Torque plates for boring and honing ???

[43tutor]

I'm getting ready to have my 400 bored so I can build a 451. My question is how critical is it to use torque plates during the boring / honing process? I understand this is to make sure the cylinders are pre-loaded (to simulate the heads being installed) so the when the cylinders are honed they will be as round as possible. Does anyone have any data about engines that were honed with or without torque plates? How much distortion is there in the cylinder walls? Just how critical are the torque plates? I could certainly see this on a race engine but is it totally necessary for street motor? I'm leaning towards honing with torque plates but is that a unnecessary expense?

I have thought about measuring the bores on my block and then installing the heads and measuring the bores from the crank side to see just how much distortion really happens after installing the heads.

I've been searching locally for a machine shop to do the work. If anyone knows of a good machine shop in the Upstate South Carolina region let me know. I have numbers matching block and don't want it screwed up.

 

[MCODECUDA]

Midland Machine but it's in Midland North Carolina just southeast of Charlotte.

 

[rev.ronnie]

Torque plate honing is required for that block. I would also recommend some water jacket filler too.
If I were doing it in my shop, I would do the following, in this order.

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Calculate sound velocity of your block, Sonic test, record data. Verify that the block will work for your HP application.

Clean, strip, spray wash, soda blast, install block plugs in water jackets. Chase threads & chamfer. Final spray wash cycle before fill.

Short block fill, install plate for curing, use Rok Blok. Drill and tap new drain plugs. Stroker engines with short rods have higher stresses on cylinder walls.

Line hone mains, install caps/studs, whatever you're going to do with the mains. Now is the time.

Square and index decks to cam/crank datum line. This should be under .001” from any direction. We get them less than half of that. The decks will now be 90° indexed and perfect from front to back.

Bore cylinders from corrected deck reference, use BHJ bore tru. Compare where metal will be removed to correct index, to sonic test data, to ensure thickness on thrust side will be maintained. Sometimes you have to give up some on correct index to maintain structural integrity.

Hone cylinders with torque plate with correct finish for your ring application.

After that, stroker clearance, clean casting flash, and whatever else you plan to do.

Final wash, install cam bearings, fit if required.

Away you go!

 

[snakeoil24]

Rev.ronnie you know your stuff wow!

 

[Photon440]

Take a look at this, pick a machine shop that knows...
http://www.circletrack.com/techarticles/cylinder_block_honing/

 

[bigmanjbmopar]

clean casting flash,

Time consuming! lol and if you want to maximize every single ounce of weight loss on your motor then hell yeah get out the grinder and whip those nasty ole factory cast marks off could be they win you the race!

 

[Garys1969RR]

I always pay the shop to use torque plates when boring/honing.

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Not for sure, but I have heard that there can be as much as .002 to .004" distortion when you bolt the heads on.

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They used torque plates on my 451 build. It sealed up great! I now wish I would have had them true up the decks, as I found the decks were about .008" further from the crank centerline on one end of the block.

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But this 451 is a great running motor!

 

[rev.ronnie]

I always pay the shop to use torque plates when boring/honing.

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Not for sure, but I have heard that there can be as much as .002 to .004" distortion when you bolt the heads on.

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They used torque plates on my 451 build. It sealed up great! I now wish I would have had them true up the decks, as I found the decks were about .008" further from the crank centerline on one end of the block.

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But this 451 is a great running motor!

I only hope the block was not bored using that cooked deck as a reference. All your bores will be out of line with the crank centerline.

I just bought $900 worth of torque plate and studs for 4.5" bore Hemis because some people want them done with an aluminum plate when running aluminum heads.

Whatever the customer wants. I'm game.

 

[Garys1969RR]

They indexed off the crank centerline when boring the motor.

 

[rev.ronnie]

They indexed off the crank centerline when boring the motor.

Good deal. If not, they "crescent moon" the bearings and the rings won't seal.

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Time consuming! lol and if you want to maximize every single ounce of weight loss on your motor then hell yeah get out the grinder and whip those nasty ole factory cast marks off could be they win you the race!

Yeah, knocking off the obvious loose flash inside is a bad idea...

 

[coloradodave]

No doubt if you're building a race motor for maximum power take it to a shop that shares rev.ronnie's example of how to do it right. As a guy who was building motors before there were torque plates, I'd say using them on a motor intended for street duty is an unnecessary expense, as is block filling. As has been said, do what your budget will allow; just don't expect that you will 'feel' the gain on a street motor. Another opinion to add to the mix...

 

[43tutor]

Thanks guys for all the great information. That does help. I'll keep this thread updated with my results.

 

[Supershafts]

No doubt if you're building a race motor for maximum power
As a guy who was building motors before there were torque plates, I'd say using them on a motor intended for street duty is an unnecessary expense..

I'd say it's just as important on a street motor as it is a non F/A race motor.

I can tell you that for a fact F/A motors DON'T care if they're bored and honed with torque plates, a outlaw motor made no difference at all with and without tq plates, that motor set the record for a bit without the tq plates.

 

[ga66mopar]

I questioned the machine shop I use about using torque plates. They took a sb chevy block honed a cylinder without torque plates then torqued down a torque plate and re-honed the cylinder. I was shocked at the high and low spots the cylinder had. I never thought the cylinders could distort that much. Even on a budget build the ring seal is greatly improved by using torque plates. Plus my machine shop only charges $40 more to use torque plates.

 

[Supershafts]

Why do you think i always say to use elephant ears and not mounts.... There is lots of distortion

 

[rev.ronnie]

Why do you think i always say to use elephant ears and not mounts.... There is lots of distortion

You try to run motor mounts on a 400 Chevy making any steam and you'll wipe out #3 piston.

I have to have both heads torqued on aluminum LS engines to line hone the mains or they will be .0015"-.002” out of whack.

Some engines are very sensitive to plate honing, some not as much. I have to leave .006” to hone on Buick big blocks because the plate moves the bores around so much. Some 400 chryslers are the same way.

 

[Supershafts]

Im not a gm guy but i cringe when i see solids on those blocks, i also don't say anything....it's the competitive issue i have

 

[Photon440]

Does anyone measure for distortion as the block heats up?

http://www.circletrack.com/enginete...on_part_prevention/viewall.html#ixzz2n2EaydHP

 

[Challenger340]

IMO,
Even for a street deal, still nice to use a T/plate. Most of the bore distortion occurs at the top around the fasteners, but some will extend down further as well.

Will it run fine if done without using the T/Plate ?
Most certainly !
But at this point... why NOT just get the best you can and use the T/Plate ?

If anybody wants an "eye opener" as to what happens to Cylinders during the Thermal stabilization process, just for shits & giggles.... put a Honing Oil Heater on their CV616 and Hone the Block @ 200*F with the Heated Oil circulating in the water jackets....
that's the way I used to do them for important stuff !!

Use really good ventilation as well !