cylinder finish issues

[trond]

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

[MST0118]

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.

[Peter M]

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?

[trond]

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

[Neil Harvey]

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.

[trond]

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

[Walt Fricke]

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

[trond]

Correct. Ra measured was the cylinders. Not the pistons

[Helix8]

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?

[targa72e]

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

[winders]

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

[trond]

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

Originally Posted by Helix8

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?

[KNIGHTRACE]

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.

[Helix8]

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.

[Neil Harvey]

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

[Trackrash]

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?

[KNIGHTRACE]

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

[racing97]

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

[KNIGHTRACE]

Millennium results until they change coatings.

[Neil Harvey]

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.