Perfect bore size without torque plate?

[MOPARoldtimer]

There is a machinist in my town who builds the best engines in the area. He has a great reputation and all his customers seem really happy with the engines he's built for them. He has built lots of Mopar small blocks and big blocks, and he doesn't use a torque plate when boring them; somehow he knows how to bore them for a perfect piston fit without using one. The proof is in the pudding: he has built 2 small blocks for me with forged pistons, and they display absolutely no piston slap when cold. If using a torque plate really changes the effective bore by as much as .004" as they say, I am really curious how he is able to get by without using one, but I don't want to ask him because he might feel it's a secret.

 

[70aarcuda]

just a note..the torque plate is used during honing..not boring of the block.

 

[jos51700]

It has nothing to do with slap.

It's all about insuring the the bore is perfectly circular when under the load of the head bolts, with that load distributed through the head. Look as some BBC motors and you'll see the ghosts of the threads in the cylinder where the metal has distorted when torqued. If the cylinder is slightly out of round when the head is torqued (and yes, they shift a lot), then the rings, which are nearly perfect circles can't seal as well, and you get extra blow-by.

That pressure sneaking past your rings? That's pressure that's not pushing on the piston, and is contaminating your oil while it does so.

I've always bored and honed with the plate on. On the Harley cylinders (iron liner, aluminum jug), the plates could be worth a couple thousandths in OoR.

FWIW, a piston with not enough clearance won't slap, either.

 

[OldmanRick]

The torque plate really covers any distortion in the bore from top to bottom. It definitely helps with perfection, but a overall 4 thou difference with or without sounds really excessive to me.

I see know way of fudging a hone job to make up any difference in the bore shape. I think he's giving you a good hone pattern with good tolerances and it's working decent. I've put together some engines without a plate hone and have been satisfied. Were they perfect.....no way, but they sealed pretty well. I'm not recommending not using a plate, but if you have no choice, it can work decently.

 

[tubtar]

The " pudding " would be the thousands of dyno tests and the fact that any " serious " race engines are honed with a plate.
As stated above , it has nothing to do with size and more with concentricity.
Real big shooters even go as far as circulating fluid that is heated to operating temperature through the block and some even have torque plates that allow for coolant flow through them to simulate actual conditions that the cylinder will be affected by when running.
Not using them worked for a long time.
Still works for that matter.
But there is a better way to do it.
And that is with a plate.

 

[Abodybomber]

I have personal info,on this. Was around a certain ,very healthy 340 build ,in the day. Still ,owns,the only B-H-J ,plates,on the Cali central coast. Checked cold. The .030" bores,stretched. .0005-0008,compared to a non torque plate bore.This was a cold block,50 degree at night check.Still ,good information. Checked against,old Arias,fit at .006". Just my; personal experience.

 

[raymond]

There is a machinist in my town who builds the best engines in the area. He has a great reputation and all his customers seem really happy with the engines he's built for them. He has built lots of Mopar small blocks and big blocks, and he doesn't use a torque plate when boring them; somehow he knows how to bore them for a perfect piston fit without using one. The proof is in the pudding: he has built 2 small blocks for me with forged pistons, and they display absolutely no piston slap when cold. If using a torque plate really changes the effective bore by as much as .004" as they say, I am really curious how he is able to get by without using one, but I don't want to ask him because he might feel it's a secret.

Wait till your engine has 40 or 50,000 miles on it and pull the heads, you will see the bores are pretty much perfectly smooth except for the area right next to the four head bolts from the top of the bore and down about 2 inches, you will see these areas still have most of the original hone marks. That's because the rings have never had a chance to wear these areas because after you torque the heads the tops of the bores are pulled 'square' How do you stop this and get some GOOD ring seal???? USE THE PLATE!!!

 

[Abodybomber]

X2!

 

[MOPARoldtimer]

70aarcuda: "just a note..the torque plate is used during honing..not boring of the block."

Thanks for reminding me. I had forgotten that.

The "pudding" would be the thousands of dyno tests and the fact that any "serious" race engines are honed with a plate.

That pressure sneaking past your rings? That's pressure that's not pushing on the piston, and is contaminating your oil while it does so.

"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy." - Hamlet, Act 5, scene 1.

Thanks for all your feedback. I don't mean to disrespect your opinions, and I don't intend to echo Hamlet because that borders on "know-nothingism", which of course is dumb. However, the fact remains that this engine builder has constructed record-setting gas and fuel dragster engines, road race engines and land-speed record engines, all without a torque plate, so I think something else must be going on there. I wouldn't presume to know what it is, though.

 

[moper]

My response would be - a record is a combination of the engine, vehicle in its entirety, driver, and mechanics. It's not a record setting engine unless they threw it a certain distance. It's part of the sum of the parts of a machine and driver combo. A pefect example is the thousands of torque plate honed engines that don;t set records or really run that good. There's a bunch of those too - but that's no reason not to do the best one can building one. Record setting or no - if he used plates his engines would make more power. It's proven fact. The technology exists to quantify the loss of cylinder presssure due to ring seal being lost or interrupted - which is more the case. The distortion can be much more than .0005". I measure between .0015 and .0005 on the top of the bores on my small blocks. It was such a big deal to me that in the 90s I bought my own plates because no local shop had them. Now most do have them and I'm sure these guys wouldn't drop $300+ each for them if there was not a damn good reason.
I'll also add - there's more than one way to skin the cat. He may not have plates but still may be preloading the castings...

 

[JBurch]

Something we should always remember...........people were able to go fast before torque plates were invented!

To be sure people go fast using them; I even own my own Mopar Performance small block plate, I do beleave in them, BUT I am not gonna say you can't fast if you don't use one, and I'm not gonna discount an engine built with out a plate by a guy who earns his living building engines; he wouldn't be earning a living if he didn't deliver, simple as that!

There was a time plates didn't exist, so you had to figure how to go fast with out one.

 

[famous bob]

Something we should always remember...........people were able to go fast before torque plates were invented!

To be sure people go fast using them; I even own my own Mopar Performance small block plate, I do beleave in them, BUT I am not gonna say you can't fast if you don't use one, and I'm not gonna discount an engine built with out a plate by a guy who earns his living building engines; he wouldn't be earning a living if he didn't deliver, simple as that!

There was a time plates didn't exist, so you had to figure how to go fast with out one.

like the guys above said: torque plates are an attempt to come up w/ a perfectly round cyl. after torqueing the heads in place. you can get the right or wrong clearances with or w/o a torque plate, it really doesn`t have a whole lot to do w your clearances, mostly like stated above, less than a .001 distortion in most cases:wack:

 

[inkjunkie]

SO safe to say the countless folks that USE the plates must be boneheads......Worked in a shop that did production rebuilds, never used a plate. When the shop owner built the powerplant for his own hot rod it went to the race shop up the road to get done with plates...

 

[jos51700]

The factory doesn't use plates (at least back then, not sure about now), and it's true. You can go fast without plates.

This is about going faster.

 

[70aarcuda]

The factory doesn't use plates (at least back then, not sure about now), and it's true. You can go fast without plates.

This is about going faster.

Yes, it is about getting the most out of your rebuild..

perfectly sealing rings make more power then rings that are not sealing as well..pretty simple..

 

[Mad Dart]

Hand Hone Junkyard 360, no machine work not even a line hone for the Main Studs that were installed....... NO Decking of the block either Just sayinn.............

[ame="http://www.youtube.com/watch?v=OeX3LWkJKWg"]360 Mopar Dyno Test AIRWOLF 220 heads 522hp - YouTube[/ame]

 

[JBurch]

I don't think there is a single person on here who would turn this engine down, OR feel that they are some how inadequate cuz this engine isn't plate honed...............

It's just a step in the process, but it isn't a make or break event!

Hand Hone Junkyard 360, no machine work not even a line hone for the Main Studs that were installed....... NO Decking of the block either Just sayinn.............

360 Mopar Dyno Test AIRWOLF 220 heads 522hp - YouTube

 

[Mad Dart]

I don't think there is a single person on here who would turn this engine down, OR feel that they are some how inadequate cuz this engine isn't plate honed...............

It's just a step in the process, but it isn't a make or break event!

The engine I posted is on Page 8 of MOPAR MUSCLE this month. How much of the article is true is subjective....... Lol

 

[grimreaper]

I knew an old timer who built really powerful and durable engines and he never used torque plates. He never even used a torque wrench!! Because he was successful (or lucky a lot) would it make good sense for others to forgo the torque wrench?

 

[OldmanRick]

I knew an old timer who built really powerful and durable engines and he never used torque plates. He never even used a torque wrench!! Because he was successful (or lucky a lot) would it make good sense for others to forgo the torque wrench?

I had to comment.......When I was about 11yrs old (1970), my first mentor didn't use one either. I watch him tighten stuff and would get the shakey arm, and tell me he was the human torque wrench. Still makes me laugh even today......

 

[70aarcuda]

The engine I posted is on Page 8 of MOPAR MUSCLE this month. How much of the article is true is subjective....... Lol

It did not even need the water pump to be turned....

 

[Mad Dart]

It did not even need the water pump to be turned....

Yup they figure it gets so much air through the heads it will stay cool enough no need for it. Lol I wonder what the water temp was brought down to on the bottle?
So to be fair lets subtract 15 HP.

 

[bad440]

The engine I posted is on Page 8 of MOPAR MUSCLE this month. How much of the article is true is subjective....... Lol

thats an understatment lol. even mopar recommends using a torqueplate,had mine done with one.why chance it?

 

[moper]

Something we should always remember...........people were able to go fast before torque plates were invented!

To be sure people go fast using them; I even own my own Mopar Performance small block plate, I do beleave in them, BUT I am not gonna say you can't fast if you don't use one, and I'm not gonna discount an engine built with out a plate by a guy who earns his living building engines; he wouldn't be earning a living if he didn't deliver, simple as that!

There was a time plates didn't exist, so you had to figure how to go fast with out one.

There was also a time where cars ran on kerosene, had 6 volt generators, and cable operated brakes. All which "worked just fine" even for race cars of the time. Time and technology march on and I'd offer the arguement that ignorance is bliss and a builder will work diligently on what they know about and for certain moments in time will be "in step" and top of the heap. Zora Dontov made some amazing small block Chevies and components in his day and I'm sure his heirs would have no trouble sticking his name on a box and finding someone to buy it and capitalizing on that reputation today.
Kind of like sticking a monicker like "Hemi" on a modern pushrod V-8 and living off that reputation. Good marketing will always triumph over sense for some people.