Torque Plate? [Merged 11-6]

[steel_3d]

I'm not saying the machining was perfect. I wasn't too happy with it in the first place, since with his torque plate it was about .0003 out of round and/or tapered (I wasn't doing the measurements the guy was all over the place so I didn't catch what was out of round and what was taper, though I'm pretty sure there was both). There was one spot that was .0004" loose at the bottom, which is obviously bad machining. I told him the same thing, that he should've made sure his stones were straight and the pressure was even. I saw spots where you could see the stone skipping. But now going from that to .002" taper just by swapping the plate for the head, and swapping gaskets that are the same type, that has little to do with machining.

Bishilvr, I don't want to condemn all steel torque plates, since I only have one data point, but you should measure a block with the head on after honing with the plate, and see if it's really as good as you think it is. You can measure all the cylinders from the bottom through the mains. This guy never thought of doing that, and it seems he's been machining blocks all wrong all along.

It's even possible that his torque plate is warped?? Who knows.

Blue1, I've seen the bore change all along its length from torquing, not just the top, and by more than .0002-.0004. I'll have more data with the new block. Maybe it was just a very weak block. I kinda doubt it.

 

[lasertim]

Do you realize how little .0003-.0004" is? Your block will probably distort more than that when it is under operating temps compared to cold.

If he held tolerances to .0003-.0004" I would say he did a damn good job. Hell, most bore gauges are only accurate to .0002." That is sooo small, I wouldnt worry about it.

 

[GVR4592]

Do you realize how little .0003-.0004" is? Your block will probably distort more than that when it is under operating temps compared to cold.

If he held tolerances to .0003-.0004" I would say he did a damn good job. Hell, most bore gauges are only accurate to .0002." That is sooo small, I wouldnt worry about it.

Thermal expansion is accounted for with the piston manufacturers reccomended clearances, out of round and taper are not. I believe those measurements were taking with the steel torque plate, with the aluminum head they were .002" out of round.

 

[steel_3d]

lasertim, I realize .0003-.0004 is not the end of the world and I would have run it like that if it was only that bad with my head on. But .002" is way too much. I'm awware that warpage happens at operating temperature. The reason I said the machining wasn't perfect was because someone said that's the only reason (I was arguing that the machining didn't cause most of the .002" taper but the torque plate), while most people say that a decent honing job should be closer than .0003-.0004:

Quoting blue1: "Taper and out of round bores are caused by a bad or worn boring and honing equipment! A good machine will bore and hone a bore unrestrained (no torque plate) within .0002 for the length of the bore (Taper)."

 

[groundPork]

I'm not saying the machining was perfect. I wasn't too happy with it in the first place, since with his torque plate it was about .0003 out of round and/or tapered (I wasn't doing the measurements the guy was all over the place so I didn't catch what was out of round and what was taper, though I'm pretty sure there was both). There was one spot that was .0004" loose at the bottom, which is obviously bad machining. I told him the same thing, that he should've made sure his stones were straight and the pressure was even. I saw spots where you could see the stone skipping. But now going from that to .002" taper just by swapping the plate for the head, and swapping gaskets that are the same type, that has little to do with machining.

Bishilvr, I don't want to condemn all steel torque plates, since I only have one data point, but you should measure a block with the head on after honing with the plate, and see if it's really as good as you think it is. You can measure all the cylinders from the bottom through the mains. This guy never thought of doing that, and it seems he's been machining blocks all wrong all along.

It's even possible that his torque plate is warped?? Who knows.

Blue1, I've seen the bore change all along its length from torquing, not just the top, and by more than .0002-.0004. I'll have more data with the new block. Maybe it was just a very weak block. I kinda doubt it.

You need to remember that taper in the bore is not so bad as out of round, and just cause the hole tapers a .0005" top to bottom, doesn't mean the rings won't seal. as long as its round the ROUND rings will have suraface to ride and seal against. And .0003 - .0004 is not bad at all... believe it or not, .0005 out of round can work. It's not ideal, but you have to think of it the same way you'd think of a warped head... typical SAE is like .003 of warp per 6" length of deck surface. The ring is flexable and has a certain amount of conformability to seal against the bore wall. think in terms of circumference instead of actual bore diameter (much longer for a skinny ring to lay against, in spite of .0004" uneveness! ). Now, that been said, That doesn't mean he did a good job... if the cross hatch angle was incorrect for the ring, and the finish roughness not correct the rings will never seat to the cylinder wall (too shiny or too rough). If all engine builders procrastinated on absolutely perfect bore, we'd never know what could be gotten away with. My advice is to put the thihng togather and run it under a load. if it smokes at first and doesn't stop after a solid half hour of break in, it may not ever, and then you need to discuss this with your engine builder.

Keep in mind you're not likely to get any difinite answers for a lot of questions regarding engine builds very easily... remember guys get paid a lot of money to do what your trying because they earned the answers. You're trying to save money, they wanna make it from guys like you. I'm just sayen, don't be surprised.

 

[steel_3d]

Right, I hear you man. But my #3 cylinder was .001" out of round and .002" tapered when I torqued my head down. Would you have put it together like that? I talked to a couple of the well known dsm engine builders and they all said no.

I'm pretty sure it would have run and not caused major problems for a while. I'm guessing the most obvious issue would have been burning oil, and if I ever took it apart the pistons would be all scuffed up. Would it have sealed? Maybe... Would it have seized up? Doubt it, with .004" clearance which is on the high side for Wisecos.

 

[groundPork]

Right, I hear you man. But my #3 cylinder was .001" out of round and .002" tapered when I torqued my head down. Would you have put it together like that? I talked to a couple of the well known dsm engine builders and they all said no.

I'm pretty sure it would have run and not caused major problems for a while. I'm guessing the most obvious issue would have been burning oil, and if I ever took it apart the pistons would be all scuffed up. Would it have sealed? Maybe... Would it have seized up? Doubt it, with .004" clearance which is on the high side for Wisecos.

Ahhhh ok... next step then... If you don't want to go back to him, start shopping for block machine work. I know most piston manufacturers of DSM pistons have their recommended tolerance actually at .005" so you may very well be able to save the block. I know Wiseco recommends about .004", but try giving them a call see if .005-.006 is ok. And I know the next thing you'll say is "but what about piston slap!!!" well, trust me it'll only be mild at cold start up. If they say no way, coat the pistons, or get a new block. I would say try to get your money back in small claims, but it is a very tough case to ague (I know many that have tried, and failed or gave up, and know few who've succeeded). As many will tell you... that's racing. Good Luck!

 

[steel_3d]

Oh yeah I have my money back and a new used block that hasn't been touched before. This is a big name shop, they're not out to mess with me. It just so happens that the machinist they use is not bright enough to check his work. Or maybe I'm the only unlucky one whose block happened to warp like that.

I ordered a BHJ aluminum plate for $525, the shop's gonna buy it off me for $400, so basically I lost a month and a half on my project (this is my daily driver, so it sucks), and I'm paying $125 out of my pocket for this plate. I'm using another shop, the guy here is more willing to chat and sit down and measure shit over and over. He already wasted a bunch of his time checking this other shop's work. I brought it to him when my bore gauge at home was telling me it wasn't right and I wanted to be 100% sure. It wasn't just the cylinders either, the #3 main was like .001" out of round and a bit bigger than the rest. I was willing to live with that as well since I've heard the mains are pretty forgiving. The new guy says he makes the mains perfectly round, so we'll see.

Edit: That's a pretty unconventional piston setup you got as your avatar...

 

[steel_3d]

This is an educational article about hot honing: http://www.circletrack.com/techarticles/82438/index.html

I was mostly looking at the last table, that shows how the out of roundness changes with heat. Seems like it's over a thou in some cases. I don't particularly like their data though because all of their configurations are warped. It would've been much more legible if they had heated an already straight block or cooled a block that was hot honed straight.

 

[groundPork]

The avatar is a joke for those that know piston design... yes very unconventional, and very ineffective... detrimental in fact.

circle track, engine masters, race engine tech, race tech magazine, engine rebuilder's magazine are all reputable mag's with tones of info ono bore and hone. Glad you're reading up in real race mags.

I just wan't you to enjoy your project the most you can. I have built many engines, and I can tell you honestly it can be very stressful. If it gets to that point with me, i step back and assess. I may come up with a simple and efficient resolution from doing so.

this forum is a good reference place to coincide with real shops in the field. COLLECTIVE EXPERIENCE!

 

[nikkeebabee]

I got my pistons and rods so I have been calling around to machine shops and was wondering about the torque plate...

Is it really needed during the bore/ hone process?

advantages or disadvantages?

I'll be running eagle/wiseco combo...

Thanks in Advance

 

[FORMONTOYA]

IMO.......any shop worth their weight will use a torque plate to bore the cylinders. Now putting a cross-hatch hone is a different matter and doesn't require a torque plate.

Advantage: the block is under the condition it will be with the head torqued to specs which assures that the bore is true and round. If one is not used, then the bore could become "out of round" once the head is torqued in place.

Disadvantage: finding an engine builder (since most are V8 guys) that has one for an import.

 

[awdtalontsi1992]

Torque plates are one of those things were you can get away with not using one. If I was building a race motor with high hp figures in mind then I would want a torque plate to be used. They generally are needed more on larger bore motors. If you have the extra money to spare go for it. But it will be hard to find a shop with one for the 4G63 and your money is probably better spent elsewhere.

 

[GVR4592]

I think anybody that says a torque plate isn't necessary has never measured a cylinder with and without the torque plate installed. Generally it's only used during the honing process.

There is a pretty significant amount of distortion when you bolt the cylinder head to the block, if you hone without it the cylinder will be out of round.

 

[steel_3d]

I think anybody that says a torque plate isn't necessary has never measured a cylinder with and without the torque plate installed.

I think anybody who says a torque plate is crucial hasn't compared the measurements with the torque plate and the actual head torqued down [not trying to be an ass to you, just making a joke ]

Not to mention, that even when machined with a torque plate, the cylinders (nor the mains, really) won't be perfect when measured a few days later with the same torque plate, espeically if everything's disassembled and reassembled once or twice.

Also, nobody has measured the cylinders under running conditions. I'm sure not many people have measured the block with the loads on it from being installed in the car (the measurements change just from being mounted on an engine stand). Or measured an engine after a teardown and compared it to when it was built.

Basically there's so many variables that make the cylinders warp, that I don't think I'll bother next time. If out of the two machine shops I dealt with, one of them could have made my cylinders and mains straight with everything torqued down, I would say I'm satisfied cause one of the large variables has been eliminated. But they can't even accomplish that. Maybe you guys can find the magic machinist.

Whoever wants to try their luck can have my BHJ aluminum torque plate for a decent price. It's the best you can get for a 4g63, and it's still not very close to the actual head. Whatever you do, do NOT use a steel torque plate. Been there, trashed that block. Over 0.001" taper and out of roundness with the head torqued down is a little too much for my taste, just as bad or worse than using no plate at all.

 

[EclipZ]

someone said earlier in the thread to take an old cyl head and have the bores cut out, would this work?

 

[insanewayne]

I am in the process of trying to get that done right now to a old junk head i have....not easy to find where I live...Water Jetting them will run $200+....or I can buy a $200 slab of alluminum and give it to my machinist to toss on the CNC and then he keeps it....

On the last page a Member posted that he had the CAD file for a plate, I'm hoping he's still around to send that to me, could really help out right now.

 

[insanewayne]

Ok, I'm in need of a bit of help here. Does anyone have any experience with turning a junk head into a torque plate. I think it will work fine, and also be the best way to do it, my machinist mentioned it might ruin the structural integrity of the head, and not hold up to being torque'd down with the 4 holes in it.

Thanks,

 

[steel_3d]

Try it and let us know how it works out. It should be at least as rigid as a normal aluminum torque plate. And I can tell you that even a 500 dollar BHJ torque plate doesn't simulate a head anywhere near perfect anyway, so you might as well go with what's cheaper.

 

[blue1]

It does work!! thats how i did mine send me your email in private messages and i will send you a pic" and by the way the bores only moved .0002 in the top areas. not really worth the hassle

 

[insanewayne]

Were you using ARP's? To what torque?

Pm'ed.

 

[blue1]

yes i am 4g64 7 bolt with the 63 head cant remember torque but it was to the arp spec

 

[woooop]

Im working on a 6 bolt swap and im down to just finishing the block ,do i have to use a torque plate on the block what whould hapen if i didnt

 

[TwoLiterLaser]

Are you talking about a torque plate that is used to simulate the stress a cylinder head exerts on the block while the block is being mahcined? Are you actually machining your block or only honing? Torque plates are usually used on lighter-weight blocks such as aluminum, but it could not hurt to use one on a cast-iron block.

 

[Sharadon]

When ever possible use a tq plate. Especially on iron blocks, even if you just hone it.

You'd be suprised how much the head bolts pull on cylinders.

You can see shadows in cylinders that have been run and didn't use a tq plate.