Aluminum for set-back plates?

[Guest JAMIE T]

I'm starting to make my mounts for my LT1/6spd conversion. What do you guys think of using aluminum instead of steel for the JTR style set-back plates? It would be 6061-T6. I've already started on the spacers, there awesome. I was thinking of making the spacer and set-back plates as one unit.

[j260z]

you took the question right out of my mouth! I was thinking the only reason not to would be stress related but if you were to make the spacers and setback plate as one unit you could always make the plate thicker and thin the spacers to compensate. i think that would make for a much cleaner looking unit, not to mention slightly lighter. one other thing would be whether the threads in the aluminum, where the motor mounts bolt up, would hold up.

[iaconsultants]

If you plan on using Aluminum it should work fine but I would recommend putting some inserts for the threads. Most machine shops that deal with aluminum would be able to point you in the correct direction. There are some newer inserts out there now that you will not need to break off the tabs so once they are in place it is a go. I was wondering something else, because it seems that you either machine or have access to a shop that might not cost to much. How much would it run to make a second set of conversion parts or even better would you or they concider making ones that would work for the LS1 and LS6 motors.

Robert

[Guest JAMIE T]

I think someone in Texas makes LS1 mounts. Having said that, I'd be glad to make mounts for anyone, I'd just need a motor to mock-up in the engine bay. Maybe if Mike Kelly see's this, he might consider using his car and his Vette's LS1 to mock up and we could fab some mounts. He has another motor being built for his Vette, so he'll have a spare.

 

As for the motor mounts for my car, I'm not worried about the threads pulling out of the aluminum. Basically, the loads on the motor mounts aren't nearly high enough to pull the threads out. Aluminum(especially 6061) is stronger than most folks give it credit for. Remember, this is not a casting.

 

Me, my job is an aluminum fabicator for a high end(or should I say VERY high end) garden furniture company. I have pretty much unlimited access to high grades of aluminum including 2024(very strong).

[j260z]

if you do make a set be sure to take pictures. i'd be interested in seeing how they turn out.

[SpeedRacer]

I think you would be amazed at how much torque is put into a motor mount. On race cars we have a cable that goes from the frame and/or suspension to the left hand side of the engine that saves a nasty situation when a motor mount fails. Aluminum spacers sure, but set back plates - no way. Even if you use 6061-T6 they will bend. In time they will work harden and crack.

[love-my-V8-280Z]

I wouldn't do it either, Im no aluminum expert but there is a huge difference between aluminum and steel. I to think it would crack in a short time. Why would you use aluminum, steel is cheaper and even if you get the aluminum free the steel is only $20.

[Guest JAMIE T]

So, you guys really think that the plate will fail before the rubber motor mount?

[SpeedRacer]

Absolutely!