[GoreMaker]

Anyone know where I can rent an aluminum Pontiac torque plate? AllPontiac rents them, but they're intended for aftermarket blocks with huge bores. I'm looking for something for a stock-ish bore. Half the people I discuss this with are like "You don't need a torque plate for a Pontiac block!" and the other half are like "a torque plate is essential!" and holy crap who knew this was so controversial?

[25stevem]

The way I like to look at it for a street motor that starts with a 4.120” bore and will not go more then ,030” over is that the factory did not use one, and if Pontiacs where still being made we would be quite happy with a motor done as such in a new car right?
On the other side of the coin, even for a pure street motor using one is likely worth 8 to 12 hp once you have a motor making 450 hp or more.

In terms of factory blocks and bore sizes above 4.150” with strokes of 4.00” or more, I would sure do my best to get a hold of one to bore and hone with!

[GoreMaker]

My main concern is with longevity and minimal oil consumption. Since this is a numbers matching block, and I plan to keep the car until I die, I'd like it to last that long without needing another rebuild. I figure perfectly round cylinder bores are more conducive to an engine lasting longer. Everyone keeps telling me I should expect a solid 450hp from my build (even though I was aiming for 400, hah!), so I'd like it done right

[tanksteve]

https://www.ccaracing.com/

I got one from these people and its a very nice looking piece

[GoreMaker]

Hey those are a really decent price! Thanks!

[BLANK1]

Cylinderheadsupply.com has them

[GoreMaker]

Oh I know they're available to buy all kinds of places, but I want to rent one. No way I can justify spending $600 to $800 for something I'll use once and probably never need again.

[i82much]

Originally Posted by tanksteve

https://www.ccaracing.com/

I got one from these people and its a very nice looking piece

i'm no engine builder, but should't that thing have more than three holes

[GoreMaker]

It's a stock photo, they use the same photo for all the torque plates. BHJ does the same thing

[tanksteve]

here is a pic

[n20ta2]

I bought one from CCA a couple years back. Arrived in a couple weeks and was good quality. I think I paid 400 shipped back then though. I think I looked into renting one and the shipping and everything all said and done was close to 250.00 if I remember correctly.

[GoreMaker]

So thanks to this thread, I have a couple of good leads for getting my hands on a torque plate, this community is awesome.

But that still begs the question, how necessary is a torque plate? The way it was explained to me by a couple of local machinists, the head bolt holes on a Pontiac block are so far from the cylinder walls that their effect on bore distortion is minimal at best, especially compared to something like a Chevy small block where the holes are really close to the bores. Plus there's only 4 bolts per cylinder, vs 5 for the Chevy. That means fewer bolts pulling at the cylinder walls.

There's a whole bunch of Pontiac enthusiasts around my area, and every one I spoke to was like "meh, don't need one for Pontiac engines", followed by the usual anecdotes of "my engines make over XXXhp and I ain't never had a problem" (which doesn't actually answer anything about the benefits of honing with a torque plate). Meanwhile, most of the Internet and all the Pontiac engine rebuilding book authors are advocating for a torque plate as "essential" to a healthy, long-lasting build. Does the truth lay somewhere in between? Like maybe it's somewhat beneficial but not essential? 25stevem makes a good point that Pontiac didn't use one, but then we're making the cylinder walls thinner when we bore, and I'm hoping this build will last longer than a stock Pontiac one.

For what it's worth, I'm definitely planning to use one.

[Mike Davis]

If you are trying to squeeze every ounce of HP then yes torque plate it. If this is a street performance car you will notice no difference. 90% of the blocks out there do not get torque plate honed and you don't hear complaints about using oil or wearing out prematurely. Factory never used one and those engines would go 100K plus miles.

[mgarblik]

Your getting "mixed messages" from the local machine shops and even in this thread because your not asking the right question? Lets try it this way. Is a torque plate necessary? Absolutely not is the correct answer. As said, the factory didn't use them when they built millions of Pontiac engines. Next question. Is their any benefit to using a torque plate? Yes, absolutely. Next question. How much of a benefit to a Pontiac engine? Depends on the individual casting and core shift. But I have verified on the engine dyno 3-4 HP per cylinder increase on a 500 HP engine. This would be the difference between a ball hone job or flat stone 2 step hone, no plate vs a proper 4-step plateau hone with plates. So 24-32 'Free HP" with a proper plate hone. Question. Will you "feel" the difference in a typical street car? Some will, some wont. It would amount to about .2 seconds difference in the quarter mile for a typical muscle car. Question. How good do you want your fresh engine to be? Only the owner can answer that question. I hone "everything" with a plate if possible. From a 5 HP Briggs and Stratton engine, "I have a little plate for it", to a 1963 Studebaker 289. It makes the finished engine better. How much extra does it cost? About double the cost of a basic hone job and if done properly, takes about 3 times as long. Hope this helps with your decision.

Reading the OP's last post causes me concern with the machine shop he may be using. Any machine shop that feels the use of a torque plate is not needed on a Pontiac block but feels they are necessary on other American V-8's, obviously has a low opinion of a Pontiac and does not consider them a performance engine. They are thinking of the Pontiac as a boat anchor or tractor engine, where sloppy, low grade work doesn't matter because it's just a "Pontiac". I would run like hell from any shop with that attitude. Most know I am not a Chevy guy, but when one comes into class for a rebuild, it gets the same care and all the tricks we can possibly do to make it as good as possible.

[n20ta2]

I actually wanted my machine shop to bore and hone with the torque plate, he told me the bore wasn't necessary with it but that he would leave enough material to hone with it. He checked distortion with it bolted on before the hone and found some but it easily cleaned up with the hone. I asked him if he thought it was worth doing and he thought it was, he said I would definitely get a better ring seal and the engine would break in quicker and have less blow by. I'm at the upper level of what this block can handle at around 700hp but I think it would be worth it even on a street engine if you want a better then factory ring deal

[AG]

Machining for a rebuild is so expensive, so from a cost perspective it's only a little more money to get it honed with a plate. I have every block I do honed with a plate regardless of the application since it only helps.

[Sirrotica]

Truth is most shops don't want to invest in a Pontiac plate because they never see one come through the doors.

How many times have you considered buying a tool to do a job that you may never use again? I know I have, and either made something to work, or borrowed one from someone that has it. It's economics, so the guy says you don't really need it.

Truth is, as many Pontiacs as I've built, not one was ever honed, or bored with a plate. No one in my home town owned one, so it was done the same way the factory did it, no plate.

Is it better, I'm sure it is, it's been proven that it is a preferred operation over no plate, but I was never in the position that anyone that did machine work for me owned one.

I have an ancient adjustable hone ( my father gave it to me, I believe it's Ammco brand ) I use that is graduated in thousandths for how much material it will remove, It works off of a 1/2 inch drill motor, so with 2 stones and 2 wipers it keeps the hole round, much better than a berry bush does. It surely isn't high tech, but it does the job...... It probably was high tech in the 40s though....

[77 TRASHCAN]

Originally Posted by n20ta2

I actually wanted my machine shop to bore and hone with the torque plate, he told me the bore wasn't necessary with it but that he would leave enough material to hone with it. He checked distortion with it bolted on before the hone and found some but it easily cleaned up with the hone. I asked him if he thought it was worth doing and he thought it was, he said I would definitely get a better ring seal and the engine would break in quicker and have less blow by. I'm at the upper level of what this block can handle at around 700hp but I think it would be worth it even on a street engine if you want a better then factory ring deal

I was fortunate that the smallish town I lived in, in the center of Southeast Oklahoma, had a legit engine builder/dragracer living there. He performed engine machine work, and buiding services, to any that could afford his services.

A good friend of mine had him build an engine (of course it was a Chevrolet, builder was a Chevy guy, as most are...) Builder has a torque plates for a SBC 400 and one for the smaller bore SBC's and of course BBC's also...

My buddy had a small block 400 built for his 66 Chevrolet C-10. That darned engine was a mild build BUT ran like gangbusters in that old pickup, had truly incredible performance!!! Builder also had a Superflow 800 dyno, he had bought not long before the 400 was build. THere was no doubt in my buddies mind that he wanted it dyno'd!!! The NET numbers were 300 HP, and 400 ft/lbs torque. I'm sure that if this had been done by a magazine, it would have achieved bigger numbers...

My point....I had my 283 for my 67 Bel Air built shortly after, all the same details, dyno'd (200 HP for mine, after all it is a 283)...........I still have the engine, under my work bench, it's doing in my 67 Chevy pickup, soon. It has 175,000 miles on it. It ran as good the day I took it out of my car, as it sis the day I forst drove it....

[Tom Vaught]

[QUOTE=Sirrotica;6334914]Truth is most shops don't want to invest in a Pontiac plate because they never see one come through the doors.

How many times have you considered buying a tool to do a job that you may never use again? I know I have, and either made something to work, or borrowed one from someone that has it. It's economics, so the guy says you don't really need it.

I bought a Browell tool for checking bellhousing to trans input shaft centerline.

I have checked 4 Lakewood bellhousings using the tool and now have 4 steel bellhousings that I know are going on the engine blocks correctly.

So knowing the job was done right basically cost me $25 per bellhousing and I sleep good at night.

It can sit in my tool cabinet forever now and it has paid for itself.

I personally will pay for a properly made Aluminum Torque Plate to know the Pontiac bores are machined properly for aluminum heads.

Tom V.

[Dragncar]

Originally Posted by GoreMaker

So thanks to this thread, I have a couple of good leads for getting my hands on a torque plate, this community is awesome.

But that still begs the question, how necessary is a torque plate? The way it was explained to me by a couple of local machinists, the head bolt holes on a Pontiac block are so far from the cylinder walls that their effect on bore distortion is minimal at best, especially compared to something like a Chevy small block where the holes are really close to the bores. Plus there's only 4 bolts per cylinder, vs 5 for the Chevy. That means fewer bolts pulling at the cylinder walls.

There's a whole bunch of Pontiac enthusiasts around my area, and every one I spoke to was like "meh, don't need one for Pontiac engines", followed by the usual anecdotes of "my engines make over XXXhp and I ain't never had a problem" (which doesn't actually answer anything about the benefits of honing with a torque plate). Meanwhile, most of the Internet and all the Pontiac engine rebuilding book authors are advocating for a torque plate as "essential" to a healthy, long-lasting build. Does the truth lay somewhere in between? Like maybe it's somewhat beneficial but not essential? 25stevem makes a good point that Pontiac didn't use one, but then we're making the cylinder walls thinner when we bore, and I'm hoping this build will last longer than a stock Pontiac one.

For what it's worth, I'm definitely planning to use one.

Well, if that is what a couple of local machinists have to say about tq plates and a Pontiac I would not use them.
I had some very long conversations about this with Dan Whitmore. The numbers he gave me were the same numbers in mgarblik,s post almost to a T. He knows what he is talking about on this. Dan, had a tq plate for every American V8 engine. All of them.
Its about the size and tq of the head bolt and the distance from the bolt to the wall. A In a Pontiac a 455 will distort the most, 326 the least (287?) 1/2" bolt= 90lbs tq.
Chevies run a 7/16 bolt so less tq, less distortion.
He told me a 289 Ford has almost no distortion. 7/16 bolt and a lot of distance between it and the cylinder wall.
A Pontiac 455 will have .004-.005 distortion a 1/2" below the deck right next to each 4 bolts. Right at peak cylinder pressure.
Dan told me on a Pontiac, use a tq plate "if you want your bores to be ROUND".
There is even a measurable difference in distortion with different types of head gaskets. So use the same gasket on the engine the machine shop uses under the plate.