cannot make it through the intercooler to the engine. Theoretically though it could "possibly" get back into the rotors of the Eaton which would most assuredly seize the blower.

 

[mustangtw]

No, it cannot make it through the intercooler to the engine. Theoretically though it could "possibly" get back into the rotors of the Eaton which would most assuredly seize the blower.

How about possibly puncturing the intercooler? Could that cause the engine to hydro lock?

 

[1BADSNK]

No, it cannot make it through the intercooler to the engine. Theoretically though it could "possibly" get back into the rotors of the Eaton which would most assuredly seize the blower.

That is good info to know. If the plate welds all cracked & the plate was loose what would then happen. Would I feel an obvious loss in power or is it something you would only see on the dyno numbers???

 

[JMD0346]

I was told the only thing different about "aircraft grade aluminum" and normal is that aircraft grade has a sheet with all info from inception shipped with it to the final destination.

That's the only difference between aircraft grade 6061 and non aircraft grade 6061.

The alloy of the aluminum determines the grade. The "60""61" is a numerical designation for the percent of present elements. I dont remember off the top of my head which one represents what so Ill do a little research.

 

[Zak Attack]

It would be a million to one chance but I think the intercoolers are actually pretty stout. I had mine welded after it split due to freezing water.