Anyone with experience with machining GEN III 5.7 Hemi Blocks?

[Notalent]

If so, are you seeing any issues with the cylinders going out of round with torque plates? Trying to hold a 3.9272 -3.9278 spec and all looks great after honing and measures within spec. After removing the plate, moving to assembly and torquing the plate back up to double check it shifts and goes out of round in different areas of the cylinder 3-8 thou. Spoke to a few a few machine shops and they said they see the same thing. Is it due to the thin cylinders? We have machined up about 10 blocks now, tried honing 1 cylinder at 1 end of the block than an opposite side to try not to get it hot, different torque plates, etc and nothing changes.

[SupStk]

Does it do the same thing when the heads are torqued?

.003-.008" is bunch, wouldn't think they would be that far out without plates.

[rebelrouser]

never built one, but the mopar forum has a Gen II topic line. http://board.moparts.org/ubbthreads/ubb ... -tech.html They discuss torque plate honing quit a bit, so I think it is an issue.

[Notalent]

Does it do the same thing when the heads are torqued?

.003-.008" is bunch, wouldn't think they would be that far out without plates.

Yes, whether we torque up with the plate or the head....its crazy. Trying to sell some bare blocks, and in the public eye it would be out of spec every time even though I dont think you can help it.

[Notalent]

never built one, but the mopar forum has a Gen II topic line. http://board.moparts.org/ubbthreads/ubb ... -tech.html They discuss torque plate honing quit a bit, so I think it is an issue.

Ill do some reading there, thank you!

[statsystems]

I always gone to .0005 undersize, break the torque plate loose, let the block sit for a couple of hours, come back, retorqe the plate and finish hone the bores. After the second torque the blocks stopped moving.

I can say I've never seen bores that moved that far after removing the torque plate. That's crazy.

[Notalent]

Its not in all areas of the cylinder. Mostly at the top, see if this attachment works....this is one of the blocks we were working with for R&D. The RED numbers is where its out of spec.

[statsystems]

Its not in all areas of the cylinder. Mostly at the top, see if this attachment works....this is one of the blocks we were working with for R&D. The RED numbers is where its out of spec.

If I'm reading your attachment correctly, the bores are .0003-.0009 out not .003-.008 which is a HUGE difference.

Your attachment shows what I've found, but I've never done a Gen III hemi.

[SupStk]

The X measurement in location A seems to be the issue. Still a long way from being .003 out, if I'm reading your specs correctly.
Like was mentioned, I untorque and repull the fasteners when plating, using the same torque sequence.
Since you end up with the same results with heads, I'm thinking your proceedure is good but just needs some tweeking to get the desired results.