torque plate honing makes a differance


Staff member

posted much of this
This is a pic of a 454 block that has come in for some work as it only has about 3200 miles on it since the rebuild and it was making some lower end noises. We line honed it and squared and decked it flat and bored it and we blued up the 2 center cylinders installed the gasket and torque plate and went in for 6 strokes on each cylinder as you can see the results and look at the piston as it has blow by right to the oil control rings as we could measure .003 distortion on the cylinders.

"I have seen the difference over the years, I am a believer. I have done blocks this way and gone to trade shows and guys are usually amazed at what a torque plate does to a cylinder and Id point out that on the thicker and stiffer after market blocks the distortion is minimal , but still there,compared to the OEM stuff."





bores must be honed with a deck torque plate to simulate the stress a installed cylinder head stress on the bore walls induces to hone the walls concentric

gaps must be correct for the application

ring ends must be, correctly gaped, cut parallel and de-burred before installation

use of the proper tool helps keep the gap and ring ends square and parallel

Ive used several sets of total seal gapless rings in several engine builds over the years, they usually have a slightly better leak down test result , but I can,t really see and measurable power or durability increase

remove the burrs from the ends of the ring after gapping them,but don,t round off the ring ends like the left side, in his fingers here ... 0Rings.htm ... D&tabid=83 ... index.html ... index.html

here is where you, or your machine shop can get block deck hone plates, keep in kind you want to use the same (STUDS OR BOLTS) the machine shop used and the same torque settings they used when the cylinders were honed with deck plates or the distortion of the bore and ring seal won,t be identical (exactly round)or ideal

ask to see the hone machine and deck plates before you pay some shop to torque plate hone your block, you would not believe this but Ive been charged to have my block honed with torque plates and the machine shop did not have any torque plates that fit my engine!

if you don,t know what your looking at, in the picture posted above, its the RESULTS of the distortion to the block the head bolts exert on the bore when torqued into place like the cylinder head being installed, on a block does to the block, theres thousands of pounds of tension applied to the cylinder walls when the bolts are torqued on the cylinder heads, stress that pulls on the back of the cylinder walls,if the torque plates are not used when the bores honed it will distort to a different shape when those stresses are applied later, greatly reducing the cylinder wall/ring contact area, in this case it should be rather obvious that the upper cylinder walls were pulled away from the ring contact area when the heads were installed, resulting in less contact and wear, and most likely compression losses.
look closely the areas near the bolt threads were distorted to a greater degree than areas further away resulting in a very shallow area approximately to the depth the bolts thread into the block deck area that was pulled away from the bore center line when the heads were torqued into place

just some info for future builds

aluminum heads ALWAYS require head bolt washers with oil or ultra lube to get consistent clamp values and the flat surface faces the head the inner bevel faces the bolt head
on head STUDS the same things required on aluminum heads to get even clamp loads and no galling

unlike a OEM block DARTS blocks have blind threaded head bolt holes that don,t enter the water jacket so you need to be sure the threads are clean, theres no crud in the threaded holes and you use minimal thread sealant on the lower threads because theres little chance off coolant leaking up thru the threads like with an OEM block where head bolts enter the coolant passages


this should be used only in head bolt holes that don,t enter water jackets in the block on the lower threads



viewtopic.php?f=50&t=50&p=12558&hilit=threads+lube+torque#p12558 ... index.html ... lates.html ... n17180532/


make sure you have the block sonic tested and mag tested theres no sense in wasting time and money if the blocks cracked or the cylinder walls are too thin

is popular, for filling blocks with thin cylinder walls, up to the lower edge of the freeze plugs which generally will not cause heat issues but does add support on thin cylinder walls, to gain ring support

Ive used a slurry of steel bird shot and liquid EPOXY for my blocks, rather than the concrete hard block ... STEEL_SHOT

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Staff member
Ive had MIXED results , using gapless rings vs standard rings,
and Ive found the condition of the surface of the cylinder , the care taken during the assembly, the piston, design and the use of a hone with a deck plate , during the hone process and the grit used and angle of the hone job all effect the power results more than swapping from standard to gapless, rings, also keep in mind the brand and type of rings does effect results.
no one has mastered all the skills and going back over even rather common assembly skills and looking for tips on how to improve existing procedures seldom hurts.
as time progresses, theres always on-going documented testing, and in many cases the old established way of doing things has proven to be less than ideal as newer and more detailed testing proves.
I well remember the advice in the later 1960s to keep end gaps on upper piston rings in the .004-.005 per inch of bore diameter, and secondary compression rings , to a tighter .04 max per inch of bore diam, as they experience less heat related expansion, the gaps could be tighter, well testing over the last 40-50 years has proven that approach to be less than idea, a looser .005-.006 second compression ring end gap is now been rather conclusively proven to work a bit better as it tends to lower and trapped combustion pressure, that could reduce the top rings bore seal.








this style hone with 220-240 grit stones and a constant flow of coolant cutting oil works very well for cast rings, its strait stones tend to remove the high points and show low points easily and provide a more uniform and concentric hone
ph_2174.jpg ... delId=2174
the dingle berry or flex hones conform to any cylinder shape and won,t necessarily give a round cylinder or concentric walls, getting a slightly barrel shaped, or funnel shape bore diam. from their use is easy to do
ph_16016.jpg for cylinders.htm ... elId=16016


a ball hone with 320 grit used sparingly produces a very good surface finish for moly rings to seal with but a ball hone follows the cylinder wall surface even if its a bit egg shaped or hourglass or cone shaped so its NOT going to be ideal in a well worn cylinder because the rings will not be able to fully contact a non-cylindrical cylinder wall.
watch this video, but remember , if you intend to partially fill a block to add cylinder wall rigidity, the block should be filled at least 48 hours prior to any machine work being done on the block, as the fill in the coolant passages will generally expands slightly as it sets and will change the bore dimensions slightly.
Id also point out that a DART after market blocks significantly thicker and stiffer and made from a stronger alloy than the OEM production block casting

its well worth the effort of reading thru the links ... index.html ... oning.html

hone plates ... iceNET.pdf ... s/hp_h.php ... pChart.pdf ... index.html

this info should help
Things You'll Need: to hone a block in your home shop

* Drill
Cylinder hone
Motor oil
Anti-rust protective oil

1 Set the engine block on an engine stand if you have not done so already. You can use the top of a sturdy workbench instead; just make sure the engine block is set firmly on the surface.
2.Set the honing tool in a large drill with a slow speed setting. You may use a brush hone if the condition of the cylinder walls is fairly good and they just need deglazing. Use a flex (stone) hone if the cylinder is worn but not excessively; use a rigid (stone) hone if the cylinders are excessively worn but still within manufacturer specifications. Also, if you are installing cast-iron or chrome-faced rings, use a 280-grit stone; for moly rings, use a 400-grit stone.
3 :Mix equal amounts of 20-weight. motor oil and kerosene in a clean plastic container and use the mixture to lubricate the cylinder walls. Put on your safety goggles. Hand-squeeze the brush or stone hone and slip it into the cylinder.
4.Turn on the drill and keep the hone moving up and down the cylinder wall at all times, at a pace slow enough to produce a crosshatch pattern of about 50 to 60 degrees on the wall. Keep the cylinder wall well-lubricated. When you are finished, shut off the drill, but keep the hone moving until the drill stops. Compress the brush or stones and pull the hone out of the cylinder. Continue with the next cylinder until you are finished.
5.Chamfer the top edge of the cylinder walls with a small file so the pistons will not seize during installation. Thoroughly wash the engine block with soap and warm water, to get rid of the grit produced during honing. Dampen a white cloth with new motor oil and wipe the cylinder walls. If the cloth picks up gray residue from the wall, wash the engine block again.
6.Rinse the engine block and cylinders with clean water. Dry the engine and lubricate the cylinders with anti-rust protective oil. Cover the engine with a plastic bag to keep dust off. ... z1FeOOneJL

dust rust that appears almost in seconds on a completely clean engines easily wiped off with a lint free rag soaked, dripping wet in a mix of 75% diesel and 25% marvel mystery oil, and a cup of this stuff (BELOW) per gallon, as the mix absorbs water but prevents rust from forming, you can use a wet rag soaked in just the cutting oil concentrate to prevent rust but it cleans better with the diesel/MMO

btw I had a .100 over bored 454 block, that was filled with an epoxy/steel shot slurry , in the lower coolant passages,that I raced for several years , but I had it sonic tested , before it was bored and the epoxy poured and set up before the machine work was done and had the block honed with a deck plate and it was a rather rare heavy casting and even then the machine shop STRONGLY suggested the partial block fill up to the lower edge of the freeze plugs to support the cylinder walls a bit better. ... -Oil/H8256 ... ishing.htm

just do it where theres no ignition sources and over a large drain pan
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Staff member

well worth reading thru

have the block sonic tested, if you've got any doubts and have it honed with a deck plate, as a general rule cylinder wall thickness should ideally be a minimum of .200-.250 thick, getting much thinner,due to boring it larger, allows too much distortion for proper ring seal, and yes we all know guys who get away with .180 occasionally, but remember just because something, sometimes doesn,t fail the first few dozen or even the first few hundred times, its used, doesn,t mean its operating correctly, Id suggest getting an aftermarket block if you want a larger bore, and your pushing those limits on a stock production block, simply because the decks and cylinder walls are significantly thicker and the basic casting design is stronger, and if the stock casting fails at high rpms you might loose all your components, machine work, etc, certainly making the up front higher cost of the aftermarket block looking far more reasonable if looked at in that light.


Staff member
yes the bore surface prep does matter ... index.html ... shing.aspx ... &Itemid=11

Cylinder Honing

One of the concerns expressed by OEMs who have engine reman programs is that many aftermarket engine rebuilders may not have the know-how or right kind of honing equipment to reproduce an OEM type of cylinder bore finish. With emissions testing a fact of life for many motorists in many parts of the country, the worry is that a rebuilt engine with cylinders honed the "usual way" may not pass an emissions test. The challenge here is to develop procedures that allow aftermarket engine rebuilders to duplicate an OEM bore finish.

Ring manufacturers are concerned that some engine rebuilders may not be using the proper honing procedures or stones for their rings. Too rough a bore finish will produce a lot of scrubbing when the engine is initially fired up. With prelapped rings, this is not good because it creates unnecessary wear. The challenge here is to use honing procedures that produce the best possible bore finish for a given set of rings.

Most ring manufacturers specify a #220 grit honing abrasive for finishing the bores when using cast iron or chrome rings because the recommended bore finish for these rings is 28 to 35 RA (roughness average in microinches). A #280 grit stone is generally recommended for moly rings because moly rings like a somewhat smoother finish of 16 to 23 RA. But these recommendations are for conventional vitrified abrasives, not diamond. Diamond cuts differently from a vitrified stone, so higher numbers are generally required for an equivalent finish. A #325 to #550 grit diamond stone may be required for the final honing step to achieve an RA finish in the desired range. One manufacturer says a 500 to 550 grit diamond honing stone will produce a surface finish in the 13 to 15 RA range.

To add to the confusion over which honing stones may be required to produce a certain kind of finish, some vitrified honing stones with identical grit ratings will produce different finishes that may not always agree with the reference charts.


ball hones are fast and easy, to use but have the problem that they easily follow non-round cylinder surfaces, rather than tend to keep the cylinders surface flat and concentric like the bar hone design


For example, one #220 grit vitrified stone may produce a surface finish of 28 to 35 RA while another may leave a much rougher finish of 35 to 60 RA, which is too rough for most prelapped rings. The difference in actual surface finish is due to the bonding agents and fillers that are used to hold the abrasive particles together. The type and quality of lubricant used during the honing process can also make a difference, too.
Cylinder Boring
Boring out cylinders to accept oversized pistons or sleeves has long been a common practice in the engine rebuilding business. Boring allows worn blocks to be salvaged, and stock cylinder bores to be enlarged for more displacement. More recently, boring is also being used to install special cylinder liners with hard surface treatments in high performance racing engines. The hard liners almost eliminate ring and bore wear so the engine can run race after race with no increase in bore clearances blowby.


common result of boring the cylinder walls too thin