to torque plate or not to torque plate?

[Mark00s4]

so im at the stage of my build where i need to get my block bored and honed for oversized pistons. i have talked to a few machine shops and im getting a mixed bag of answers. a few shops say its an absolute must other say they have built high hp 2.7 without and 0 issues.
so im asking people that have first hand experience with this for their input. my thinking would be to use them,but every shop that i want to use doesn't have them.
little info about my build;
28-30psi
mahle motorsport pistons 81.5mm
stock stroke crank

[slow ride]

It's the correct way period. Only reason they would say otherwise is because they don't have the plate. It's best to do this procedure with the same head studs you will be using when complete.

[Mark00s4]

yeah that's what I was thinking. plan on using oem head bolts do you think that is a factor?

[slow ride]

Well it's a little harder since I believe they are torque to yield and make it a bit more of a pain to re torque to an accurate level or you use more than one set which adds up. Generally I would use studs for most builds since they can be reused and in most cases have can provide more clamp load. Basically the torque plate is just simulating the head and with torque applied to the block it distorts a given amount, that's when you actually do the finish honing. That said it's always best to use the same torque figures at the time of honing as when you built the engine.

[MacDaddy]

Talked to the oldest shop in town and he said the cylinder deflects more during the power stroke than it does from torquing down the cylinder head.

And also the amount of cylinder deflection from torquing down the head depends on the design of the block, if the head bolts thread in at the top by the deck or down low by the crankcase.

I'd be more concerned with the temperature during machining, if the work is done in a cold shop being machined there will be a bigger variance due tonthermal expansion than say if it was machined in san diego in the middle of summer in an unairconditioned shop. Is it enough to worry, IDK, but it would be foolish to worry about cylinder deflection and not thermal expansion.

[Mark00s4]

yes one shop mention that the head bolts threaded holes are a factor .the deeper in the block the less distortion compared to the threads closer to the deck. he also stated that they don't use torque plates at the factory. i guess thermal expansion is a factor how much idk.

[Mark00s4]

so has anyone had their block bored without torque plates? if so any problems; excessive blow by, piston slap,etc.