[Jays76bird]

Having run a boring bar I would say yes, however my shop teacher used to have me just bore stock engines without the torque plate and reserve it for performance builds. But since most people on here are building at least a mild performance engines I say it should be used.

[Dragncar]

Rocket Racing & Performance LLC makes aluminum plates for 365$ CCA Racing Products makes one too.

[Will]

Originally Posted by mgarblik

I bore without a plate and ALWAYS hone with a plate. I leave .005-.007" for honing depending on the job. My boring mill makes using a plate very difficult and not really necessary if you leave enough material to hone. Also, one less operation which would save the customer about $100.00.

This is the way we did it at the shop I worked at.

Originally Posted by Dragncar

... I had long conversations with Dan Whittmore on this. He told me you not only need to hone it with a tq plate you need to bore it with one "if you want your bore to be ROUND". That is a direct quote. The guy was anal about such things.....

I understand being anal, but round is round.

Once the honing is done, per the technique above, the bores would be round and taper-free within +/- .0001" Well, that is until you unbolted the torque plate, then they'd go out of round as the block relaxed. Bolt the heads on and measure from the bottom and back to round though they were never perfect. Still, way better than without the torque plate. Near as I can figure, a torque plate is not a head and the stresses on the block end up being slightly different between the two.

A good plateau-hone, the proper cross hatch pattern, and some moly faced rings and an engine will seal up almost instantly.

[mgarblik]

Originally Posted by hurryinhoosier62

Mike, I wasn't aware that Sunnen made torque plates for Pontiacs. We made our own, but we had access to TONS of 1 inch steel plate and a tool and die department.

I can't swear if Sunnen actually makes the plates themselves or buys them from someone else and paints their name on them. When we bought a bunch of equipment for my college from Sunnen, we were able to get some "accessories" for the new equipment as part of the package deal. I was able to pick 6 torque plates and of course a Pontiac V-8 was one of the 6. Since that purchase, I bored the plate for large bore IA II blocks. 4.425". So now it's too big for typical 400-455 stick blocks. That's when I bought a BHJ plate for the smaller bore Pontiacs. After using both, the BHJ one is just a little nicer because it has counterbores for the fasteners that work nicer with spacers when running studs. Either will get the job done. We made our own plate for a student with a Jeep 4.0 L inline 6 and another one for a student racing a Studebaker 289 RIII. It's allot of work to make one IMO.

[Dragncar]

Originally Posted by Will

This is the way we did it at the shop I worked at.




I understand being anal, but round is round.

Once the honing is done, per the technique above, the bores would be round and taper-free within +/- .0001" Well, that is until you unbolted the torque plate, then they'd go out of round as the block relaxed. Bolt the heads on and measure from the bottom and back to round though they were never perfect. Still, way better than without the torque plate. Near as I can figure, a torque plate is not a head and the stresses on the block end up being slightly different between the two.

A good plateau-hone, the proper cross hatch pattern, and some moly faced rings and an engine will seal up almost instantly.

They distort .004 right under each head bolt. .004 on each side is .008 total. Thats a LOT. Dan told me the PMD design that was supposed to get rid of bore distortion was just "some engineers idea that did not work. Pontiacs distort more than most simply because they are a 4 head bolt engine with 1/2" bolts in close proximity to the edge of the bore pulling with 90lbs tq. 455s distort more than a 326, smaller bore, bolts farther away.
Engines with 7/16 head bolts and small bores distort the least. Dan told me he had his own personal tq plates for every American V8. Even AMC. They guy was anal about bores.
When I told my local guy about how much they distort he is the one who decided to bore it .010 under so he had a solid .002 to hone out.

[mgarblik]

Originally Posted by 69TempestCustomS

when you buy a torque plate does it come with its own hardware to bolt it up to the block ?
If I am paying to have my 455 bored and honed by a machinist should he have the hardware to bolt his torque plate to my block?
Does it matter if its studs or bolts?
and if he uses his hardware to bolt the torque plate to the block when boring and honing, And I use different hardware to bolt the head to the block will the use of different hardware, his studs vs my studs make a difference in the roundness of the bore?

I have not decided what heads to use in my build so the ARP stud choice is up in the air too, but cant the machinist do the bore job at least using his plate and hardware?

Am I thinking to hard on this?

No you are not. Good questions. The answer is slightly complicated. It depends on the brand of plate the shop is using concerning the hardware. A Sunnen plate for example, comes with socket head cap screws to attach it. If your engine is going to use bolts, the socket head screws are fine. If your using studs, then you need to install the studs and take it to the shop that way with your ARP Nuts and washers. Most shops have a large variety of hardened sleeves they will need to slide over the studs and then use your nuts and washers and ARP lube. You will also need your EXACT head gaskets you are going to use. If it's a Felpfo 1016 for example, you will need to buy 3 of them. One for honing, 2 for the build. The honing oil will ruin it. A MLS gasket you can re-use if you clean it carefully. You are basically trying to replicate the installed condition of the heads on the engine while leaving the cylinders open for honing. I have found the .004" of distortion mentioned in above posts to not be a reliable amount of distortion in every cylinder of every engine. There are just so many variables in each block, there is no certain number. Some blocks are much better than others. Also, each cylinder is unique. The way the blocks are cast with the cylinder offset and the way they are supported at the bottom of the bore to the bulkheads, there can be allot of variation. Bottom line is when an experienced machinist is finished plateau honing the block, it should be within .0002" top to bottom and .0002" out of round. Personally, I think Pontiac V-8's are about average for how the bores look before honing compared to other engines. By far the worst V-8 engines for pulling out of shape are Small Block Fords. They really respond to a torque plate hone and make allot more power when done properly. Big Block Mopars seem to be a little more rigid than a Pontiac.

[PontiacJim1959]

My 2 cents. I think a torque plate is overkill for a street engine.

OK, so you use the plate, but think of all the variables that can get that precise perfectly round cylinder out of round.

Heat & expansion. Heaven forbid some of your cylinders don't run even temps and one runs hotter/colder and it expands differently. Are all cylinders the same temperature from top to bottom, left bank to right bank, front of the block and back of the block?

What if the intake is not perfectly matched to the heads and one head is .010" less on the intake side than the other and you torque it down and the bolts draw the head in, pulling on the head bolts, pulling on that one bank of cylinders. OMG, distortion.

How much block distortion do you get when the engine torques over against the motor mounts? Or the twist applied to the back of the engine via the rubber trans mount as the driveshaft loads up the posi unit and sends it to the wide tires that dig in and twist the frame.

For a drag race only engine, I can see the benefits where every ounce of HP can make the difference between win & lose. Blueprinted assembly, hard block fill to stiffen the casting, front/rear engine plates, roll bars to stiffen/eliminate frame twist, etc.. But for a street engine, I can't see it and have never used one. That's why engines have tolerances.

[hurryinhoosier62]

Originally Posted by PontiacJim1959

My 2 cents. I think a torque plate is overkill for a street engine.

OK, so you use the plate, but think of all the variables that can get that precise perfectly round cylinder out of round.

Heat & expansion. Heaven forbid some of your cylinders don't run even temps and one runs hotter/colder and it expands differently. Are all cylinders the same temperature from top to bottom, left bank to right bank, front of the block and back of the block?

What if the intake is not perfectly matched to the heads and one head is .010" less on the intake side than the other and you torque it down and the bolts draw the head in, pulling on the head bolts, pulling on that one bank of cylinders. OMG, distortion.

How much block distortion do you get when the engine torques over against the motor mounts? Or the twist applied to the back of the engine via the rubber trans mount as the driveshaft loads up the posi unit and sends it to the wide tires that dig in and twist the frame.

For a drag race only engine, I can see the benefits where every ounce of HP can make the difference between win & lose. Blueprinted assembly, hard block fill to stiffen the casting, front/rear engine plates, roll bars to stiffen/eliminate frame twist, etc.. But for a street engine, I can't see it and have never used one. That's why engines have tolerances.

I would respectfully disagree. Having machined as many blocks as I have, I have personally seen the difference torque plate honing makes in regards to cylinder sealing in both gasoline and diesel applications. We witnessed faster break-ins and better cylinder sealing with blocks that were torque plate honed verses non torque plate honed. In 6.2/6.5 GM diesels the difference was nearly stunning. Cummins recommends torque plate honing for ALL of its mid range diesel engines.

[mgarblik]

As hard as it may be to believe, torque plate honing is worth 8%-10% in peak HP on an engine dyno. It has been proven time and time again. On a 400 HP street engine, that's 32-40 HP. That's not just on a Pontiac, but typical for American V-8 engines. If the goal of the rebuild is to cruise around on a Sunday afternoon from one car show to another, or drive the car in a parade, I agree torque plate honing is not necessary. I have run a ball hone through many, many engines and put the old pistons right back in and away they went. But there is real HP just sitting out there waiting to be had and it's a fairly inexpensive up-grade to an engine rebuild. My rule of thumb is, if the engine is getting new pistons, it's getting torque plate honed. This includes even 5 HP Briggs and Stratton engines for say a Jr. Dragster. It makes a huge difference in those little engines. Joe Mondello was under contract with Briggs and Stratton to develop machining practices for their Jr. Dragster engine. Torque plate was worth 2 HP on a 20 HP Jr. Dragster engine. Same 10%. Verified on the little dyno.

I would like to add that PontiacJim 1959 made some good points about the many variables of heat cycles, uneven heating of different cylinders, and external forces on the block from mounts, and even the intake. Huge money has been spent trying to duplicate those forces while honing. I have honed blocks with the mounts on the block, the bellhousing attached and used a hot hone that circulated 180 degree honing oil through the block while honing. Believe it or not, going through all that aggravation on different blocks, Chevy, Mopar and Pontiac, it didn't show much on the dyno. Possibly a few HP, but not enough to really verify. So we discontinued the process. Some cup teams and Pro Stock still hone that way.

[Rincon]

Chris at BHJ states that their plates should be used for final hone and cast iron plates are used for cast iron heads and aluminium plates are used for aluminium heads. And spacers not stacks of washers should be used to hold the plate down. He emphisized this because there are two different lengths of spacers used for pontiac heads ; one for cast iron heads and another for ram air. Aluminum heads like edelbrock that use longer hardware. Interesting. Says BHJ does not supply bolts or studs with their plate . Interesting that sunnen does. There's a thread about this same subject on yellowbullet right now too

[Formulajones]

Originally Posted by mgarblik

I have honed blocks with the mounts on the block, the bellhousing attached and used a hot hone that circulated 180 degree honing oil through the block while honing. Believe it or not, going through all that aggravation on different blocks, Chevy, Mopar and Pontiac, it didn't show much on the dyno. Possibly a few HP, but not enough to really verify. So we discontinued the process. Some cup teams and Pro Stock still hone that way.

Funny you mentioned that. Bill Jenkins used to do that as far back as the early 60's when building his stock eliminator engines. In fact there is a famous photo floating around of him doing that very thing. But I'm sure he wasn't the only one.

[Formulajones]

I disagree with not torque plate honing on a street engine. Maybe I'm pickier than most but I prefer the cylinders to be as round as can be in operation for proper ring seal and less blow by for a nice tight running engine, regardless of the HP goal. As much as it costs to build these engines today and the amount of time and effort involved, I just don't see why someone wouldn't want that.

[Dragncar]

Pontiacs need it more than most engines, not less. Myself, I am wondering how much of a difference there will be since my engine was honed with a iron plate but will use aluminum heads. At least for awhile.
I would like to put the HOs and Warrior Dan did for me back on after I play with the High Ports. If I can get to 10.83 with 9.3-1 and a junk 455 with a cam I bought of E Bay on a whim, maybe I can get to 10.60 or even 50s with a engine with better stuff, all fresh and custom Crower cam he designed for the heads on pump gas.
10.50s in a heavy car at 9.3-1 on 91 piss gas would be a accomplishment for me.
I know its best to use aluminum plate with aluminum heads, what is the actual difference in power if iron plate is used ?

[Rincon]

Call BHJ and ask for Chris. Iron ones go for 550 dollars an come with spacers for factory iron heads. The other spacer hardware kits cost another 60. The aluminium plate goes for 750 but that's because they are heat treated. If your machinist does not know when or how to use one Chris said you should bore the block to within .007 without the plate then hone the last .007 using the plate. They make the plates so it's a good bet. They know how to use them.

[mgarblik]

Originally Posted by Rincon

Call BHJ and ask for Chris. Iron ones go for 550 dollars an come with spacers for factory iron heads. The other spacer hardware kits cost another 60. The aluminium plate goes for 750 but that's because they are heat treated. If your machinist does not know when or how to use one Chris said you should bore the block to within .007 without the plate then hone the last .007 using the plate. They make the plates so it's a good bet. They know how to use them.

That's exactly how I do my blocks. Chris is a good resource and a Pontiac guy. I think he has a 71 Trans Am, but not positive. FWIW, I don't have any aluminum torque plates. All the ones I have, about 20 of them are iron. In a perfect world, iron and aluminum plates would be used as appropriate for the heads. In reality, there is little to no difference in results with the plate material used if very careful methods are used to install the fasteners, gaskets and tightening methods. I have iron plate honed a block, then attached the aluminum head to be used and re-measured the bores from the bottom. They come back very close to perfect. Don't do enough blocks to justify another 10-12K buying them all in aluminum as well. Big, commercial, race shop, possibly. If buying a plate from BHJ, be sure to ask about some "blem" plates. We were able to buy several with minor cosmetic or machining errors that didn't hurt their use and for 25% off.

[hurryinhoosier62]

Originally Posted by mgarblik

As hard as it may be to believe, torque plate honing is worth 8%-10% in peak HP on an engine dyno. It has been proven time and time again. On a 400 HP street engine, that's 32-40 HP. That's not just on a Pontiac, but typical for American V-8 engines. If the goal of the rebuild is to cruise around on a Sunday afternoon from one car show to another, or drive the car in a parade, I agree torque plate honing is not necessary. I have run a ball hone through many, many engines and put the old pistons right back in and away they went. But there is real HP just sitting out there waiting to be had and it's a fairly inexpensive up-grade to an engine rebuild. My rule of thumb is, if the engine is getting new pistons, it's getting torque plate honed. This includes even 5 HP Briggs and Stratton engines for say a Jr. Dragster. It makes a huge difference in those little engines. Joe Mondello was under contract with Briggs and Stratton to develop machining practices for their Jr. Dragster engine. Torque plate was worth 2 HP on a 20 HP Jr. Dragster engine. Same 10%. Verified on the little dyno.

I would like to add that PontiacJim 1959 made some good points about the many variables of heat cycles, uneven heating of different cylinders, and external forces on the block from mounts, and even the intake. Huge money has been spent trying to duplicate those forces while honing. I have honed blocks with the mounts on the block, the bellhousing attached and used a hot hone that circulated 180 degree honing oil through the block while honing. Believe it or not, going through all that aggravation on different blocks, Chevy, Mopar and Pontiac, it didn't show much on the dyno. Possibly a few HP, but not enough to really verify. So we discontinued the process. Some cup teams and Pro Stock still hone that way.

X 2, Mike. Only situations where you absolutely have to drag every horsepower out of an engine warrants running hot oil and the correct temp coolant through a block while honing. For a street engine it's overkill.