Moly rings but not torque plate honed

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femtnmax

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383/432 bored 30 over, honed wth NO torque plates. Can I run moly rings or am I better off with iron rings that will wear into the bores? Trying to not have oil blowby the rings.

I assume I cannot torque plate hone it now without leaving the pistons too loose in the bores.
thanks
 
I don't believe plates have an effect on the wall finish - only the final shape that the ring rides over. Plate honing means the ring doesn't have to flex over the not-perfectly-round cylinder at the top pf the bore. That's predominantly a sealing issue between the ring and the piston's ring land. The sealing between the ring and the wall can be effected but it's much less of an issue.
The moly is all about the ring seating to the cylinder wall itself. Moly will help the rings seat immediately on a properly finished (meaning having the correct crosshatch and "Ra" or roughness average value) cylinder wall. Otherwise a moly top ring is simply and iron ring, with a molybdenum dry lubricant bonded to it. Once the ring seats fully - the moly has rubbed off.

Edit - I'll add the moly is only on the top ring - the compression ring. The 2nd ring is not a compression ring - it's an oil scraper - and it's not moly coated. Make sure you go through the right break in process for the ring type you run, and oil control should not be a problem.

Run any ring you want - if the Ra is too rough, the moly is rubbed off quickly and then the ring just seats over time like a plain iron faced ring does.
 
You need a smoother surface finish on the bore for moly rings than cast iron.

Torque plates are irrelevant when talking surface finish.

If it was honed with the proper stone, then you can run moly rings, if not just use cast iron...
 
femtnmax said:
383/432 bored 30 over, honed wth NO torque plates. Can I run moly rings or am I better off with iron rings that will wear into the bores? Trying to not have oil blowby the rings.

I assume I cannot torque plate hone it now without leaving the pistons too loose in the bores.
thanks
Click to expand...

What matters is if the bore is round when the heads are on. Finish is secondary. Rings can't seal to bores that arent round and if they "wear in"...you have other issues by then.
The big Chrylsers move around quite a bit, if they don't have a plate to hone your block you might as well burn your money.
Here's an example of a 413 that was honed without a plate and had less than 1500 miles on it. Notice the wear on the ring, it only makes contact (seals) in certain areas. This engine was using 1qt of oil in 500 miles.
Piston%20ring%20wear%20413%20Chrysler.jpg
 
CPMotorworks said:
What matters is if the bore is round when the heads are on. Finish is secondary. Rings can't seal to bores that arent round and if they "wear in"...you have other issues by then.
The big Chrylsers move around quite a bit, if they don't have a plate to hone your block you might as well burn your money.
Here's an example of a 413 that was honed without a plate and had less than 1500 miles on it. Notice the wear on the ring, it only makes contact (seals) in certain areas. This engine was using 1qt of oil in 500 miles.
Piston%20ring%20wear%20413%20Chrysler.jpg
Click to expand...


Yes, the cylinders need to be round.

I don't buy that the only way to hone is with a torque plate. Many engines have been made with blocks machined without torque plates that have lasted hundreds of thousands of miles. ie. the car companies do not bore and hone with torque plates and their cars go thousands of miles....

It is how good the machine work is done. If the bores are machined properly, they will hold up. Unless the block has become so weak that torquing the heads will distort the bores too much, in that case the block was no good to begin with.

Boring and honing with torque plates is a great idea. But is good to do if you have the money and need, but is not necessary for a street driven engine... For a race engine, yes...

Who is to say that the 413 in the picture was machined properly. How good was the machinist? And what condition was the machine in?
 
I'm one to use plates. So much so that years ago I bought my own because nobody around me had them. But lets be honest - for the first 40 years these engines were built they didn't use plates. That oil use issue looks more to be from the wrong finish (too rough) than out of round. At least looking at the amount of material removed from the scraping edge of that 2nd ring, and the fact that with 5 bolts around the bore on a 413, there would be a high spot of the wall, and a corresponding mark on the ring, exactly facing the camera in that pic if what you were thinking was true. Too rough is a much more of a common problem from the engines I've seen, and depending on the owner, it may have fixed itself if given enough time to finish seating. The older engines might have needed 500 to a few K miles on them before they'd "tighten up".
 
krazykuda said:
Yes, the cylinders need to be round.

I don't buy that the only way to hone is with a torque plate. Many engines have been made with blocks machined without torque plates that have lasted hundreds of thousands of miles. ie. the car companies do not bore and hone with torque plates and their cars go thousands of miles....

It is how good the machine work is done. If the bores are machined properly, they will hold up. Unless the block has become so weak that torquing the heads will distort the bores too much, in that case the block was no good to begin with.

Boring and honing with torque plates is a great idea. But is good to do if you have the money and need, but is not necessary for a street driven engine... For a race engine, yes...

Who is to say that the 413 in the picture was machined properly. How good was the machinist? And what condition was the machine in?
Click to expand...

moper said:
I'm one to use plates. So much so that years ago I bought my own because nobody around me had them. But lets be honest - for the first 40 years these engines were built they didn't use plates. That oil use issue looks more to be from the wrong finish (too rough) than out of round. At least looking at the amount of material removed from the scraping edge of that 2nd ring, and the fact that with 5 bolts around the bore on a 413, there would be a high spot of the wall, and a corresponding mark on the ring, exactly facing the camera in that pic if what you were thinking was true. Too rough is a much more of a common problem from the engines I've seen, and depending on the owner, it may have fixed itself if given enough time to finish seating. The older engines might have needed 500 to a few K miles on them before they'd "tighten up".
Click to expand...

I don't know how many different blocks you two have honed but I haven't seen a single domestic V8 block that doesnt move when you torque down head bolts with a plate. Small and big Chevy, Chryslers, Fords, Buicks, Olds, Pontiacs...they ALL move, some more than others. Even the aftermarket blocks move around. 4 bolt blocks like the Fords and Pontiacs are even worse than the typical 5 bolt deals. I just finished a Dart SHP based 363ci SBF and that block moved an easy .0025".

And the reasoning that its been done that way for 40 years makes it ok doesnt make any sense, especially when you see how bad those same engines that are 40 years old with thick 5/64" rings are so worn out in 100k miles you have to bore them .030" or more just to clean them up. Personally 1/16" rings are the biggest I will use and I won't use a piston with a 5/64" ring. All my street engines use a 1.5mm ring pack, even the basic restoration deals that won't see anything for rpm or abuse. So in my book the only "correct way" to finish hone a block is with a plate, gasket, and the same hardware used in the final build. If you want to "buy" that line of thought is up to you, for me the machine work for a "street" engine has to be just as good as a "race" engine.

Maybe you guys are unaware of all the modern vehicles that have constant oil burning issues because the bores aren't round. The nice thing about the new vehicles at least is with the lighter metric ring packs they dont wear out the bores as bad as they use too. I just pulled down a 150k 6.0L LS that will clean up with a .005" hone job.

As far as the piston pictured above..it was done at a shop that won in their class in the early Engine Masters contest, and the finish was fine. For whatever reason this didn't get honed with a plate and it's pretty obvious where the oil was coming from in that photo.
 
I appreciate the responses.
I had a Ford Fe with 4 bolts per cylinder, 90ftlb head bolt torque spec, bored/honed without torque plates, and the rings looked similar to CP's photos, and that engine burned oil. At the top of the cylinders you could easily see where the rings were not touching the bores, basically at each head bolt.
That's the problem living in the sticks out west...no good machine shops around or have to drive long distances to find one. I did finally hear of a shop 150 miles away, of course this is after the block work was done on the Mopar.

I'm trying to avoid the cylinder wall distortion when the heads are bolted down on my Mopar 432. Any comments on how much would be need to be removed from the cylinder walls if torque plate honed now? Is it parts of one thousandth of an inch, or more? I'm running Diamond forged flat top pistons. The bores have already been sized to the piston/mfr clearance, so more honng could end up with too much clearance of course.
 
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