Advanced Engineering Tech - Iron 6.0L bore question.

Is it necessary to bore a 6.0l iron block with torque plates? Never thought about it until I dropped off my LQ4 block to the machine shop with the new pistons. My machinist looked at me and asked, "...bore and hone with torque plates?" He has not really done too many Gen III engines. I just would like all of your thoughts regarding the necessary use or non-use of torque plates with the iron blocks. Thanks.

Post in correct forum please
http://www.ls1tech.com/forums/generation-iii-internal-engine-5/

YES bore and hone with torque plates

Post in correct forum please
http://www.ls1tech.com/forums/generation-iii-internal-engine-5/

I did post in the correct forum...I was looking for the advanced engineering type of persons to address my question.

Is it necessary to bore a 6.0l iron block with torque plates? Never thought about it until I dropped off my LQ4 block to the machine shop with the new pistons. My machinist looked at me and asked, "...bore and hone with torque plates?" He has not really done too many Gen III engines. I just would like all of your thoughts regarding the necessary use or non-use of torque plates with the iron blocks. Thanks.

No, it isn't necessary. GM didn't use torque plates on most of the LSx engines and millions of those run fine. But it is a good idea if you're trying to make more power. If he has them, use them.

Thank you, KCS...It would be a "no-brainer" to have torque plates installed for an aluminum block while boring/honing, but I didn't think it was that big of a deal to do it with a iron block, due to the added strength characteristics of cast iron. I shall have it bored/honed with torque plates.

Thank you, KCS...It would be a "no-brainer" to have torque plates installed for an aluminum block while boring/honing, but I didn't think it was that big of a deal to do it with a iron block, due to the added strength characteristics of cast iron. I shall have it bored/honed with torque plates.

i guess its added peace of mind but the reason its done with the aluminum blocks is to keep the cylinders perfectly round. IIRC correctly, what happens if honed without the plate on an Al block is the act of torquing the heads down causes an ever so slight out of round condition. the iron sleeve is a very small part of the whole and is flimsy when compared to an all iron block. the ls1/2 ec blocks are thin iron sleeves with soft'ish aluminum for the rest (besides main caps).

the question then becomes... how much, if any, does an iron block bore go out of round without a torque plate compared to an aluminum block?

Well, my aluminum block was honed without a torque plate in place. We'll see how much piston slap there is with these 2618 alloy pistons... :)

The place I took the block to to get it honed and cleaned up said that it didn't need a torque plate because of the way that Gen 3 blocks are designed with the bolt holes separated from the cylinder sleeve by the water jacket. They said that it's mainly a problem in motors that have bolts that are in the same material area as the cylinder wall, where the act of torquing a bolt down directly influences the cylinder wall due to the bolt hole being essentially through the same material as the cylinder wall in a Gen 1 type motor with no gap in between the bolt hole surround material and the cylinder wall material. :eyes:

I still think a torque plate would help. Whether or not it's worth the time/effort/cost involved is debatable, and that's why this thread is in the Advanced Engineering section.
Gen 3:
http://www.fast-autos.net/diecast-cars-models/diecast-car-image-large/3066-new-ls1-ls2-ls3-l92-7-0l-427-stroker-short-block_200445160770.jpg

Gen 1:
http://www.abad71camaro.com/catalog/1289_1_bl_4336_1.JPG

Without saying too much

yes we do bore blocks with a plate, BHJ makes a bor-tru plate

This plate allows you to center the boring bar to the centerlines of the block, Instead of centering the boring bar on the bores alone which may've shifted. Unfortunately this causes you to bore blocks more then you would like to, often .030" may still have a mark in the bore. So you need +.040 piston to have clean bores, which is a custom piston size and becomes a headache.

You can bore block without torque plate or bor-tru or CNC, just drop the boring bar in and start cutting, results may vary.

hope this helps

Thank you ZexGX!
This IS why I posted this topic/thread in this section...
I wanted and needed this info to help me make a decision...Thank you AES Racing for the insight. Very helpful.

Without saying too much

yes we do bore blocks with a plate, BHJ makes a bor-tru plate

This plate allows you to center the boring bar to the centerlines of the block, Instead of centering the boring bar on the bores alone which may've shifted. Unfortunately this causes you to bore blocks more then you would like to, often .030" may still have a mark in the bore. So you need +.040 piston to have clean bores, which is a custom piston size and becomes a headache.

You can bore block without torque plate or bor-tru or CNC, just drop the boring bar in and start cutting, results may vary.

hope this helps


Care to elaborate? What kind of bar do you use.. insert type? Carbide or ceramic.. probably not HSS, eh? I would love to line bore.. I think thats the term.. re-bore the line for my crankshaft bearings. I have a machine I can use.. cnc to do this with.

From info I've come across, since the torque is pulled from main web area and not the cylinder area like blocks of the past, not as critical on LS motors. High dollar build? I would prefer the torque plates. Any pro builder would do that, I would think.