EBS/Millenium Cylinder roughness - should I worry
 

I happened across something of concern in another thread on a 3.2 SS build using EBS racing bored/honed cylinders and JE pistions. As everyone is probably aware, EBS sends the cylinders to Millenium for bore/hone. Folks were commenting that the cylinder honing process Millenium uses is too rough and can cause the rings to either not seat or wear improperly causing oil consumption issues, plug fouling, poor compression etc...

I have just completed a 3.2 -> 3.4 build using EBS cylinders/JE pistons. The motor is fully assembled but have not fired it up and started the break-in yet. The work was done early in 2019, so possibly they have fixed whatever problems they had as some of the threads I found were several years old.

Should I be worried? I have a seventh cylinder done with the same process in which we found a crack which can be used for inspection...

Thanks,
Bill

I'd inspect the cracked cylinder. It can be checked by most machine shops in five minutes or less using a profilometer. If the surface roughness is 15-17 Ra you're going to have an oil consumption issue. I don't think it matters what brand of rings, it's going to eat them up.

If you can't find someone locally to check it, ship it to me. Like I said, it takes two seconds to get a reading if you have the equipment.

-Tony

The issue is not with Millennium's boring/plating/honing process as they can deliver RA 4-8 BUT it needs to be specified which EBS did not in my case. This was early 2019 going from 3.2L to 3.4L. Fortunately for me my builder checked RA/RPK/RVK for any issues and was able to send my cylinders back to Millennium to get it right. My RAs were 20 to 26 and EBS was not concerned with these values btw.
I would have the RA checked now otherwise I'd always worry about this.

Thanks, I will check with EBS. Total bummer as my engine is completely assembled.

I may take you up on that, will send you a PM if I can't find someone local to take a look for me.
Bill

Ra 20-26 and EBS was not worried says it all. If you want to order via EBS then you have to specify what surface finish you want. They either don't understand or they don't care. When I raised a concern they quickly concluded my issue with oil burn must be the aftermarket Megasquirt.....

I did speak with Don at EBS racing today. He said they are seeing Ra between 10 and 15 and that is well within the tolerances of all the ring manufacturers that he has spoken with, including he manufacturer of the rings I used for my build. He didn't seem to be dismissing my concerns, and offered to check and re-do my cylinders if required, which would be easy enough except that I would need to tear the engine down to do so.

Is there another spec besides what the ring manufacturers would required, according to Don at least the ring manufacturers are OK with Ra of 15 being "well within spec".

Bill

Ra10-15 is for cast iron cylinders (as most engines use) which will be run in and thereby smoothened. With Nickasil a smoother finish is required. Original Mahle cylinders are Ra less than 5.
Ra15 will not work with nickasil

Hmmm I sent a set of Carrera alusils to be bored to 98 mm and plated with EBS in 2018. Still sitting on the shelf until I get all my parts set up for the build. They look good but I am going to have a local shop put a profilometer on them to check - hopefully they come out to Ra 4-5. Hopefully not screwed. I will report back once I know.

I did not check the Ra on the 90mm millennium cylinders with JE pistons I fired up last week. I had concerns about some pitting in the bore itself, but was told by millennium that was perfectly acceptable and within their range. So far so good though per the owner

What does it cost to have a set of cylinders replated?

Do you know when the work was done on the cylinders. Seems like early 2019 was when the issue first started to come up (exactly when mine were done).
Bill

In Canada going through Millenium's subsidiary Fast Enterprises it's $329 CAD per which could mean that I am potentially out $1974 CAD if the Ra is out of spec. Hope mine are OK as I would have wasted $1600 CAD on the first go round. I can't find anyone locally to check the Ra so I will have to ship one out to be checked first, then decide what to do.

There a couple things I need to chase down before I go that step. I quite frankly don't know what to think.

I just spoke with one of our local engine builders here in Campbell CA, they are well know around the world building race engines and air-cooled engine service/repair. I spoke directly with the guy who's name is on the business. I don't want to publish his name here, but he should be considered a trusted source of information regarding this topic.

I explained the situation of having Milenium bore, plate and hone a set of Carrera 3.2 cylinders and have concerns that the surface roughness is too high to allow proper ring seating. His response was, "we do exactly that with that same supplier all the time, I have no way to measure the surface roughness, we install them as they come in and have never had any issues. I would not worry about it."

He did recommend using a "break-in oil" from a supplier called "Driven" or equivalent.

Bill

Just because JWE has not had a problem does not mean there is not a problem here.......

It was indeed early 2019 as I secured them from EBS just after they came back from Millennium in about Feb/March

This was back in 2018, but everyone I talked to either was unaware this was an issue, said it wasn’t an issue, or blamed it on the rings. Except for Henry at Supertec. He knew right away and said he specs his builds at 5 Ra.

I'm having a hard time understanding what exactly happened here though. Millenium's main business is Nicasil plating. I really doubt they confused the spec for a cast iron cylinder with a Nicasil. Did something in their process change unexpectedly during the 2018/2019 timeframe where they allowed a rougher surface finish when they had previously been OK? They claim they measure everything before it goes out. Of the failures that occurred, has it be verified that everything else was done correctly - primarily the ring gaps? What is the percentage of motors built with their cylinders where the rings failed to seat properly?

I can't speak for anyone besides myself, but all of my measurements were in spec and verified repeatedly throughout the process. Inspection of machined components for aerospace is my field - I probably went a little overboard verifying tolerances on my 3.2ss.

The question I have is, what is the average oil consumption of cylinders plated by Millennium vs. new Mahle cylinders. I think we had a poll going a few years ago - I get 700-1000 miles/quart and swap in new plugs at every oil change.

I spoke directly with a tech at Millennium this morning, and he checked the EBS racing spec. sheet and they call out 8 Ra on all Porsche cylinder work. He said this spec. has been in place for a long time and not changed. I plan to have a 7th cylinder that was done in 2019 (in which we found a crack after processing) measured and will report back. Only issue is I'm not 100% sure if the crack was found after they were completed and sent back to EBS or if found by Millennium before they finished the processing... Based on the cross hatch pattern it looks like all the processing was completed.
Bill

It seems to me that Porsche spec for oil consumption is a qt or a ltr every 1000 km

That may be their spec, but Trond will tell you his came back as 20+ and he redid his rings three times. Proceed with caution, which you seem to be doing.
good luck

Another data point: Here's one of my 3.2ss cylinders plated by Millennium in 2018 (16 Ra)

http://forums.pelicanparts.com/uploa...1591376804.jpg

And a 3.6 cylinder plated in 2020 (5 Ra)

http://forums.pelicanparts.com/uploa...1591376840.jpg

I went back through my emails with EBS (they sent my cylinders to Millennium) this is dated June 28, 2019.

(my builder's name is "X'd" out) and my cylinders Ra measured as high as 26 not 20.

Best advice is to specify Ra if using EBS and verify when received.

This is from Don:

I do apologize for the delay in getting back to you on this issue but I felt, since this is essentially a “defective parts” claim, it prudent to collect the best information I can from some of the respected, brand name manufacturers we work with such as Mahle Motorsport, Total Seal and NPR. Below are some technical sheets provided by Mahle which covers a wide range of cylinder materials including Nikasil. When asked very specifically about their Nikasil finish on the cylinders that come from Germany, the specification is 12-16 Ra.

Conferring with Total Seal (who actually supplies many ring packs to Mahle Motorsport) they specify 10-20 Ra.

NPR, which supplies rings for most of the “off the shelf” Porsche air cooled pistons from JE and CP, specifies a range of 15-35 Ra.

Millennium’s target for our cylinders is 15-25 Ra with XXXXX measuring 18-20 Ra which makes sense as it lands in the lower/middle part of that range. I believe that XXXXX wanted cylinders at 8-10 Ra which is below any of the ring manufactures recommendations, below that of new Mahle Motorsport cylinders and below the recommendation of Millennium for most applications. The exception being if the engine is carefully broken in on a dyno under carefully controlled conditions.

Unfortunately, this comes down to XXXXX personal preferences which are not generally backed any of the manufacturers. Of course, we had no way of knowing this during the initial order phase as we could have had them made to his custom specifications, regardless.

Thank you,
Don Weaver-EBS Co.
don@ebsracing.com

800-357-2088
775-825-2217

www.ebsracing.com

After reading the initial posts and posting myself I inquired of Millennium through their Canadian subsidiary about the Ra of the Millennium cylinders. The rep indicated that, without specification, Millennium hones their Nikasil to Ra 20-25. He offered to look at what EBS specified for my cylinders based on the serial numbers that Millennium stamped on my cylinders. According to their research regarding the order they were specified for an Ra of 8-14. I must say that Millennium has been most helpful and forthright in this matter, any issue is not theirs. At the time I placed my order I was not asked as to what Ra I wanted on the cylinders - this is something that I think EBS could do on their end. I understand the notion of builder responsibility; however, continuing the food analogy in an earlier post, even if I go to a high end restaurant and order filet mignon the waiter will ask how I want it done. If I'm a regular customer the waiter may say as per usual sir and as a new customer would be obliged to ask. That's the way the service industry should work.

Beyond the discussion regarding business practice lies the technical aspect of Ra. I've read multiple threads and items regarding initial Ra. One post that stands out is that an Ra of 5 on replated cylinders is appropriate for racing applications where people want immediate seating of the rings for that application. For standard break-in procedures then an Ra of 10 to 15 is appropriate. The key for ring sealing appears to be the plateau of the peaks in the honing process.

The next question should be is there a possible way of creating a plateau without excessively abrading the Nikasil finish? Is there a home honing method? Woodworking tool supply companies sell diamond surface sandpaper in extremely fine grain size. Lee Valley has diamond lapping film 15 micron (1000x) grain size and finer in 3"x 6" sheets; the finest sheets are 3, 0.5 and 0.1 microns. Could these be used in the manner that red scotchbrite is used for deglazing used cylinders? I am not an engineer and am asking out of pure curiosity as to whether this is a viable method or not. The core issue for excessive ring wear based on my reading on the matter appears to be the initial Ra and specifically the roughness of the peaks on the plateau portion of the honed finish.

Lastly, Henry Schmidt, in one of his postings on the matter, pointed out that people "will believe what they want to believe, as they should." He tempered that with the notion that belief may be out our lack of knowledge or the refusal to acknowledge what is known. I only hope that I can gain enough understanding about this to make a reasoned decision I can hang my hat on. So, on that basis, I may be comfortable living with the Ra of 8-14. I would be really happy if we can arrive at a reasonable, unexecessive manner to create the plateau effect without having to have cylinders stripped, replaced and rehoned. This last possibility scares me at $329 CAD per cylinder.

cylinder finish
 

I agree that the final Ra is important.So the ring pack is important as well.A few times I have had cylinders cleaned with a hone where the Ra is 3-5.Using Total Seal gapless on the top ring which not cast iron is hard to seat.But the end result is 1 percent leakage when broken in.Not for a DIY guy.But once broken in they last a long time.The soft cast iron ring just gets chewed up over 8-10 Ra.Some of my best results have come from cleaned up original cylinders with a custom slightly larger piston.Because you are using an original cylinder you can control the Ra better.I should probably not mention this.Lo siento mucho.Ciao Fred

I found the post I was referring to earlier regarding Ra 5 and racing application. See post #11
http://forums.pelicanparts.com/911-engine-rebuilding-forum/912382-millenium-cylinder-fine-grit-honing-right-way-go.html#post10033067

This was all thoroughly hashed a few years ago, sorry if it was mentioned here already.

Check out post #40 here. http://forums.pelicanparts.com/911-engine-rebuilding-forum/163663-do-i-need-hone-2.html Then go to the last page for more info than necessary.

I used the JE ringset that came with my pistons. Seems that this issue is quite dependent on the ring materials/manufacturer. Most of the discussion is around the Goetz rings, haven't seen any comments on JE. Anyone have any experience good or bad with the JE rings?

FWIW. I used new JE pistons with the supplied Goetz rings in my old Mahle cylinders. SC motor, unknown miles, and I used the scotch brite method to deglaze the cylinders. They were in spec so not refinished. Seemed to take for ever, maybe 700 miles to fully seat the rings, but it seems fine now. Believe me I did not baby the motor. The first drive was a spirited 70 mile drive with the local club, then several autocrosses, plus a track day. I was concerned at first since there was smoke coming from the oil tank when warmed at idle. I now have around 6K miles on the motor and it runs great. I wasn't paying close attention to oil consumption on my last oil change, but probably less than a quart per 1000 miles. Plugs are not showing any oil. No smoke on startup.
Cylinder before scotch brite.
http://forums.pelicanparts.com/uploa...1591628647.jpg
http://forums.pelicanparts.com/uploa...1591628729.jpg

Bringing this up again regarding the possibility of "cleaning" new cylinders in the manner of red scotchbirite but using 1000 grit or finer diamond lapping film as described below.

Thoughts please - possible or just nucking futs?

The next question should be is there a possible way of creating a plateau without excessively abrading the Nikasil finish? Is there a home honing method? Woodworking tool supply companies sell diamond surface sandpaper in extremely fine grain size. Lee Valley has diamond lapping film 15 micron (1000x) grain size and finer in 3"x 6" sheets; the finest sheets are 3, 0.5 and 0.1 microns. Could these be used in the manner that red scotchbrite is used for deglazing used cylinders? I am not an engineer and am asking out of pure curiosity as to whether this is a viable method or not. The core issue for excessive ring wear based on my reading on the matter appears to be the initial Ra and specifically the roughness of the peaks on the plateau portion of the honed finish.

Quick update on this thread now that I have the motor seemingly broken in. I've been using Lucas 20W50 break in oil, 20 minutes at 2000 RPM (changed oil), 50 miles somewhat spirited shakedown driving (changed oil), 375 miles so far of more spirited driving, lots of hills to get engine braking from 5000RPM down to 1500 etc...

No smoke at startup or under any driving conditions, no signs of oil in the plugs, no noticeable oil consumption and the butt-dyno indicates that the engine is pulling as I would expect up to 6000 RPM. I pulled the #2 plug today and ran a leakdown test, which showed a 2.5% leakdown (I think the actual is better since I don't think I the insert was fully sealed and I could hear a bit of air coming from the spark plug hole). All of the plugs looked exactly the same with no oil residue or signs/smell of fuel so I didn't bother to run the leakdown on all six cylinders. I'll probably get to that on the next oil change when I adjust the valves.

http://forums.pelicanparts.com/uploa...1672182320.jpg

So the moral of the story is, at least in my case, looks like my rings have seated fine and the engine is performing as it should. The only long term issue could be excessive ring wear which would not show up for quite some time, but based on the early results I don't think I'll loose any sleep over it.

interesting that this thread should come up now.

I just tore down my motor for using excessive oil. I had EBS re plate and provide me rings.
They did sell me the a single piece cast iron oil ring, later when I brought my concerns to EBS about the smoking and oil use they said "you should not have that" as a ring.
Ill have to call them tomorrow and see what happens.
I suppose at this point having been run a bit the RA will be impossible to determine.
That being said while it consumed tons of oil the leak down numbers did test very good.

You’ll be able to measure RA.

One piece of advice faapgar (RIP) gave me - clean the living crap out of the cylinders after they've been honed, to make double sure all the debris and sanding grit is out or the rings will not seat. Makes sense to me. He recommended putting the cylinders in an oven to like 250 degrees, and then rub with a rag and some solvent until it comes off clean. Took my probably 10-15 minutes of wiping per cylinder until no more residue comes off in the rag / paper towel.

Anyone else do this?

Yes, I did this hot cleaning with clean white rags and ATF. First @150 deg F then 200deg F then 250 F. Double layer of nitrile gloves reduced the burning to my hands. Even new Mahle motorsports cylinders were not clean enough.

Cleanliness is key
 

Faapgar is right.
As a kid reading Hod Rod magazines, I remember those builders were meticulous in cleaning their bores.
They used soap and water as the final step.
I use multi stages.
Brake clean solvent, ATF and acetone, then really hot water and Dove dish detergent scrubbing in a 5 gallon bucket. Really hot as reclino says.
Plateau honing creates a flat cap to the surface. The hone grove below needs to be open and hold oil for break in.

yep.
Just installed a brand new set of Mahle cylinders and pistons.
It took many passes of solvent and lint free towels to get all the residue out of the cylinders. The first pass, the rag came out nearly black.

i had horrible experiences with plated cylinders from both EBS/Millenium and US Chrome. Had my set in cylinders in twice to rectify and paid more than a new set. + time and cost for 2 needless rebuilds. Final result after the struggle is 5 cylinders are OK wrt surface roughness and 1 is a loss with porosities. Take extreme care

We had a similar experience years ago, 10 years or so. Pulled apart a 3.4 (98mm) build 3 times. It was in otherwise stock 72 911. Very cool car. Sent cylinders back twice, and to hedge our bets the last time installed total seal gapless rings. All worked out, learned a very expensive lesson. We were dealing with the businesses mentioned in this thread as well....

That said, since then, we have had good success with other bored and plated cylinders. At the end of the day, the onus is on the engine builder (us in this case) to ensure that the parts we are installing meet OUR specs. We did not do that and relied on the reputation of others, which was a massive mistake. A mistake we have never made since....

We learn and grow.

Cheers