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By 55blacktie - Last Year
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Generally speaking, is a torque plate used when boring/honing Y-block cylinders? When does distortion become a concern?
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By Ted - Last Year
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I prefer to use torque plates for cylinder wall honing on most engines regardless of their intended use. That makes for an expensive collection of torque plates especially considering that some of them are for the same family of engines but are bore size specific. By using torque plates, the rings do seat in quicker with fewer break-in issues. But on my end, most engines have the thinner piston rings which are sensitive to cylinder wall finish. The newer Mahle pistons for street applications are now using the 1mm rings which are 0.039” thick versus the old 3/32” rings found in some of the Ford Y’s that were 0.094” thick.
The use of torque plates for cylinder wall honing becomes increasingly more important as the cylinders become thinner as a result of over boring and also when using the thinner metric piston rings. Either one of those scenarios makes the use of torque plates recommended. Engines with blind head bolt holes like the Ford Y tend to have less distortion at the decks due to head bolt torque but there is still some measurable distortion regardless.
Expect to pay more for torque plate honed cylinders versus not being torque plate honed. For the Ford Y, not very many shops have the torque plates which means you either have to select a shop with that capability or furnish the torque plates to the shop doing the honing. To get the most out of torque plate honing, it’s always best to use the same head bolts and head gaskets as being intended for use on the finished engine. Even the amount of thread penetration of the head bolts into the deck is a player. There is obviously more to this than just bolting a torque plate to the block and honing.
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By 55blacktie - Last Year
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Thanks, Ted, I'm glad I asked. Should the torque plate be the exact diameter of the finished bore size?
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By Joe-JDC - Last Year
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There has to be enough space to clear the stones so that you don't damage them. Most used head gaskets are slightly larger than the bore. If you had the torque plate the finished size of the bore, then you would need dozens of torque plates for each individual engine you honed. Some shops keep two each and torque both in place to simulate a better finish. Other shops use hot oil circulating to near 200* to simulate operating temperatures. The list of possible scenarios is endless. The torque plate and bolts/studs used simulate the bore distortion with a head torqued in place. The torque plate needs to be thick enough so it will not flex when torqued to the upper torque value of the heads. Joe-JDC
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By KULTULZ - Last Year
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At what stage would one consider using torque plates now? Common rebuild or HP?
I know in the olden days it was mainly for a competition engine.
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By Ted - Last Year
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The use of a torque plate helps to reduce the head bolt distortion that occurs if honing the cylinders without a plate. It simply boils down to how good you want those cylinders to be when first cranking up the engine. Torque plate honed cylinders simply seat the rings in very quickly as compared to non- torque plate honed cylinders. Those engines with thin cylinder walls and/or non-blind head bolt holes in the decks will obviously distort more than those engines that are built beefier or more robust.
To add to what Joe said, the head gasket sealing ring must be fully incapsulated by the installed torque plate. That small detail makes using the same style of head gasket as is being used on the engine extremely important to the torque plate honing operation.
I recently honed the cylinders on a Dart block with a 4.600” bore and used a torque plate that would accommodate up to a 4.660” bore. With still over 3/8” thickness for the cylinder walls and having blind head bolt holes in that Dart block, the bores still distorted up to 0.0007” when the torque plates were removed. A major part of the distortion was occurring at the head bolt hole locations. I have seen up to 0.0015” of cylinder wall distortion on some Ford Y engines when the torque plates were removed, so Yes, using torque plates raises the bar on having truly round cylinders when the heads are bolted in place.
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By KULTULZ - Last Year
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THANX! Again ...
So nowadays, it is considered that boring and honing is to be done with a plate as normal/quality procedure?
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By Ted - Last Year
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KULTULZ (1/3/2024)
...So nowadays, it is considered that boring and honing is to be done with a plate as normal/quality procedure?
Just depends upon the shop and what quality of work is dictated by the either the shop or the customer. It’s definitely more expensive to torque plate hone the cylinders which originates from the perspective of buying the necessary plates, gaskets, and fasteners but also from the perspective that it takes more time to do cylinder honing with plates versus not.
I cringe when someone tells me “It’s good enough” as that suggests that some quality was left on the table. Torque plate honing just adds another level of getting the machine work closer to perfect. The same thing goes for balance work where 0.5 oz/in is considered acceptable but in reality, most performance work calls for 0.1 oz/in or better. Don't get me started on that thought process that says performance engines should be built to a higher standard than stock engines as I personally think they should all be built to a higher standard.
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By KULTULZ - Last Year
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'Don't get me started on that thought process that says performance engines should be built to a higher standard than stock engines as I personally think they should all be built to a higher standard.'
I understand that fully. I know someone else like that ... 
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By 55blacktie - Last Year
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The hard part is finding someone with the skills and integrity to do it right.
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By Lord Gaga - Last Year
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CAMS (Canton Auto Machine) in Canton OH made a torque plate for me when they machined my 312. So they have one if anybody in the area is looking for a Y Block savvy machine shop in NE Ohio.
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By KULTULZ - Last Year
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Ya' know ...
Years ago (in a GALAXIE far far away) ...
The modulator (Germany domiciled) of the MEL FORUM came across a specialty plate, bought it and had it sent to me initially (US) and then would let MEL ENTHUSIASTS use it as needed by shipping it to/amongst others.
Did they charge you machining/materials costs for the FYB PLATE and if so you didn't keep it?
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By FORD DEARBORN - Last Year
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What would be involved in making a pair of torque plates? How thick does the steel need to be? I assume besides the bore holes the bolt/stud holes would be the only other holes needed? Would one pair work for the usual Y-block machining or would the plates need to match a specific bore size? Ted, would you post a picture of these plates? Thanks................
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By Ted - Last Year
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Many of the cylinder honing torque plates I use are between 1¾” and 2” thick. Some have counterbored holes for the head bolts to mimic the correct amount of head bolt penetration into the block. Where the long bolts are being used, spacers are used on those longer bolts. The hole size in the plate can be considerably larger than the actual cylinder bore size which helps with easing the hone itself into the bores without interference from the plate. However, the cylinder bores in the plates cannot be so large that the head gasket sealing ring is not fully incapsulated or covered by the torque plate. The head gasket is an integral part of the torque plate honing operation as it does need to duplicate the stresses being submitted by the actual gasket being used. Likewise, it’s important that the same style of head bolts also be used along with the same torque values as is being used on the engine during its assembly.
Here’s a picture of two different torque plates. The top plate is for the Ford FE engines while the lower plate is for the Ford Y-Block.
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By FORD DEARBORN - Last Year
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Thanks Ted for the thorough explanation of the plate design and the photos put it in perspective. The difficult part would be obtaining steel slabs of that thickness and having a mill large enough for the task. If I happen to rebuild another engine in the future, I will for sure ask the machine shop if they will use torque plates for final honing. As always, excellent information from this site, thanks again................
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By 55blacktie - Last Year
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It is highly unlikely that a shop will have Y-block torque plates. If you ask, they'll answer your question with a question: "Why do you think you need it honed with torque plates?" The torque plates are expensive. Like any business, they have to make a profit on their investment, if they want to remain open. Seldom, if ever, will a Y-block pass through their doors. Unfortunately, you'll not find a Ted Eaton, John Mummert, JDC, or Tim McMaster on every corner; I've looked. The average owner of a Sunday-driver/grocery-getter probably wouldn't even know about torque plates.
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By FORD DEARBORN - Last Year
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You're absolutely right. Unless we invest our time and resources into machining a pair of these it will be business as usual and that's not all bad.
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