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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
I bought a 1990 5.7 out of a Police cruiser. Not trusting the typical "it was running fine, just drop it in" I have torn it down. Well, it is so close to factory specs everywhere I heave measured I suspect it is a 50k or less mileage motor.
Anyways, on to the question of the post. I measured top ring gaps to get an idea of wear and get .022 to .023. I know .016 to .020 is considered stock and .030 is the in-service limit. So, replace while the engine is apart or just keep them? I put about 1,500 miles a year on my vehicle so this engine is not going to see much use over time.
If you tore it down, the rings need to be replaced. They will not go back in and seal effectively again. Therefore the gap of those particular ones no longer matters.
Ignore the ring gap specs you quoted. Problem being, those look like factory specs for factory rings for an in-warranty factory motor in a factory dealership. Not at all the same as replacement in the world at large.
A good rule of thumb is .0045" on the top ring and .0055" on the 2nd, per inch of bore dia, ABSOLUTE BARE MINIMUM for a naturally-aspirated street-duty gasoline motor. (meaning, no blower, no turbo, no nitrous, no racing, no abuse, not a diesel) Rings expand when they get hot. The hotter they get the more they expand. As they expand the ring gap disappears. If the ring ends reach each other, .... INSTANT COMPLETE AND VIOLENT DESTRUCTION is the result. They will reach a VERY high force against the bore, and either the bore gets destroyed, or the ring lands get blown off the piston. In any case, it is a total and catastrophic failure. Stock motors that fail due to excessive hot-rodding often experience this exact failure mode.
If the gaps are too tight, the motor self-destructs. If they're a bit too loose, you get slightly more blowby (emphasis on "slightly"... the difference is theoretical, so tiny as to be virtually undetectable) when cold. Now, consider the severity of the 2 consequences: too tight, you get instantaneous destruction; too loose, within reason, you can't even tell. There is no "perfect"; only error. Which direction would you prefer to err toward?
I usually shoot for .020 - .022" in a 350 on the top ring, and .024 - .027" on the 2nd.
Get new rings. Give the block a "glaze bust" hone, being careful to use the correct grit for whatever material the new rings have on their face (220ish if chrome, 400ish if moly). You'll have a tough time finding rings to fit those stock pistons anywhere except GM, expect to pay dearly. A set of rings from them might cost more than rings AND pistons from somewhere else.
You really shouldn't have torn it down. But that's water under the bridge now, just gotta move forward from wherever you are now and not waste mental grief looking back at where you used to be since that doesn't matter anymore. Next time you're in this situation, if the cyl walls look good, leave the pistons in them and put it back together. Replace the bearings maybe, grind the crank maybe, but leave the pistons in.
Use new rings. Chrome faced top ring, Napier cast iron second ring.
Honing should only be done as the final step to a plateau finish rebore using a boring plate to torque the cylinders. Otherwise touch the cylinders with a ball hone at your own peril. Trust me don't do that. It's an old wives tale and really hasn't been applicable for many decades. Lube the piston skirts and rings with ATF to promote quick seating and run a break in oil such as Amsoil Break In.
ATF is also a old school thing too.
I use Soap,water and brushes to clean the block. Blow it off, wipe with lint free towels and use normal oil for cyls/ rings.
My reasoning is that ATF is a 10 weight oil so less thick than the engine oil but still a lubricant. I'm open to trying other things but so far our engines use basically no oil when lubed with ATF, new rings on used bores. For that matter when I do have occasion to assemble a plateau honed rebored engine I haven't had any problems there either. Cleanliness and proper machining is key.
Bottle brush hone you will regret. Terrible idea. They have no place in a modern shop.
If you kept the old rings numbered and in order, they will work again.
Make sure they haven't lost their tension.
Use Marvel Mystery Oil to coat.
If you want to buy new rings, check out Hastings.
But then you will need to break the glaze with a dingle ball hone.
There CANNOT be any ridge at the tops of the cylinders.
And you have to move it up & down very quickly to get the correct crosshatch.
You MUST then clean and wipe the cylinder walls until they are operating room clean!
And make sure there is NO GRIT left in that block ANYWHERE.
Last edited by NoEmissions84TA; 03-26-2017 at 09:18 PM.
Police cruiser engines might not have a lot of miles on the odometer,
but they have a lot of run time - if it's summer, the car is running all
shift(s) long running the A/C; winter - the heater.
You do not need to remove ring ridges (it is unlikely to have much of one anyway and if it does rebore it) and you do not need to hone it for ring seating. THE RINGS WILL SEAT JUST FINE on a used, good condition bore. I've reringed engines with 300k miles with no honing and they use about 1/2 quart in 6000 miles running full synthetic with factory perfect compression. I also routinely cut oil filters and send in oil analysis to inspect our rebuilds and rerings and they always come back perfect with rapid decline in ring seating by products.
Hastings is a good choice for rings. All the Wiseco pistons we use come with Hastings rings. JE pistons seem to be using NPR rings which are also excellent and very inexpensive.
Sealed Power E251K.... Should be the rings you require. But measure first to insure it hasn't already been bored and also compare your piston grooves to the specs from SP.
Rick
Last edited by GeneralDisorder; 03-26-2017 at 10:44 PM.
The cylinders had no ridge to speak of. None that could be felt for sure. My worst bore measurement was 4.0017. Some places it was 4.000 and in a couple cylinders I had about .0005 under further down in the bore.
I have no qualms about using these rings again. I wanted better opinions, though. I have never torn down a motor that I didn't then rebuild. I was expecting to have to rebuild this engine until I got inside and found this condition. In every previous rebuild I had the blocks bored, etc.
I did not remove the rings from the pistons other than the top rings on two pistons to get an idea of the gap. Like I wrote, one was .022 and the other .023. I believe the rest would come in similar. I did note that the top ring gaps lined up within one inch of each other on all cylinders rather than on opposite sides. The bores have very evident cross hatching all the way down.
I will replace bearings, for sure. A couple has some scoring even though there was no sign of it on the crank journals.
sofakingdom has a good point of busting the glaze, though. I don't think the cylinders need a hone for sure, but a light rub with 220 or finer sandpaper following the cross hatch pattern does sound like a decent idea to me. I will ponder that and I am sure there will be lots of conflicting responses for and against
I am going to start looking for a seal and bearing master kit and talk to Summit or Jegs about rings.
Oh and one surprise. It is a roller cam motor WITH a lobe for a mechanical fuel pump plus drilled for it. I didn't expect to see the pump lobe. My vehicle didn't have FI (I added TBI) so I am running an external pump. Been thinking of a sump system with internal pump being fed by a mechanical pump. I didn't pursue that idea because I knew I was going to upgrade from the 305 at some point. This engine will make that possible.
I'll give this one more shot here. DO NOT HONE IT.
If you didn't bother to read the previously linked article, here's another from Chevrolet Power 5th edition from the era in question:
(checkout this dudes ring!)
There is no good reason to do that except needlessly and randomly removing metal from your perfectly good cylinders. Trust me if you use moly/cast rings they will seat no problem within about 5 minutes of startup.
READ THE WHOLE SENTENCE before jumping to conclusions, not pick and choose the parts you like best the way people do Scriptures. It talks about "max power", NOT "best results", "longest life", etc.
If you're willing to tolerate a permanent oil smoker in exchange for 0.5 HP during the first 100 miles, then not honing and used rings are for you. If on the other hand you want a motor that runs its best for a hundred thousand miles or more, then proper cyl wall prep, and NEW rings, are essential.
Have you tried it? We have been doing it for a decade and not one engine has smoked or used oil. NOT ONE.
The rings are seated to within 1% cylinder leakage within 5 minutes of operation.
I get that everyone does this and thinks it will end badly if they don't. But doing something "because you have always done it" is not science. Science says the soft cast rings will seat without issue. Modern rings are almost perfect right out the package.
I have heard it said (correctly) that on the first rotation of the engine the rings are seating - on the second they are wearing out.
I have tried MANY things over the years. I only post the ones that work on here.
Sounds like I have about 35 yrs more experience at this than you do.
And yes, I remember that edition of the Power Manual well; if memory serves, I bought it in about 1985, when the Busch Grand National series (now Xfinity) gave you I think it was 300 lbs for running a 6-cyl as shown on the cover instead of 8. I guess that makes it the latest word in such matters.
And yes, rings may be near perfect, but bores rarely are, especially after a head swap.
The best advice remains the same: new rings, bust the glaze with the right grit for them.
I'm sure you have plenty of experience as do I. And you obviously have a lot of respect around here as well, but you have neither answered my question, nor provided any science or evidence to back your claims.
Now I'm willing to listen to your arguement for honing - but can you provide more than "because I say so". I have offered several sources to back my claims besides my own experience and views.
It's a controversial subject to be sure. A lot of people listen to their machinist - who unfortunately has a major stake in getting your block into his shop for that Sunnen machine hone job so he can sell you other services or just keep his lights on which is no small task in our modern age of throw away parts.
Seriously though - no disrespect intended and I'm sure you know what you are doing but have you actually tried it on *good condition* bores? Not some ring ridged ancient junk yard trash but an otherwise good engine that's seeing a maintenance overhaul. We do this quite often due to fouled oil control rings that cause excessive oil consumption. We routinely (twice a week or more) put in new rings on untouched bores and they then run 5000 to 6000 miles with basically zero oil consumption.
I don't see how changing the heads would matter. The machinist does not use your heads to bore the engine he uses a bore plate. If changing the heads mattered then the difference between the heads and the bore plate would also matter. It does not.
Rick
Last edited by GeneralDisorder; 03-27-2017 at 04:24 PM.
To go along with the re-ring or not (yes new rings) what type might be best for my engine use. I run 1,500 miles a year max and low RPM mostly with occasional full throttle. Not much high RPM use though.
Typically a moly faced or chrome faced top ring (though I do mostly forced induction applications) and I like a napier profile cast second ring - contrary to what most people think the second ring's job is primarily oil control. I'm sure that a plain cast iron barrel faced top ring would work just fine and seat very quickly. In a naturally aspirated application I would probably go for the plain cast rings as you don't have the additional boost pressure to help seat the rings. At least in theory. In practice we only very lightly boost them during break in (5 to 10 psi) so it obviously doesn't matter much. What's important is to run it medium hard after the camshaft break in. Hastings wants "at least 10" full throttle pulls from 30 to 50 for ring seating with a short cool down between them. You need that cylinder pressure. Baby it and it will take longer to seat or possibly not seat at all. That's where most people end up with smoking piles of garbage - they wrongly assume that they should be "nice" to it. What you want to do is flog it pretty hard. Cylinder pressure seats rings - not driving it like grandma.
GD
Last edited by GeneralDisorder; 03-28-2017 at 10:53 AM.
When I was racing my 427 big block I never honed the walls.
I would replace the rings at 40-50 runs. what I found with this procedure
was that the rings took a little longer to seat but would show a better leak down
in the long run.
The first 3 or 4 runs would be down a tenth or two but would come back by the 5th run.
I'll give this one more shot here. DO NOT HONE IT.
If you didn't bother to read the previously linked article, here's another from Chevrolet Power 5th edition from the era in question:
(checkout this dudes ring!)
There is no good reason to do that except needlessly and randomly removing metal from your perfectly good cylinders. Trust me if you use moly/cast rings they will seat no problem within about 5 minutes of startup.
GD
Putting new rings in cylinders with no RVK is not the hot set up.
The point is not how old the book is, the point is how long people who really know their stuff (and are publishing books because of it) have known this. More than three decades. Nothing has changed in that time - if anything fuel injection and proper oils leave cylinder walls in better condition and rings are manufactured to better tolerances making this more true than ever.
Most modern engines, after a few hundred thousand, still show acceptable cross hatch and RVK will be entirely adequate. There are of course exceptions to every rule and if you recently drove through a volcanic eruption with no air filter then you will probably need a rebore. But that's not the OP's question is it?
My point is simply this - you rebore a cylinder or you leave it alone. This "rehone for ring seating" is hogwash. Use good cylinders as is. Rebore and plateau hone bad ones. There is no middle ground for excellent results IMO.
Rick
Last edited by GeneralDisorder; 03-29-2017 at 01:37 AM.
The point is not how old the book is, the point is how long people who really know their stuff (and are publishing books because of it) have known this. More than three decades. Nothing has changed in that time - if anything fuel injection and proper oils leave cylinder walls in better condition and rings are manufactured to better tolerances making this more true than ever.
Most modern engines, after a few hundred thousand, still show acceptable cross hatch and RVK will be entirely adequate. There are of course exceptions to every rule and if you recently drove through a volcanic eruption with no air filter then you will probably need a rebore. But that's not the OP's question is it?
My point is simply this - you rebore a cylinder or you leave it alone. This "rehone for ring seating" is hogwash. Use good cylinders as is. Rebore and plateau hone bad ones. There is no middle ground for excellent results IMO.
Rick
I would probably go by what Total seal would say and from what I have seen and what profilometer would come up with.
I think we need to remove the term "honing" from this thread. Honing is what takes place after a cylinder is bored. Honing removes the last few thousandths material from a bore, creating a round cylinder, adding the proper cross hatch pattern for oil control and to aid in ring seating.
A nominal bore in an in-service engine may need to have the glaze broken and the cross hatch pattern refreshed, but this is not really "honing". The debate being discussed is if a bore should be deglazed or not before installing new rings.
My original question was if I needed to replace the rings or not. I am convinced I do. Thank you for helping me with that decision. I now understand the engineering behind the "why". It's quite obvious to me now.
As for the controversy around "deglazing" I know there are a lot of opinions as well as facts that prove both sides of that argument. From what I have read it is about 25% against and 75% for deglazing. I will follow the recommendations of the ring manufacturers and deglaze the cylinders (they just replied to my question about it).
While the ring manufactures do often say that, it's mostly a CYA on their part. They can't see your bore and of course the #1 reason they get complaints is "your rings didn't seat", etc, etc. So they just tell everyone to deglaze - then they can say you didn't do it right or whatever when you moan about ring seating. Also they could care less if the rest of your engine gets chewed up by deglazing byproducts - it will be far enough down the line to not be their problem. The deglazing process will end up with poorer leak down, higher oil consumption, and more engine wear, but it will still run and it will be sufficiently sealed on the part of the rings to satisfy the not-so-discerning end user, or shade tree type. I build (and rebuild/refresh) for high HP turbocharged and supercharged applications and cylinder leakage means lost power on the dyno and blow-by in the crankcase. That's a problem when you are pushing 30-40 psi and you are blowing the customer's oil dipstick out of it's tube. Not to mention the darn power loss.
At any rate, from the perspective of someone that's not tried it both ways - simply judging based on the available information being spouted online - I'm sure it is about 75% for and 25% against. We are making headway though because 20-30 years ago it would have been 99.5% for deglazing.
One of these days we will get through to the masses. Till then - burn that oil you deglazers
Rick
Last edited by GeneralDisorder; 03-29-2017 at 07:42 PM.
They make good rings. They make at least some, if not all, of the rings for Wiseco. I use Wiseco in many of my builds running on good used bores - I send my blocks to be line honed and decked with specific instructions to not touch the bores. If I thought it would result in a better end product I would just have him bore them oversized or deglaze them because these are $8,000 to $12,000 overhauls. I'm buying new pistons here..... The cost would be negligible in the scheme of what I'm doing. But the results wouldn't be better so I don't do it.
This is not a matter of trying to save a few bucks. It's about getting the best results from what you have to work with. Boring oversized is fine but costs more and you lose material from your block. That's lost strength, less mass for heat dissipation, and one fewer time you can machine that casting.
Turns out the seller lied to me. I was just now able to decode the block code. The engine is actually from a Caprice wagon, not a police car. It's a 175HP version with swirl heads and a L03 peanut cam. My current 305 has just about the same power. I am going to have to rethink this now.
Yep, I know. I had thought long and hard about that. I put a list together of what it would take and came up with nearly $1,200 when complete. That much for an additional 50ish HP gain. I will think on it. I am not in a rush.
Originally Posted by NoEmissions84TA
Then put the bottom end back together and add some good Vortec heads and the camshaft of your choice.
03-26-2017, 03:28 PM
