cylinder finish issues
 

two years ago I converted my 3 liter 80SC to 3.2SS, with bored out and nikasil plated Carrera cylinders from EBS. I installed Carillo CP 10.5CR pistons and also went with twin spark. My initiation run was a 3000 miles run around Scandinavia and I was very pleased with the engine. Great torque from low RPMs and real nose-up power around 4000 and all was good. Except for the smell of burnt oil. I had run the engine in by loading it properly, at night in the hills, and no idling or careful run in procedures at all. Being too careful seem to be the recipe for glazed bores and rings that don't seal, and this way of breaking in an engine has not failed my yet with all the different engines I rebuilt. At the end of Scandinavia round trip I started having detonation issues on hairpins and had to retard ignition and add octane booster to even make it home. The smell of oil never left me in the following two years, and every time I give it some there is that stench of burnt oil. And I still have to run retarded ignition timing compared to what I started with. There was never visible smoke and I don't need to add more than maybe a quart in 3-4000 miles. There is just this embarrassing smell. And I have been unable to use regular gas, unlike the initial 2000 miles when it ran awesome on regular with much more ignition advance

So a few weeks ago when i had a empty slot in my 'working from home' regime, I took the engine out to take a look.

What I found was all the combustion chambers had a thick layer of a tar like buildup. I have never ever seen anything similar. It appears the cylinders must have been letting oil past the rings, and the resulting carbon buildup have caused increased compression and detonation.

I took the cylinders, along with one 100 000 miles stock Mahle cylinder to a shop who measured the EBS pistons to Ra 16+. As a comparison the used stock Mahle piston was 4-6.

Unfortunately EBS denies any responsibility but blames it on the aftermarket Megasquirt engine management. Also there are no shops in this part of the world that does nikasil so I am a bit lost. And as I see it the investment in parts is a complete loss as I can not sell the kit, or use it

The 3 vertical stripes on the cylinder wall can not be felt by fingertip btw and disappeared when I cleaned it with soap water and red scotchbrite


http://forums.pelicanparts.com/uploa...1588968551.jpg

Wow a RA of 16 sounds way too rough. I was reading another post here (do I need to hone this) that Nikasil should have an RA between 4.2 and 6.0. Supposedly even a 10.5 Ra can cause premature ring wear because the rings are relatively soft and will wear before cylinder gets smooth. I have heard recently in other posts about this same problem from places that replate cylinders. It sounds like the stock Mahle of 4-6 is right there with new being about 4.9. I think you found the issue.

Trond,
This is good news that you have got to the bottom of the cause of dissatisfaction with your engine. I know you have been pulling your hair out for a while.

So next step is to have the cylinders re-plated and finish honed to your existing pistons and a new set of rings?

budget was blown on this failure and I will go back to 3.0 liter. Not happy. Incomprehensible to me that this problem seems to be not talked about on the forum much. Instead the consensus seems to be to just get a set from EBS they will sort you out. Not helpful for those of us not in the know

Several things at play here.

First, if someone is going to sell this service, they should understand it completely and know what is required. Also, if they make money on a third party service, a check before its sold to the end user is a must. It appears from this and other complaints (one I had party to) this was or never is done.

My advice here is to have this service provided by a knowledgeable engine person or company, not a parts supplier. People who do this and have experience and success. There are plenty of these companies in the Porsche aftermarket.

Trond, it would be good idea to check the size as well. Check the ovality and taper. The finish is only part of the repair. Making sure the sizes are held are important too.

A little info as well.

Nikasil is extremely hard. It's used as it has good non wearing properties. You have to use a softer ring face with Nikasil. The top rings are typically a moly faced ring, the 2nd ring a cast one and the oil rails non chrome.

If the Nikasil finish is high the rings will wear not the Nikasil. High finish numbers have large peaks and valleys. In the "old" run in procedures, these high peaks where worn down and mated to the ring surfaces. Both will wear down to each other to give a good seal. This was usually with a cast block or stell liners and hard ring faces. But Nikasil is a lot harder than steel. It doesn't wear the peaks down. It wears the ring faces instead. This is why the final honed finish needs to be low. An RA if this is the measurement used, needs to be 8 or less. 4-6 is best.

These engines do not need the oil retention on the walls either. We have piston squirters that do a good job of this. This is one reason why the 2nd ring is often a scraper type.

Not only does this failure create bad sealing, it increases the friction and the oil temps. The loss of performance is often unseen when the oil consumption and smoke level is.

At PD, we have gone away from using Nikasil. Lowering friction is very important and some of the newer surface finishes offer greater friction reduction. An added advantage is the cylinder sizing. Sizing is done to softer base materials where the control of temperature is a lot easier. The cylinders are sized to their final size and the surface finish is applied and no further sizing is required. Where as with Nikasil, it is applied several thousands thick then honed to the final size. Holding a size when honing extremely hard surfaces is a difficult process, one that takes patience and skill.

it is pretty obvious these guys should not take on the responsibility to sell parts they know very little about. Consequences for the unlucky customer is significant. Engine in engine out and thousands wasted. I am furious

Trond - you had the RA of the cylinder surface measured, right? Not that of the piston?

Correct. Ra measured was the cylinders. Not the pistons

I too had a 3rd party, large parts seller, handle my 3.2L cylinders sent to Millennium for boring and plating to 3.4L. Fortunately, my engine builder has the $4k+ Profilometer and measured Ra when cylinders came back. My cylinders measured Ra 20 to 26. The 3rd party was contacted and they do not specify Ra for cylinders when sending for boring and plating. They also do not measure Ra before sending to customers. My cylinders were returned to Millennium, at my expense, as 3rd party took NO responsibility even though they say they are Porsche "experts" (at least at selling parts). Millennium was able to get my cylinders to an acceptable Ra btw. I have asked others along the way, after they have sent cylinders for boring and plating, if they specified Ra and most have not. Does the average hobbyist engine builder know the importance of Ra?

When I recently sent some cylinders to millennium for bore and platting. I specified the ovality, taper and RA. I also sent a piston and specified the piston to cylinder wall clearance. My specifications for ovality and taper were what they listed on their web site as standard (and better than Porsche spec) I specified RA between 4-7.

john

It's never EBS's fault.......

don't be shy mr helix; who messed up your cylinders go through ?
This is a private forum where beginners go to seek advice and it would be useful for them to know where they should not send their cylinders. Or money

Remember you were lucky or clever enough to find the issue before assembling the engine. Most are not

Some companies are trying to pick up where motor meister left off. I had HORRIBLE experiences with ???. In the end I was robbed. Ultimately they denied everything to the point of insanity. There are incompetent companies selling junk to turn a profit that don't care how your project turns out. sad people get the bad end of the deal of the junk they sell. Some is junk some isn't that is what keeps them in business because of mixed reviews.

EBS. I was neither lucky nor clever my engine builder knew to check. Good news was the cylinders could be brought to proper Ra but the bad news was the time lost (about 3 weeks) and cost to remedy (I'm thinking around $700 including shipping). With the investment I had in parts (pistons, valves + springs, cams, rockers, coatings and machining) I asked my builder to assemble the long block. Glad I did as I would not have checked or been able to check Ra. Which is why I was curious how knowledgeable the average hobbyist is about cylinder Ra. Maybe along with my "parts seller" we are below average but I do not provide machining + plating services.

Its a real shame that some companies offering parts and services don't stand behind what they sell.
This gets somewhat convoluted when they "sell" third party work.

Its always a good idea to seek out those places that do their own machining and send very little out for a third party to do. I the case of plating, this is specialized and several places offer this work but they must receive a spec as well.

That spec should be the min/max diameter, the allowable taper top to bottom along with the final surface finish. There is a lot of info out there now with what these specs need to be. I suggest that you use a well known shop to be the intermediary or go direct to the plater. Remember the plater can screw up as we all can. Its the final checks that are the most important. If you do not have the tools to measure your cylinders or the finish, ask around and I'm sure there is someone with what you need.

We do our own honing in house so we have gages, Profilometers etc to check this stuff. Any good industrial honing shop will have these too and will be able to check for you. It might cost you a sandwich!!

One last thing, before you have the finish lowered to where it needs to be, check the size first. When lowering the surface finish, you are removing material and adding clearance. This was the issue with the cylinders we received from the company used acting as the middle man. Our customer had them provide this service and when we received the cylinders we have some with +20 RA. we tried to hone then but we were adding clearance so the cylinders had to be returned to the plater , stripped and re-plated and hone to our specs.

The company acting as the intermediary took no responsibility and if my memory serves me, they told me they had not had any issues in the past. I had read tons of complaints about their cylinders.

Quickest way to go out of business is to disrespect and piss off your customers

IDK. How can anyone who has the technology and equipment to nikasil plate and hone not do it correctly. I mean did they not know they were Porsche cylinders? The spec for ra is in the manual.

Perhaps an oversight or rookie on the job?

I called Millennium first part of this year to see if the issues we were being were corrected, I measure and check everything I have made but I don't have a way to replace the cylinders or make my own pistons. The young guy I spoke with told me William we replace millions of cylinders a year and maybe a few have problems what's the big deal.. I kindly said I understand and hung up. US Chrome has been doing a good job for me ONCE I give them the necessary guidelines needed and they have given me a code to put on each barrel to achieve that. There pretty quick but there not the friendliest to deal with.. I am not trying to slander the above companies with the exception of one company that was good for many years that in my opinion is out to scam anyone they can. my email is knightrace@mac.com if someone needs assistance getting there work done I am willing to help. There are some credible people out there that are willing to help. I do not know Niel Harvey personally but I have heard he is knowledgable and to my knowledge helpful, I think I have a meeting with him before long on some studs and case bolts. I have meet many great people in this business and I appreciate the clients I have gained. William Knight

So what is the Ra for L&N's product they use Millennium?

Millennium results until they change coatings.

I hope I did not open a can of worms here.

To be clear, I have not and are not finding fault with Millennium or any other plating service company. You need to give the plating company some spec of what you need. Do not leave it up to them to decide. They plate many different cylinders, for many different companies that may require different spec's. In the end, the assembler is ultimately responsible for the engine result. Check everything before you fit.

If I do have an issue, it was with the company that decided to offer this service as a third party. They stiffed my customer and took no responsibility. When we sent the cylinders back to Millennium with what spec we needed, we received them back as asked for. I have not heard of any issue from my customer regarding oil consumption or tell tale smoke.

I have spoken to Charles (LN) about this on several occasions. The last time at last years PRI show. I can tell you that Charles is on top of this and knows what is required.

So, just to be clear is it the consensus here that the Ra for new Nickies is similar enough to the Ra for new Mahle cylinders if purchased direct from LN Engineering for a 911 application regardless when purchased? Or does one have to confirm the appropriate Ra from LN in that situation as well?

You will find the LN cylinders match if not better the standard Mahle versions. The one thing you can count on is, Charles N makes very well made parts, understands what quality is and supplies such.

Give him a call and within minutes you will quickly see he knows what he is talking about. I have known him from many years, done very little business with him but we always have reason to discuss many engine issues.

We actually discussed this exact issue at PRI last years and came to the same conclusion, some people should stay well away from supplying parts they have no idea about.

Just got a set back from millennium I gave the the size and the spec for Ra
They came back exactly the way I wanted them
You are the engine builder so don’t blame bad results on other people

Thats like ordering a set of wheels and you have to specify that they should be round....

The RA spec is specific for Nicasil not a 911, if you are in the business of doing Nicasil coating you have to know what you are doing AND have a quality control (the latter is probably whats lacking/missing altogether).

Did you check the RA of you cylinders?

Sure did
These people handle hundreds of cylinders mostly non Porsche
So you have to be specific of what you want
I mark all my cylinders to make sure I get the same ones back
Tell them to check a number of things like hight and squareness
Top to bottom
If they are bad when they come back you have something to ***** about
And no it is not like ordering wheels
It like telling the waiter you want something to eat and he brings you a cheeseburger
Instead of a steak
You need to tell them what you want
The eyeballyo meter probably works for most of there work
😀

Anybody who's bought CP pistons should take note of the spec sheet that comes with them. Their sheet actually includes the cylinder surface roughness spec you need to relay to the plater, if you're having original Mahle cylinders re-plated. I don't have the sheet handy with me right now but i'll post a picture of it here when I get my hands on it at home.

As Neil said, the desired roughness is not just based on "hey plater, it's Nikasil so please establish roughness accordingly for that." It's the ring material that dictates your roughness value(s). Charles Navarro has shared some of this roughness data before

http://forums.pelicanparts.com/911-engine-rebuilding-forum/1001374-smoking-newbuild.html

http://forums.pelicanparts.com/911-engine-rebuilding-forum/1012296-excessive-oil-after-rebuild.html

cylinder finish issues
 

The old eyeballs still work, he had it nailed but had to check it anyhow and it was spot on!!!https://uploads.tapatalk-cdn.com/202...490e52b26e.jpg

Nice time machine!!!!!!

Thanks to T Collins for reminding me to post the info from the CP pistons spec sheet. See pictures below

http://forums.pelicanparts.com/uploa...1589634471.JPG
http://forums.pelicanparts.com/uploa...1589634471.JPG
http://forums.pelicanparts.com/uploa...1589634471.JPG

Thanks for posting the CP specs but I think even relying on this could be problematic. For instance, the sheet recommends an RA of 10 to 12 for ductile moly rings but some builders might prefer to use softer rings with less tension, like certain Goetze rings used on Mahle pistons. I think under those circumstances, it’s probably recommended to go with the 4-6 RA as generally recommended above regardless of what CP generally states above.

I’d be interested to see what RA that LN uses for its Nickies when it sells a combo of pistons/cylinders and if it varies between Mahle, JE and CP. I suspect the RA would be close if not the same because LN probably tries to select the highest quality rings regardless of what piston is used but I could be wrong. I don’t the same knowledge of ring options like others here.

I didn’t mean to imply the CP specs are what everybody should follow, regardless of whether you’re using Mahle, Kolbenschmidt (KS), JE, CP, Omega, Neil’s pistons, or whatever other brand piston. The CP specs should be followed only if you’re running CP pistons with their CPN (nitrided) rings. The specs are specific to the type of rings being used from each piston maker, or more specifically, their chosen ring manufacturer

Be careful here. The honing specs by CP appear to be more general and I assume for steel lined blocks. It does make caution not to use Chrome for Nikasil, but the honing suggestions are not typical for Nikasil.

What is very good advice given is the note to make sure of the expertise of the shop doing the work.
This disqualifies the third party supplier named often in this thread. Best to use a shop that knows what is required or go direct to the palter of your choice and tell them what you need.

It took me Three top ends to figure out the rings were never going to seat. A wasted 2015 season.

The cylinders were inspected and yes the honing cross hatch was too deep. The cylinders were replated with the specified Ra.

May 2016, the fourth top end, the Rings seated almost immediately.

Seems to me, this is too easy to fix, yet remains unfixable. No good reason.

Cost me $$$$ on the parts to keep cleaning and rebuilding.

Disappointed to hear this still happens.

VFR; you should consider coming out and tell us who screwed up with your cylinders. This need to stop, I am shocked at the scale of this; how many have wasted time and money on buying unsuitable parts and it is allowed to continue. Hard to understand

EBS was very good to me, they had the cylinder inspected, found the issue, and had Millennium re-plate them with a focus on a low Ra
So here is a history in pictures

You be the judge if the original Ra look too high to the untrained eye: March 2015, "new"

http://forums.pelicanparts.com/uploa...1590091738.jpg


The rings never seated. and i did two more top-ends to chase the issue. ~400 miles per Qt. and smoke on every start. Disassembled in August 2015:
http://forums.pelicanparts.com/uploa...1590090825.jpg

Still leaked so torn down the third time in November 2015:

http://forums.pelicanparts.com/uploa...1590090978.jpg

This is when EBS took care of me and got the cylinder re-plated and specified a smoother finish. As an added bonus, the coated the piston skirts. All for free. Can you really tell the difference? Well, it mattered. Seated well, but still al little bit of blow-by causing some foaming of the oil. Overall >
http://forums.pelicanparts.com/uploa...1590091071.jpg

Since I was getting pretty good with rebuilding my engine, i figured I'd swap in a bigger cam. This turned into an opportunity to re-ring again, with better.

Here is what they looked like in March 2018:

http://forums.pelicanparts.com/uploa...1590091360.jpg

I used Scotch-brite and soapy water to refresh the cross hatching. Plus later I added the Total Seal dry lubricant prior to installing the pistons.
http://forums.pelicanparts.com/uploa...1590091507.jpg

As of today, works really well. Leak-down late last year was 1-2% at 100psia, and compression 148-150 psia on all cylinders.

I should be appreciated that in 2015 I beat the absolute c**p out of this engine to force sealing.
I did the 20 minute cam break in. Since i did (3) build in 5 months, I had the opportunity to use: SAE 30, VR1, Joe Gibbs , Lucas break in oil, Lucas hot rod oil. Really made no differnece. Many WOT 3000 to 7000 rpm runs and long down hill compression braking. Ring refused to seat. The leakage during the decelleration created some really loud backfires (BANG), and fouled the plugs and the engine would slowly idle and stall. I can document those too.....

In March-May 2016 when I rebuilt the engine for the 4th time, I decided to use Lucas break-in oil (I had the cam refinished for other reasons) And went with JG DT-50 20W-50 oil. In October 2017, I blew a RMS on a really cold track day (15-20F??)

I rebuilt the 5th time(this time for the FUN OF IT!) with a new DC40 cam. Used Lucas break-in oil then switched to only Mobil 1 15W-50 since then. BTW, drove the car 250 miles after this rebuild, and went to Thompson Motor Speedway for a track day. Hammered it after only 250 mile of "break in". All good now.

Finally
With the Goetze rings I always had a little bit of oil foaming. Early (2015) on there would be a vapor cloud coming from the oil fill.

The Total Seal rings, I tried in 2015, that did not happen, but they did not seat either.

I went back to Goetze in March 2016 (free set of rings from EBS!) still had a little bit of foaming.

Went back to Total Seal May 2018, (with the 2-pc second ring) and aeration of the oil pretty much stopped.

I recommend the Total Seal rings, with the dry-film lubricant.

Updated results, no improvements

Seems this has become a generic thread on cylinder finish. Pls slap me this July 4 if not.

I’ve had 95mm Mahle cylinders replated to 6Ra. From what I gathered then and since, that was for Goetz rings. Engine builder wants to use Mahle rings. My concern is Mahle rings may be a different substrate and require different specs on roughness? Would greatly appreciate a steer before it goes back together.

Below quote was very helpful KTL.

Many of the older rings were cast and more forgiving than newer hardened steel rings. Not sure of your question Glenfield. I am not trying to be negative, we're having issues and I am not calling out names. I am in need of a solution but I am VERY VERY close...... William Knight